[Rickyg]

hi out there.
Running into an odd problem outside my scope of understanding.
I have been trying to cut a series of holes, basically my version of the penny damper.
I redrew the damper to work with Canadian pennies so a slight change.
But I find the cut isn't round. Its nearly round sort of like my waistline.
It seems to be oblongish with the y axis being the short direction, yet i confirmed the calibration appears to be pretty accurate on the steps per inch.
I have run it fast and slow, no change.

So I am lost. Any thoughts would be appreciated.

[mcphill]

You may be losing steps, or you may have backlash on one of the axes.

[Rickyg]

hi there.
Thanks for your response.
I have installed new Anti Backlash lead nuts.
I also drew up a 3 inch by 3 inch square and cut it repeatedly with my machine each time checking the dimensions on the x and y.
I had to make a slight Y adjustment and found the y was not square and had to adjust that.
I am now cutting what appears to be a good square with right angle corners. I figured, lets start with something simple and make sure everything is adjusted right.
I will re-cut my damper in the next day or so and check the results.
I have a couple questions before I do.
First my board provides a max output of 3 amps.
It has 4 settings, 25%, 50%, 75% and 100%, I currently have it set at 75% or 2.25 amps.
The motors are rated at 2.8 amps, so I am wondering if I should run at 100%. However when I run at 100% I notice the motors are very warm. I don't want to leave my hand on them. So question is, should it be 100%.

Next question drilling a hole or using inside profile. Which is better and more accurate for say a hole less then 1 inch.

Last question, are there any settings that affect how a circle is cut. I see Constant velocity vs Exact Stop and Arc Center Mode can be either incremental vs Absolute.

Sign puzzled in pickering

[ger21]

Any flex at all that your machine may have will show up when cutting circles, especially smaller ones. Try cutting them much slower, and see if the results improve.

[Rickyg]

Will give it a try.
Have set the feeds and speeds down in the G code.
In the mean time any thoughts on the amperage question.

[Rickyg]

Well I can see a couple problems.
My router is actually rocking slightly in the mount. I am shocked. I thought it was solid. So will address that, but first I need to fix the lead nut on the z axis. I just broke the mount. It's designed that way so I am not upset.

[Rickyg]

Well
I remounted the router with a slight change to the lower mount. I didn't see that there was a gap on one side that caused the router to shift to one side. I corrected it last night and ran one fast test before the boss called dinner. The one circle was bordering on perfect. I need to try again tomorrow and test it a few more times and see how it goes.

[Rickyg]

Ok
So Now I have a question to the forum participants.
I cut my nickel damper last night. Nearly spot on, nearly.
Some irregularity stil exists. I observed that there is a slight rocking of the gantry as the gantry moves. Not a lot, but its there.
I don't know the cause as yet. Not sure if its missed steps causing a bouncing sort of affect or what.
So here is my question. Is it possible to add a counterbalance to the bottom of the gantry to reduce the rocking affect.
I know I need to look at the root of the problem, but I have noticed that these slide bearings have some play in them that allows for this rocking affect.
Ergo the question. Would a counterbalance make sense since gantry's are top heavy.

Cheers