Spindle bearing Replacement
HTML-код
- Опубликовано: 4 мар 2018
- So it's time to get going on the belt drive and to start I'm replacing the spindle with one I threaded and new Nachi bearings. The I have tried to be as detailed as possible to the point of being informative but not boring. I will try to keep the videos around the 15 minute mark. Please comment and let me know if the content is spot on or you would like more information and details. Thanks for watching , please subscribe, thumbs up if you like the video, and most importantly , Be Safe!
Nachi Bearings 30205 and 30207
Show support with a pledge: / cnc4xr7
For Plans and other Information visit www.cnc4xr7.com
Follow the PM-727M CNC Build Here: • PM 727M CNC Project
Follow My G0602 Build Here: • Project G0602 CNC conv...
Folllow My X2 Conversion here: • X2 Mini-Mill CNC Conve...
www.machinetoolonline.com
Or At Amazon with Stand: amzn.to/2eptgeS
Without : amzn.to/2fgHMaw
Precision Matthews PM-727M $1849 Shipped
www.machinetoolonline.com/PM72...
Disclaimer. I am not a professional. My videos are intended to
document my progress . I express no warranty as to the accuracy reliability or safety of the information provided here. By using any of the information provided in this video you acknowledge that I am not responsible or liable for injury or damage to property. Electricity is Dangerous proceed with caution follow all local regulations in your area. 
Хобби
Thanks for explaining how you took the bearings out, gave me confidence in doing it myself. Cheers.
Yes it can be a little intimidating. but it's really fairly easy to do.
GREAT VIDEO! Seriously, this video had all of the best tips for upgrading the spindle bearings. I'm about to do this soon, so thanks!
Thanks your welcome.
Nice job Sam, looking good. Fantastic information!!
Thank you!
Good video Sam! That belt drive is going make a big difference:)
Let's Hope so
Thank you Sam, definitely saving this video. I've been running my PM25 at higher than standard spindle speeds without problems after reading on CNCZone the bearings were spec'd at least 5000 RPM (one was 5000 RPM and the other was 8000 RPM, if I remember correctly, if using the correct lubricate.) It's an older post, but Hoss commented that's likely right, but that it's a crapshoot with the original bearings even if they are lubricated. So, I'll keep "overclocking" the spindle until the bearings are out and then come back for instructions.
Your Welcome! Yeah its funny when you start shopping for bearings hard to find the big bearing higher than 5600 rpm for the taper roller variant.
Sam
It has been so helpful to me to follow what you have done. Your videos contain all the info that anyone might need to renew their bearings. The Mill I am converting is a Warco GH18 and it turns out to be the same mill as the PM727 but painted green and cream. I have my spindle out as I write this and am just waiting on the Kluber grease before I reassemble it. I had not run the mill at all before stripping it and I had noted that the spindle was a little stiff to turn. It turns out that the bearing seats were a little tight and the locking ring had been tightened up little too much. Also the blue grease that the bearings were lubed with was very dry. The original bearings were German manufacture but I do not know the company. I bought SKF replacement ones that have a higher rating than the Nachi ones you used. When I cleaned the original bearings up the top bearing in particular was full of debris. I washed them out with paraffin and blow dried them with the air gun. They now run freely but will only hold them as spares for the future. I carefully miked up the journals and they were really accurately ground. I just cleaned them up with emery cloth and checked the amount I was removing, a micron at a time. Even if you were not doing the CNC conversion and belt drive it would be worth taking a new mill apart and removing the spindle and washing out the bearings and re-lubeing with Kluber grease.
John
Hi John, It's always a good Idea to at minimum give the spindle a once over before you start as you say debris can be in there from shipping etc. After the initial run in of the spindle I did not change the original bearings. until the belt drive was to be installed. the Stock mill will only get up to 1800 rpm and e e with a vfd and 3 phase motor I was only running at 3600 rpm. well within the bearing spec. I figured I would change them when the belt drive was done as I always had that planned . Be sure to seat the bearings and recheck after the run in most likely they will need to be re tightened.
Nice Sam. In the H-D tech world we freeze the races prier to installation, in most cases slip right in.
Yes Great Idea of course the tolerances did not require that in this Case.
The belt drive and the pulleys are going to make a tremendous difference in RPMs. You will love it!
We will see
The keeper ring is what seats the outer bottom bearing. It should be fitted before torqueing the top bearing down, as it may seat the bottom bearing further in.
Hi Mike Great point! thank you!
Would like to watch again of your video
Thanks
Sweet!
Thank you!
Hey Sam, looking good .. just a friendly heads up. Kluber grease is so efficient and clings so well it takes considerably less grease that what would normally be used in packing wheel bearings. Watch your temps carefully as you do your break-in procedure .. If memory serves me correctly I believe it was Nick from 'The Grizz' thread who had to pull his spindle back apart and remove some 'Kluber Goober' to prevent over heating. While building my machine I ran accros a chart that gave requirements for how much Kluber to use in various different bearings. Sorry but I can't locate it right now or I would add a link. I recall that I was rather surprised by how little Kluber was actually needed. I even did a tear down after about 6 months to inspect the spindle bearings and was amazed by how well the grease was clinging to critical bearing surfaces.
Thank you,
Yes This was a error on my part and I think you are absolutely correct a little goes a long way.
I ordered new bearings but will they come with a new race? Do I need to install a new race with the new bearings? Thanks for the video! FYI, I was having overheating trouble and found an EXTRA quill lock pin when I got things apart. It had chewed up the dust cap on the upper roller bearing.
Yes the Natchi bearing should come with a Race . You should always replace both and do a proper break in. once set they will run cool.
Good video. Heat and cold are a wonderful thing. Would have made the job a lot easier in my opinion. Patience!! At 13:38 I found something I didn't like and would have have used a different method. It is so easy to do and not everyone has the tools, JMO
I agree there are a few ways to get it done. Having tools helps.
Sam another great video. Perfect timing for me. My bearings are grinding like crazy and the spindle is getting really hot. Did you ever post a video of how you removed your spindle? I just ordered the Nachi bearings and am starting the spindle removal. Do you have to remove the spindle feed shaft?
The grinding you hear may be the 2 Top bearings which are 6007 radial bearings 2 back to back mine are a little noisy and need replacing will be doing that soon. Been awhile since I removed the quill handle but the lock handle on the left needs to be loosened good and I think once you disconnect the depth gauge you can just use the tri handle to lower it out. put a block of wood or something just in case you drop it or if falls out.
Thanks for quick reply! I did finally get the spindle out. I removed the lock handle bolt and the depth gauge completely and was not able to remove the spindle. I had to pull the whole quill feed shaft out to remove my spindle. Hope I can get it back together. lol I couldn't see any other way to get the feed shaft to disengage with the quill groves without pulling it.
My spindle was grinding and difficult to rotate after I had it out, so I am sure that is where problem is. After pressing out the spindle, I was expecting to see a mess of chewed up bearings, but all looked good. I think the spanner nut holding it all together was just cranked way to tight which was causing the bearings to grind and heat up. I have new bearings on the way so just going to replace them.
Cant wait to see your rebuild completed.
Ok check the set screw pin that is there to guide the r8 collets Mine backed out and chewed things up
I also just left it out
Great job Sam. I must have missed it, but why did you have to buy a new spindle instead of threading the old one? Ciao, Marco.
So I can still run the mill! LOL
Fantastic video. One question, you sanded down the top of the spindle to allow the top bearing to slide over the spindle with less effort. I am replacing the bearings on my PM833 which has an almost identical design. What is confusing me is that the top bearing fits very tightly on the spindle. How loose did you make it. Does it still have some friction when you slide on the top bearing?
Place the spindle in the freezer and put the bearings in the sun. That should do the trick
Thank You!@@CNC4XR7
Anybody know some common spindle sizes? I'm trying to get parts rounded up to build a complete head stock.
80mm is pretty common.
Please share the dimenssions of the quill and the shat in future, thanks
Sorry I dont recall off the top of my head I think the bearing size is listed which will give you the ID and OD . 35mm ID I believe.
Can a MT2 Mill be converted to R8 Taper Spindles? If so is it a PITA? I see LOTS of mini mills on Aliexpress but all have MT2.. and theyre the same mills LittleMachineShop sells except LMS mills use R8 Taper
Try and see if they can offer you a R8 option most can im sure.
You put almost no preload on the bearings using that nut... Are you sure that's correct? What are the preload specs for that bearing combination?
I set mine by feel, Sorry not very technical I understand. I'm sure I checked this several times before installing the spindle. so what is on the video may not be the final preload. sorry about this.
When bedding the bearings if you have to much preload the spindle will lock up from the heat expansion running at high speeds. the preload needs to be checked again after this step.
You do not need to press the bearings on just emerge them in hot oil and put the shaft in your refrigerator freezer and they will slide on.
Sam, where did you get the new spindle? Still R8
Precision Matthews
Do you remember what you paid for the spindle? I just received my 940 a couple weeks ago and will eventually do a belt drive on it. I don't know if it will be the same spindle as the 727 but it will give me an idea about what to expect to pay.
How much better do you believe the nachi bearings will be? Of course, proof will be in the pudding.
Well Time will tell They are highly recommended and not to expensive.
Im new to machining and milling and trying to learn right now the anatomy of a milling machine. Currently researching the Spindle-Chuck-Tapers(R8 vs MT2 [by the way does MT in MT2 stand for Morse Taper?]), types of collets used for the R8 Taper Spindles and whatever else connected to the Spindle and Draw Bar.
At 00:20 you touch the a part that I'm assuming the Spindle slides into .. what is that technically called?
EDIT: ok so after watching more of the video at 02:52 you called it the "Spindle Housing" Ok so the Spindle isnt just one piece but a two piece item. So the rod and housing make up whats called the "Spindle". This will help me look for parts down the road on aliexpress.
Yes Morse Taper. Yes the Spindle itself slides into the spindle (housing/ Cartridge) R8 is popular because a lot of people convert to TTS type tool holders which require a 3/4" collet.