A nice video that can really help folks working on both older/cheaper machines and a limited budget. Many people in poor countries manage to keep their equipment running well for many years using this type of procedure.
Hey Stan, Very cool. Nice work and setup. Lots of folks will be empowered to fix their wonky spindles now. Nice disclaimer at the end. Talk to you soon buddy. Tom
Stan, I've been following your videos for a year. I think you do good work. This latest where you grind an R8 taper to restore it to new geometry and concentricity is excellent. Well done and well described. This IS a job of 95% set up for 5% actual work but many tricky jobs are like that Done a few spindle tapers myself. All your remarks and caveats are real-world without fussy BS. Your final remark: "Be very very careful; you only get one shot at this," is absolutely true. For every 0.001" you take off the taper radius you sink the gage line: 0.001 / Tan of taper half angle - or a bit less than 0.007" for the R8. That can be a lot to grind from the face and in extreme cases you may have to deepen the socket. You made no mention of dust or the need to drape the machine against dust infiltration. Grinding and wheel dressing produces clouds of drifting abrasive dust. I admit I get a bit hysterical on this topic but I don't think I'm being too stringent when I suggest your machine should be completely covered prior to start of grinding and thoroughly cleaned afterwards including servicing the way wipers. I want to post a link to this video on PM and HSM websites as a textbook method for grinding a machine tool spindle taper applicable to any machine with a tilt or swivel. Is that OK with you? Forrest Addy
+Forrest Addy Hi Forrest, I used to hang out @ PM, tough crowd with a smattering of very nice guys willing to truly help out, your name stands out as being one of the good ones :) Feel free to post a link and let the hazing begin!
Cool setup Stan. I had to think about what you said in the beginning about the runout not mattering that much, but then I thought about drilling or reaming small holes. Then you cleared that up at the end. Nice job.
Very good thinking on that job. I remember having to modify a Suzuki rod to fit a Yamaha one time because the Yamaha rods were out of stock. I chucked up the rod in my lathe and I attached a Dremel grinder to my compound and ground out the crank pin end to fit the Yamaha. It worked fine too. Thanks for the video.
NIce thinking and work there - catching up with the latest shenanigans from you lot... I also noticed Mr Lipton using an spin- indexing fixture to do some cylindrical grinding on his surface grinder - I like these types of can do clips - employing what is at hand set up possibilities. Thanks for posting.
No...!!! Not checking mine now... If it's all right, good, but if it's kinda really off, it will start bothering me.... Nicely done, excellent results... ;)
As a machinist you always have to come up with outside the box setups or you will not be able to do many jobs that come your way, this is a good example of that.
I had a spindle re built from my VMC. They spot ground all the bearing spacers to get them flat. The back part of the cartridge was bored out and a sleeve fitted as the back bearing pair had been spinning in the housing. After the spindle unit was re assembled they ground the taper. Final taper run out was 2 micron! Before they reassemble the unit they check that the spindle nose OD is running true to the spindle shaft..then they can easily find the centre for grinding the taper.
Thank you for sharing this video, it was a very interesting way to clean up the spindle socket and true it up without having to disassemble the machine and send out the spindle.
Nice job on the grind Stan. But I think you should run the spindle the opposite direction of the grinding stone. Any way that is how I grind large flywheels in my lathe. Good Luck
I had a spindle reground on a horizontal machining center. The man that came out did it almost the same as you. He had a machine he made himself witch was a angle plate (so he could do both horizontal and vertical spindles. On the inside of the angle plate he mounted another plate on a pivot pin with a slide mounted on linear ball bearings. On the slide he had a NSK precision air grinder. He had a feed mechanism (it was a long time ago I think it was a electrical motor) that feed the slide. On the slide he had a precision surface to indicate, to set the angle. This was a Cat 50 taper he ground for me so he used air gages to check the taper angle. He also used a test bar with bluing. The test bar was about 12" long he said he likes to get a maximum run out of about .0002 along the test bar and at least 90% contact when he blues the taper on the test bar. The total cost was $3000.00 that included travel for this. It took him about 2 hours to do it.
I know this may sound like a lot but like you said in your video. If I had to remove the spindle in this machine(integral spindle and motor) it would have cost a fortune and than theirs shipping and down time. Not to mention the cost of repair, spindle bearings (probably more than $3000.00 alone). This also included his travel time. He came from up north (I am in TEXAS). He did have another job in the area. So I was glad to get going for just this cost. If you have to make a living sometimes the time is more important, at least to your customers. It was interesting to see him do it.
Runout will also cause an endmill to make slightly oversized (single pass) slots. (Of course, for really accurate slots you would want to mill with a smaller cutter and then make finishing passes to bring the slot to size.)
Great job Stan!....any reason not to make another spring pass, and was wondering if you did any final lapping.?? My opinion would be to shorten the spindle a bit, just because of the likely damage to the collet end during normal handling and use. I just picked up a 45,000 rpm Precise Grinder, and in the process of making tooling to mount it for various operations. Thanks!
+Jim Liechty Hey Jim, I actually machined off the face of the spindle after uprighting it, a CNMG lathe toolholder clamped in the vice made short work of it. All in all I took off .032 from the face to get the collets flush again.
Resourceful!! High level of competency required. You got that, not all do. Bet you intended to run the spindle the other way round during the grind. Didn’t hurt nothing though. Now you got’ta buy some super expensive highly accurate Hardinge collets!! Brad
I'll be checking my little baby mill as you called it tomorrow. I'm very curious as to how far out it is. All I have is a .0005" indicator but should get me a good idea.
I'm scared to see where mine's at now. I need to bore some holes and the bearings on my BP clone were toast. With the spindle out to replace the bearings I can see the taper is all chewed up on the inside. There were 3 other tabs on the lock washer previously bent, so I think I'm swapping in the 5th set of bearings on this machine. It was run a lot drilling cast iron so it would go through bearings quickly the PO said. Who knows, maybe all the dings on that taper will cancel each other out. Probably not, I think I'll be having to do something like this before I can bore those holes.
I wanted you to know that even though you posted this 8 years ago I finally got around to doing this to my mill today. I have a project coming up where I need to cut some gears. I figured it was time to get my end mills from dancing like one of those Hulu dancer dolls.
@Shadon HKW, I can see what the tip looked like and the back relief in it but what type of stone did you use for this. Part # or any info so I'm using the right type. Great Job!!!
Bridgeport should go in a counter clockwise rotation. Better finish when grinding material rotates opposite of grinding wheel. Standard in the industry.
Hey Stan, I just noticed out of 540 views, me being #540, you got no thumbs down!! After seeing what you did I can see why! Pretty damn impressive! Your right about only getting one shot at this repair! Thanks for sharing.
Although it would not necessarily be a good thing, if you did get it slightly wrong, you could regrind. Then if the Collet was too far up inside the spindle, grind the end off.
I saw somebody true up his collets with a fairly simple setup and a properly sized rod in the collet. He just did the outer flare as I recall. Didn’t take long.
Maybe someday I will try to get the .001-.002 out of my Cincinnati mill. Would have to either fab a compound slide off the table or pull the spindle on the horizontal though as no way to align the bore angle with any of the axis.
That is a hell of a simple and nice idea!! I'll keep it in mind! So far I never have borrow parts from one machine to place it on the other! but grandpa use to do even more complex whit way less! Thanks
There's lots of ways to set a sine bar to precise angles besides jo blocks. All you need is a precisely known height either from a stack of handy shims and blocks, a purpose made block machined in a mill, or an adjustable parallel or planer gage. Be carefull of your measurements and parallelism, keep your apparatus clean of chips and debris, and you can hit your setting angles to arc seconds or xx.x% slope.
Nice video, sometimes you just need to throw the "box" away, not just think outside it. One thing about doing the grinding this way is that it also compensates for any issues that could have come from the rest of the spindle.
Hi Stan. One thing I don’t get is how do you get away with using a die grinder? I would have thought you’d need a high precision spindle like those found on a Dumore. I can’t imagine what the run out would be on an automotive pneumatic tool. Apologies if this has been answered somewhere.
Protip: If you ever do something similar with the die grinder, put a semi-loose zip tie around it. That way you can slip the zip tie on the trigger to keep it on and then slip it off the trigger once you are done :)
MAn!! that was a very good video and opration. You guys are going crazy grinding, measuring Like Tom Lipton....that millions in measuring tool . But that was very informative and thanks for sharing with us. Also good luck with the 2 pattons you have on those angle what blocks?? Manny
I noticed you running the mill spindle in the same direction as your grinder, effectively making it climb cutting. Wouldn't it be better to run the mill in reverse?
Stan on what surface did you put the sin plate to establish the r8 half angle? I was thinking to would be tricky to put it on the quill because it has to be perfectly 90 deg to vertical. What’s the trick? Some great out of the box thinking. I need to do this because I have a dingus mcgee in my spindle taper with a nice raised burr. This looks like just the ticket. Thanks for sharing it.
Stan, Very nice set up! Have to check my BP mill for run out as well. Was the grinding wheel going in the opposite direction of the spindle rotation while grinding? Eric
esoomreltna I really don't think it makes much of a difference. he was turning the mill spindle at a very low rate of speed..maybe 50 rpm. compared to the die grinders 15,000 to 20,000 rpm spindle speed. Very slow feed rate too. The difference in turning the mill spindle one way or the other is negligible.
Well done Stan, nice setup. Just one thing which came to my mind while watching that. Doesn't that rather big stone produce a little bit too much contact area. As far as my understanding goes it is supposed to be better to have less contact area when you do ID grinding, should give you less deflection and therefore better surface quality. Please tell me if i am wrong, i am certainly not a grinding expert at all.
+Shadon HKW Good one, but i was expecting from "Mr Grind" that you did something like that. However, my point is slightly different, maybe i've just worded it poorly, sorry for that. With OD or surface grinding the wheel has a tendency to push itself away from the surface, so the cutting depth is slghtly less than you dial in. With ID grinding, the situation is essentially the same, but the contact area is much longer and curved, so it "snugs" itself into the surface and any deflection other than directly towards the center will increase the cutting depth. Worst case is that you get some un-controllable grabbing effects which may cause out of round or poor finish results. Any ideas on that, or is it just me worrying too much about it ? Sorry for being a pain, but i am about to re-grind an internal #3 morse taper with almost no material to spare, so it's got to be right first time.
+dynoguy Reduce your cutting surface area as much as possible for 2 reasons 1) heat, pure and simple, your part gets hot and swells, it has nowhere to go except deeper into the grinding wheel, making more heat 2) free cutting with light cuts, you can effectively remove .0002 per pass with very light tool pressure (no push off) Dress your wheel to run true with as little contact area as your comfortable with. Good luck with the regrind.
Hi Stan, I was wondering how did you make sure your head is horizontal. I hate to think that you clamped a straight round bar in a collet and indicated it, because the collets are not running true to start with. So, I missed that part in the video. BTW, I planned to do something else this evening, but your videos kept me glued to the screen...
Thanks for this unique look at addressing this problem in a DYI way. Would you address the grinding wheel. Did you true it? Was the tip at a certain angle? Thanks
+Morris Gallo The wheel was the pointed type right out of the box, I dressed the flat on it with a small back relief, I only had about 1/8" of wheel in contact with the work. Dressing was done in the toolmakers vice over on a loose mag plate with the tangent dresser. Sorry, this was already completed when I thought about breaking out the camera.
hey Stan, that's pretty slick! one question tho: it looks like your spindle and grinding wheel are turning the same direction. does it matter which way they turn or should they rotate in opposite to each other? toolpost grinding is a new field for me and on my planer feed roll grind (did a video on it) i got a better looking finish with counter rotation than synchronized (i tried both ways) cheers mike
+HolzMichel Hiya Mike, I ran it both ways, no detectable difference. I did however try running the (mill) spindle at a higher speed and got some bad chatter on the first skim pass.
Shadon HKW another question i forgot to pose: how did you manage the sine bar against the quill? use of magnets or by hand? i would tend to think holding the sine bar by hand against the quill would be pretty challenging.
+HolzMichel Ha ha .. very challenging, I used a couple of 1-2-3 blocks on top of the mill vice flat and used them as sort of a "pallet" to hold the sine bar square, a large rubber band through the sine bar hole around the spindle kept tension against the gauge blocks.
Stan, I look forward to and devour every one of your videos. Only on this one it would have helped me a lot to see how you set up to measure the angle. I can only assume you used a sine bar but how did you hold it to the spindle?
Nice! I'm guessing you used your indicator at an angle of about 45 degrees? Doesn't that mean you can even correct the measured runout by 0.7 to get to the real value?
I have a die grinder with a thin black rubber hose that fits over the whip hose on my die grinder over the black boss and quiets a lot of the noise. What kind of stone did you use?
I wonder if a Roto-Zip would be better to use, than the air powered die-grinder. Electricity over air power. That is the one air tool I dislike using. I have found that a Roto-Zip used far less electricity .
Stan Could the setup be done with out rotating the turret , eg tilt the head over to horizontal but less the half angle and grind on the bottom ? Reason my hobby mill has a fixed colum but has a rotating head , fortunately it's ok for runout up the spout , I just ask for interest Stuart
Nice work. I noticed the roster of YT Machinists on the whiteboard. I have a few names not on that list, but you have a few names I don't have. Do you [or anyone] know of a comprehensive list of chip makers?
Curious as to why you made the two head setting adjustments (the 90 degree tilt and the 8.425 degree rotation of the turret) rather than just tilting the head 81.575 degrees? The only difference I could see is that your way, you are cutting on the back side and have to move the Y to adjust your depth where as my idea of just a single head setting adjustment and thus would have to cut on the top rather than the back and would have to adjust the Knee for to depth of cut. Is there something I'm missing as to why it would have to be done with make the two different rotation adjustments like you did? *EDIT:* Fixed my miskey on the degree number
Never really thought about it that way, I would just have ground at the 6 o'clock position rather than the 3 o'clock. End result is the same. This video is pretty old, the spindle is still running within a few tenths after all these years.
@@ShadonHKW Thank you for the reply. Yeah, I knew that it was a pretty old video and remembered seeing it a while ago but couldn't remember exactly how you did it. It came to light the other day because I just recently picked up a mill for next to nothing because it needs some work. Part of that is it might need the taper trued. It is out by a mile but also has bad spindle bearings so cant accurately judge if its really out or if its just because of the bearings. In preparation in the event that after I rebuild the head, it is still out beyond an acceptable limit, I wanted to be prepared to regrind this one. It should be the 12 o'clock position though, not 6. 6 would require the head to be rotated past 90 degrees.
+Shadon HKW And align them by eye? I'd figure one could use a height gage in the same way you leveled the quill but the best you could get it this way are the 1.5 thou that you had as runout at this moment. I might have to calculate how far the angle would be off in this case to see if it's of any relevance. Gimme some time
+Shadon HKW I couldn´t really come up with a way to factor in the wheel diameter on the fly. But if you neglect that and the centerheights were 1.5 thou apart you´d be off by 0.11 arcsec. The fact that I ignored the wheel diameter would add some more error cause the cut would actually occur a tiny little bit above centerheight of the grinding wheel. I set my calculation up so that the grinder was placed above centerheight of the spindle, all the above and belows would certainly flip if you´d place it below the spindle height in the first place. No matter how much error would add this way, I think its safe to say that the the effect would be absolutely neglectable and shouln´t be of any concern. One would introduce multiple amounts of that error when you indicate the R8 taper parallel to the X-Axis cause you can only indicate over the inch or so length of the taper I´d say. Just for the sake of it, If your centerheights were to be 10 thou apart the error you´d introduce (neglecting grinding wheel dia) would be about 5 arcsec. So sorry from my side, nothing to worry about the centerheights i´d say.
Yes it cost a bit! It was £2517.85 That's a cat 40 spindle with a total of 6 angular contact bearings..a quad set at the front and a duplex set at the back. The noise was deafening before I had the spindle re built and the part finish was awful. All good now ;-)
Hi Stan-I thought that you would have wanted to have the spindle rotating the opposite way for grinding-that is, assuming the die grinder rotation was standard.
+Shadon HKW Yeah I always wondered why the instructions always said to have the surfaces of the spindle and the grinding wheel running n opposite directions.....
+Andy Wander It is so there is no back lash between part and grinder. If they run the same way you are more likely to get chatter or other odd finishes from irregular movement.
A nice video that can really help folks working on both older/cheaper machines and a limited budget. Many people in poor countries manage to keep their equipment running well for many years using this type of procedure.
Hey Stan,
Very cool. Nice work and setup. Lots of folks will be empowered to fix their wonky spindles now. Nice disclaimer at the end.
Talk to you soon buddy.
Tom
Hey Stan, it takes years to get the space shuttle ready whilst the flight time lasts a few minutes. Great job, appreciate your efforts.
Awesome rigging man. You machinists have so much skill beyond feeds and speeds. Well done
Stan, I've been following your videos for a year. I think you do good work.
This latest where you grind an R8 taper to restore it to new geometry and concentricity is excellent. Well done and well described. This IS a job of 95% set up for 5% actual work but many tricky jobs are like that
Done a few spindle tapers myself. All your remarks and caveats are real-world without fussy BS. Your final remark: "Be very very careful; you only get one shot at this," is absolutely true. For every 0.001" you take off the taper radius you sink the gage line: 0.001 / Tan of taper half angle - or a bit less than 0.007" for the R8. That can be a lot to grind from the face and in extreme cases you may have to deepen the socket.
You made no mention of dust or the need to drape the machine against dust infiltration. Grinding and wheel dressing produces clouds of drifting abrasive dust. I admit I get a bit hysterical on this topic but I don't think I'm being too stringent when I suggest your machine should be completely covered prior to start of grinding and thoroughly cleaned afterwards including servicing the way wipers.
I want to post a link to this video on PM and HSM websites as a textbook method for grinding a machine tool spindle taper applicable to any machine with a tilt or swivel. Is that OK with you?
Forrest Addy
+Forrest Addy Hi Forrest, I used to hang out @ PM, tough crowd with a smattering of very nice guys willing to truly help out, your name stands out as being one of the good ones :) Feel free to post a link and let the hazing begin!
Cool setup Stan. I had to think about what you said in the beginning about the runout not mattering that much, but then I thought about drilling or reaming small holes. Then you cleared that up at the end. Nice job.
Great video. I especially enjoy your videos because I see you film things no other channel films.
Very good thinking on that job. I remember having to modify a Suzuki rod to fit a Yamaha one time because the Yamaha rods were out of stock. I chucked up the rod in my lathe and I attached a Dremel grinder to my compound and ground out the crank pin end to fit the Yamaha. It worked fine too. Thanks for the video.
Don't try this if your spindle bearings are not in good shape or if they are out of adjustment and have play in them!
NIce thinking and work there - catching up with the latest shenanigans from you lot... I also noticed Mr Lipton using an spin- indexing fixture to do some cylindrical grinding on his surface grinder - I like these types of can do clips - employing what is at hand set up possibilities. Thanks for posting.
Also possible to avoid setting up the 2nd axis by offsetting the head tilt by the same angle, either above or below horizontal.
That was awesome, must be scary to grind away at such an important component but glad that now there is a video on a way to do it
No...!!! Not checking mine now... If it's all right, good, but if it's kinda really off, it will start bothering me....
Nicely done, excellent results... ;)
As a machinist you always have to come up with outside the box setups or you will not be able to do many jobs that come your way, this is a good example of that.
I had a spindle re built from my VMC. They spot ground all the bearing spacers to get them flat. The back part of the cartridge was bored out and a sleeve fitted as the back bearing pair had been spinning in the housing. After the spindle unit was re assembled they ground the taper. Final taper run out was 2 micron! Before they reassemble the unit they check that the spindle nose OD is running true to the spindle shaft..then they can easily find the centre for grinding the taper.
Ouch, that sounds expensive, but great results!
Thank you for sharing this video, it was a very interesting way to clean up the spindle socket and true it up without having to disassemble the machine and send out the spindle.
great ideas! never thought about my air tool as a drill/grinder for the lathe... will use that!
I have an old beat bridgeport J head I am working on. I'll have to check the run out now and regrind if needed. Thanks for posting this.
Nice job on the grind Stan. But I think you should run the spindle the opposite direction of the grinding stone. Any way that is how I grind large flywheels in my lathe. Good Luck
Very critical set-up for sure... most informative.
Wow! This is taking the use of a die grinder to a new level. Love it!
I had a spindle reground on a horizontal machining center. The man that came out did it almost the same as you. He had a machine he made himself witch was a angle plate (so he could do both horizontal and vertical spindles. On the inside of the angle plate he mounted another plate on a pivot pin with a slide mounted on linear ball bearings. On the slide he had a NSK precision air grinder. He had a feed mechanism (it was a long time ago I think it was a electrical motor) that feed the slide. On the slide he had a precision surface to indicate, to set the angle. This was a Cat 50 taper he ground for me so he used air gages to check the taper angle. He also used a test bar with bluing. The test bar was about 12" long he said he likes to get a maximum run out of about .0002 along the test bar and at least 90% contact when he blues the taper on the test bar. The total cost was $3000.00 that included travel for this. It took him about 2 hours to do it.
+Edge Precision Wow, I'm in the wrong business ....
I know this may sound like a lot but like you said in your video. If I had to remove the spindle in this machine(integral spindle and motor) it would have cost a fortune and than theirs shipping and down time. Not to mention the cost of repair, spindle bearings (probably more than $3000.00 alone). This also included his travel time. He came from up north (I am in TEXAS). He did have another job in the area. So I was glad to get going for just this cost. If you have to make a living sometimes the time is more important, at least to your customers. It was interesting to see him do it.
Great work Stan, thanks for that as I also need to do mine and had not thought about doing it on the machine. Great vid keep it up !
Runout will also cause an endmill to make slightly oversized (single pass) slots. (Of course, for really accurate slots you would want to mill with a smaller cutter and then make finishing passes to bring the slot to size.)
Great job Stan!....any reason not to make another spring pass, and was wondering if you did any final lapping.?? My opinion would be to shorten the spindle a bit, just because of the likely damage to the collet end during normal handling and use.
I just picked up a 45,000 rpm Precise Grinder, and in the process of making tooling to mount it for various operations. Thanks!
+Jim Liechty Hey Jim, I actually machined off the face of the spindle after uprighting it, a CNMG lathe toolholder clamped in the vice made short work of it. All in all I took off .032 from the face to get the collets flush again.
Resourceful!! High level of competency required. You got that, not all do. Bet you intended to run the spindle the other way round during the grind. Didn’t hurt nothing though. Now you got’ta buy some super expensive highly accurate Hardinge collets!!
Brad
Great idea! Never thought about grinding in a mill spindle on the machine.
I'll be checking my little baby mill as you called it tomorrow. I'm very curious as to how far out it is. All I have is a .0005" indicator but should get me a good idea.
Thanks Stan, you're the man. Mine has always had about a thou and a half run out. Now I know how to fix it. Thanks again.
I'm scared to see where mine's at now. I need to bore some holes and the bearings on my BP clone were toast. With the spindle out to replace the bearings I can see the taper is all chewed up on the inside. There were 3 other tabs on the lock washer previously bent, so I think I'm swapping in the 5th set of bearings on this machine. It was run a lot drilling cast iron so it would go through bearings quickly the PO said. Who knows, maybe all the dings on that taper will cancel each other out. Probably not, I think I'll be having to do something like this before I can bore those holes.
That turned out great. The die grinder made a good tool post grinder.
I wanted you to know that even though you posted this 8 years ago I finally got around to doing this to my mill today. I have a project coming up where I need to cut some gears. I figured it was time to get my end mills from dancing like one of those Hulu dancer dolls.
Never sorry I did this, still running within a couple of tenths here!
I watch all you guys and that is the smartest video I have seen.
@Shadon HKW, I can see what the tip looked like and the back relief in it but what type of stone did you use for this. Part # or any info so I'm using the right type. Great Job!!!
Great Ingenuity in your setup, awesome results.
Bridgeport should go in a counter clockwise rotation. Better finish when grinding material rotates opposite of grinding wheel. Standard in the industry.
FUH! at around 10:24 i thought somebody was calling me from behind, due to the headset and the way you recorded ... What a surprise :D
Nice job, I like the way you dealt with the issue. Did you dress the stone relative to the spindle?
Hey Stan,
I just noticed out of 540 views, me being #540, you got no thumbs down!!
After seeing what you did I can see why! Pretty damn impressive! Your right about only getting one shot at this repair! Thanks for sharing.
Although it would not necessarily be a good thing, if you did get it slightly wrong, you could regrind. Then if the Collet was too far up inside the spindle, grind the end off.
I saw somebody true up his collets with a fairly simple setup and a properly sized rod in the collet. He just did the outer flare as I recall. Didn’t take long.
Maybe someday I will try to get the .001-.002 out of my Cincinnati mill. Would have to either fab a compound slide off the table or pull the spindle on the horizontal though as no way to align the bore angle with any of the axis.
+bcbloc02 Maybe "borrow" the compound off the lathe for a day :)
That is a hell of a simple and nice idea!! I'll keep it in mind! So far I never have borrow parts from one machine to place it on the other! but grandpa use to do even more complex whit way less!
Thanks
Stan, very nice! Makes me less concerned about buying a used mill. Now if only a good set of Jo blocks and sine bar didn't cost more than the mill...
There's lots of ways to set a sine bar to precise angles besides jo blocks. All you need is a precisely known height either from a stack of handy shims and blocks, a purpose made block machined in a mill, or an adjustable parallel or planer gage. Be carefull of your measurements and parallelism, keep your apparatus clean of chips and debris, and you can hit your setting angles to arc seconds or xx.x% slope.
Nice video, sometimes you just need to throw the "box" away, not just think outside it. One thing about doing the grinding this way is that it also compensates for any issues that could have come from the rest of the spindle.
Hi Stan. One thing I don’t get is how do you get away with using a die grinder? I would have thought you’d need a high precision spindle like those found on a Dumore. I can’t imagine what the run out would be on an automotive pneumatic tool. Apologies if this has been answered somewhere.
Protip: If you ever do something similar with the die grinder, put a semi-loose zip tie around it. That way you can slip the zip tie on the trigger to keep it on and then slip it off the trigger once you are done :)
MAn!! that was a very good video and opration. You guys are going crazy grinding, measuring Like Tom Lipton....that millions in measuring tool . But that was very informative and thanks for sharing with us.
Also good luck with the 2 pattons you have on those angle what blocks??
Manny
Hi stan, nice work!
How is the spindle behaving after a few years?
Thanks!
Still running within a 1/10th, finding good collets is a different story, its hit & miss unless you buy the really high dollar units.
Great video.... very creative setup and great results.
from the sound the diegrinder made , there was still some un evenes even after the spring pass
I noticed you running the mill spindle in the same direction as your grinder, effectively making it climb cutting. Wouldn't it be better to run the mill in reverse?
I noticed that too. Might affect the finish.
Brilliant! Must be a pretty good die grinder. Great video.
Stan on what surface did you put the sin plate to establish the r8 half angle? I was thinking to would be tricky to put it on the quill because it has to be perfectly 90 deg to vertical. What’s the trick? Some great out of the box thinking. I need to do this because I have a dingus mcgee in my spindle taper with a nice raised burr. This looks like just the ticket. Thanks for sharing it.
It was sine bar directly on the quill, with magnets and big rubber bands.
Stan,
Very nice set up! Have to check my BP mill for run out as well.
Was the grinding wheel going in the opposite direction of the spindle rotation while grinding?
Eric
esoomreltna I really don't think it makes much of a difference. he was turning the mill spindle at a very low rate of speed..maybe 50 rpm. compared to the die grinders 15,000 to 20,000 rpm spindle speed. Very slow feed rate too. The difference in turning the mill spindle one way or the other is negligible.
Very nice results. What are the disadvantages of using a die grinder for something like this versus a 'proper' tool post grinder?
+svenp Most quality hand grinders will have a double bearing nose and precision spindle, perfectly adequate for this, but no good way to mount them.
I've mounted die grinders using the threads on the front of the body. There is only four or five threads to engage, so I wouldn't load it heavily.
Well done Stan, nice setup. Just one thing which came to my mind while watching that.
Doesn't that rather big stone produce a little bit too much contact area. As far as my understanding goes it is supposed to be better to have less contact area when you do ID grinding, should give you less deflection and therefore better surface quality.
Please tell me if i am wrong, i am certainly not a grinding expert at all.
+dynoguy Hiyas, I cut a back relief in the wheel with a diamond point, only 1/8" of wheel was contacting the work :)
+Shadon HKW Good one, but i was expecting from "Mr Grind" that you did something like that. However, my point is slightly different, maybe i've just worded it poorly, sorry for that.
With OD or surface grinding the wheel has a tendency to push itself away from the surface, so the cutting depth is slghtly less than you dial in. With ID grinding, the situation is essentially the same, but the contact area is much longer and curved, so it "snugs" itself into the surface and any deflection other than directly towards the center will increase the cutting depth. Worst case is that you get some un-controllable grabbing effects which may cause out of round or poor finish results. Any ideas on that, or is it just me worrying too much about it ?
Sorry for being a pain, but i am about to re-grind an internal #3 morse taper with almost no material to spare, so it's got to be right first time.
+dynoguy Reduce your cutting surface area as much as possible for 2 reasons
1) heat, pure and simple, your part gets hot and swells, it has nowhere to go except deeper into the grinding wheel, making more heat
2) free cutting with light cuts, you can effectively remove .0002 per pass with very light tool pressure (no push off)
Dress your wheel to run true with as little contact area as your comfortable with.
Good luck with the regrind.
+Shadon HKW Thanks alot for the tips, will certanly think of you when i am on it...:)
Very impressive and so helpful! Thanks for sharing.
Enjoyed...thanks for the education on issue/setup/repair
Hi Stan,
I was wondering how did you make sure your head is horizontal. I hate to think that you clamped a straight round bar in a collet and indicated it, because the collets are not running true to start with. So, I missed that part in the video. BTW, I planned to do something else this evening, but your videos kept me glued to the screen...
I used the OD of the quill, extend and retract, zero-zero reading.
Innovative setup. Nice job. Doug
Thanks for this unique look at addressing this problem in a DYI way. Would you address the grinding wheel. Did you true it? Was the tip at a certain angle? Thanks
+Morris Gallo The wheel was the pointed type right out of the box, I dressed the flat on it with a small back relief, I only had about 1/8" of wheel in contact with the work. Dressing was done in the toolmakers vice over on a loose mag plate with the tangent dresser. Sorry, this was already completed when I thought about breaking out the camera.
I have ground many tapered bores but not like this well done stan
Great job Stan. I know a lot of guys are nervous about grinding dust near their tools. Was this a consideration for you?
+Clayton Firth I only made 2 passes to clean it up so it was minimal, but yes, it is always a concern.
Add a shop-vac to the set up. That would catch almost every trace of grinding dust.
Fantastic. I am going to go check mine. I find myself thinking it would be OK if it was out so I could do this:)
How are you my friend Thank you very much you inspiration
hey Stan,
that's pretty slick! one question tho: it looks like your spindle and grinding wheel are turning the same direction. does it matter which way they turn or should they rotate in opposite to each other?
toolpost grinding is a new field for me and on my planer feed roll grind (did a video on it) i got a better looking finish with counter rotation than synchronized (i tried both ways)
cheers
mike
+HolzMichel Hiya Mike, I ran it both ways, no detectable difference. I did however try running the (mill) spindle at a higher speed and got some bad chatter on the first skim pass.
Shadon HKW
another question i forgot to pose: how did you manage the sine bar against the quill?
use of magnets or by hand? i would tend to think holding the sine bar by hand against the quill would be pretty challenging.
+HolzMichel Ha ha .. very challenging, I used a couple of 1-2-3 blocks on top of the mill vice flat and used them as sort of a "pallet" to hold the sine bar square, a large rubber band through the sine bar hole around the spindle kept tension against the gauge blocks.
Stan, I look forward to and devour every one of your videos. Only on this one it would have helped me a lot to see how you set up to measure the angle. I can only assume you used a sine bar but how did you hold it to the spindle?
+Russell Thornton Hey Russ, I laid it sideways on 1-2-3 blocks off of the milling vice and used it as sort of a "pallet"
SLICK is the only word that comes to mind.
Here's hoping my new mill doesn't have that problem for a long time to come!!
Fussy job...not one for Bozo to drop by..
Colin
Nice! I'm guessing you used your indicator at an angle of about 45 degrees? Doesn't that mean you can even correct the measured runout by 0.7 to get to the real value?
+Zorgoban the indicator probe was less than 10* from the surface being measured, so I would call those real numbers.
Great setup and video. Thank you. By the way, how many people have told you that you look like Comedian Ron White. Be safe and great work.
How much are you pushing the grinder out of alignment with your hand?
+Grandpa Cocky well ... I can say with all certainty, no more than .0001, the measurement speaks for itself.
Excellent vid Stan! Thanks for sharing.
Stan, once you get your mill etc set up to true the spindle taper, how much more trouble would it be to turn the inside bore of your collets?
Shit, i won't be able ignore this, I'll have to check mine now, dam you Stan and your buddies, I was happy in ingnorance. Nice job you did!
I have a die grinder with a thin black rubber hose that fits over the whip hose on my die grinder over the black boss and quiets a lot of the noise.
What kind of stone did you use?
I wonder if a Roto-Zip would be better to use, than the air powered die-grinder. Electricity over air power.
That is the one air tool I dislike using. I have found that a Roto-Zip used far less electricity .
very good thinking. good video. will follow ur suggestions
How come the grind does not get the spindle runout to 0 without collet? Theoretically it should come out dead on!?
Nice
Did you try Dychem? in the socket on a good collet?
+Dennis Williams Upcoming episode, prussian blue transfers :)
Stan
Could the setup be done with out rotating the turret , eg tilt the head over to horizontal but less the half angle and grind on the bottom ?
Reason my hobby mill has a fixed colum but has a rotating head , fortunately it's ok for runout up the spout , I just ask for interest
Stuart
+Stuart Hardy As long as you can create a tool path for the grinder to match your (half) collet angle, you can make it work.
+Shadon HKW thanks
Now back to milling the ears on my excavator bucket + 25 - 0
Good job Stan
Nice work. I noticed the roster of YT Machinists on the whiteboard. I have a few names not on that list, but you have a few names I don't have. Do you [or anyone] know of a comprehensive list of chip makers?
+indoorherbivore Keep an eye on that list, it will be growing over the next few months. Announcement coming late this month.
This sure beats doing it by hand.
you are a great aftro engineer
Ah, machinists abusing hand tools. The tradition continues. :)
Excellent demo
Curious as to why you made the two head setting adjustments (the 90 degree tilt and the 8.425 degree rotation of the turret) rather than just tilting the head 81.575 degrees?
The only difference I could see is that your way, you are cutting on the back side and have to move the Y to adjust your depth where as my idea of just a single head setting adjustment and thus would have to cut on the top rather than the back and would have to adjust the Knee for to depth of cut.
Is there something I'm missing as to why it would have to be done with make the two different rotation adjustments like you did?
*EDIT:* Fixed my miskey on the degree number
Never really thought about it that way, I would just have ground at the 6 o'clock position rather than the 3 o'clock. End result is the same. This video is pretty old, the spindle is still running within a few tenths after all these years.
@@ShadonHKW Thank you for the reply.
Yeah, I knew that it was a pretty old video and remembered seeing it a while ago but couldn't remember exactly how you did it.
It came to light the other day because I just recently picked up a mill for next to nothing because it needs some work. Part of that is it might need the taper trued. It is out by a mile but also has bad spindle bearings so cant accurately judge if its really out or if its just because of the bearings.
In preparation in the event that after I rebuild the head, it is still out beyond an acceptable limit, I wanted to be prepared to regrind this one.
It should be the 12 o'clock position though, not 6. 6 would require the head to be rotated past 90 degrees.
Awesome! This is excellent. Thank you!
What kind of stone did you use to grind the spindle socket?
Well done, creative solution!
Great job buddy!
Hi, please what is the name of the cleaning company you hire and how much do you pay for them to clean your shop to it's spotless condition???
+Coffieman5150 It's Ray's cleaning service, no chip goes undetected. ruclips.net/user/RSC1254
I didn’t see you check for wiggle in the spindle and bearings.
How did you set your grinder on center height on the spindle? If it's not dead on you're gonna get a wrong geometry.
Great work though. Keep it up.
+Dope Nope Center points in the collets (both of them), adjust the knee as required. That was the easy part :)
+Shadon HKW And align them by eye? I'd figure one could use a height gage in the same way you leveled the quill but the best you could get it this way are the 1.5 thou that you had as runout at this moment. I might have to calculate how far the angle would be off in this case to see if it's of any relevance. Gimme some time
+Dope Nope I think you will need the grinding wheel diameter to make your calculation.
Pssst ....... (1/2")
+Shadon HKW I couldn´t really come up with a way to factor in the wheel diameter on the fly. But if you neglect that and the centerheights were 1.5 thou apart you´d be off by 0.11 arcsec. The fact that I ignored the wheel diameter would add some more error cause the cut would actually occur a tiny little bit above centerheight of the grinding wheel. I set my calculation up so that the grinder was placed above centerheight of the spindle, all the above and belows would certainly flip if you´d place it below the spindle height in the first place.
No matter how much error would add this way, I think its safe to say that the the effect would be absolutely neglectable and shouln´t be of any concern. One would introduce multiple amounts of that error when you indicate the R8 taper parallel to the X-Axis cause you can only indicate over the inch or so length of the taper I´d say.
Just for the sake of it, If your centerheights were to be 10 thou apart the error you´d introduce (neglecting grinding wheel dia) would be about 5 arcsec.
So sorry from my side, nothing to worry about the centerheights i´d say.
Nice work!
Yes it cost a bit! It was £2517.85 That's a cat 40 spindle with a total of 6 angular contact bearings..a quad set at the front and a duplex set at the back. The noise was deafening before I had the spindle re built and the part finish was awful. All good now ;-)
Cool stuff Stan.
Hi Stan-I thought that you would have wanted to have the spindle rotating the opposite way for grinding-that is, assuming the die grinder rotation was standard.
+Andy Wander It was, but 10K RPM vs 50 RPM, it didnt really make much difference :)
+Shadon HKW Yeah I always wondered why the instructions always said to have the surfaces of the spindle and the grinding wheel running n opposite directions.....
+Andy Wander It is so there is no back lash between part and grinder. If they run the same way you are more likely to get chatter or other odd finishes from irregular movement.
+bcbloc02 Ahh, that makes sense, Thanks!
thanks this is very useful info.
Very impressive. Subscribed.