Hi All,

I've been lurking and talking onboard bits of various designs, In particular

http://www.terry-is.f2s.com/future/linbearing/linearb.html

although I've used the generic design some years previous.

This uses 60 x 8mm and 25 x 10 for the bearing holders, the bearings being 19 x 7 x 6 shielded. You'll probably notice that its in steel, I guess it would work as well in aluminium and be much quicker to machine.

Do you know how long it takes to chain drill that lot? I don't I've a cnc mill lurking in the corner of the barn :) There's no reason why you couldn't do it with a windy handle mill (manual) if the sole objective is to save money. Well I have to save money I've spent it on a cnc mill :)

They look really good, with a cnc machine you can make them in alumn. look pretty easy to produce also.

thats a very nice and solid piece, I can't wait to see it assembled


Pablo

Well I try to adhere to the KISS principle Keep It Simple, Stupid! and as many bits the same as possible. For those skates there's only 3 different bits, yeah OK each bit isn't particularly easy...

The joining rail will be replaced with an ali upright when in action and maybe the sides also if I find some suitable ali, I'm not so sure about replacing the bearing holders with ali as I think there's a chance they could crack depite only being 34mm long, the weak point is where the bolt goes through.

I think the full assembly is a few months away yet but when anything significant happpens I'll post some pictures.

Thanks for the interest peu

I have been lurking here awhile myself and reading and reading and reading...

When I opened that first pic I literally said "wow." That looks like something I could put my confidence in. Are you planning to make the specs available or manufacture yourself for sale? Either way an excellent job and something I'll keep tabs on.

edit: spelling

Nice move --integrating the bearings/car and toothed belt drive (in the cad). Will the final bits be belt driven too?
:cheers: Jim

Hi repairmanski,

Well I guess I could make them for sale though then I don't think that they'd be any cheaper than IKO and the like, maybe if I jigged up proper and stacked a set at a time...

I'll post a dxf & dwg in the next few days - If you've the equipment to make them I've no problem with you doing that for personal use

and yes, Highseas, it will use elastic bands for motion, oops sorry,engineering talk only :) I mean synchronous belts, though I'm still designing the gearing as a direct drive will give in exces of 200m/min and its not likely to have much grunt, oops there I go again, I mean power.

I'm working on a 1250mm work area, but it might grow if I have enough metal :)

ahm back to the drawing board...

Ok,

I've had a bit of time to spare & cleaned up the dwg file and made a dxf so if you're any good at chain drilling and using a file... take a look

I opened the drawing file and when i rotate the view -90 degree's (the one in the middle which shows the profile of the 3 bearings on the pipe) there does not seem to be enought room for a suported rail? I think if you changed the bearing contact points to 12:00, 4:00 and 8:00 for example this will allow for the weight of the gantry to ride at the 12:00 point and the other two to stop any lateral movement, and the bolting plate for the gantry will be in a horizontal possision.

Hope this makes sense.

Joe

I really like this design, much like the design on Dave's site buildyouridea.com. But the one on his site provides for adjustement on the bearings. I think that idea could be incorporated easily enough with this design. I love this design, seeing how you just need a CNC mill, and not a foundry setup. I think this will definetly be the ticket for my CNC router. Great job! :cheers:

Edit: Also, would their be any disadvantage to 3 sets of bearings? Too much friction? I would think that three adjustable sets would be extremely ridgid! I concur with Joe though, I will have to switch it so the weight rides at 12 o'clock, and I'll have to have a supported rail. My gantry will be all steel and weigh quite a bit!

Nice setup.

Does anybody know if eccentric bushings exist for skate bearings?
and where to buy them ? :-)

David

Joe200che, The design is, um, designed to be used in the plain shown, that is with the support at the side. There is enough room drawn for a max 12mm wide support, but that's with no clearance! I plan on using 10mm dia pillars as found necessary.

Skate-o-rail is supported sideways so that it can have a cover over it as shown in the drawing cross-section.

Of course you're free to hash it about for your purpose as you see fit...

WilliamD; Skate-o-rail does has means of adjustment, the bottom 2 bearing mounting holes are slotted and in this design it will accomodate either 1 inch or 25mm bar/tube.

I guess you could use 3 sets each side but I really don't think its necessary, The sensible thing is to keep weight on the gantry to a minimum as "porky" gantrys will cause problems cutting sharp corners and excess strain on the drive train.

Good feedback - carry on

If you've the equipment to make them I've no problem with you doing that for personal use

la_coterie,
Sice you had already given permission to use your design for personal use I thought you or others might find the assembly drawn in solids useful.

It is in .stp format, If any one need it in another format for loading let me know.

Hi ken_Shea,

I'd like to see that, can you do anything that I can see in autocad please :)

la_coterie,
I can export to the following additional formats, any of these importable by AutoCad ?
.xfa
.3dm
.igs
.stl
.sat

Ken

.sat

Yup, it appears it will be happy with .sat files
cheers

Here ya go.

I though I did this once...

.sat will be nice ken

DOH! Us newbies eh?

Thanks Ken,
thats great, It looks just like that, only problem was I turned it around and the bolts fell out ;-)

If you coloured bits different colours it loses it in .sat

do you want to do the rest of it?

la_coterie,
I also found that .sat does not maintain original colors or layers when importing, same thing with .stp, as the different components were different colors. It seems to import to the same color that is active.

I will have to pass on doing the rest of it as a commitment although as you/if you post parts I will see what time permits in converting them to 3D solids/surfaces.

Maybe this will encourage you to get your feet wet in solids/surfaces. :)

Ken

I like it and I want to ad that it is possible to cheat a little more. E.g. you can make the table let’s say 300 mm, keep the rod just above 600 and put a support in the middle under the rod. By letting the table have one cluster of bearings on either side of the support you will increase the stiffness dramatically (I guess 4 to eight times). Anyway, the thicker the better.
Another cheat is to only use a thick, circular rod like the one in your picture on one side of the frame (table or whatever), letting it guide the direction and on the other side of the frame just use a flat iron standing on the edge. A simple ball bearing carriage (ball bearings above and under the flat iron) is all it takes on that side to keep the direction and you get around the problem with keeping two circular guides exactly parallel and you save time and money as well.

/jan
(Sorry about all bad typing in English. It isn't my native lingo, I just do the best I can.)

la_coterie that skate-o-rail looks very interesting concept

Like alot of other people in here im constantly searching for a DIY table where i can make all the stuff myself , rather than just purchasing expensive industrial linear bearings.

will defantly consider this setup for my plasma table

cheers

la_coterie....Very nice design!!! Thanks for sharing it.

I myself am kinda new here and have been lurking for awhile. I've looked at different designs and found a few that I liked and this I really like. K.I.S.S

Anyway, I may be way off here but I can't help but think that it might work better to flip it upside down and have the 2 bottom bearings at the top (at roughly 11:00 and 1:00 or 80 degrees apart) without elongated holes.....meaning that they would be fixed. Then put the single bearing that was originally at the top, on the bottom now (6:00) with elongated holes to allow for adjustment. My reasoning is that by having 2 fixed points at the top, you're creating a "V" that will allow the pipe to automatically center itself on both sets. Then you just tighten the bottom bearing up against the underside of the pipe and that's it. I just think that 2 adjustment points allow more room for error. I've added a .dwg file to show what I mean...

I'm thinking that this might cause some stress to the part by having a "wedging" effect but by closing the angle to maybe 70 degrees this could possibly be avoided???
I'm no engineer so I can't say for sure, but that's my 2 cents. Anyone with an opinion please let me know what you think....

la_coterie....Very nice design!!! Thanks for sharing it.

I myself am kinda new here and have been lurking for awhile. I've looked at different designs and found a few that I liked and this I really like. K.I.S.S

Anyway, I may be way off here but I can't help but think that it might work better to flip it upside down and have the 2 bottom bearings at the top (at roughly 11:00 and 1:00 or 80 degrees apart) without elongated holes.....meaning that they would be fixed. Then put the single bearing that was originally at the top, on the bottom now (6:00) with elongated holes to allow for adjustment. My reasoning is that by having 2 fixed points at the top, you're creating a "V" that will allow the pipe to automatically center itself on both sets. Then you just tighten the bottom bearing up against the underside of the pipe and that's it. I just think that 2 adjustment points allow more room for error. I've added a .dwg file to show what I mean...

I'm thinking that this might cause some stress to the part by having a "wedging" effect but by closing the angle to maybe 70 degrees this could possibly be avoided???
I'm no engineer so I can't say for sure, but that's my 2 cents. Anyone with an opinion please let me know what you think....


That is basically what i did here on my Z Axis, and it locks it to the rail very well.

http://cnczone.com/forums/showpost.php?p=137440&postcount=207

Joe

hi

I'm still searching on the world wide web , and come across this website seems alot of good bearings for CNC made machines

link www.vxb.com i went to there linear bearings section http://www.vxb.com/page/bearings/CTGY/LM

have a look guys see what u think

cheers

hi

have a look at this CNC Bushing 25mm Linear Bearings Aluminium Pillow Block

http://www.vxb.com/page/bearings/PROD/25mmLinearMotionSystems/Kit7270

Code: Kit7270
Price:$39.95 not a bad price if u ask me


Chrome Plated Linear Shaft 60" (5 feet) Long 25mm Diameter Hardened Rod
http://www.vxb.com/page/bearings/PROD/25mmLinearMotionSystems/Kit7198
Code: Kit7198
Price:$79.95 again not a bad price

cheers

Looks nice -
I would like to use something similar to that for my rails....

Hi All,

I've been lurking and talking onboard bits of various designs, In particular

http://www.terry-is.f2s.com/future/linbearing/linearb.html

although I've used the generic design some years previous.

This uses 60 x 8mm and 25 x 10 for the bearing holders, the bearings being 19 x 7 x 6 shielded. You'll probably notice that its in steel, I guess it would work as well in aluminium and be much quicker to machine.

Do you know how long it takes to chain drill that lot? I don't I've a cnc mill lurking in the corner of the barn :) There's no reason why you couldn't do it with a windy handle mill (manual) if the sole objective is to save money. Well I have to save money I've spent it on a cnc mill :)
How long does it take to chain drill this on a windy handle mill compared to the cnc mill you spent your money on? and hows the patent application going? could the same effect be achieved with 3 bearings? thus slimming down the patent application?

Hi. I was surprised to see a link to my website at the start of this thread. I was intending to make some prototype bearings of that type, but never got around to it. I posted that rendered CAD drawing on this forum quite a while back to get some feedback and try and improve on it. As I remember there was not that much interest. Looks like things have changed though, and I'm glad somebody has taken the idea and tried to make something of it. I know what you've made is not exactly the same, but if my CAD rendering inspired you to make what you have, then I'm very happy. I really hope it works out.

Wow I just dug out the old thread. Over 1.5 years old now......

Here's the link...

http://www.cnczone.com/forums/showthread.php?t=8133&highlight=idea

Best Regards Terry.

Hi All

Sorry I've not been very active in my thread, I'll try to answer some of the posts.

Steve_01 I think your idea would be very good for a Plasma table. My logic is as follows, with a plasma table the weight of the gantry is always downwards, with a router table the weight is being lifted when in cutting mode, so that's why I designed it with 2 bearings underneath. On a small hobby router I can't see that in practice it would actually make much difference.
I've drawn a revised version for those wanting to put a table on top of the rails rather than at the side, see attached.

Kipper, I'm not sure if you're talking tounge in cheek or not. Anyway I think it could be done on a manual mill with a rotary table, after all you're making 16 or maybe 24 of the side plates..

MrBean thanks for giving me the light bulb moment and linking what a project I'd already done with this one. I'd been searching the web for design ideas (cribs) but to me many had seemed rather complicated to what should be a simple thing. I guess it depends what equipment you have available, after all with only a drill and a hacksaw my design is damn near impossible!

I've moved on a little, I have parts of the gantry assembled, but being loathed to spend money I lack the rails, I'll post a photo soon.

Here's some photos, of the gantry, not finished, there are some stiffening rails to add and the brackets for the motor and gearing to add, and of course the rails, and the table - heck there's a lot to do still...

Here we are, avid reader(s)

I've moved on a bit, got some rails now, well actually stainless steel and triangulated the support beam as it has to hold a 18kg motor!

As best I can tell with a dti sitting on the floor and putting my weight on it I seem to have about 0.002" deflection, at which point I thought f**k it that will do :)

Once the guide rails were aligned, which wasn't too difficult having a fairly large mill table to rest it on, it was relatively easy to adjust the skates to roll without play, the best way was to tighten the blocks loosely (if that makes sense?) and tap with a nylon hammer.

After all the designing & machining it's good to actually be able to "play" with a real one instead of a computer generated one. In fact when I go in the workshop I feel a compulsion to move the chariot along its axis :)

It will propel itself along with belts & servo but next will probably be the table as I have the material for that & I keep modding the belt drive system. Once I start making the drive train bits I won't change it as it only leads to errors

Do you have picture of the bearings from the abouther side?

I'll take one over xmas.

belt drive works a treat! :D

Cool, I am truying to make my machine based on your berings so if you could take pictures og moutings and how you solved a Z axis and please take pictures of your belt drive solution.

Very interesting..

One thing I can say. The bearings are asome....

:wave: Here we are a xmas treat, now as this progresses I'm not sure if I should start a new thread in build logs, whats the view?

A few shots of progress so far, the Y drive belt system which under power using a servo seems very good and fast though rather dangerous at the moment because it's just powered by a battery rather than computer so doesn't stop quick! and has a good chance of crashing into the ends:eek:

For the technical minded its on a 12.25 reduction with a 28Tooth pulley on final drive, 5mm pitch which according to my spreadsheet with a 1000ppr encoder will give over 17metres/min in Mach3 at 25khz mode or to be really crazy at 45khz mode nearly 31metres/min holy cow! :wee:

The Z axis is almost conventional with linear rails and a ball screw, I considered that this was probably the best way to go as it can be kept more compact and hence the Z will remain close to the Y minimising any twisting action.

As an aside, here's a party piece for the season, take a linear rail and take a carriage off the rail allowing the beaings to drop on the floor, preferably a tiled one, you won't believe how for those balls travel:devious: It can also be used for an ice breaker at a meeting. (I acceppt no responibility for the bearing that remain missing :)) don't ask how I know this...

Asome!
Nice xmas pictures:)

How big are yout servo? (torque)

I am planning to use 1160oz-in stepmotor on y and Z axis and 2 of them to drive gentry...

I hope it will be enough

How big are yout servo? (torque)

urmm, don't know! I think it's a bit of overkill (too big) but the price was right it's about 100mm diameter and 200mm long.

Don't forget your torque gets multiplied my the reduction gearing at the expense of speed, so I could probably pull lorries out of the snow with this setup :)

:)

Last question, do you have some cad drawings of your gentry?

I am using a machmate machine but with simular to your gentry.

I need dimensions of steel profiles used...
I can show you a cad drwaing of my machine...

Here you go, Goos80 (with a name like that arn't you feeling nervous at this time of year :)) dxf of the Y axis, only uses 25 x 25 x 1.5mm tube and is really solid with minimal weight, though with that servo... and the spindle weight 15kg I think... It's still a heavy lump though I can still move it easily enough.

Usual discalimer with the drawings - if you break you leg don't come running to me :)

At this point I'm not sure about the uprights, I think they might sway so there could be come external bracing to do

Hehe, We in Norway are not Eating Ducks and Gooses for xmas so this time I not concern :)

Thank you for DXF. It will help me a lot. The only think is that I am using another support for Y-axis.

As for the weight I am not afraid. I will use 1160Oz-in motors and If they are to week I can always gear them ones or twise as you done.

And with Gecko 203V it will fork very well...

Are you using M8 screw to support shafts?

Hello.
What is a specification of belts you are using?

Hi Goose80,
I'm sure I put a reply to no.44 - I'll do it again..
Yes M8 studs evry 300-400mm otherwise it'll bend, despite being 25mm solid diameter :(

I'm using 15mm wide belts in T5 form - that's 5mm pitch & here's the guy I got them from in Holland. Great guy gets my vote!
http://www.stappenmotor.nl/
does good english, a bit of french & erm, dutch I guess:lol

:banana: I think this deserves a dancing banana!

A quiet xmas. Kept all the relatives away and got to work in my playroom. The table is basically made, still got to do some braces below, when I've decided how high to mount them. The legs will have adjustable feet though at the mo wheels would be better due to cramped building conditions.

The gantry whizzes up and down superbly, there is some whip, wiggling, but when the belts are connected I don't think this will be an issue.
I can see the light at the end of the tunnel although it's a only a pinprick at the minute :)

I think I must have perfected the perfect router table here as nobody has chirped in :D

I have to admit, I'm waiting on building my CNC router, until I have my CNC mill done, so I can build something very similar to your rollers. It will be a cross between your idea and some others. I really do like your design. One question though, that table with those legs seems like it would be pretty wobbly. Are you going to reinforce it? Maybe some cross braces? Kudos on your progress so far! :rainfro:

Yeah, I know what you mean about wobbly, I thought that too when it was on the drawing board. It really suprised me that it's so solid. But yes there is some bracing to put in. I've got an enclosure to mount underneath so I'm gonna put braces to mount that. kill 2 birds with one stone so to speak:)

I would imagine that if I left it like that it would move about doing some rapids.

Do the cnc mill to do the router... I know the feeling. so many catch 22's !

I can see the light at the end of the tunnel although it's a only a pinprick at the minute :)

Be aware that the light at the end of the tunnel can be a guy with a torch bringing more work.... Sorry it just struck me as funny :D

love it:D

I have these servo motors with encoders, made by Shinano Kenshi, 30volt 1.5amp.

If anyone wants them, let me know.

(wrong)

Hi All,

Been a while, I've rather busy with business but now things are moving on again.
I've attached a video link for your amusement of the Y axis doing 21m/min
http://video.google.co.uk/videoplay?docid=-8484198931643396274

Like the look of your skate-o-rail. Think I will try and build one this weekend to see how it goes. As a suggestion how would it go if the 2 center plates were removed and the 25mm x 10mm steel with the bearings in them went end to end. I find it hard to believe that steel that heavy will flex over that distance but I have been wrong before. This would mean only 2 end plates would need to be machined making construction easier but maybe you have already tried this.
Your machine looks great. I hope my next one looks as good.

Cheers
Peter

Once I thought I was wrong but I was mistaken! ;)

Yeah I thought of that, after the event. I guess it will depend how far apart the 2 ends are.
I reckon it would work with 200mm between then assuming the bearings are near each end.
The only slight concern I would have is the reducing of the mounting points for the gantry & Z axis.

Keep me informed, as you say it halves the plates to make and I'm all for that!

Great execution. Please report back on the half plate experience. I've got some 1.5" linear rail I've got to make bearings for and this looks like the ticket. Even better if the number of plates could be reduced by half.

Well has it really been 18months since I started this thread!

I guess that's the problem with hobbies - they take the back burner when work gets in the way.

The router is more - or - less finished and has cut some great signs. I still need to make something to adjust each side of the X axis so that it will cut a real square but it's not far out as it sits.

I'll post some piccys in the next couple of days and give some more insight on my findings with this design. ;)

Here's a few shots as it stands now, sorry the photos seem fuzzy.

I've got to take it apart shortly to move & paint it, something I'm not looking forward to :(

The design:
the table is made from 80 x 40 x 3mm tube and it rock solid. I should have made the gantry out of it as well :rolleyes: weight straight down is fine but it can be made to twist.

Belt drive - does it work?

so so, would I use it again - no. I have steel braced T5 x 15 on the X and that still has some give on it. I could probably tension it some more if I had more adjustment. (This is a 120cm x 120cm travel machine) on a smaller machine I guess it would be acceptable...maybe.
Yes, some might say the belts are too small but then buying bigger belts would probably be as expensive as ballscrews! If starting from the begining again I think I would use ballscrews, in the end it doesn't come out any more expensive.

The X is driven both sides and the side without the motor does seem weaker which I put down to the size of the cross shaft - only 15mm over 1300mm so it does wind up, I'm guessing I need something about 30mm :eek: But I knew that when I started:rolleyes:

Ideally the gantry uprights need angling so that the cutter force comes down inbetween the X carriages, and Aluminium for them is a waste of time - too much flex despite being 10mm. Go get a decent lump of half inch steel plate:D

I use Mach Quantum which suits this machine rather well. cutting the road runner file on normal Mach3 was horrendous, immediatly suggesting things need beefing up :(

On the good side, my home brew rails seem to do the job, as best I can tell, time will tell.

Would I do it again? not like that, but then thats what the experience is about.

save yourself the grief & uncertainty and go and buy some linear rails and ball screws :) and a load of industrial strength steel tube!

At least I've got my Tee shirt now :)

Just a couple of piccies of it painted - only has one coat but looks much better. I changed the rear cross shaft for one of 25mm, but I haven't actually used it in anger since doing it...
It had to come out of its original build placeandmore to this "hole" thats not much bigger than the actual router! It is in fact all back together now and has been for a long time, I'm just rather lazy in getting some electric to it.

la_coterie
Nice design, would you post the patent number for the bearing?
budP

pmsl...I'll wager the makers of this design may object. Jet Rail.....Pat Pending was the nutty Professor in Whacky Races...Wasn't he?