[ger21]

Not Backlash.
Your horizontal axis lost position at some point.

[gregoose]

Interesting. Draw another circle with a dot or small square in the middle so we can see that more plainly.

Do you have backlash comp turned on? Assuming you are using mach3.

Try measuring your backlash by starting zeroed against your dial indicator, travelling away a few inches in one direction. Then back to zero then write down the number. Do the same in the other direction and let us know what you get!

Or maybe you already have these numbers? At a glance, it seems yes you can axis has play on change of direction.

Sent from my XT1254 using Tapatalk

Ok, I'll try when I get home, just got to work. I don't have the numbers off the top of my head. I initially had backlash turned on, possibly not configured correctly, but doing my test drawing at first, it kept making jerking movements at the edges of circles so I turned it off. When I get home I'll put the dial indicator back on it and measure again. I hadn't changed the shuttle speed and left the percent of max at 20%. After reading some other posts I noted that most set the shuttle speed to about
.005 and the percent of max to 50-100%, some saying 100% is bad for the machine.

[gregoose]

Not Backlash.
Your horizontal axis lost position at some point.

That was also lingering in my mind, my lead screw seems to wobble or oscillate near the center when I do rapids which for me is around 200-230ipm. Makes me think the mount is twisted and possibly binding but it only does it near the center. Tried the drawing at different ends of the machine with identical results. Everything was looking good until it finished the rope piece around the outside. I'll be doing some more investigating when I get home.

By the way, the drawing is only 1.8" diameter.

[ger21]

Reduce your acceleration by 50% and try again.

[gregoose]

Ok, I'll give that a try too, I think my acceleration was set around 12 or so. The feed was set at 10ipm for this drawing. I'll work on it tonight and hopefully can update tomorrow morning.

Thanks for your help ger & papp!

[gregoose]

Ok, so reducing acceleration down to 8, then 4 with no improvement. Reduced velocity to 100ipm with no luck. The feed rate set by the code is 10ipm. Set backlash on .003 on Y and .005 on X, jerky movements but identical results. So I'm stumped. As the program runs, it completes half of the bee, then half of the rope, does an outline of the rope then goes back to complete the rope. That's where I notice the problems begin as it complete the second half of the rope. Then it finishes the rest of the bee. As it finishes the rope I notice a small gap between the start and finish.








Ran a test of a 2" circle inside a 2" square with a 1" circle inside and two more 0.5" circles.



This was with backlash on, 2" circle.

[gregoose]

The test circles look perfect to me with no signs of missed steps

[gregoose]

This is the gap in the rope, upper right quadrant. .


Possibly something to do with the code or CAM program F-engrave. Cheap Chinese steppers, the X is on a KL-4030 driver and the Y & Z are on KL-5056 drivers. X is controlling left-right relative to the drawing. All three are 3 amp steppers. The X driver is set to 3 amps while Y & X are set to 2.7 amps.
At this point I'm open to any ideas.

[nlancaster]

Be sure you have the stepper drivers set to the correct voltage/amperage. My first CNC was using KL4030 drivers and I thought I had it set to 36v at 3amp, but it was only set for 1amp. Couldn't even do 65ipm without loss of step, until I realized the issue withe amperage. Then I could move at 200ipm.

[gregoose]

Be sure you have the stepper drivers set to the correct voltage/amperage. My first CNC was using KL4030 drivers and I thought I had it set to 36v at 3amp, but it was only set for 1amp. Couldn't even do 65ipm without loss of step, until I realized the issue withe amperage. Then I could move at 200ipm.

Ok, thanks for the input, I'll double check the amperage settings tomorrow, they are a little confusing as they use reverse logic, on=off/I=O. The documentation for them isn't the greatest.

Also my power supply is only 24V.

This is the KL-5056...

[nlancaster]

Yeah, I had the KL4030s and I had to look very carefully at the dip switches. Basically the way keling uses them is bassackwards. 1 should = On.... not OFF!

[gregoose]

Ok driver pic and current settings. Aiming for 2.7A and 1/16 micro step.


Also, note: the step setting is also inverted. If I set the step switches normally, and command 1" movement, actual movement I get is around .6"

I'm assuming down position is "on" according to the marking.

[nlancaster]

It looks like the amps is set to 4.3a.

Because if your microstepping is working at 1/16 then you need to reverse the dips for the amperage.

But I could be totally wrong. Been 4 years since I had the kelling stepper controllers.

[steve123]

I read that as 1 = up, 0 = down.

101 = 2.7A

[gregoose]

I read that as 1 = up, 0 = down.

101 = 2.7A

yes that is what I assumed. However the arrow on the left points down and is labled "on". Hence the confusion. Could just be "0"

[gregoose]

I foresee many trial and error tests in my future but for now, its on hold for the next day or so during the holidays. For some reason, on christmas morning, no one is running downstairs to play with the CNC machine, although thats almost all I'll be thinking about all day, ha! Happy holidays everyone!

I was also thinking of reducing the microstep setting to 1/4 or 1/2 in order to increase torque and possibly overcome any slight binding causing missed steps. We shall see.

[gregoose]

Reduce your acceleration by 50% and try again.

What is your opinion on racking, I mean do you think it is something I should be concerned about for a machine this size? Total width is only 18", approx 16" from rail center line to center line.

[gregoose]

Ok, so my conclusion the the Keling drivers, is that up="on" and applies to all the dip switches.

I'm also thinking that the motors may be under powered with less voltage than required.
Data sheet...


Right now I have a 24V power supply connected. Ordered a 48V.

I'll be checking for tightness and alignment of the X axis and we'll see what happens with the new power supply.

[gregoose]

Success! Power supply up to 48V and upgraded the X axis stepper to a KL-5056 driver and no more missed steps! Next I'll be trying a test cut, soon hopefully!

BEFORE:

AFTER:

[gregoose]

Well, my machine is engraving quite well so far and I'm very happy with it, just a few engravings done. I think I need to tram the router still, surfacing is leaving tiny lines, maybe about 0.01" but things are looking good. May try some aluminum soon but for now I have to finish the seabee plaque as that's a paying job. Just trying to get the lettering correct.
Sorry for the bad pictures.

This one didn't engrave very deep so I ran it a second time lowering the Z by 0.1" The lines at the top and bottom of the lettering should be flat. It's a v-carve, 60° 1/4", 20ipm. I'll keep trying...

My oldest helped design the second one, carved into a piece of scrap wood using F-engrave.