[rayder13]

hey guys i was wondering if anyone could give me some advice on parts for my first cnc machine. i want to mainly do woodworking on it but in the future i want to possibly mill aluminium etc.

These are the rails and ballscrews i want to order:
Link

And this is the G540/stepper package i want to get from kelinginc:
G540 3 axis package (One G540 + Three
KL23H284-35-4B (1/4” Dual shaft with a flat) 387 oz-in + one KL-350-
48 48V/7.3A 115V /230V power supply: $494.95

So if these components are ok, i've got the table and stand sorted, i have a 12,000rpm adjustable router and an old pc to control it.

The only other bit i can think of that i need are:

Limit switches
E-Stop Switch
Mach3 (will order from keling to get discount with G540)
Routing/Milling bits

Is there anything else i'm missing? And will it all work well together?

Any help will be greatly appreciated guys.

BTW. it will be a fixed gantry cnc to aid in rigidity as i'm not confined by space.

[rayder13]

just had a look at my router its actually adjustable between 14,000rpm and 31,500rpm. its just a 1250w ryobi woodworking router. i shouldn't have any problems using this should i?

[LeeWay]

Hard to say on the router. Mounting it may give you cause for some head scratching. Runout may be too much or within tolerances. The VS part is good though.

The rest of the components look great. A fixed gantry will limit the size of your cutting envelope, but would likely be an easier built to get the rigidity you want.

Lots of good designs around here to look at and decide which you might want to do. Good luck with it.

[rayder13]

The rest of the components look great. A fixed gantry will limit the size of your cutting envelope, but would likely be an easier built to get the rigidity you want.

Limit the size of my cutting envelope? i would have though there would be no difference between a fixed and a moving gantry in that respect.

[LeeWay]

Your table size would nearly be cut in half.

A moving gantry will allow you to travel nearly the full length of the rails.

With a fixed gantry and moving table, you always need the table supported by bearings under the cutting force, so you loose about half travel.

[ger21]

Is there anything else i'm missing?

What are you going to build it out of? Wood? Aluminum?

For a moving table, the rails need to be at least twice the length of the table. For a moving gantry, they only need to be the table length + the length of the bearings on the gantry sides. This is to cut the full length of the table.

[LeeWay]

Thanks, Ger. I didn't really say what I meant very well.

[rayder13]

i never thought about that. i was going to support the overhanging of the moving table with roller bearings but the cutting length will still be minimised depending on the width between the rail bearings. thanks guys. the table is actually being made from tube steel due to its cost and added rigidity. i'll send linearmotion a msg and see if he can supply 1250mm rails instead of one of the sets of 700mm rails. i can still use the 750mm ballscrew for the table axis though can't i? seeing as it still won't be travelling further than that.

[LeeWay]

If it's a rigid gantry or bridge type, you will still only be able to use half of the table rails for cutting. Your table will really only be around 15 inches long or so on 30 inch rails. One edge of the table is at the edge of the spindle. It then travels the other 15 inches and thats all the rail you have. Longer rails won't help unless you get longer screws too.

Most moving table designs are on the small side for this reason. Larger machines would need an extrodinarily large footprint.

My moving table gantry cuts about 22" wide and 39" long. The outer dimensions are about 30" by 48". It would need to be 96" long with a rigid gantry.


A fairly easy way to see this is to hold a pencil steady across one end of a sheet of paper. Then slide that paper under to the opposite end. It just took 22" of space and your pencil was only covering 11" of paper.

[ger21]

The screw only needs to be the table length (+ a little), not the rail length. You're only moving the table an amount equal to it's own length.

[rayder13]

hey guys i ordered the g540 package and it should probably arrive week after next. i also got meshcam and mach3. now i'm just waiting on a reply from linearmotion about my rails and ballscrews and put my table together . yay. is there anything i've forgotten besides router bits? speaking of router bits, where is the best place to get them from in aus? or is it cheaper to get them from overseas as well?

[rayder13]

nobody knows where to get bits for routing?

[LeeWay]

Google is your pal. I get my bits from Mcmaster Carr sometimes. Depends on how fast I need them.
MLCS has good prices. I think you would need to look down under though. Surely they sell decent bits locally for you.