Random z depth changes

[dajack21215]

You say it's only happening with the 1/8" bit? You have very different settings for that between the files so I would suspect you're losing steps by running too slow and bogging the machine or too fast and bogging it down.

In one file you're using a feed rate of 65ipm at 10k rpm and another it's 35ipm at 22k rpm.

I noticed the difference in the feed after posting but the rpm is manually set since i have a router and not a spindle, with the 1/8" i set my rpm to roughly 22k

[dajack21215]

Are you sure of your Z zeroing procedure? Manual or puck?

You said it only happens on 1/8" bit. Is it a 1/8" shank also and all the rest are 1/4"?

Are the collets damaged?

Are you tightening the collect nut enough?

Are you inserting the bit far enough in so that the collet fully engages the bit?

I have also used a 1/16" endmill without this issue, 1/8" and 1/16" shank are both 1/8" everything else is 1/4". Collet is not damaged and is tight with the bit in far enough to fully engage. I am zeroing Z with a probe.

[ohiolyons]

Another issue that could complicate static issues.

In the mist of our current heat wave where Is this CNC?
A) Inside in climate controlled (both heat and cold) air space?
B) Garage without climate control?

[ohiolyons]

I have also used a 1/16" endmill without this issue, 1/8" and 1/16" shank are both 1/8" everything else is 1/4". Collet is not damaged and is tight with the bit in far enough to fully engage. I am zeroing Z with a probe.

So on the 1/8" shanks are you using an 1/8" collet or a reducer ring/adapter to the 1/4" collet?

[Adrian]

I noticed the difference in the feed after posting but the rpm is manually set since i have a router and not a spindle, with the 1/8" i set my rpm to roughly 22k

That means you're running it at two very different feed rates (35ipm and 65ipm) with the same RPM though.

[dajack21215]

Another issue that could complicate static issues.

In the mist of our current heat wave where Is this CNC?
A) Inside in climate controlled (both heat and cold) air space?
B) Garage without climate control?

Its in the garage without climate control but issue started when temp was still mild. I called Bobs CNC tech support earlier and they are guessing its static or possible a bad board, since then the power cable to the router has been rerouted to get more distance in between it and the control board and Im not using the vac until project is complete. Running my first project now and so far no issues but this had been completely random.

[picone5]

I have the same issue with mine. I have tried everything that everybody suggested. I can't lie, I have wasted so much wood now I am actually considering giving this up. No one can help!!! The most frustrating thing I have ever dealt with. Made several beautiful projects and the machine decides to change the depth on its own. Very frustrating and costly,

[dwilli9013]

Well I just got done helping a friend out on a Bob's CNC. After much trouble shooting and threatening to give up CNCing
The issue was resolved. Turns out the grub screws on both x axis were loose. So while at it we checked all of the set screws on all of the couplers. Bada Bing machine cuts like a dream now. It was originally trouble shot as a board issue as well.

[dajack21215]

Latest update. We have gone over and have done everything that has been suggested. Bob (Bob's CNC) was very helpful and even sent us a new control board. We started doing our projects again, and everything was going fine, until today. We ran 4 pieces today without a hitch. Nothing intricate or elaborate. we started our fifth project carving an F in a FAITH sign. Right off the bat the carving changed from a single pass .050 in. clear out to multiples passes that was down to .150 in. before I cut the project.

[dajack21215]

I didn't mention but after the last issue after we stopped the project we powered down the router and the cnc. We closed Vectric and gsender. We did not change any settings in the toolpath, after we fired everything back up, the project went as planned. Just going to throw this in their too, but we have been using a touch probe and double checking with a manual z depth and both were in harmony. When this last issue happened we checked the z depth manually, and there was a difference between our original touch probe setting and the manual check.

[Adrian]

If the Z depth is changing between the original setting and the finished setting then you are losing steps during the cutting process. That can be caused by binding on an axis, loose connections between motors and pulleys/gears, pushing the machine too hard, cutting too slowly (should notice burning on the wood), hitting a stop, power saving features on the PC, updates running in the background and many other machine and computer issues.

There is no quick solution to problems like this. It's especially hard when it's not repeatable on command. I would look at what was different between those first four projects and the fifth one. If you can identify something there that is triggering it then you will have a repeatable use case. Perhaps that file is cutting in areas of the workspace that the others didn't reach?

[dajack21215]

Any answers as to why gsender disconnects from my cnc when I turn the router off for tool changes? Happens quite often.

[Adrian]

Sounds like noise on the circuit to me. That could explain a lot of things if your setup is being affected by electrical noise from the router be it the router itself or the wiring.

[wilkigr]

Any answers as to why gsender disconnects from my cnc when I turn the router off for tool changes? Happens quite often.

What post processor are you using? You may want to look on the Sienci forum for discussions on tool change commands in gcode and gSender?

[MarshaJ847]

Any answers as to why gsender disconnects from my cnc when I turn the router off for tool changes? Happens quite often.

In your Jun 15 post you mentioned using an extension USB cable, how long is it? is it good quality?
I was having some problems at work that seemed be solved by a double shielded cable.
https://www.ebay.com/itm/142708535490 I believe is sold by Corvetteguy50 on YouTube.

( I am not associated with, nor make anything from this post, I just bought one of the cables )