Jagged lines

[Austin Shafer]

Hey guys I have had some issues with getting jagged line when cutting diagonal or circles there is no problem when cutting straight X or Y line only when combining the two. I have some pictures attached that show some problem areas. My work has a old shopbot buddy set up for 4'x8' sheets and we run plastic on it. Any help is greatly appreciated.

[genek]

[QUOTE=Austin Shafer;182905]Hey guys I have had some issues with getting jagged line when cutting diagonal or circles there is no problem when cutting straight X or Y line only when combining the two. I have some pictures attached that show some problem areas. My work has a old shopbot buddy set up for 4'x8' sheets and we run plastic on it. Any help is greatly appreciated.[/QUO

Turn your machine off, and then back on. try to move the x and y if it moves you need to adjust it. I had that problem turned out the gears were lose just a little.

[Brady Watson]

With the control box on & machine at rest, push the table in & out. Then push the YZ car left & right. Hear/feel any 'clunks' ? If so, where?

-B

[Austin Shafer]

There seems to be a little play in both. How much should I be able to wiggle them?

[Brady Watson]

Typically around .005-.007" give or take depending on how worn your gearboxes and pinions are.

You DO have grease on the racks, right? If your racks are dry, your pinions are shot. Order a set and put them on; then grease. It's really the only maintenance item on the tool - yet very few do it.

If they are lubed, drop each motor down, then shove them all the way up and tighten. Then check for play again. A dial indicator is the only scientific way to check - otherwise it's hand/ear method.

-B

[Austin Shafer]

Thank you so much. I was thinking that the pinions might need replacing. When I was "trained" on this machine 9 months ago they said nothing about routine maintenance so a few months ago I decided to search and found that I should be greasing the racks weekly for how much this machine runs but im almost positive that it was not done for a very long time even a year or so before I took it over. I had our maintenance guy here check the pinions and he said they were good but I know for a fact that they have been on the machine for at least twice as long as they say they are good for. Luckily we got the pinion sizes so I can order some and hopefully that fixes the problem.

[Austin Shafer]

would that cause the X axis to get off sometimes while cutting?

[MogulTx]

Going too fast for the cut that you are doing... if it is an older machine you will probably have to cut back the depth of cut or the speed of cut or both.... You should also look at the "chip size" coming off your current cuts and decide if the chips are too large or too small. If too large, the router bit is trying to take too large a "bite" with each rotation and it can cause a lot of violent vibration which causes quality problems. If it is too small a cut in a plasticine material, it can heat up and gum up and gum up the material or bit or both..... and this can cause some heating/slurring of the material issues.... This can be affected by speed of travel, depth of cut, rotational speed of bit and bit cutting edge geometry and sharpness.... a proper, plastic cutting bit, that is good and sharp, with Pinions that are new-ish and tight to the track will help all things. If you can feel slop in your pinions, you have a problem.... check them first ( as indicated above) and check and modify the bit type and condition, then the speed and feed rate.... and modify as needed to make your material serve you.....

[Austin Shafer]

Thanks for the help!

I have recently been running into another issue. The zeroing plate is input 1 so when they are in contact input 1 is lit up on the control screen but sometime input 2 and 3 are lit up instead and when that happens it wont zero Z correctly. It usually doesnt do it for the first 5 or so hours of my shift but the end of the day it happens alot, usually when I restart the machine that works but it still does it again eventually. The maintenance guy here is worried its the board. The cables look and test good.