Z-zero problems??

[woodesign2@juno.com]

I am having problems getting the z-zero to cut the depth required, after i zero the z axis on the project,it does not engrave but goes through the motions at about the same level as i had zeroed it at??

Thanks!

[paco]

Is the location display says 0 at Z while moving X & Y?
Check your Z plate thickness setting in the Zzero.sbp routine...
"&ZBOT=0.125 'Put THICKNESS of your plate HERE ... NOW SET FOR 1/8inch Standard Plate
'Our plates seem to mic out at .??? these days ..."
at about line 23...

[woodesign2@juno.com]

Excuse me i don't use the zero plate, I only zero on my project.

Thanks! Ray

[garyb]

Ray, your a little short on information, eg. are you trying to do a center line v- carve? or just a single depth engrave? did you use a program to generate your NC code? If so, which.
I would suspect you have incorrectly set your parameters. If you send me your file or 1st 100 lines of it I'll have a look at it for you.
gary

[woodesign2@juno.com]

Single depth engrave is all i am talking about when i set the z-zero axis to zero it does not engrave at a single depth and i know i have it programed for for a certain depth engraving or had anyhow.
Thanks for your input!

Ray Hershberger

[robtown]

As I mentioned in another thread, I've done some ADA Braille on my PRT96. I had to trick it into going shallow enough for the Braille dots by playing with z and my final engraving depth. It's almost as if PW rounds decimals up or down .05 when it goes to a z depth.

[woodesign2@juno.com]

I am sorry, I think i goofed, I did not put a number in my finished depth department,therefore it did not engrave.

Thanks! Ray Hershberger

[robert_cheal]

I Need help urgently.
I having one of those days where I need to deliver a project this afternoon and I'm having a problem with the "Z". Here is an idea of the problem:
start 0,3,0
M3 78,3.125,-.125
M3 78,5.875,-.125
M3 0,6,0

When I cut this cleaning pass the Z will stay at "0" about 2/3 of the way down the X axis at that point it starts stepping down and arrives at the end "-.125" and when it returns up the other side it stays at
"-.125" for about 2/3 of the cut and then it starts stepping and reaches the end of the cut at "0". I know this by reading the display on the monitor.

I figured that the SB would follow the taper and step evenly the whole length of the cut. I have 6 more pieces to go and when your using a 1 1/4" round over bit the problem shows up very well.

I have a PRT 96 , SB version 2.21m , older Pentium I with windows 95. The machine is grounded and I will double check on that.

I am wondering if its the "Z" motor , the software, or the computer. I know that I need to do something but not sure where to start first.

If any has the time and some advice I would appreciate it very much.

Thank you,
Robert Cheal

[paco]

Hi Robert!

Was it OK before than not?

Should'nt you run/use 2.39sx? Have a look at this page (http://www.shopbottools.com/download.htm)...

I would think that it should do as you wish... sorry I have'nt used 2.39 from a moment now; I cannot help much with settings.

[bill.young]

Hey Robert,

One quick possibility. Make sure that they are M3 moves instead of J3's. In the DOS software Jogs don't necessarily break up moves into even segments.

I'd also suggest upgrading to the newest software at some point though I don't remember any problems like that in 2.21...2.39 is the current one.

Good luck,
Bill

[gerald_d]

Hi Robert, the theory is that there should be a nice even ramp, but I've never really tested a 3D linear move over such a long distance. Maybe, to get the job done, divide that long move into shorter pieces.....

start 0,3,0
M3 39,3.0625,-.0625 <------ mid point
M3 78,3.125,-.125
M3 78,5.875,-.125
M3 39,2.9375,-.0625 <------ mid point
M3 0,6,0

This done without a calculator - double-check please.

And then insert quarter points and eigthth points as well.

A quick guess, I know time is of the essence.

[robert_cheal]

Paco, Bill, & Gerald,

Thank you very much for your responses. I do need to update my software for me I guess been like "don't fix it if its not broken" or that I plan to update it when I get a minute but I always realize that the minute never comes until their is a problem. These last 6 cuts are the first with a more visable taper in depth for me to notice the problem. I think I will go out and try Geralds idea about breaking the move into segments. The project is a shaft for 20' long fluted column , 30" base dia. , 25" top Dia. I am making 1/4 of the total column shaft to be used for a mold. Until now every thing has gone smoothly and fit very well.

Gerald, I'll let you know how the segment idea goes.

Thanks to everyone,
Robert Cheal

[robert_cheal]

Well for me the great news is that the last 6 parts are cutting and will work out. I ended up dividing the length into 8 3D linear segments about 9" long
the "Z" still does all of the movement in the last 1/3 of each cut. I can see it on the display, hear it, and see it on the piece of wood being cut. but I don't expect any problems with the result so I will gladly take it and be happy to finish this project today. And tomorrow I can get the updated software and all run some tests and find out whether this is just my machine. If find anything of merit to post from my little world I will share it, but I really learn more from the rest of your guys and blokes than I could come up with on my own.
Thanks for now,
Robert Cheal

[gerald_d]

Hi Robert,

I cross-posted a list of numbers with you and then saw you already had the job done.

*a sigh of relief*

Can I go to bed now?

[robert_cheal]

Gerald,
The project is done and 4 calm hours later, its almost my time to go to bed. I did not have time run a full range of tests but on my machine I found out that the "z" steps through out the 3D
move if the angle is more pronounced. The subtle inclines that I was cutting produced the problem.

I did some test M3's from my keyboard and there was a variable range of when the steps started counting. They ranged anywhere from the last 3rd to first 3rd of the move and when the incline and angles where over approx. 1/4" it appeared to work fine over the distance. I'm not sure yet what this all means but it leaves me curious if there is some setting on my machine that needs adjusting other problems to deal with. I guess the coming days will tell. Thankfully I dodged the bullet today.

Thanks for checking back.

Robert Cheal

[gerald_d]

Robert, I hope that the SB folk are following this thread. This has shaken my faith a bit in that I would have been adamant that the SB follows straight lines from point to point. Apparently, sometimes it doesn't, and that dispels the most basic assumption of what the machine will do.

[bill.young]

Hey Robert,

I went back through the release notes for the DOS software and they include "-removed slight error in long shallow diagonals" in version 2.25. Now that the job pressure is off I'd suggest updating to the newest version and see if that fixes the problem.

*** Remember to update the firmware in your control box after you install the new software.


Bill

[robert_cheal]

I wanted to thank everyone for their advice last week it certainly helps one feel less alone & helpless when trouble shooting. I have not been able to get the SB 2.39sx software to work. I’ve followed all of the procedures and I still get the message about not being to communicate with the control box. I erased the “shopbot.ini” file, I did the “load46” to install the firmware and it would not connect. So for now I will continue with the
SB 2.21 and I won’t plan on any “shallow diagonals” for awhile. I plan to replace the computer about the first week of September when the local University has a surplus sale depending on the features one can pick up something like a Pentium III for about $75 -$150. Then I would install the windows version of the ShopBot software. As far as a
computer to run the PRT96 I wonder if anyone has any advice on getting a older “shop” computer like I’ve mentioned above or just invest in current model, I do like the idea of being able to take files to the shop with a USB flash drive. The main objective would be to get the best performance for the most reasonable expense.

[dingwall]

I bought a used 1.8 Ghz machine from a friend. 1.8 Ghz is I believe the minimum for running the windows SW. It lasted a couple of months before blowing the hard drive and motherboard. $450.00 later I had a new motherboard, processor, videocard and hard drive. Plus a UPS. In retrospect a new computer would have still been under warrantee.

Someone correct me if I'm wrong, but I spec'd a 5200 RPM drive this time as it should run slightly cooler.

[mock_pool]

I have a PRT and have installed the windows version and parts wizard 2 programs. I have run the x,y,z calibration and have it set to the home in the bottom left corner. When I command the tool to move y,10 it move about 14. same with the x. Is there something I misssed when installing programs. I have racked my brain, and my fist, to try to figure this out. HELP!!!!!

[gerald_d]

Patrick, search your documentation and this Forum for changing the "Unit Values"

Read your current "Unit Values" off your system and report them here. Then we can suggest what you should set them to.

[mock_pool]

Okay, Here are my User Values: X=733.386; Y=733.386; Z & A 916.7324 and B=16.000. The table is 48 x 144. I hope this is what you where asking for Gerald. Thanks for the help.

[gerald_d]

Patrick, from the rough information that your x and y axes move 14 inches when told to move 10, it appears that your x,y "scale" is 1.4 times too big. Therefore you should multiply 733.386 by 1.4 and have a unit value (for the x,y) around 1026

Looking at this table (http://www.talkshopbot.com/forum/show.cgi?tpc=312&post=18437#POST18437) you actually need a unit value of 1018.59 (the closest value to 1026)

I am sure that you can follow this logic through to get the get right unit values for the z-axis as well. (You can't simply assume that the z is also 1.4 times out - you have to measure it)

Caution, it is 7am here and I havn't had my second cup of coffee yet - you might have to divide by 1.4 instead of multiply!

[mock_pool]

Thanks Gerald,
I will try it out and let you knoe hte outcome.