Nice work my friend! :-) You are getting there!
RNR
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Nice work my friend! :-) You are getting there!
RNR
Getting there at last.
Made the support for the ballnut and motor for the z axis:
Attachment 6519
Sorry, that's not a very clear picture. The side cheeks are rebated so that I could sit the mounting plate on top and slide it fore and aft to get the best alignment with the ballscrew (with the head in it's highest position). The assembly was then clamped and the position of the fixing screws was spotted through onto the sides of the mounting plates for accurate drilling and tapping. Side to side alignment is achieved by slotting the screw holes in the ballscrew bottom mounting plate slightly to allow adjustment.
The stepper motor is mounted on a 5 mm ali plate which can be slid back and forth on two arms at the back of the mounting plate to adjust the belt tension before being clamped in position.
I checked the backlash of the z axis and could not measure it on my dial indicator. It is certainly less than half a thou. However, leaning heavily on the head with it at the top of it's travel (with the gib tightened) gave me about 3 thou movement which must be due to the column flexing. If I'm going to want high accuracy I will have to keep the cuts light but then it is a light machine.
A replacement spindle motor mount was made to move the motor forward sufficiently to clear the ballnut and pulley assembly:
Attachment 6524
The observant amongst you may notice the skinny drive belt. This wasn't part of the design. I ordered a 15 mm belt from the French RS Components and they sent a 9 mm wide one instead due to an error in their on-line catalogue. Rather than sending it back I am using it and doubt that I will overload it in use. The spindle drive electronics have been mounted lower down on the column to clear the z stepper motor and connected up. The spindle still works :smile:
Just the x and Y limit switches to fit and look for a cheap second hand computer. Then the learning will really start!
Russell
The braket looks good, nice and solid!
The big pulley on the nut, why is there no edge ? It would stop the belt from sliping. But should OK I guess.... :-)
Now, when are you making the first swart ? :D
Yes, I used some 12.25 mm dural plate I found cheap on Ebay. Wanted to make sure nothing would flex.
Some of the pulleys I've seen with flanges have steel ones pressed on which would have made the machining difficult. I machined the pulley with a recess each side to locate the ballnut and the bearing and keep everything lined up. The pulley on the motor is one I rescued from a dead belt sander and has flanges both sides so that should keep the belt in place, if not I can always make a flange for the big pulley.Quote:
The big pulley on the nut, why is there no edge ? It would stop the belt from sliping. But should OK I guess.... :-)
I hope I don't make any SWART :-) but I've given up predicting when things will be finished!Quote:
Now, when are you making the first swart ? :D
rgds.
Russell
Another two weeks gone - where does the time go?
It's been too hot here to do much in the workshop (at about 35C) but at last the conversion is now finished - well as much as anything is finished:
Attachment 6655
The box under the monitor houses the drivers. I bought a 4 axis TB6560 board from Fleabay. Yes, I know, but they are cheap and seem to work OK if you don't want high speed. I've built a b****y great fan into the box and the board doesn't get hot at all. One fault I've noticed is that one of the motors gets hot when the axis is stationary while the others don't. The board includes a circuit to reduce the motor current when there is no drive and I guess it's not working on one driver. I'll investigate when I've time and can borrow an oscilloscope but in the meantime I can live with it.
I must build a pull out shelf under the bench for the keyboard rather than balancing it on my knees.
Yes, I have at last made swarf but only operating the machine from the Mach3 console. Not done any programming yet. I've installed Mach3 and EMC2 and need to spend some time to understand them. Any recommendations for other software I might need?
Off now to start reading up on Gcode!
Russell.
How are you getting on with the TB6560?
Hi there! that's some brilliant work there thanks for sharing!
Can you re host the dxf for the leadscrew nuts as the link seems broken, unless im missing some thing!
thanks again!
Sorry, I don't know what happened but for some reason a load of files have gone from my dropbox. Here they are again:
z-axis%20plan.dxf
Leadscrew_nuts.dxf
leadscrew%20support%20modified.dxf
Hope that works. Let me know if you have any problems.
Russell.