Help needed

[JAZZCNC]

It's earned it's money but yes, one step up from a hobby machine.

Ermm actually NO it's not, this is why you are having the problems.!!
Most on here are hobbyist and I'd say 99% of those who have a self built machine would outperform a merchant dice machine by a factor of at least 2x upto 10x +..!! . . . But your correct if it's for business then your best concentrating on what you know best and earns the money.!

[cropwell]

Did the installation 'engineer' check all the alignments? - I would bet not!

You need to check is that there is no twist in the gantry rails*, this will cause all sorts of inaccuracies. First rough check is with a large engineers square. Just eyeball the contact with the rails at each end of travel.

If you clamp a decent size engineer's square to the bed and align it with the X or Y axis using a dial guage, does it give a square reading when jogging along the other axis.

Then, when you have sorted that out, does the Z axis run true vertical wrt the bed. Again using a square and dial guage, testing at both ends of the gantry travel and also in the middle.

* this is also true for all rails. If they are not set up in tram and at 90deg to each other then you will never cut true geometry.

[PeteHowlett]

I am grateful for your advice but I don't want to do the work. My time is better spent doing the stuff I know.

[cropwell]

I am grateful for your advice but I don't want to do the work. My time is better spent doing the stuff I know.

In that case, just buy a decent machine. I was under the impression that you wanted to increase your output by doing the mundane stuff by machine.

[PeteHowlett]

Look folks - I don't want to nor do I intend to insult people. You don't have to spank me any further. I know I have a turkey on my hands!

I am a full time Artisan Ukulele Maker who happens to use a CNC machine bought in complete ignorance. Over the past 3 years it has achieved for me a great deal and added value to my work. I have abused it, mis-used and now push it to its limits machining hardwood with deep cuts using large diameter cutters!

Because of workload I just do not have time to go at this machine in a major way and furthermore, It is central to my current work and I have to have a working machine. So grateful as I am for the advice, my original post was for someone to come and do the repair/restoration for me. I neither have the technical capability or confidence to do it myself.

After speaking to Dean who kindly called me (mahalo Dean) I am now developing a project which will pay for a new machine soooo Dean, check your bt account - proposal in there.

[PeteHowlett]

So I repented my error and got the Z axis within 0.02mm left to right. Just don't know how to correct the 1mm drop over 400m on the Y axis. Good job `i am commissioning a new machine. Problem is I am asking my little machine to do tough work. Thanks for shaming me to get out the allen keys and dial gauge.

[Clive S]

So I repented my error and got the Z axis within 0.02mm left to right. Just don't know how to correct the 1mm drop over 400m on the Y axis. Good job `i am commissioning a new machine. Problem is I am asking my little machine to do tough work. Thanks for shaming me to get out the allen keys and dial gauge.

Is it out by 0.5mm over 200mm ? if so the steps per might be wrong

[cropwell]

Is it out by 0.5mm over 200mm ? if so the steps per might be wrong

Clive, I don't think this will be the case. More likely the frame geometry.

Peter, If it is cutting squarely on the X-Y plane, then the easiest thing to do is put an MDF sacrificial bed on and machine it flat with a largish cutter. IF that produces a rippled surface, then your Z axis is not going squarely up and down, again geometry!

You are a lucky bugger to be in a position to order a new machine from Dean. I would if I could, but only so he would not be able to criticise it (not that I would expect it to have any flaws )

[AndyUK]

Peter, If it is cutting squarely on the X-Y plane, then the easiest thing to do is put an MDF sacrificial bed on and machine it flat with a largish cutter. IF that produces a rippled surface, then your Z axis is not going squarely up and down, again geometry!

Can we deviate slightly from topic and discuss this? As a rather inexperienced user, I'd have thought that ripples here would indicate that the spindle isn't trammed - I wouldn't have thought a misaligned Z axis will show when the cut is at a constant Z.

[cropwell]

Can we deviate slightly from topic and discuss this? As a rather inexperienced user, I'd have thought that ripples here would indicate that the spindle isn't trammed - I wouldn't have thought a misaligned Z axis will show when the cut is at a constant Z.

If the cutter face isn't square to the bed, when you cut it will do an angled cut. The larger diameter cutter you use, the more the effect. This will make a sawtooth wave ripple on the bed and it is quite noticeable. the distance between the ridges will depend on stepover. I am assuming that you use a raster or spiral pattern, trochoidal will be less noticeable.

This error will also be noticed on the side walls of a deep cut.