Question about steppers and gantry weight...?

[adam_m]

I'm working on trying to size my CNC build and had a question with regard to the weight of the gantry.

My plan is to use CNCRouterParts bearing blocks with 1/4" steel and rack and pinion gearing. I planning on a rough size of 48" x 48" surface area for cutting.

So, for my Gantry/"Y" I was planning on using some lumber I had left from a job we did some work on, 1 3/4" x 6" Oak, laid flat spaced apart with an 8" piece of steel to bolted to the front then to connect that with the the x axis using an aluminum plate on each side to the x axis bearings.

I'm planning on using the following for the steppers and controller, thoughts..

G540
KL23H2100-35-4B 381 oz motors
KL-350-48 48V/7.3A power supply

Obviously cost is a factor, so my concern is about the weight of the gantry and your thoughts on the stepper demands.

Thanks for your input.

VB,

[oneturboneeded]

do you have a speed you want to hit??

[adam_m]

I haven't targeted a speed per se - as always the faster the better. I'd forgo some speed for accuracy though, any day.

I see a lot of aluminum builds with 80/20 so I'm concerned I might be doing myself injustice for using some handy scraps.

Adam,

[jsheerin]

I would not use the wood - just get a piece of 80/20 off ebay. Your motors should be fine.

[jsheerin]

For example:
http://cgi.ebay.com/8020-T-Slot-Alum...item3355dd4b42

[adam_m]

Thanks jsheerin for the comment.

I kind of thought it might be a bit too heavy for the job.. I'll look into the 80/20.

Out of curiosity what speeds do you think this might reach?

Off topic of the gantry weight, but who is selling rack for rack and pinion drives at the best price?

Adam,

[jsheerin]

With Ahren's rack and pinion setup and motors, you should be in the 1000ipm range for rapids. Look for other builds here using those parts for more info.