Hey Guys,

Just want to share some of my recent work, my first machine was out of MDF and cutting area is only about 12x15inches. I was quite limited, it was slow with 182oz nema and unbiopolar driver. Therefor I went ahead and look for new parts and want to build a bigger/better. I am currently shooting for 24x48inches cut area.

Here's the Z, I got this off ebay, have to take the whole thing apart and remove the coreless motor that came with it and cut off a bunch of stuff and use my mdf cnc router to cut a g-10 plate out... this will allow me to mount my own Nema stepper.

On the X axis, it was a hard decision whether to make it out of MDF again or aluminum. But I end up with aluminum purchase from HomeDepot. Total cost of aluminum for the X so far is 30.00.

I was thinking to mount the X motor inward drive by belt... Just simply to make it more compact, since I will be using the Nema 425oz and it long, having it on a side and moving back and forth would be crazy.... Do you guys think it worthed? By the way, will belt cause backlash?

Here's the pic so far.

wow, 70 something view, no coments at all?

I like the Z-Axis where did you get it from? and cost.

The frame work may beed some extra bracing.

Joe

Hey,

The Z is found from ebay, 70.00... If you search for linear actulator on ebay you will find quite a few.

Yes, the X is not done, still need some corner cross support... But it pretty stiff right now, becuase of all the L and the way how it corner, it dead lock... I use all of my strengt and it only flex about 1mm.

Thanks for the reply.. :D

More part came in today, gathering up the Y axis just to see how it look.

Yes, it bow, but I got a idea how to stop it... It start to look sweet now... :D

Yes, it bow, but I got a idea how to stop it... It start to look sweet now... :D

Looks like you may need some X bracing in the back and sides of the Y axis.

And one thing you might try to support thoes long rails is to put wheel on the Y axis. Never saw any built this way but it would add support.

Good luck and keep posting pictures.:)

I got some open bearing that I will switch out, and the rail will be support it.

I got some open bearing that I will switch out, and the rail will be support it.

A fully supported rail is the best way to go. Your Y and Z axis have very nice looking bearing so the fully supported one will now complement the others very nicely.

This type rail will be transferable if at some time in the future you decide to reengineer your CNC, this is a common practice for hobby as well as the experienced builders.

Just keep in mind what you will be cutting, weight of the finished gantry and the loads that will be on your machine.

You’re on the right track, keep up the good work.:rainfro:

Supporting the rails is the only way to go. The rest of the gantry looks good. Designed modular so easily changed later as Mr. Chips pointed out. Are you going to be driving both sides of the gantry?

Sorry guys, been too busy with so many thing, finally got sometime and work on the machine.

Well, I ran into a lot of problem trying to get the X mount onto the Y, such a pain, I have to cut the linear bearing holder out, change it to a open bearing in order to support the rail.

So far so good, it moving pretty smooth, but still tons more stuff to do, here's some pix.

PS: I don't think I will drive both side, since it only about 26inches in witdh, one in the middle should do it... One big one. 3/4inches screw.


J

Hi - it's looking good so far! The aluminium frame should be nice and light - and easy to add bracing to, wherever you find it necessary.

Can I ask what size angle you have used?

It looks like it mght be 1" x 1"' x 1/8" - good guess or not?

And what sort of (and size) bolts did you use?

Hey,

Thank for the reply, you're correct, I do believe it 1x1x1/8. It seem strong enough, the frame is light but because of the Z axis is some really tuff and heavy it almost a good 15pound by itself, the frame is like 5-8pound.

But I don't mind it being heavy, as it will help to push down the Z when drilling into marterial.

As for the bolt, it just one of those 1/8 self drill bolt for metal.

:)

PS: I don't think I will drive both side, since it only about 26inches in width, one in the middle should do it... One big one. 3/4inches screw.


J

Size of the screw won't make it any stiffer. Clamp one side down so it can't move, and push on the other side. You might then change your mind back to two screws.

Your design screams for two screws. I can tell you for a fact that it will rack badly with a single screw. I was able to use a single screw on mine, but it is made of heavy steel and I built in adjustments to tighten the gantry up. I was able to load the gantry up tight enough to get it squre and eliminate racking.
There is nothing on your machine sides that will take that kind of pressure. Those rails will flex inward just as easily as down and up.
Two screws is really the only way to go. It will cost a little more, but you could run them both with one larger motor using a belt. That would likely be less than buying an extra motor and drive.