Building a Cnc Router

[ezland00]

Hey, i am building the same route(in aluminum).

i'm use 4"x24x1/2 for base
17x4-1/2x3/4 for 2 sides
bearings link
acme leadscrew, oil harden rod from enco

planning to spend less than $800

i'll try to post some picture when i get all parts togather

good lurk on your machine

[ezland00]

i also though about using thk linear slide, but they cost little bit too much for me. any cheap thk around?

[ballendo]

Cold,

Better. But you still have a bullet to bite...

Need to add at least ONE more linear bearing to the y. I'd put it on the bottom shaft(nearest the cutter) to decrease deflection.

Raise the black frame supports ands they will add support for your table.

Definitely need a cross brace between the gantry uprights...

Hope this helps,

Ballendo

P.S. I think you may later "wish" your steppers were larger. 3210 will work, but is a bit on the small side if you're planning for any kind of fast traverse speed.

Originally posted by Cold Fusion 1.25 shaft, dual pillow blocks, extrusion down the X for bracing.

[Cold Fusion]

As far as the steppers: I would only be cutting up to 3/8 Lexan or 1/2 wood. Any metals can be done with a friend's cnc router.

[limbo]

Hey Cold fusion,

Now thats a familiar setup! Great work on the CAD drawings. Think your gantry will probably come out lighter than 60lbs. I have -lots- of steel where alu could be used, for instance in the bearing blocks and Z-assembly, and that gives around 60lbs.

About the double bearings: What accuracy are you aiming at? Mine has double bearings in a single block, 16cm (6.25") wide, giving up to 0.5mm (0.02") gantry skewing in both directions when pushed fairly hard. If thats too much for you and you're not willing to give up travel think about dual leadscrews?

Good luck,

John

[buscht]

Cold, another thought. You probably don't need as large a stepper motor on the Z axis. I would think that 100 oz-in would be fine.

This might allow you to offset some costs for the additional linear bearings.
T

[Cold Fusion]

Ok, things just swung 180 degrees. I am now the proud owner of 4 30 inch Thk rails. Here is the auction I won. http://cgi.ebay.com/ws/eBayISAPI.dll...category=42899

[Mr.Chips]

Congratulations.
That settles a lot of questions.
Now for the best way to utilize them.
Hager

[Hobbiest]

Hager..."Now for the best way to utilize them"

how about on a CNC machine? HAHAHAHAHAHAHA (sorry, couldn't resist!)

[dlenox]

if you moved the bearing blocks to the outside of the frame you might be able to get some more workable table movement

[Mr.Chips]

"Now for the best way to utilize them"
The tips have started to come in. These bearings are small and strong, and require different mounts and save a lot of space over the "rail bearings"
Good luck, now let's see some new drawings.
Hager

[Cold Fusion]

Here are pics of the latest cad. The red and grey square stock is 1.75 inch aluminum , the green sides are .5 inch, and the red end plates are .375 inch. The pockets in the gauntry are for extrusion, which has not been added yet. Tomorrow I'll get the ball screws in along with the cross gauntry brace.