[rcbamm]

Thanks for your reply Matthew.

I'm not looking down on the hardware store built CNC machines. Just after a little research on the Phlatpriner I decided it was not what I wanted. I would much rather have a CNC table. Seeing parts such as slides and what not, are very reasonable in price now, I can build a nice CNC router table for around the same price. Like I said I would much rather have a table. Not taking away from the Phlatpriner because it is a really good design.

Anywho.

I'm gonna research on routers. I really didn't think what router or dremel I used would matter as long as I could fully adjust the RPM. I have a rotozip that I use on restoring cars. I use it to grind away rust and as a cut off wheel. The thing works good but gets way to hot to touch after grinding away underload for long periods of time. The thing I like about it is that it has a fully adjustable speed control. There are no preset stages of RPM speed as seen on other dremels. I don't know much about collets but I knew that I was gonna need something like that other then the stock drywall cutting bit the rotozip comes with lol.

Do you think those 20mm slides will bend when under 128oz of pressure?

I'm coming to some considerations. Trying to keep the budget low, I can go with an x axis cutting length of no smaller then 45". Do you think those slides will still need full support?

[mlabruyere]

Thanks for your reply Matthew.

I'm not looking down on the hardware store built CNC machines. Just after a little research on the Phlatpriner I decided it was not what I wanted. I would much rather have a CNC table. Seeing parts such as slides and what not, are very reasonable in price now, I can build a nice CNC router table for around the same price. Like I said I would much rather have a table. Not taking away from the Phlatpriner because it is a really good design.

Cool, no problem. The PhlatPrinter has it's place but it can't be used everywhere...

I'm gonna research on routers. I really didn't think what router or dremel I used would matter as long as I could fully adjust the RPM. I have a rotozip that I use on restoring cars. I use it to grind away rust and as a cut off wheel. The thing works good but gets way to hot to touch after grinding away underload for long periods of time. The thing I like about it is that it has a fully adjustable speed control. There are no preset stages of RPM speed as seen on other dremels. I don't know much about collets but I knew that I was gonna need something like that other then the stock drywall cutting bit the rotozip comes with lol.

Do you think those 20mm slides will bend when under 128oz of pressure?

I'm coming to some considerations. Trying to keep the budget low, I can go with an x axis cutting length of no smaller then 45". Do you think those slides will still need full support?

128oz will not move the rod too much but you have to keep in mind that not all forces are the dynamic type generated by the motors. You also have to consider the weight it will support (the gantry, router, stepper..etc). My gantry weighs in at about 100lbs (1600 oz) so my rails have to support that with no cutting force.

[stangtjk]

I'm currently building a similar machine to what you have in mind. I'm not sure how well the 3/8" belt will work for you, but you can get 3/4" wide L pitch belt from here and its even a little bit cheaper.
http://shop.polybelt.com/L075-Poly-S...-BL075-MPS.htm

That's what I'm planning on using to drive the gantry and I'm using the 3/8" XL pitch belt and pulleys for the gear reduction.

Here is my basic design. (still missing a few pieces but mostly there)

[rcbamm]

I want to design my CNC table very similar to that. I am trying to figure out if using timing belts is going to be cheaper than ballscrews. At some prices I'v found belts to be $10 a foot and pulleys at $20 a piece. I would rather buy a chinese ballscrew setup for that price. Polybelt.com seems to have some decent prices on steel chorded belts.

I think two 1/2" 3/8" pitch belts, one on each side of the X axis for my CNC design I have in my head seem to be good. I still have no idea as to if certain pulley sizes make a different, and how big of a reduction pulley I need. Instead of using two seperate steppers to drive the X axis, I want to make a pillow block bearing axle that is bolted to the right and left X axis pulleys (pretty much where your steppers are placed) that has a larger reduction pulley system in the center of the axle going to one stepper motor.

I just ordered the Probotix.com 3 Axis Probostep driver kit for my CNC table. These will be the first purchased parts to my CNC project.

[stangtjk]

You can use a long shaft to run both sides of the x axis but don't put the pulley for the gear reduction in the center of the shaft. It would cause way too much deflection unless you support the shaft in the center as well. It would be better just to put it off to one side or the other.

It only cost me around $140 for all my belts and pulleys. I used 10T XL pitch pulleys on the motors that I found on amazon for like $2.50 a piece. They will be paired with 48T pulleys for the gear reduction. I got them off ebay for $4.99 each. He had more but I just looked and they're already gone. The belts for the gear reduction came from amazon as well, they were 11" and cost like $6 each. The pulleys for the driving belts were 12T L pitch and I got them off ebay as well, a lot of 6 for only $15. He upped the price to $18.50 but he still has hundreds of pulleys left. Here is the link http://cgi.ebay.com/ws/eBayISAPI.dll...m=380199077491

Everything but the 48T pulleys are still available from where I purchased them. I can look up the amazon seller if you want. He had good prices on larger pulleys too. Not as cheap as what I found on ebay but better than most of the common online retailers like sdp-si.