Vibration issue with lettering

[kencraft]

I have a PRS Alpha 60x 96. I am just getting it running and have been experimenting with some cutting. My issue is when I am v carving letters anywhere from 1/2" tall to 2" tall and about 3/16" deep + or -. The letters are not smooth they are bumpy, when the machine is moving back and forth to make the letters and it is not holding a nice smooth character line. You can feel the machine kind of shake when the x and y move rapidly back and forth. It does not seem to be an issue when the machine is cutting out a part when it goes all the way through the material.
By the way I am using Baltic Birch plywood with a 90 degree v bit 12000 rpm.

[woodworx]

Make sure you are not getting backlash in either axis. While the power is on, shake each axis by hand to see if you get a clunking sound. You might need to dial that in. Next check your file. Are your vector lines smooth. Open the node editor in your software and make sure you don't have 50 nodes that make up each curve. That will also cause the machine to be jerky. Check your communication speed between the control box and the computer. This is in the utilities tab on your control software. Any thing else I am missing?

[kencraft]

I checked the text, my 2" letter has about 60 squares some solid some open. The smaller letters I cannot edit aspire asked if I want to convert to curves making the text uneditable. I used the text straight from the add text feature without doing anything to it. Should I be doing something to it when I have it the way I want it?

[blackhawk]

Ken - Some letter fonts have very jagged lines just like Justin mentioned. I ran into this last week on a sign that I was working on. You do have to convert the text to curves, which will prevent you from being able to add letters or fix misspelled words. If you have the text written as you want, there should not be any reason to fear the change to curves. Once you make the text as curves, you can go into the node edit function. Right click on the squares and there is an option to convert them to a smooth node. In some cases it is good to just delete nodes altogether. There is no use having 10 nodes for a straight line when you only need 2 nodes, one at the start and one at the end.

[kencraft]

Ok I did what Justin and Brad suggested. Thank you guys. As far as the backlash goes, I can move the x and y just a little bit, maybe 1/32. It feels like the play in the gear. Should that be tighter?


I also converted the text to curves which cut done on the nodes tremendously. However when I go to create a tool path for that text it follows most of the text but in some spots it creates several big divits kinda at random.
What did I not do right?

[ron_moorehead]

Hi Ken,

I have a PRT Alpha and I can not move the carriage in any axis, you need to check your pinion gears and make sure they are tight on the motors shafts. 1/32 movement is way to much.

[woodworx]

Ideally you don't want any play, but your 1/32" won't be a huge deal. Just try to pull motors a little more snug up to the teeth on your rack. Maybe that will help, otherwise check to make sure your rails are dead flat. That is what those little plastic shims were that came with your machine. You can check by shaking your x and y axis while it is in different points on your table. Shake them in the home position, and then shake them at say 42,42.

As far as your nodes go, Vectric does a pretty good job at cleaning up the fonts as they convert to vectors, but you might have some that will always need cleaning up. ArtCAM has a vector doctor that will identify potential problems such as little tiny curly Q's in the corners of the letters. Then the machine identifies them as intersecting vectors and doesn't know how to machine them. Other curves as you have found just need to be cleaned up.

[kencraft]

I am trying to check the usb speed as mentioned earlier. The speed test says it cannot find shopbot, but everything seems to be working. On the red positioning window in the control software the input indicators are all light green 1 2 3 4. 2 and 3 have a red x in them and 4 has a red circle around it. Can someone explain what this means and does it have something to do with not finding the speed?

[woodworx]

you have to close the shopbot program before you run the speed test.

[kencraft]

How do you run the test without the program? Do you know why I have red x's through input 2 an 3?

[kencraft]

When I start the control software the 1 3 4 inputs are green. When the keyboard control is activated the 2 input turns green and the 2 and 3 get red x's in them.

[woodworx]

That is ok. When you go to (UT)the diagnostic tools will open up in a separate window. Then close your SB3 software. Run the speed test at that time.

[kencraft]

I did see that when I tried it. I just didn't close the program. Thanks Justin.

[kencraft]

I ran a speed test and got 76. I converted the text to curves. I loosened the x motors and pryed them up into the rack to tighten them. There is less play in the car now. I ran the lettering again and it did not change much. I am using the font Arial Unicode MS it seems to be a very basic font with no tails on the ends of letters. I am using a 90 degree v bit at 12000 rpm in Baltic Birch plywood. I have attached a picture of the letter so maybe someone can see the jaggedness of it. It appears to have a tail on the ends of the lettering with little divits in them. Should I be using a different font?
8497
8498

[kencraft]

I found I am getting the same effect with bigger letters also