cnc router x axis starting before y axis finished when pocketing ?

[Robin Oakapple]

I've attached the toolpath

The CNC router is made by Rob Whittaker, he advertises on eBay

https://www.ebay.co.uk/itm/CNC-Route...0AAOSwt6RdtyD5

I' very happy with the one he made me, and I will be part exchanging it for an 8 x 4 as soon as he's finished it. I don't have any connection with him apart from being a very happy customer.

I contacted him about the problem that is the subject of this thread, and he advised me to go to General Config in Mach3 and check the 'turn off cv in corners'. I've done that but haven't had a chance to try it out since.

Although I've been using the machine for a good few months I'd have to confess I have so far only learned enough to get it to do the work I need it to do (I make kitchens, it's very much a production machine). I should, and will, eventually, try to learn more.

Thanks for your help, it's much appreciated..

[JAZZCNC]

I contacted him about the problem that is the subject of this thread, and he advised me to go to General Config in Mach3 and check the 'turn off cv in corners'. I've done that but haven't had a chance to try it out since.

That's like sticking a plaster on a wound that needs stitches.? The machine should easily handle cutting a 10mm radius at 3mtr/min and to prove this here's a video of your code cutting the first part, I stop it before cutting the outside profile. Ignore the other slots that was me messing around with G-code to cut away the holes and profile shape, the video is your code untouched.

Turning off CV in corners will at some point give you problems elsewhere, ie: large arcs If the code uses segmented lines for arcs, which this code does.
In this code, only the small circles use G2/G3 moves for the radius. The slot uses G1 moves which means the corners are made up of very short lines so if this had been a large radius and you turn off CV in corners those little lines will cause the machine to shake and shudder as it stops n starts at the beginning and end of each line.
If you want to see this happen then before running the code type G61 into the MDI which will put you in exact stop mode. Now the machine will most likely shudder in the corners or be very jerky. Type G64 to go back to CV.

Now I've got into many arguments over these Ebay machines and their flimsy build quality and low spec but it's little things like these that really show up the difference between a good machine and a poor one. Any Router worth it's salt should easily do this, now I'm not saying it won't do this but if the guy who set up the machine knows his stuff then it should be capable of doing it and he would set it up that way, so if it's not then I'd be wondering why not.?

[Robin Oakapple]

You've given me a great deal to think about over the weekend, thanks.

The machine I have doesn't strike me as being in any way flimsy, in fact when I saw it I was surprised at just how much I was getting for my money (which is always a factor in a production situation, where there are always other ways of making the parts I need).

It's quite possible that it's was me that caused the problems I've encountered by uninformed fiddling, it's obvious I need to learn a lot more about this stuff and if my work didn't keep me so busy (workshop during the day, designing and quoting in the evening) I would have made a start on that. One of the problems is finding good and comprehensive sources of information, what I have learned has been picked up in bits and pieces here and there.

[JAZZCNC]

The machine I have doesn't strike me as being in any way flimsy, in fact when I saw it I was surprised at just how much I was getting for my money (which is always a factor in a production situation, where there are always other ways of making the parts I need).

Well with all due respect if you haven't got any experience with CNC machines then you have nothing to compare it with.!

At the moment you are not seeing its weakness because you are not cutting correctly so are not pushing the machine, which isn't a good sign because it's struggling to cut correctly now.!
You mention production and when working in a production environment cutting at production feed rates then you can rest assured its weaknesses will some come to the surface. Because while the frame and gantry seem quite sturdy to you they are actually very flimsy when it comes to cutting at anything like correct feed rates with a good depth of cut (DOC) which are required in the production environment.
The things you will find when cutting at anything like production parameters will be poor finish quality along with poor tool life or worse broken tools. All these things make a huge difference to cycle times and the quality of finished parts. They also affect tool life greatly and if your underperforming you are actually wearing tools prematurely which can lead to breakages and worse damaged work but more importantly lost time.

I'm sorry to say this but this machine is at best hobby level, yes it can be used in a business environment but I promise you it's underperforming in comparison to a more substantially built machine. Which means it's costing you money.!

[Robin Oakapple]

...I'm sorry to say this but this machine is at best hobby level, yes it can be used in a business environment but I promise you it's underperforming in comparison to a more substantially built machine...

What would you suggest as an alternative?

[JAZZCNC]

What would you suggest as an alternative?

Well that's the problem isn't it and why so many people buy these machines because the alternatives are far more expensive. The Honest reply is I can't give you one without declaring a self-interest which is not why I said what I did.

Now I'm sure others who know I build machines are thinking I pull these machines down for my own gain but I promise you and all the others that's not the reason. I don't need to do that to sell machines, they sell them selfs and I'm never short of work.

The reason I point out the things I do is purely to help others who have little or no experience understand exactly what they are buying.
Also, I'm not calling the guy who builds them or the build quality, thou some of the eBay versions of this design leave a lot to be desired on build quality, this one does look like one of the better-built versions. Thou it's too expensive at £5k for what you get.!

My objection to these machines is the flimsy design and poor component selection. £5k should get you a much better spec machine than this at this size.

[Robin Oakapple]

Well that's the problem isn't it and why so many people buy these machines because the alternatives are far more expensive. The Honest reply is I can't give you one without declaring a self-interest which is not why I said what I did.

I have the same quandary when I see some of the kitchens posted on forums. I can see that they're not very good but I can't say very much because I don't want to make it look as if I am touting for business when I already have all I need, for the time being anyway.