Hi, I'm Mark. I need some help on the design of my new CNC. Never made one before.
I will receive a new gecko 540 , power supply and stepper motors (495 oz) on Monday. About 3 years ago I tried making a simple X table for doing doming so I had a computer set up with mach2 and a full step board (I still have) from Stepper3.
I bought three linear slides, they have NSK ball screws and Thomson ball slides. Not sure who made these though. Last night I tracked down the three sensors they each have and found them to be OMRON TL-W3MC, the sensors alone cost 60 bucks each so these units must be pretty accurate.
Not sure why they need such expensive sensors if they are just e-stops. There are two on one side about 1/4 inch apart.
My question is how big do you think I should make the table. I plan to have a fixed spindle using one of the slides for the Z access. I plan to put two of the slides on top of each other to make the XY table.
The small table that attaches to the ballscrew is 5 3/4 x 4 3/4 wide. The slide moves 11 inches (1 turn is 1/4 inch) The 5 3/4 in parallel to the screw. They weigh about 10 pounds each.
As I don't know much when it comes to physics I don't know how big of a table I should put on the slide should I stay at the size of the existing plate or is there enough stiffness to go bigger.
The two ball berring slides that ride on the rails are 3 1/2 inches.
The second question is should I make the XY table using two of the slides or should I make a X access table with one and use two for the spindle?
I think similar ball slides cost over $2000 each but I am not sure I only paid $60 bucks each for them from craigs list, they were pretty dusty when I got them. A friend of mine with a bridgport is going to machine a shaft and keyslot that will fit the ends of these screws, they are 5/16 with a .125 key and i can't find any stock shafts that will fit. He will then bore the lovejoy to fit 5/16 as I can't find those either. I bought the motor connectors as well as the motors and gecko online at keling.
Any input appreciated.
Make it no bigger than you need.
Phil, Still too many interests, too many projects, and not enough time!!!!!!!!
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