Cylindrical grinding attachement - Part 1
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- Опубликовано: 14 окт 2024
- Here I show a simple jig to do cylindrical grinding on the surface grinder.
Inspiration taken from:
Robin Renzetti:
• ULTIMATE KELVIN CONNEC... (At the 47min mark)
And the Lectric-Centers by Harig:
www.harigmfg.co...
Web:
gtwr.de/
Instagram:
/ stefan_gtwr 
Наука
31:35 "what a stupid construction" that cracked me up. Cant tell you how many times I have looked down at parts I designed & made and thought "what asshole made this this way."
Stefan, your videos are always a delight to watch and a much-welcome relief from the depressing news. Love that you share your concept development and reasoning.
Certainly Robin is a brilliant master machinist, but all he has on you is is years of experience. There are only a handful of people in the world who have the combination of knowledge, vision and problem-solving ability to develop the amazing solutions that you and he so generously share and delight us with.
Thanks!
I agree with Richard. Stefan, you are no slouch when it comes to you machining knowledge! I always look forward to your videos! I also like how you draw your parts. I gave a mechanical engineer friend that does his rough drawings in a graph paper notebook before he then does it in a CAD program.
Yo Rich, you don't have to watch the news. I don't. It's so much better that way.
Richard i totally concur
Stefan I think you do some of the most interesting machining videos on RUclips. Keep up the great work.
As an apprentice machinist myself, I find this video to be particularly valuable because you included the iterative design process along with multiple camera angles to capture your detailed and up-close machining. Thank you very much for this video series.
ROBRENZ deserves a shout-out, he is giving a wealth of detailed information and practical tips and tricks for free basically!
free or not? you sound "basically" like a cellphone cable company commercial.
Excellent video as always Stefan! Nice solid design you made there. Thanks for mentioning my video and your very kind words. Looking forward to part 2.
ATB, Robin
Thank you Robin, I would never came up with the idea building this attachement, if I hadnt seen it in your video :)
I learned very much watching this, thank you! I think you have a great sense of humor throughout the process which keeps things light and fun but still at a high degree of technical know how. I will be watching more... G.
Also I have been building a large 9.45' tall Robot and your ideas are helping enormously with the hydraulic spool valve I have to make. Thanks! Wish you lived next door to me!
31:02 You know the 'UUaghch' sound will end up in a ThisOldTony video.
I believe that is the biggest project I have seen you work on. Look out Abom, Stefan is coming after you. Love your videos.
Nice idea esp for smaller parts. Really good to see someone actually drawing an idea out! So many people are so keen to jump straight on the computer- drawing is an essential skill for any one making things with machines as it helps to save lots of set up time and wasted processes. Thanks for your video-Kudos on your English too!
~13:00 min the rail has three sides out of two that were removed, or a glitch in the Matrix. Thank you Stefan.
Very happy to see you showing the engineering and the design as well, most folks don't show this part. And nice to see you even take care of your band saw table to keep it from getting scratched. I need to do that too, just got a new one! Also, you got very good results. This was another good one. : )
Always impressed when watching your videos, your professionalism and attention to detail is out effing standing. And yes I do learn something ever time I watch. It may be something as simple as what you did by putting the spring center spring mount at the back the way you did. The way i was thinking was putting the spring in the hole then just locking it in with a roll pin. But the way you did it, it can be removed and replaced.
So well done my friend.
hi there from the USA, very nice thought process you possess. you have been an inspiration to me above all others on RUclips, not knocking other machinists, its that our minds seem to work the in the same way. the local economy likes me watching as well, because of your shop, I've added a B&S micro-master 510 surface grinder, south-bend 9a lathe, George Gorton 1a pantograph yes quite old but does the trick. and most recent a shape rite 8" shaper that is very nice. please continue the videos. I look forward to every new release, thank you!
I agree about Robin being a master machinist, I love your vid's, Tom Lipton, AvE, MrCrispin, and the other machinist here on RUclips, but Robin is really doing some crazy intricate work. I think we need to have an intervention though, to get him to do more videos! I'm so curious to know what he's working on now?!??
I tried a cheap spindex to cylindrical grind on my grinder and the surface finish was aweful because the spindle was too loose fit and it chattered like crazy. This is a much better setup especially for long parts. I kind of question the need for the spring loaded center for expansion though as in my mind if the part is growing that much you will not be able to hit your diameter size as you will be way inconsistent on size thanks to the temp variance in your part. Cool parts are happy parts when grinding and I think with the proper coolant you will find your surface finish improve even more. I know it is noticeable on my machine. The limiting of grinder dust with the coolant is another great benefit. You have obviously thought this thru well for your setup. Might i suggest trying a heavy flat rubber band for improved drive over the o-ring. More contact area should help with the slippage.
Agreed about cooling the part since the slightest heat seriously works out the part, the only serious way to grind is with flood coolant... ;)
Yes and no :D
With the same temperature change the part will way more elongate than grow in diameter, just due to the different proportions. Steel grows about 1/100mm per meter per 1°K difference.
d20x100mm long part, 50°K temperature rise will grow it in length 5/100mm but in diameter only 1/100mm. If you had the parts between rigid centers it would definetly seize on the centers or bend itself - Which would result in a horrible geometric error :D
Yesterday I ground a part 12mm diameter, roughly 70mm long - Directly after grinding it measured 12,006mm, after it cooled down completely, it measured at 11.999 (Plus the error from the digital mitutoyo mic).
Cylindrical grinding isn't as bad as flat grinding since the heat is distributed evenly all around the part, as on flat grinding it's only on one side and mostly on thinner parts it seriously warps as the heat builds up...
Those are very good results...!
Yes dimensions certainly effect part growth and for long thin parts this is very true. It is just my preference to prevent part growth while grinding so I don't have to estimate what my finished size and locations will be or wait for the part to cool down after every op to determine the next move. My only experience with a cylindrical grinder was doing shaft about 1m long and 50-75mm in diameter with 3 critical journals. It had fixed centers and flood coolant and was not difficult to hit size within 0.005mm the first time with a rough pass followed by an adjusted spark out. I hope to someday have a proper cylindrical grinder in my shop as I rather enjoy using them much more than a surface grinder. I have no idea why. Thanks for the great video!
With the o-ring or rubber band, you are side loading the part... seems like a bad thing?
I realise this is almost 4 years ago Stephan , but I am really impressed with the finish and your fantastic attention to detail in all of your projects 10 out of ten mate!
I really like how you gradually build up high quality tools from scratch or from inexpensive chinese stuff. I'm subscribed to a longer list of channels than I'm able to keep up with, but your channel is one of very few that I make sure to watch ASAP when there is something new. Totally agree about Robrenz, he has some real gems. Just wish he would do more videos.
I heard you are going to the Denmark scraping class this April. Dare we hope for some more scraping projects/videos this summer? I'm also signed up for a class, but it will be in Norway the week after.
A tool post grinder for my Weiler LZ330 has been on my wishlist for some time. This video makes me question whether it's worth it?
Using what are essentially bench centres on a surface grinder is a brilliant idea, thanks for that.
Not trying to tell anyone how to suck eggs, but for the benefit of others, it's generally considered best practice in metrology to measure a flat surface with a ball indicator tip, and a round surface with a flat indicator tip (ie an "elephant's foot"). The reason is in case the tip is slightly off centre and/or the part is not quite square to the measuring axis,
That is a very wide wheel on a grinder that size.
I was interested in what you said about using water based coolants versus oils and the tolerance when drilling precision holes so I called an acquaintance of mine who sold machine lubricants for a number of years. He told me that the reason that oil drilled holes tend to end up larger than water borne lubricants is essentially two fold.
The first is to do with the cooling effect of water. If you heat a piece of material evenly it will grow evenly and the bore of a hole will normally grow larger. The problem with drilling and reaming holes is that the holes tend to shrink in diameter while machining since the surrounding material is still relatively cold in comparison and forces or upsets the diameter inwards against the cutting tool. When the bore perimeter cools and stabilizes with the surrounding material the hole grows slightly outward as it cools giving a larger bore diameter. Oil is a good lubricant and breaks down surface tension very well but tends to hold heat unless freely circulating which of course is not possible in a blind hole so the heat in the immediate area of the hole tends to rise in relation to the surrounding material causing upset. In addition, the hot oil will cause your drill bit or reamer to run at higher temperatures causing expansive growth of the tool itself. When using thicker or more viscous oils this phenomena will normally be more pronounced since they hold more heat than their thinner counterparts. When using water borne lubricants there tends to be a cooling effect since the water will boil off and the resulting steam carries the heat up and away from the material thereby keeping the material and cutting tool cooler resulting in less upset. This is also why air driven water lubrication and cooling systems tend to give better dimensional results than oil flood when machining large flat surfaces as the material arches up and away from the cooler lower side.
The second reason that oil drilling holes tend to be over size is to do with the molecular adhesion characteristics of oil. When drilling holes, the adhesion of oil to the material will cause cutting particles to stay in place between the sides of the bit and the material being drilled. These small particles act as an abrasive or small cutting edges that cause the hole to be greater tan the bit or reamers nominal size. Water has a much lower coefficient of adhesion and the particles have less tendency to adhere to the bit and bore perimeter resulting in less residual abrasion. Essentially the particles are more likely to be carried up and away by the bit flutes since the water will not grab and hold them in place as readily as oil. When boring a hole in a piece of material in a lathe you can visibly see this happening. If you use oil as a lubricant the chips in the bore tend to stick to the sides of the bore and travel around and around with the piece. Some times the chips will come in contact with the cutting tool and cause it to jump or chatter as it gouges out the surface of the bore. If you use water coolant, the chips tend to flow out of the open end(s) of the bore instead of adhering to the bore thereby reducing the chance of cutter contact.
I hope this is of use to you when determining what type of coolant to use for a given application.
31:02 Love it, laughing in my bed and the wife don't get it. You are doing fantastic films, when I go down to my shop the accuracy turns out a little different then yours. Thank you.
Hi Stefan,
I'd love to spend lots of time with Robin, in my books he's a great master... ;)
This device will be so much better than a tool post grinder, mostly on a smaller lathe since vibration is a major inconvenient.
Looking forward to see how you managed the drive part.
This just became a reason I need to procure a surface grinder. Amazing concept Stefan.
Excellent job Stefan. There must be another use for this as I do not have a surface grinder. :-) Looking forward to the next part.regards from the UK
"...to give the reamer a fighting chance."
Love it.
I would have never thought about that spring loaded end. way to go loved all these ideas I can use them on thing I do. Thanks
Saw something similar on ThatLazyMachinist video about how a universal grinder works. It had a lever added to make removing the part easier/safer. In some ways Stefan has produced a solution that is similar to the functions of the universal grinder, by ingenious design.
The sprung centre compensates for any length deviation if the part cools or heats up, keeping it clamped securely.
I definitely learned some things Stefan. Never heard of the gutting oil/coolant would create different size holes. Looking forward to the next part. :-)
Now that is clever and thinking outside the box. Love it!
I worked with the harig fixture and it got some interesting design element. You can use a half center if you need to square the end of your shaft, and work on very small diameter. No need to had a vise to fine tune the concentricity with the tail stock flexture.
Always good to find a solution to your problem, nice build enjoyed the video, keep them coming, and thanks for your time and effort Stefan.
Lovely job Stefan.Some fine threaded adjusting screws through the bottom to help when setting angles for tapers might be useful.
Nice addition to the shop. Now I need to build one.
Thank you Richard! You need one, just like I need the rotary broach :)
Great build, discussion ,instruction!
Thank you! :)
I enjoyed your design approach with pencil and paper, calculator and measuring devices. Then the translation with Onshape, to 3D Model. Onshape is my go to CAD tool now. I still use Solidworks with HSMXpress for my CAM work though. Clever grinding aid, Stefan. I look forward to the rest of the project.
I would prefer a local running Cad anyday. I am used to ProEngineer/Creo at work and I would love to have a license for me at home...
That's great - I can now build something like that for my LIP grinder!! Look forward to the next part. :)
Well done. Truly professional way to do it, I suppose.
Perfect grinding is possible with a lathe as well, but it's very hit and miss. I have managed to achieve surface finish like that with a Dremel in the toolpost, but it took a longer time than it took you to build that contraption, I suppose. And like I said, to repeat it you probably need quite a few lucky stars aligned.
Regarding the Dremel, I have noticed your comment in another video and based on my experience the biggest problem with these is the imbalance in the tool rotor which causes vibration. I have used a Proxxon as well (they actually sell a special toolpost attachment), and those are a bit better balanced hence a better shot at a good finish. In the end, the Proxxon proved to be more fragile and it crapped its bearings (which are not replaceable, you have to buy the whole gearbox), so I'm back to my el cheapo Dremel copy (surprisingly this is better balanced and has less play in the bearings than the real Dremel I have).
Surprisingly (again) the dremel copy takes the Proxxon chuck and collets (the dremel has a different thread, so you can only use the crappy collets that come with it, I agree with you there, they really are crappy).
Hi Stefan Gotteswinter. I think the cutting liquid viscosity the reamer "floats" in while cutting influences hole size. I get bigger holes with more viscous cutting fluids than with thinner cutting fluids in general. Interesting way to nudge the hole size depending on what you want. Great project, vid, comments, and info. Thanks!
Very informative Stefan. I look forward to Part 2.
Bob
Nice Job Stefan! I had to make something very similar a while back to measure torque reaction forces caused by tiny motors. In my case I couldnt use spring loading on the center, I used a super fine thread to set a very light preload. in your case you can always say "the proof is in the pudding" (USA slang meaning something like " the end justifies the mean") Thanks for sharing.
Excellent idea and execution Stefan!
Great job Stefan!.....I have the big KO Lee Tool GRinder with all the goodies, and can do cylindrical grinding up to 20" with a powered workhead....just need to get it setup!...your killing me!
Finally new video☺ We missed you Stefan.
As always, informative and interesting. Thank you for being both a top tier machinist and a content producer.
Great setup. Thanks for the sharing.
For the bandsaw I see another project soon from you - stops for making straight cuts ;)
Great work Stefan! I really look forward to your videos!
Love you're work Stefan.
Beautiful work as always!
Nice video and build Stefan. I was thinking about how the difference in fits in a reamed hole can be influenced by the cutting oil. Is it possible that the water soluble oil does a better job of cooling the cutter than the straight oil does? That might account for the difference.
Pete
My guess as well. Water keeps it under 100C and has a good amount of thermal capacity while oil lets it go way up high and really fast
Another fine "window on the human creative process.Like being invited into Frank Loyd Wright's architechteral studio and witnessing the construction of masterful drawings,Or Tiffany studios.Through the internet,your message is being spread far and wide.Let us hope you continue and contribute to Global reason and peace among us by example of your uncomprimising character ,and search for excellence.That is a true leader
Thanks for the video, you are revealing the possibilities of this machine, purchased a similar МИ-172
Excellence as usual :-) Please keep dropping things, it makes the rest of us feel normal ;-)
Bill Todd
Great work Stefan as usual.
Have you ever thought about building a right-angle head attachment for the surface grinder? Always wondered why I have seen such things on the market.
Yep! But with an auxillary air- or electric high speed spindle, primarily for ID grinding. :)
great video for DIY. is it possible for you to make a video showing air bearings for grinding end Mill?
keep up the good work, danke.
john
Im thinking the slide vs press fit on the cutting fluid has to do with the viscosity of the cutting fluid. The oil will have a higher viscosity, which will result in higher/broader localized pressures at the tip of the cutting edge. Sorta the same thing as positive vs negative rake angle on cutting tools, but on a smaller scale.
Awesome videos as always! Like others have contested, we have learned a lot about precision machining from watching you and Robrenz. I have a question for my own curiosity about the alignment of the centers. Obviously they have virtually no run-out as you have shown so using a vise work stop worked out great for alignment of the holes for your purpose. My question is when would you match drill and ream the centers in one setup vs using a vise work stop?
Nice drive setup!
I'm just glad you didn't put the work in the chuck, the play on that Bosch drill is crazy (and seems to get worse over time).
Maybe it needs one of your famous overhauls...
Clever!!! Another fine video production.Thank you..
it's been a while since you trammed your milling machine with epoxy, is it still standing right? love your videos
Funny enough - Yes I checked it just a few weeks ago. As expected, no movement at all :)
That cast iron machines beautifully.
Next up: "How to fix your v-block after you dropped in front of the whole internet."
+1 on Robrenz. Master machinist is a bit of an understatement, I am always in awe of his work.
I'm thinking yo might want to go ahead and grind that base on all surfaces to be square and true. You never know when you might want nice straight (and not round) reference surfaces. It would probably help setting up in the mill as well for doing roughing work.
I'm looking to buy a bandsaw like that, but can't decide if I should spend the extra money for the three phase version.
Your saw seems plenty strong, do you have the single phase or the three phase, and could you possibly check the motor rating?
I don't particularly trust those chinese motors any more, I just replaced the one on my drill press with a three phase one (I could easily stop the chuck with my hand, it was ridiculous). In china the horses must be very small indeed.
Der Sound ist um Welten besser! Die Videos wie immer sehr lehrreich!!
Freut mich das das auffällt :)
ROBRENZ (Robin) is one RUclips machinist that I wish would make a lot more content.
Great project. I want one. I have a WWII era reid surface grinder that this would work well on. What sort of indicator holder is the base from? I've never seen one like that.
I love your stuff. How about showing us how to make a precise surface grinder.
The reamed hole getting bigger with oil in my opinion is due to the fact that oil has less of a cooling effect and/or it it moves the heat away more slowly than water based. I've noticed the same thing and yes, when the print calls for a hole on the looser side I just use oil and in smaller quantities.
Sounds like a good explanation. I will use that in future ;)
Excellent work but I have one concern with the adjustment of the setup within the vise to the desired angle. You didn't show how it was done, was it tapped into position? Or did you use screw jacks. Considering the accuracy of your project I would have thought an incremental adjuster would be in order.
I just knock it in place. It can be seen for a short moment in the video - I didnt want to overcomplicate it. What I might do, is to grind the fixed centers point about 1/10mm excentric and add a hex to it, so rotating it changes the alignment.
Na toll, da sitzt man sich gemütlich mit einem Kaffee auf Sofa und will sich eigentlich berieseln lassen und jetzt will ich wieder in die Werkstatt. xD
Sehr Schön :)
Die Akkuschrauber Geschichte hatte ich für meine Frikla auch schon geistig in Planung ^^
Try a rubber emery wheel on your tool post grinder for finishing work. You can achieve a mirror finish on hardened steel.
best home shop on youtube. And its European !!!!
Cool stuff. Thanks for posting!
I really enjoyed the part where you were drawing the parts. nice job with the video
Nice Job! Very inventive!!
I am a true follower of your work, I think you do some amazing stuff. However I was curious as to what stops the sprung center from spinning with the work ???
Hi Stefan, I'd like to build one of these grinding fixtures. You having the indicator base already was lucky, I will have to hog something out of a bar stock. What would you recommend? You think the cast iron is a good choice? What kind of cast iron?
Thanks.
Ps, I've been building your squareness comparator. I just got the drill bits to drill the holes in the spring steel, then I'll be done. You dedicated yours as a squareness comparator, I made the base on mine a bit heavier and pushed the post a bit further to the back with the idea I can swing the clamp body and indicator around to the other side and use it as a surface guage too.
Have you measured the height of the two centers in relation to the base of the entire attachment? If they were prefect you could clamp straight in the chuck for non-tapered parts. Indicating them level will still always be a good idea.
:thumbs up:
Very innovative! I love it!
Thanks! :)
the part might be held better between the centers if you replace the spring with a bolt , basicly tighten the part between the centers , that should be able to hold more of a sideload from the drivemotor without pulling out of the center on that side
A more than interesting and versatile project Stefan. And nice touch adding the design sketching into this. Your mill runs extremely smooth. Do you think the epoxy bedding compound you added under the rear columns mounting foot made much difference in how the machine now cuts?
An add on 90 degree drive and wheel mount for your surface grinder would give you the full normal table direction while radial grinding. :-)
This device is a necessary step before grinding a taper. the question I have is how to be precise when adjusting the taper angle after prussian blue. are you going to build a micro-adjuster to tilt the rail?
Great video! Thanks for the inspiration and information!
verry nice video!! one question... how are u compensating for wear of the grinding wheel during grinding?
I'm sorry to hear that your tool post grinder didn't work as expected.😢
Moving onwards and upwards 😊
Nice contraption man!
Hi Stefan. I'm jellous! I don't have space for a surface grinder. I wonder if fitting a horizontal grinding spindle to my mill head would be sensible? Just a thought. It guess the critical aspects would be Z axis resolution and rigidity. Bob.
The grinding dust on the milling machine would scare me...but apart from that, yes, with a grinding spindle it might be posible to get parts within the precision of the milling machine.
+Stefan: Good point. Thanks. Bob.
I swear it looks like you ran that 6mm reamer backwards.
I was just thinking. Couldn't you use your offset lathe chuck as part of your device so you would be able to judge the remaining amount of grinding needed without withdrawing the work from position?
Thanks for sharing; enjoy your videos very much
Could it be that oil based allows the reamer/part get hotter, thus increasing the size of the reamer/part and creating looser fits?
Water based can't get over 100 degrees before the it starts to boil and remove heat quite efficiently?
Is using an existing MT#2 as a ref more accurate than trying to set up the 0.050 per inch on a straight rod? I don't know if I trust any of my tapers....
How did you ensure that the two centres are co-linear. Did you bring them together with a thin shim between them to check? Like we do on our lathes to test co-linearity?
If you set the attachment at say a 30 degree angle, wouldn't the wheel both drive and grind the cylinder?
You do your country proud!!!
Just plain awesome!
stefan nice work.
Thank you for another great video!
13:10 that *THUMP* sound like something out of Tom&Jerry
Wow, I just realized that I messed up the editing there...I cut the indicator three times Oo
I have tried to find straight shank centers like the ones you used, but can only find ones with tapered shanks. Any pointers? Thanks!