Make your own V-Rollers if too expensive in your country

[Gerald_D]

Have been of the opinion that the BWC rollers selected by ShopBot for the gantry are too small in diameter. Going up to the next size is a huge jump in cost. So, set out to make own rollers.....

Also, see this later thread (http://www.mechmate.com/forums/showthread.php?t=372) and notice that Superior Bearing sells at a much better price (http://www.mechmate.com/forums/showthread.php?t=18) than BWC

The basic design dimensions are so that the roller is interchangeable with the BWC size2 roller - the offset from the left face to the center of the V is identical. The bore size and OD make these close to the BWC/Hepco/Yitong size 3.

http://www.mechmate.com/Forum/messages/11/595.gif
BWC on left, own design right

The "rings" or "tyres" are precision CNC turned, inside and outside without removing from from the chuck, then heat-treated hardened in a vacuum chamber to protect the smooth surface finish.

http://www.mechmate.com/Forum/messages/11/596.jpg

Bearings (and seals) are a pair of these ($3 ea):

http://www.mechmate.com/Forum/messages/11/597.jpg

But the inward facing seals are removed to reduce friction:

http://www.mechmate.com/Forum/messages/11/599.jpg http://www.mechmate.com/Forum/messages/11/598.jpg

A single bearing is entered slightly into a tyre and a thin ring of LocTite is applied:

http://www.mechmate.com/Forum/messages/11/600.jpg http://www.mechmate.com/Forum/messages/11/601.jpg

Quickly, the bearing is pressed in with a vice with paper towel in between

http://www.mechmate.com/Forum/messages/11/602.jpg

It is important to press in one bearing at a time, and to keep the tyre flat against the vice jaw (the jaws must be good and parallel).

The LocTite must not migrate to the inner diameter of the bearing, because that is where the seal rubs. The marks left on the towel show where the LocTite has migrated:

http://www.mechmate.com/Forum/messages/11/603.jpg

Finished job in front with some spare tyres at the back. (Made more for a later application).

http://www.mechmate.com/Forum/messages/11/604.jpg

[Gerald_D]

Roller fitted under gantry with 12mm bolt:

http://www.mechmate.com/Forum/messages/11/606.jpg

[Steve Minuskin]

Gerald, nice job. I believe that the BW bearing have dual angular contact bearings. You may have some issues with axial loads and play with the bearing you chose.

[Gerald_D]

Steve, these are "deep-groove" bearings with the result that they do have a significant axial load capability. I will do some homework on the figures and post them here some time, but in practice they are performing very well so far.

[Gerald_D]

From SKF pages:

On Deep Groove bearings:

"Deep raceway grooves and the close conformity between the raceway grooves and the balls enable deep groove ball bearings to accommodate axial loads in both directions, in addition to radial loads, even at high speeds."

"If deep groove ball bearings are subjected to purely axial load, this axial load should generally not exceed the value of 0,5 Co." (The Co value for a 6001RSR is 2.36kN (530lbs) The load is not purely axial, and the axial component is certainly less than 265lbs)

For a matched pair of 6001 bearings with standard internal clearance, the axial clearance (play) is 0.02mm to 0.04mm (<0.0015"). Radial clearance is .003mm to .018mm (<0.0007")

On Angular Contact bearings:

"..double row angular contact ball bearings correspond in design to two single row angular contact ball bearings but take up less axial space. They can accommodate radial loads as well as axial loads acting in both directions."

For a 10mm ID SKF dual row angular contact bearing (probably similar spec. to BWC2), the axial clearance (play) is 0.006mm to 0.023mm (<0.001"). Radial clearance is not given.)

Hepco/BWC don't publish clearance values, and they want a maximum axial load of only 36kg (80lbs) for a size 2.

Bottom line is that I may have half a thou more play, but I have a much higher load carrying capacity.

[Gerald_D]

Contact Frank Hu at:

YITONG INDUSTRY (NINGBO) CO.,LTD.
Tel:+86 574 8630 2585 Fax:+86 574 8630 3168
http://www.yi-tong.com
master@yi-tong.com

for economical V-rollers.

Can anyone vouch for Yi-Tong's quality?

http://www.yi-tong.com/yi-tong/en/guide_wheels.htm

[Domenic]

Hi Gerald

I cant believe your site.. Any word i choice to describe wouldn't do it justice..

I have brought some roller bearing off Frank.

I have attached a pic...

What size should i be using for the MechMate?.. the ones I brought are "W2 X"

regards
Domenic
(Sydney, Australia)http://www.mechmate.com/Forum/messages/11/1181.jpg

[Gerald_D]

I would prefer the W3X (next size up) from Yitong for the MechMate, but the W2X will work as well.

The smaller bearing has a more intense contact point with the angle iron iron rails, and we see quite a bit of "smearing" on the ShopBot's rails that uses the W2 size. The Mechmate gantry is heavier, but the MechMate rail is slightly heavier as well.

[Gerald D]

Reported this morning that the Loctite had come loose on the Dec 2005 rollers. Should have used genuine Loctite 638 (http://65.213.72.112/tds5/docs/638-EN.pdf) instead of this "copy (http://simplybearings.co.uk/shop/p30542/268+Retaining+50ml+High+strength/product_info.html)".

[Alan_c]

Gerald

What is the spec for the hardening of the wheel rims re final hardness & reccommended steel.

I can get mine vacuum hardened, will that eliminate the need for grinding of the flange faces after hardening?

I have just been reading the other thread re hardening of these tyres and would like to know if you have indeed tested the four "soft" tyres and the final result - is hardening really necessary if we are using angle iron rails?

[Gerald D]

I have forgotten about that test already, and I should go and have a good look at the machine again. (For those that don't know it, my day job is no longer located near the machines, so I seldom get to see them these days)

The vacuum hardening guys are very fussy that your steel is bought from them. Then they "guarantee" that they will hold the before & after surface finish, but not the colour. Ours were hardened by Sanderson in Parow and they were not ground afterwards.

I am convinced that I won't bother to go the hardening route again. Plain steel wheels are much cheaper to make and they will make the rails last longer. Much easier to replace a wheel rather than a rail. (Not that our rails are showing signs of wear after 2+ years either)

[ldorta]

Hi friends. I'm starting my mechmate here in brazil, but for me is a little bit difficult to find the "V" tires. does anybody knows where I can find this and ir could be shipped to Brazil?
Thanks

[ldorta]

Hi Gerald.
This V tires are done by you? They are terrific.... Do you sell them? Here in Brazil I could find only some v tires to be used in some home gates, and they are not as good as yours...
Another question, do you treat the V rails (make it harder)? What´s the iron alloy of the rails?
Thanks
Leandro

[Gerald D]

Leandro, read the drawings, all the information is there.

[DMS]

My V-rollers and Eccentric Bush are made at local lathe workshop. Ecc. Bush are made from M12 High Tensile bolts as per drg no. M1 20 210. I found that Ecc. Bush are loose fit in Bearings and has little play. Does this have any effect on roller movements.
As I see Bearing support Base and Ecc. Bush head grips Bearing sleeve firmly and there should be no effect of this play. Please suggest.

[Doug_Ford]

I don't think it will be a problem but I'd be interested in Gerald's opinion. Or maybe Greg J's opinion. He's a mechanical engineer too.

Have you measured the V-rollers and eccentrics with a micrometer or a caliper? What specs did you give the machinist? If they aren't within the specs you specified, could you go back and ask them the make another set?

[Greg J]

Sharma / Doug

I haven't gotten to the assembly of the V-rollers yet. So, not sure what the consequences might be. I can tell you that my eccentric bushings fit perfect into the V-rollers. No play what so ever. Very nice fit. Mine are from Superior Bearing.

Today I was cutting the cross members for the Y gantry. Actually, I cut them 1.00 inch [25.4 mm] too short :o so I was welding on extensions and re-cutting. Not an easy task with that 1 mm tolerance. I know: measure twice, cut once.

Anyways, tomorrow I'll drill holes and hopefully weld up the Y-gantry. I've ordered the M12 bolts for the V-rollers, so maybe next week, I'll have a better response.

[Greg J]

Had one more thought.

You could put a "light" knurl on the bushings so that there is a snug fit between the bushings and the V-rollers.

[Bill McGuire]

Sharma / Doug

Today I was cutting the cross members for the Y gantry. Actually, I cut them 1.00 inch [25.4 mm] too short :o so I was welding on extensions and re-cutting. Not an easy task with that 1 mm tolerance. I know: measure twice, cut once.


Greg... if that's the first mistake you've made all year, you get an "A". :D

Hope you and everyone else on the forum has a good New Year...
Bill McGuire

[Greg J]

Bill,

I wish that was the first and only mistake. I've made plenty :)

That's the cool part about making this beast from the ground up. It's only metal and can be corrected. It's OK to make mistakes , ONCE.

When I get the Y gantry welded up and the Y car mounted, I'll post pictures. It's just taking allot more time than I anticipated.

Happy New Year To All !!!!
I'll be bringing in the New Year working on a MechMate :D
I hope that's not a sign of insanity.
Greg

[smreish]

- no mistakes for me today.
I finally drilled, tapped, drilled some more, and then countersunk all the fasteners on the spoil board.
I finally have a machine frame that is squared and stable.
Next step on Wed, start the rails. That's if my wife hasn't had our 2nd baby yet....then I will have to succumb to another short delay. It's always something.
Sean
Happy new Year

[DMS]

Thanks Doug and Greg,
I consider proper E.Bushes, not to take chances.
It seems that mistakes are inevitable.

Sean,
Congrats on you TWO achievements.

Happy new year to all.

[Viperia]

Hmm where do i find the drawings for these rollers? Or do i just save the image that is posted in the first post by Gerald?

Im planing to start building a MechMate Mamba in a while and are waiting for my laser cut parts to be done and delivered so why not start to collecting the rest of the parts or making them. Since my build will try to be as cheap as possible i will try to make many of the parts my self since i work some extra in a industrial shop that has quite a big arsenal of metalworking machines.

Will these V-rollers work good on a Mamba? And do you Gerald have a .dxf on these or do i just need to open the image in autocad/solidworks or what ever i got? Will do these rollers in a cnc lathe i guess.

Regards,
Viperia

[Gerald D]

My V-rollers and Eccentric Bush are made at local lathe workshop. Ecc. Bush are made from M12 High Tensile bolts as per drg no. M1 20 210. I found that Ecc. Bush are loose fit in Bearings and has little play. Does this have any effect on roller movements.
As I see Bearing support Base and Ecc. Bush head grips Bearing sleeve firmly and there should be no effect of this play. Please suggest.

That play has no effect. Remember also that you have another 8mm [5/16"] bolt through the bush with with similar play - again no bad effects. It is the bush head that does the serious gripping. Realise also that the load on the bush is always from one side (does not oscillate) and the "play" will lie to the unloaded side.

[Gerald D]

Hmm where do i find the drawings for these rollers?


Drawing M1 20 121 T (Rev B)

Or you can import the rollers from www.superiorbearing.com (http://www.superiorbearing.com)

[Viperia]

Drawing M1 20 121 T (Rev B)

Or you can import the rollers from www.superiorbearing.com (http://www.superiorbearing.com)

Ah missed that one. ;) Thanks there Gerald! Now i maybe can get these done either at school or the place i work either one i guess it will get much cheaper than buying a bunch of rollers.

Regards,
Viperia

[Gerald D]

Tom, suggest you make them of cheap steel, or bronze, and replace them if they wear out. Do not bother to harden them. My experimental set of "soft" rollers is still quite happy.

I would spend a little more trouble on getting the Loctite to bond correctly.

[Viperia]

Hmm yeah that should make them even cheaper then i guess, but cant you make them of some harder type of steel to hold against wear better? Maybe real tool steel or something?

So you have been having trouble with the bonding of the loctite? Never had that myself but did you use real loctite? Think you wrote somewhere that you had used some sort of loctite copy?

Well maybe add some kind of screws on the rollers that add pressure against the bearings?

Regards,
Viperia

[Gerald D]

Tom, which is easier to replace - the rail or the roller? Which one do you want to wear out first? :)

The "hard" rollers with integrated bearings are a marketing ploy I think. Those guys couldn't use soft metal for the integrated bearing - they had to offer a hard wheel if they wanted it cheap and easy to produce in their existing bearingmaking factories. :-)

The "Loctite" was a copy that was maybe out of date as well. I do have a lot of faith in genuine Loctite applied correctly. Don't think that screws should be necessary.

[Viperia]

Well to me honest i wouldnt want to wear anything out at all. ;) But that might not be possible in the real world i guess hehe.

The thing is since i both go in school to become a cnc-operator and do some part time work on a company 5-6 mins walk from my home i have quite good resources to make some high quality rails and rollers for not much more cost than the material itself.

So one way to go is to harden both the rollers and the rails so neither of em would wear to much, but since im not going to use my machine in a company or something wear should not be a big problem for me. But why if you can not do it extra good from the beginning? :D

But it will take a couple of weeks/months untill i have came this far with my project, since being a student like me you dont have to much money plus i have a son and girlfriend that wants my money to. :mad: ;)

But now i atleast got drawings for the rollers, now i just need to figure out a good size for my machine so i know how long the rails need to be etc. Thinking about a 2x2m machine if i can have it at my mother and fathers house since i dont have room in my appartment in the city here. :D If i cant store it there then i may need to go down in smaller size. :(

Regards,
Viperia

[DMS]

Thanks Gerald for clearing this up.

[Kobus_Joubert]

Hi Gerald,

I am looking at making my own V-Tyres like you did.
On the first picture of this thread you show your own design with a flange, but the drawing M1 20 121 it looks like the flange is on both sides. Is this correct?

I was wondering if it is possible to make the tyre in such a way that your bearings are pushed in from one side up against a collar which is part of the one side flange. The other side I cut a small groove in for a circlip to keep the bearings in place.

From the forum I gather that one of your first MM are still running on UnHardend tyres. Is this correct?

[Gerald D]

The basic design dimensions are so that the roller is interchangeable with the BWC size2 roller - the offset from the left face to the center of the V is identical. The bore size and OD make these close to the BWC/Hepco/Yitong size 3.

http://www.mechmate.com/Forum/messages/11/595.gif
BWC on left, own design right


The design was since modified to be fully interchangeable the "Size 3" produced by Hepco, Superior, YiTong, BWC, etc. The V was moved to the center and the diameter slightly increased.

From this post (http://www.mechmate.com/forums/showthread.php?p=5297&postcount=36), you can see that you only have 2mm clearance on the one side - a 1mm collar will work for that side. On the other side there is a lot of space - easy to fit circlip there. You can make a bigger collar if you move the bearings slightly off center.

With the "re-Loctiting" of the wheels, I lost track of which wheels were where. The whole hard/soft wheel thing has become a non-issue for me. Next week we can have a closer look at the wheels.

[Kobus_Joubert]

Thanks for that. So if I make the copmlete wheel a little WIDER, it will not catch on anything. At the moment it is 16mm wide. If I increase it to say 19mm wide, will it pose a problem....thinking about Y and Z axis as well.

Just to make 100% sure...all the wheels needed are the same size...46mm OD....X, Y and Z axis.

[Gerald D]

Making the wheel 3mm fatter (1.5mm per side) will chew up the 2mm clearance left for other inaccuracies during the gantry welding. Rather move the bearings off-center if you are re-designing the wheel for shoulder and circlip:

830

All the wheels are the same size. The mod mentioned above will have a tiny effect on the z-axis (mounting the eccentrics).

[Kobus_Joubert]

Can one use VESCONITE in place of the bearings.

See ... http://www.vesconite.com/industry/applications/sawmills/wheel_bush.htm

[Gerald D]

No, a plastic bush will always be a bit flexible side to side, given that our wheel is only 16mm wide.

I have some spare "tyres", as per the pics right at the top - want to make me an offer via PM or mail?

[Kobus_Joubert]

Ok speak to you FACE to FACE tomorrow afternoon 14:00?

[hennie]

Since there were no action over the last 3 days let me put some pic`s on the forum !:)
I tried it and got it right!
My interpretation of turning v rollers

2249

2250

2251

2252

2253

[Gerald D]

You took that first pic at 6.44am on a Sunday?? Did the missus make you sleep in the garage again?? :D

That wheel will give you lots of good service. (havn't worn out our mild steel experimental wheel yet - it is on a y-car)

That mandrel you used in the lathe chuck is exactly the right way to get the V-groove true to the bore!

[SLINK]

GERALD
I WANT TO MAKE THIS V WHEELS WHERE DO I BUT THE TYRES AND BEARING CAN YOU GIVE ME THE SITES AND ALL THE SPEC
JSLINGERLAND@ROCHESTER.RR.COM

[hennie]

Slink , get the laser company to cut some steel for the wheels 1.5 mm over size and use the std bearings as per the spec`s that Gerald gave in his drawings.Bearings you can get from any bearing supplier.Get some extra wheels to play with.

[MariusL]

. . . . . . I am using Ertalite wheels. They are a bit softer that the steel. . . . .

[Gerald D]

Curious about the life of those Ertalyte (http://en.wikipedia.org/wiki/Polyethylene_terephthalate) wheels - sometimes I wonder if we can dump the wheels and replace them with solid plastic slide blocks, still on the v-rail, (like a lathe bed) . . . . .

[MariusL]

Gerald, So you picked up on the spelling. I sometimes do that:). Personally I would not give up on the wheels. The added friction that the slide block give will not be practical especially on larger machines. What I would look at is to increase the contact area. I am looking at designing an extrustion that will give about 10mm contact area on each side.
I am monitoring the Ertalyte wheels closely to see how they hold up. So far not a sign of wear. Also the machine runs very quite so it will be a bonus if they last.

[MariusL]

Gerald,
The machine has been working non-stop for many weeks now and the ertalyte wheels dont show any signs of decay yet. They have not yet bedded and I think it might be a good alternative. The machine noise is also very low. Kobus came round the other day and commented on the low noise level so I take it must be a lot better than the metal wheels.

[Gerald D]

Marius, that is great news on the Ertalyte (http://en.wikipedia.org/wiki/Polyethylene_terephthalate) wheels.

Kobus's machine has direct drive motors, which makes a machine sound quite rough. I guess his comment was based on this aspect. I don't think that steel/plastic wheels will make a big difference on noise, but I may still be proved wrong. :-)

[swatkins]

Gerald has anyone tried using brass for the wheels? Think it would work?

[Gerald D]

Brass (or bronze) will also work.

[swatkins]

Then that is what I will be using... I have a nice bar just the right size for this :)

[MariusL]

Gerald,
I cant believe a years has gone already since we started our build. Just to give feedback - the ertalyte wheels still look the same as when installed. The machine has worked hard almost every day of the year. So I think any of the synthetic stuff that has similar properties might work well.

Regards
Marius

[Gerald D]

Thanks for the update Marius.

[PEU]

Tom, suggest you make them of cheap steel, or bronze, and replace them if they wear out. Do not bother to harden them. My experimental set of "soft" rollers is still quite happy.

I would spend a little more trouble on getting the Loctite to bond correctly.

Gerald, is the bronze suggestion still valid? I want to try my luck at doing the V wheels with my small cnc lathe.

[Gerald D]

Yes, it is still valid

[MariusL]

I don't know if anyone is still around to read this but the Ertalyte wheels are still going strong on the machine. Almost 15 years later.

[Alan_c]

Hi Marius

That is good to know, thank you for the feedback. Where did you source the Ertalyte?

[MariusL]

Hi Allan
From our local supplier called Maizey Plastics.
I am building myself another machine now so I will go the same route with the wheels.