Greetings From New Jersey. Happy 2011 to all
 

Hello,
I am going to embark on building a Mechmate in early 2011. I have been studying the forum and, I am really impressed with the quality of machines you guys have built. I'll share some history about myself to get better acquainted with you all. I owned large manufacturing facility in Chatham,New Jersey from 1991-2010. My shop made high end residential cabinetry and millwork. I chose to downsize in 2010 but have kept a fair amount of equipment. I could not move my scmi tech 100 point to point to my garage due to size and power. I was also a sales consultant for Planit. I sold Cabinetvision Solid Manufacturing and Alphacam in the Northeast of the USA. I have a fair amount of knowledge with those softwares and would like to use them on my new MechMate. My ambitions are lofty, I want a 5' x 8' table with a 12" Z axis. I also would like to put a atc spindle with a tool bar and even include a fourth rotary axis on one side of x. I also would like to extend the rails so the gantry can cut parts at the end of the bed. i will also incorporate a vacumn holddown with several zones. Are my expectations realistic?? I am building this machine to nest and cut Plywood MDF Parts for cabinetry and some solid wood 3dcarvings and, radused millwork applications. I look forward to hearing any imput or concerns from you guys. Again Happy New Year to ALL. Joe Roth

Hi Joe, welcome! Here's one set of opinions:

5 x 8 table with 12" Z: No problem, plenty of prior art on that. Note that you loose stiffness with a long Z, and that will work against the primary use of nested plywood and MDF cabinetry parts. If you only use the extended Z off the end of the bed, and keep the bed "normal" height for sheet goods, you could have the best of both worlds.

ATC spindle: We'll wait to hear from you. No reason why it can't work. It would be nice if an electro-spindle manufacturer would start producing a spindle with an axial through hole so that we DIY types could experiment with our own drawbars like those metalworking guys, but I won't hold my breath.

Rotary axis: No problem, see various designs for indexer valleys.

Extended rails: No problem, although you may want to extend the beams as well, depending on how far you are going. Or build a 5' x 10' table with an 8' bed.

Vacuum hold down: Potentially challenging. Not because of the MM, but because of the inherent issues with the amount of power that can be required. You should think hard about your requirements and how to accomplish them within whatever your power budget is. Don't forget to budget for your spindle and dust collection, which will presumably be running simultaneously.

I agree - You should be able to do all of the things your thinkning about on the MechMate platform. Also I know (and have seen) a very large Vacuum system hooked to "regular" single phase power. It did take some serious expense and a large inverter, but it works great. Just think about using a phase inverter and a large inverter duty motor to produce your vacuum.

Of course in any of that you want to work with an electrician to make sure your feed to your shop can take the draw.

Thanks,
for the responses. Mike, I am intending to purchase plans from you later today. I have spent the last few days reading posts and, still trying to decide what size to build. A low cost spindle with ATC is not as available as I would expect. That has led me to think about making the mm with multiple spindles. I saw a post from Gerald,with a y car with two z's back to back. Brad you were talking about the amount of motors and drives. If the intended desire was to have four spindles, would it be wiser to make two gantry's with each car having the back to back z or could you have a double car with two back two back to back z's. I realize the width will have to be made considerably larger to accomodate the side by side z centers. Considering the intended applications for the MM, I dont know how you can nest cab parts with one bit.
Optimumly I would like to have a 1/2 or 3/8 spiral down for outline cuts 1/4 for blind dadoes and shelf holes. The other two would be necessary for MDF door profiles a and dovetail drawers. I have 100 amps i can dedicate to machine and dust collector. I am still researching lowest cost vacumn system. I am a light year behind you guys in the electronics area. Why stepper motors and not servos?? I have always heard the servos are better for the motion control? -sorry for the long post -Joe

Joe,
Your choice of a 1/4" cutter for blind dados is interesting. Are you planning on making mulitple cuts in the material to accept the joining piece or is the thickness of the joined piece only 1/4"?

Joe,
Cabinet guys usually use an air drill for the shelf holes,this could be mounted to the same z axis as one of the routers/spindle. Unless you are in a real production mode, why not just have bit changes when needed, one router and one air drill?

Stepper motors are cheaper and more diy because of small number of errors you can encounter, encoders can go crazy and crash your gantry sometimes, of course you can buy great encoders but $$$ . If you plan on using more powerful spindle and using high feed rate then consider servo.
On Geckodrive site you can find a calculation about power and which motors to use when.
the formula is :

considering we have two engines on the X axis and can fit one more on the Y axis.