[la_coterie]

Hi All,

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

http://www.terry-is.f2s.com/future/l...g/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

[joecnc2006]

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

[PEU]

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


Pablo

[la_coterie]

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

[RepairmanSki]

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

[High Seas]

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

[la_coterie]

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...

[la_coterie]

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

[joecnc2006]

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

[WilliamD]

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!

[smoker]

Nice setup.

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

David

[la_coterie]

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

[Ken_Shea]

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.

[la_coterie]

Hi ken_Shea,

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

[Ken_Shea]

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

Ken

[ger21]

.sat

[la_coterie]

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

[Ken_Shea]

Here ya go.

[la_coterie]

I though I did this once...

.sat will be nice ken

[la_coterie]

DOH! Us newbies eh?