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8iggles
23-06-2010, 12:46 AM
What type of bearings are best suited for a spindle, is it better with a thrust bearing or like angular contact type?
I want to use a key less 10mm chuck and I think the thread is 3/8 unf in it so 3/8 shaft size would be good.

Thanks Shaun

routercnc
23-06-2010, 02:13 PM
Hi Shaun,

I hope I'm understanding your intention. I'm no spindle expert, but a thrust bearing will only allow you to drill holes because it cannot take side loads. Therefore a pair of angular contact bearings sounds better. A spindle often runs at high speed, and therefore you might also want to consider the ceramic type of bearing.

Bit more detail about what you want to machine might help others with a spec for you.

Thanks

8iggles
23-06-2010, 06:59 PM
Hi Thanks for the reply, I have found a couple of roller type thrust bearings in a rummage through a box of old bearings I got from my Dad...I was going to use a couple of ball races and a thrust bearing.
I don't need anything too robust as I'm only going to be cutting depron and balsa / liteply at first, but was worried about the speed...My thoughts were like a model aircraft engine is reported at XX BHP at like 17,000 revs ( although I have never measured or seen one at this speed ) now these are just ball races and have temp and nitro working against them?? It would be good to continue the 22mm OD theme of the skate bearings but the shaft on them is only 8mm
Just noticed your Avatar - Is it your own design? Are you going to green acres fly in this weekend, thats in your neck of the woods ?

Ross77
23-06-2010, 08:45 PM
If you are into making your own spindles then there is a very good book in the 'workshop practice series' surprisingly called spindles.....for less than a tenner

Basically you have radial and axial loads to resist, normal skate bearings are good for radial but not so good for axial so if you use a thrust bearing as well then you should be OK, the next limiting factor is speed which is where the angular contacts come into play. they can be used as singles in opposing pairs under tension or as a preloaded pair and are sold with a speed rating.

taper bearings I believe are mainly used for high load and high speed like on my lathe..

Like I said this is a basic overview and there are many other factors like excessive friction/heat and then expansion of the spindle etc. etc....

Regarding the bearings in an ic engine are probably a high grade and could be deep groove bearing, much stronger than a similar looking skate bearing. Bearing quality is usually reflected by the price but unfortunatly they all look the same.:thumbdown:

8iggles
23-06-2010, 09:26 PM
By taper bearings do you mean taper rollers like a car wheel bearing? I had ruled these out as I was thinking a car wheel bearing is quite slow speed and high load...Angular contact are they like a front wheel drive type of bearing where its ball bearings but a closed and open side to the outer race?
If I did them out of a common car taper wheel bearing then they could be universal to source and a reasonable price - the loads are going to be a fraction of a car its just the speed and keeping the dust out

The reason I wanted to make a spindle is to be able to have a speed control from the spindle board of the system 4 - I have worked out how to switch the dremmel on and off via the relay but want to progress and use an electric motor / speed controller from an electric model motor if this is possible

ptjw7uk
23-06-2010, 09:33 PM
Best thing to use as you are thinking quite small is magneto bearings see http://www.arceurotrade.co.uk/Catalogue/Bearings/Angular-Contact-Ball-Bearings they are good for fairly high speed.

peter

8iggles
23-06-2010, 10:16 PM
They look perfect - the E10 is within my limited skill reach :) 10mm shaft will thread 3/8 unf for locknuts and chuck and 28mm outside is not too big either, I'm sure I can find some tube that would make it possible - thanks Peter

8iggles
23-06-2010, 10:34 PM
Regarding the bearings in an ic engine are probably a high grade and could be deep groove bearing, much stronger than a similar looking skate bearing. Bearing quality is usually reflected by the price but unfortunatly they all look the same.:thumbdown:

You are right about the quality, on the model engines the inner bearing is always a special order as its a big shaft size and the outside diameter is not that much more, but the outer bearing they always have and say its a common one - nothing special ... dead cheap and don't last like the originals

Thanks for the replies

routercnc
23-06-2010, 11:24 PM
Hi 8iggles,

Knew I'd seen it somewhere, try this:
http://www.mycncuk.com/forums/showthread.php?445-DIY-spindle-design

I just skim read it again and it might be just right for you given your mild loads. Based on a brushless motor intended for model aircraft, cars etc. These are all over ebay (Chinese).

Just off topic briefly, since you asked, the Avatar is my own design - called Precision3. A 1.9m span Patternship running from a 10s Lipo (36v), 2KWatt brushless motor, 100A Opto SC. 5.2kg all up weight, 2 years of design, CAD, hand cut out (pre-CNC m/c!), build, cover and fly. Maiden flight about 1 month ago. Wonderful flier with no downthrust, side thrust or incidence changes required. I'll not be at the green acres - bathroom project (but Cosford LMA is on!). OK, back to the spindle . . .

8iggles
24-06-2010, 12:33 AM
Hi 8iggles,

Knew I'd seen it somewhere, try this:
http://www.mycncuk.com/forums/showthread.php?445-DIY-spindle-design

I just skim read it again and it might be just right for you given your mild loads. Based on a brushless motor intended for model aircraft, cars etc. These are all over ebay (Chinese).

Just off topic briefly, since you asked, the Avatar is my own design - called Precision3. A 1.9m span Patternship running from a 10s Lipo (36v), 2KWatt brushless motor, 100A Opto SC. 5.2kg all up weight, 2 years of design, CAD, hand cut out (pre-CNC m/c!), build, cover and fly. Maiden flight about 1 month ago. Wonderful flier with no downthrust, side thrust or incidence changes required. I'll not be at the green acres - bathroom project (but Cosford LMA is on!). OK, back to the spindle . . .

Yes that looks just right - Mine will not be as posh as that but the size and motor choice looks right...he also talks of the z axis between the Y axis rails as I have done and the tube which is the plunging z axis bit will have the spindle built in it

Precision3 looks great - a lot of hard work... well done on the successful maiden. My son Ollie is flying with Steve Mallinder at CML, so if we go to Cosford I'll try and say hello (sorry off topic)

Thanks Shaun

Ross77
24-06-2010, 12:48 AM
By taper bearings do you mean taper rollers like a car wheel bearing?


Kind of, but I was thinking of the timken type used my lathe, little bit smaller I think.

not sure on the front wheel drive description for angular contact but if you google it you will find lots of advice from manufactures, the best way I cn think of to describe it is if imagine a normal bearing with the races opposite each other then on an angular contact bearing the bearing surface of the outer race is rotated through 45 degrees and when another one the mirror image of it is used it can resist radial and lateral loads. probably better to google it :smile:

Jeremys Spindle design is an excellent thread and I have all the parts to make one soon.
there are other good theads on here just search spindle( Bamboko's(?) 'small spindle' and Hilton Steves DIY spindle come to mind)

If you use a double row angular contact for the front bearing then the rear bearing can be almost anything is it is not taking any load. and should be able to float axially.

you also need a lathe to make most of these spindles, do you have one? I did see an easy to build version that used a piece of seamless steel tube and flanged bearings, preloaded by the spindle shaft, job done. if its for minimal use then just replace the cheap bearings on a regular basis:smile:

black5f
24-06-2010, 02:00 AM
IC engine bearings are constantly bathed in cool clean castor oil (about 30% in the fuel). Tapers will need adjustment and some preload but not too much or they'll get very hot!
Workshop practise no 27?
http://www.rdgtools.co.uk/acatalog/WORKSHOP_PRACTICE_SERIES.html

Or, http://www.sherline.com/images/30100pic.jpg for $102, these are very good. Not sure what constant speed rating is but their a friendly bunch and will soon tell you. Morsed and threaded. Not as much fun as making it yourself though!

If high speed then I would be careful of the keyless chuck, if the spindle decelerates fast they can come undone (the chuck part), or fall off the spindle if threaded on and still doing max revs. You could use a small morse shank and a draw bar or a collet. Collet is much safer and far more accurate. At 3/8 side loads are going to be relatively low I would think so good quality angular contact (ie normal ones) should do the job.
Nice plane!

8iggles
24-06-2010, 08:27 AM
Cant wait !! sent for a pair of the E10 magneto bearings, 12 posted next day...perfect for my Budget
Yes the front wheel bearings what I meant are a bigger version where they are like a roller bearing with an open and closed side, fitted back to back with a spacer between. The ones I have sent for I will use the spindle to be the spacer in between.
Yes I lost my Dad 3 years ago who was an engineer (He would have loved this site) and all the Dumb questions were directed at him!! Sorry you lot get them now :) - I inherited all his tools and have his Lathe.
Now I can burn tools and make things way under size etc etc ... but I'm getting by
I wanted to use a keyless chuck for ease of use - I'm going to try it and move on from there...Ive just got a dremmel type mini drill with a keyless chuck temp just taped to the z axis and i'm not hard to please as this is cutting the foam ok with a 1/16 polishing bit at low speed
Thanks for the replies
Shaun

Ross77
24-06-2010, 07:23 PM
Now I can burn tools and make things way under size etc etc ... but I'm getting by
I know how you feel, I've only just started to learn how to use a lathe properly, general turning is easy, getting two parts to fit together is the hard bit:rolleyes:



I wanted to use a keyless chuck for ease of use - I'm going to try it and move on from there...Ive just got a dremmel type mini drill with a keyless chuck

I may be wrong but I think you mean a collet chuck? keyless are like the ones on a dill with 3 jaws. A collet chuck is like on a dremmel where the bit is held by a tapered and slotted holder, compressed by the nose cone(? thing, bit:heehee:)

A collect chuck is far superior in all aspects including grip and run out, and is what most people use for cnc, Check out the ER 11 range for what you need.

Just out of interest what lathe have you inherited?

8iggles
24-06-2010, 09:21 PM
I have a rotary tool with a collet type chuck, but all the bits and small end mill cutters never seem to fit !! the little mini drill thing that I'm using is a little 3 jaw chuck that will just about take a 3/16 bit at a push. its just theres a new keyless chuck in dads stuff

The collet chuck would be spot on but I can spend on essentials first like software then upgrade as I go...it says jacobs taper is that the same as the taper in the back of a bigger jacobs chuck?

The Lathe is a Faircut Junior and my Dad served his time in Sheffield and started on one of these around 1950...Then when he saw this one for sale early eighties he bought it for his retirement - I just had to make room for it and could never part with it http://www.lathes.co.uk/faircut/

black5f
24-06-2010, 10:12 PM
Sounds like you're having great fun! Lovely little lathe, don't be put off if its a bit worn. as long as the headstock spindle has no lateral or longitudinal play and most older lathes can be adjusted and adjusted. I had a 55 year old tired ML7 for years. You get to know where its accurate and where not and just have fun. So the first thing to do is make yourself some bushes for the collet. I've only got about three collets because they are so expensive (they are all second hand), turned up a selection of bushes out of ali or brass. In fact, my nc mill just has one anoying metric collet and I have never got round to replacing it. Turn them to diameter and drill and ream for your cutters, then just slit them with a razor saw just over half way by hand from each end 90 degs apart, and you can use all your cutters. 2nd hand reamers are usually OK for softer metals or borrow one just for that job. Oh, if you cant already, learn to gind your own turning tools (sherline has a good pdf on that), much cheaper. Don't forget that broken files and drills are all good tool material, can be ground to the shape you want and can be mounted in mild steel bocks in the tool holder. Broken needle files make excellent small boring tools brazed into a bit of bar.

Taper drill chucks are in all sorts of sizes, popular tapers are Jacobs (JT1, JT2 etc_ and B. But they're all different. Tapers safer or just apply a little nut lock on the thread. Chucks never really run true and they wear, even if you spend a lot (drills bend anyway!). Cutters are much harder and snap, with very small cutters in a drill chuck they are really going in circles rather than rotating.

Most importantly... have fun!

8iggles
25-06-2010, 11:37 PM
Yes Its great to get out in the garage - a change from the stress at work....The lathe is just right for me not too big. I will have to learn to make and sharpen tools - I found 2 boxes of new blank tools 3/8 round and square. I'm gradually mutilating my way through the ready to go ones :)
I never thought about making bushes - So If I were to buy one I could get maybe a 1/2 one and all the tools that I have are smaller
I will still use the drill chuck at first because I have got it and the accuracy is not as important as the ease of use while I'm learning, I need to get some time in using it - However I have noted what everyone is saying to me and will upgrade to a collet chuck

Thanks Shaun

wiatroda
09-02-2011, 07:44 PM
Hi Shaun
In my DIY spindle I used 32004 single row taper bearings. ER20 chuck rotates at 3000rpm. For me it works better than expected. For details see my Web: http://malamuterun.co.uk/homemade_cnc_mill_spindle.htm . hope that helps

Web Goblin
09-02-2011, 10:15 PM
I've been thinking about making my own spindle motor as well. I have a spare dc motor and amplifier lying around but had previously been quoted silly money for high speed bearings. I think those 7205B bearings from arceurotrade go up to 15000 rpm which will do the job.
I think I'll give them a call tomorrow to confirm and get some ordered if they do go that fast.
Thanks for the link.

Ian