Better finish

[Jonathan]

Yes Jonathan there is several line on each part.
so if I slow the feed rate down and plunge rate down even farther it may give me a better finish.

how low should I go, can you give me a starting point please

This does sound increasingly like the Z-axis is loosing position. Are you sure pulleys or something else on the Z-axis has not worked loose?
Although changing the plunge rate could solve the problem it's not advisable as the Z-axis is still capable of stalling. If it's too high an acceleration causing the problem then lowing the feed-rate could make no difference. You should go to Config->Motor tuning->Z-axis and reduce the speed and acceleration. I can't say exact values as I do not remember what they are currently set to, so try halving them and see what happens.

[JAZZCNC]

How meny times have you cut this.? If you have cut it a few times did it happen in the same place.? If not then try again and see if it happes in same place.

If it does then I very much doubt it's missed steps due to Accel etc or slipping as I would expect this to be more random and not really repeatable. This would more indicate to me you have a tight spot on the Z axis making it miss steps in the same place.?

If it's random then yes go for lowering the Acceleration.

It could also be electrical noise.!

[luke11cnc]

How meny times have you cut this.? If you have cut it a few times did it happen in the same place.? If not then try again and see if it happes in same place.

If it does then I very much doubt it's missed steps due to Accel etc or slipping as I would expect this to be more random and not really repeatable. This would more indicate to me you have a tight spot on the Z axis making it miss steps in the same place.?

If it's random then yes go for lowering the Acceleration.

It could also be electrical noise.!

well the result's are in and after a painful day yesterday It looks like I have a tight spot on my z-axis as the ribbing is more or less in the same place.

I cut my samples with a slower feed rate and spindle speed and with a 5% step-over and a extra finish pass at 90 degrees to the first finish pass
this was all futile as I finished with the same results as all the other times.I will check the machine for lose nut bolts and tighten up my belts and put a little bit of oil on the ball screw and then try again.

A very frustrated, unhappy and discouraged James. I could just cry at this moment

but on a positive flip of the coin I only have until Christmas to get this right, sooner would be better though

James

[JAZZCNC]

James chin up this is all just part of building your own machine and it's just teething troubles.
It's not uncommon to have little issue's like this and thats why I say to people to give there machines lots of running in time to iron out the bugs before tackling any big or expensive job's.!! . . . . Believe me it could be far worse imagine "striking" out . .Opp's. . mean forking out 5K and have machine that couldn't even do that.

Between us we'll have you sorted and dancing round the garage in no time. .:dance:

Now check everything's tight like you said, whind it up and down by hand feeling for sticky spot's if any major sticks then chances are thats your issue.!. . . BUT . . before doing anything major like striping the Z axis down this is what you could do just to verify it is a sticking Z axis.!. . . . Pack or lift the material higher so the Z axis works in a different place then cut another.

If you want a chat then it's my day off, use the number. . . BUT . . we'll have none of this girly wanting to cry shit round here.!!. . . . Only Yorkie eaters need apply..:lmao: