roadss published a new build:

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You mean the OpenRails?

Yes, I guess you could, but I don't see why. If you wanted to stay strictly with Openbuilds parts I would just use the V-slot extrusions, they obviously work well for ALOT of people.

The shaft clamps used in this build does seem rare in the diy cnc world, atleast I havn't seen them used on any other machine, but they're not unique per se.

They are made by a manufacturer called Item which I believe is a global company so they should be available pretty much everywhere and they work with any aluminum extrusion with a 5 mm groove (so, sadly, they don't work with Openbuilds extrusions which has wider grooves)

The shafts that goes in the clamps could be any Ø 6 mm shaft you wanted to use so it's a pretty universal part.

I payed ~ €5 / 1000 mm for the clamps and the shafts I bought are precision ground steel shafts hardened to HRC 60 and they were ~ €7 per 1000 mm, so it's not very expensive and you can get away even cheaper if you wanted to by buying cheaper shafts, they are available in aluminum also for example.

 

I read a tip on Rawcnc's website that you can actually omit the shaft clamps and instead glue the shafts to the grooves in the profiles with great results.

Normally I don't really like messing around with glue and stuff because I have this obsession about tidiness, "engineering solutions" and being able to disassemble things, but I think that sounds interesting and it's something I will want to try in the future because you can then use pretty much any aluminum profile, including Openrails C-beam and I can definitely think of cool things to do with that!

You would of course need larger diameter shafts for the wide Openbuilds grooves, but that's not a problem.

Should probably finish this machine first though huh .

I have some things on order and one package already waiting at the post office. I'm hoping it will all arrive today or tomorrow so I can work on the machine this weekend!

 

Hi!

I'm not in the US, but my plates has actually been over there and back

Long story short: The plates were originally sold to a friend of mine in the US, but he wasn't able to finish the machine because life got in the way so he then sold it to me.

As far as I know there were no issues importing the plates, and he also imported the shaft clamps together with the plates. Those can be spliced with no issues whatsoever so you can order them in shorter lengths if you plan to build a large machine, to keep shipping costs down.

I don't know where he ended up buying the extrusions, I'll ask him.

 

Alrighty, got a reply now and he said he never got around to buying the extrusions but that a company called "AluFab Inc" has Item compatible extrusions.

 

Hi, thanks!

I havn't really been keeping track, I bought from many different sources and had some bits and pieces already but I would say roughly ~ €700 as it sits right now without electronics.

Plates: €280
Screws, nuts, washers etc: €60
Aluminium profiles, hardware, bearings etc: ~ €350

You can get away cheaper then that if you shop around and look for deals on eBay etc, and I noticed Rawcnc lowered the price on the plates now also.

Just let me know if you have any more questions

 

Hi!

My machine isn't actually up and running yet, but I do have some steppers for it that hasn't been mounted yet.

Those are 2.2 nm (310-ish oz-in) steppers and I'm still planing to use the Apex controller at this point and it looks like that one will be using DQ542MA drivers out of the box. Pretty much the same stuff that Rawcnc uses and sells themself then so it should work well.

I do have the BoM, but my version probably isn't up to date anymore, looks like there has been a few changes over the past few months.

Rawcnc have made a Facebook post that they basically want their machine to be opensource and had the BoM along with all of the instructions etc on their website for anyone to use up until very recently when they took it down because of hotlinking that took away too much bandwidth or something.

I'd just send them an email if I were you and see if they won't share the BoM with you or clear up any questions about what's included in that hardware kit.

Looks like a pretty good deal that kit honestly, saves alot of time and effort instead of ordering everything seperately.

You could probably get away a bit cheaper if you did order everything separetely on ebay and whatnot, but I doubt then you'd have everything by christmas hehe

Good luck and have fun!

 

Hi and thanks!

If you're in the UK you are able to buy the profiles from Motedis. Their "I -Type slot 5" is what I used for this build and they also have the shaft clamps as well as many other parts for the Raw machines.

I don't particularly like doing business with that company, they don't have the best reputation and come across as very ignorant (borderline aggressive actually...) but they are the only place I know that ships Item profiles directly to consumers and all of my orders with them has been flawless so far, so I still do use them.

I did not print the covers because I don't have any 3d-printer anymore, otherwise that would have been great and I know there are even files for them available on Thingiverse.

Instead I bought mine from DY-engineering @ 8.70 USD each.

Hope this helps!

 

Really, that's news to me. I check their facebook and website from time to time but had not seen that forum post.

Anyway if you check their facebook page from january 3rd it says this:

so it looks like it is still available and from the view of a small business like that I do understand their reasoning.

Also as someone who did get just the plates from them and sourced everything else from other sellers, if I were to buy it now I'd honestly just get a kit because if I add everything up now including shipping costs etc I'm sure I payed just as much as the kit, if not more. And that's without factoring in all the time involved browsing for every single nut and washer for this thing

 

No, I haven't. My machine isn't up and running yet, still needs all the electronics so it'll be a while still.

I also plan to use mine for both soft metal and wood and I know it can handle it, there are plenty of videos out there to prove it and I know at one point at least Raw CNC used their own machines to cut the plates they are selling.

I think you'll be happy with either one of those, they all seem like excellent machines I do think the Raw is the most rigid and hard wearing though because of the steel shafts and wheels.

 

The accuracy on belt vs lead screw in this case comes down to resolution, how much the axis travels per step of the motors. A belt driven machine will move much further then a lead screw normally.

I was also conserned about this until I saw this video:



Both the machine in that video and mine is rack and pinion drive but the resolution on them and the belt models are near enough identical.

Seeing that video made me quit worrying about it, I will never need more detailed work then that and I'm not even sure it's realistic to expect better on a gantry style machine because other factors such as backlash, flex and other errors will also play a big part in how accurate you will be.

My thinking was also that if the resolution proves too low I can always redesign the machine and use it to cut out new corner plates and make new or modify the side plates to easily convert it to lead or ball screw. But like I said after seeing that video I quit worrying about it.

Also I don't believe the statement about lead screw vs belt is the only difference between the Sphinx and Raw is true. The Sphinx uses the plastic V-wheel with small M5 screw fastening them, there will be more flex and wear there then the steel M8 wheels the Raw is using.

I biased and have very limited experience myself of course, but that's my 2 cents

 

I wouldn't say I upgraded to rack and pinion really, it just happened to be that way. I bought just the plates and had planed to make a much larger machine (2000x1300) then the desktop sized one I ended up building.

For a machine that large rack and pinion would have made sense because belts that long might have issues with stretch and flex and what-not. I had already bought the racks for that large machine when I decided to make it much smaller and that's how I ended up with racks.

If I were to do it again I'd just get belts, it's more quiet and easier to setup. Plus the machine ends up being neater with the motors inside the X-axis.

I am having some issues with my racks now that I think is because of really poor quality pinions...I will have to sort that or just switch to belt myself. Honestly don't see much advantage with rack over belt on a smaller machine.

It's a mod 1 rack and the prices for them vary wildly, but on Motedis they are ~ €20 per meter. Rawcnc recommends 15 tooth pinions.

 

Hi Eric,

I thought I recognized your name from that very branding iron Thanks for posting all those videos, they are great and your machine looks awesome!

The covers are from D.Y. Engineering, I like them a lot and mine went on without a hitch, didn't even have to shorten the motor screws. It just took quite a while for them to arrive from Israel (I'm also in Sweden so Postnord might have had something to do with that )

 

Hi!

They are 110mm and the screws are 8x25 for the upper bearings and 8x35mm for the lower.

That's weird it won't line up for you...

You have a steel tube reinforcement I assume? Have you measured that, make sure it's really the right size? (should be 60mm)

Also if you haven't already, I'd measure those 20x80's. Whoever cut those could have made a mistake.

When I built mine I also measured the nuts and washers for the bearings and found, not surprisingly, that the thickness tolerance for standard nuts and washers are all over the place, so I ended up using precision shims to get that distance perfect. I believe the total for the nut and washers should be 9.50 mm.

Far fetched maybe, but I'm thinking that if it's way off because of this on one side then you'd run into problems on the other side.

If everything checks out, I'd just get longer screws if I were you.

 

Sounds like a plan, that's what I'd do too.

About that second issue, did you screw the front and rear plate together before adjusting the bearings?

If so there could be a twist between them that could cause that issue because the screw holes in the plates are just that, screw holes, and so they are slightly oversized .

What you want to do there is to adjust the bearings on the front and rear plates individually before screwing them together. Might also be easier to see how much you need to shim that way if you just attach the front plate (with the 20x80's attached) first, with the amount to washer from the BoM and then you'll see how much you need to add to the rear plate before it'll fit.

If the hole was tapped at an angle that'd be easy to spot if you thread in a screw all the way. You'll see if the head is flush all the way around or if there is a gap somewhere.