My CNC Solution

[joeby]

Extruded aluminum might be a better choice than cast plate. The cast plate will be easier to keep flat than rolled plate, but keep in mind that t-slots will be easier to break out and threaded holes will wear faster in cast.

There were a few cast aluminum fixtures at work with threaded holes for bolting down parts. It didn't take very long for the threads to be worn out; but we used thread inserts to repair them. We got the inserts from McMaster Carr http://www.mcmaster.com/#threaded-inserts/=bdgrn1. These can be replaced if needed.

Kevin

 

[BillC]

We use aluminum tooling plate with Keenserts. It's expensive but much better to work with than t slots.

BillC

 

[kcmillin]

Thanks for the information guys.

I have decided on either the 1" aluminum jig plate with threaded holes, or 1" cast iron. If I go the cast iron rout I will have to make the 24" long table in 4 6" wide pieces connected together only by the rails. Or I could pre-stress the cast iron by clamping them together with two threaded rods passed through holes drill on each piece. The cast Iron choice will be slightly more expensive due to shipping, but I still have not figured out ho much it is going to cost me to get the machine base, and the rail slots in the table machined. Any machinist out there who could give me a general quote?

Will I have problems with a nearly 100 pound table on these slides and a 280oz/in motor?

Kel

 

[BillC]

You shouldn't Kel, if the ways are lubed. The pump type way lube system is a big help in that respect and also use a good quality way lube. That added weight shouldn't have much affect on properly adjusted and well lubed ways.

BillC

 

[Tin Falcon]

(Heaviest object * IPM) / 531 = Watts required
100 x500 /531=94.16
watts = amps x volts
3x 36 = 108
Should work kell do the math yourself with your real numbers but It should work out.
it will depend on how fast you want max rapid feed , motor amps and power supply voltage.
PS volts is limited to your driver specs. for example a G540 will handle 3.5 amps per axis @ 50 volts max (so biggest power supply would be 48 volts) I am running a 36v 8.8 amp keiling .on my X-2.
Tin

 

[kcmillin]

Thanks everyone for your help in this matter.

I have had a little bad luck recently, followed by some good luck.

Car trouble has brought me into the market for a 'new' (to me) car. Which unfortunately will be dipping into my CNC fund. I had planned on driving my current car until it can't drive no more (which is only about 500 miles away), but I did not want to spend to much. I don't feel cars are worth as much as people pay, so I had a budget of $500, which would still leave me room for a CNC, my priorities are with my shop, but something caught my eye which would eat that up quick.

So the good news is I found a car I have been wanting for a LONG LONG time, a 1978 BMW 320i. I have done a lot of research on it found the price to be quite reasonable, considering it is a 32 year old car. It does have some slight electrical issues, but with any old car, grounds corrode and funny things happen. So today was a happy day, and a sad day because my CNC solution has to be put on hold until I can find more funds.

I'm a winner, rollin in a Bimmer.

Kel