First Build 5 x 12 Steel Frame CNC router

[Scott Damman]

Are you certain they are wired correctly (you should manually trigger them and check that they match the input on the Mach 3 screen).

Also, do you have any soft limits enabled?

Sorry should have stated that, all limits were checked manually and all seem to correspond to the correct input. Soft limits were turned off during the troubleshooting process.

Jazz, system jogs great, homes correctly on all three axises. I tried MDI commands and get the message "Move off Limit before MDI command". Whats puzzling to me is that Mach says this even with all limits turned off.

thanks for the quick replies

[JAZZCNC]

Actually thinking about it I've had this before but can't remember what caused it.! . . . Got feeling it's something silly and obvious like a setting but can't for the life of me remember what.? . . . . . Nearly bed time so I''l sleep on it and get back to you.

[Scott Damman]

Actually thinking about it I've had this before but can't remember what caused it.! . . . Got feeling it's something silly and obvious like a setting but can't for the life of me remember what.? . . . . . Nearly bed time so I''l sleep on it and get back to you.

I took a little break from the machine and came back to it. Ended up being a debounce issue, it looks like my cable grounding wasnt as good as I thought. I doubled the debounce to 8ms and the MDI and Gcode both ran....

Pretty darn cool to see it run on its own, I am so close to cutting...

Here is a pic of the CSMIO-IPA Config window for setting debounce for anyone in a similar situation.

[JAZZCNC]

I took a little break from the machine and came back to it. Ended up being a debounce issue, it looks like my cable grounding wasnt as good as I thought. I doubled the debounce to 8ms and the MDI and Gcode both ran....

Pretty darn cool to see it run on its own, I am so close to cutting...

Here is a pic of the CSMIO-IPA Config window for setting debounce for anyone in a similar situation.

Not good idea to use de-bounce because it affects all the inputs and slows down re-action time. Find the problem and fix asap, esp if using servos because want any inputs to re-act fast.

Edit: Actually I see you only have set to 2 which isn't so bad thought you'd set it to 8 which would have been 32ms.

[Scott Damman]

Not good idea to use de-bounce because it affects all the inputs and slows down re-action time. Find the problem and fix asap, esp if using servos because want any inputs to re-act fast.

Edit: Actually I see you only have set to 2 which isn't so bad thought you'd set it to 8 which would have been 32ms.

Jazz, good point either way, I think I will dig into the shielding a bit more on all of the control wiring. Would like to get it back to 4ms. Like you said fix with hardware, totally agree.

thanks again, more to come

[JAZZCNC]

Jazz, good point either way, I think I will dig into the shielding a bit more on all of the control wiring. Would like to get it back to 4ms. Like you said fix with hardware, totally agree.

thanks again, more to come

Have you Earthed the Frame.? Common cause of troubles like this.

[Scott Damman]

Have you Earthed the Frame.? Common cause of troubles like this.

No I hadnt, I added a separate ground for the frame and grounded each part of the machine, i.e. Gantry and Z. Thanks for the suggestion.

I learned some hard lessons last night while continuing to tune the servos.

1st, make 400% sure that the ballscrew mid-supports can not get hung up on a sudden change of direction.


This bent back pretty easily but I will need to make some modifications to make sure it cant happen again. Basically the machine stopped before the support flipped and on change of direction it caught on the ballnut mount. No other damage observed which is good.

2nd, and this is the big one, when butting linear rail together remove the lead in on each rail. I had known this was the case but being that I got the rails for cheap and not having a way to accurately grind the rails I chose to try it.... bad choice.



What the pictures show (or what I assume happened), as the block went past the joint a ball dropped into the joint, caused alot of extra force and blew the end of the block off. At lower speeds it seems to be fine, but I was running past it at ~1000 ipm. I think the block counldnt handle it I was able to stop it before the other 2 blocks hit the joint. I have 4 extra blocks that came with the used rails so I can put it back together for now but I need to make a plan for future.

I think my options are
1 - remove rails and have them ground and put back together - this is a no go as the cost would be more than just buying Hiwin rails
2 - buy Hiwin rails and blocks - definitely the best option but costly
3 - try to fill the groove/lead in
- Im thinking of trying this method, couple options, epoxy, babbitt, other options?
- I think I just need to keep the balls from dropping in there, I think there shouldnt be too much stress on the fill otherwise.
4 - just use the 8ft of full length rail for now???

Any thoughts are appreciated...

[JAZZCNC]

Ouch.!! . . . Bad luck. That's difference between Servo and steppers. They take no prisoners! . . . Stepper would have stalled before bending that bracket or possibly ripping the bearing end cap apart.!

1st Choice is no brainer new Hi-win rails.

2nd Choice new Hi-win Rails

3nd Short term Choice fill with Metal Epoxy. Think it's called JB Weld in states.

No other choices IMO.!

[Scott Damman]

Ouch.!! . . . Bad luck. That's difference between Servo and steppers. They take no prisoners! . . . Stepper would have stalled before bending that bracket or possibly ripping the bearing end cap apart.!

1st Choice is no brainer new Hi-win rails.

2nd Choice new Hi-win Rails

3nd Short term Choice fill with Metal Epoxy. Think it's called JB Weld in states.

No other choices IMO.!

Short term I have moved the entire machine to the other side of the joint and moved my X home switch. Gives me 6.5 feet in the x and 5.5 feet in on the Y and gets me going with making parts. I have ordered machinable epoxy to do a pour to try to fill the joint. Long term after a few paying jobs, probably going to order some new full length rails. This will unfortunately require some modifications to the machine as the rail height will be different.

Im still waiting on my spindle cooling fan adapter so I cant cut anything yet. So I put a sharpie in the spindle and made a drawing. Pretty geeked that it actually made something, even just a drawing.

[Scott Damman]

While still waiting on the fan adapter so I can cut with the machine, I decided to draw up a dust collection adapter mold to lay up fiberglass in. Video shows the machine running this code.





I put the X and Y to 1000ipm as 2000ipm scared me and while I am learning about this machine I wanted to be a little safer.

I also have a question about what a ballscrew/ballnut should sound like. I have never been up close to a ballscrew before so I wonder if these sounds are normal. The sound I am referring to sound like bearings circulating through the ballnut but just doesnt sound real smooth... Sorry pretty hard to tell on the video I guess but if anyone has insight please let me know.