Y error

[aileron]

Can anyone explain to me why the Y axis would appear to jump after the first pass? See photo.

http://i476.photobucket.com/albums/rr129/aileronster/IMG_3088_zps7a20298a.jpg

Actually I believe Y is wrong at the start and then corrects after it gets to the second pass, even though the G-Code looks fine.


First pass at the area of interest:

M3,2.275366,0.625000,-0.137000
CG, ,2.279691,0.617500,-0.000006,-0.005000,T,1
M3,2.216182,0.507500,-0.137000
CG, ,2.437019,0.125000,0.220836,-0.127500,T,-1
M3,4.064035,0.125000,-0.137000
CG, ,4.284872,0.507500,0.000000,0.255000,T,-1
M3,4.222415,0.615679,-0.137000


Second pass:

M3,2.275366,0.625000,-0.275000
CG, ,2.279691,0.617500,-0.000006,-0.005000,T,1
M3,2.216182,0.507500,-0.275000
CG, ,2.437019,0.125000,0.220836,-0.127500,T,-1
M3,4.064035,0.125000,-0.275000
CG, ,4.284872,0.507500,0.000000,0.255000,T,-1
M3,4.222415,0.615679,-0.275000

I'm new to G-Code but I am use to programming so the data looks okay but I could be wrong.


Anyways I am an early adopter of the Handibot (Kickstarter), just got it a week ago, spent three days trying to figure out how to use it, and started cutting gauge blocks found on 3D Warehouse/Github... so that I could then use the blocks to build a descent jig for cutting larger surface areas then the small footprint of the Handibot.

All of them come out fine until I get to the Field blocks. Each one fails the same way even if I redo the G-Code in Vcarve pro.

http://i476.photobucket.com/albums/rr129/aileronster/IMG_3084_zpsacc3dea4.jpg

Any suggestions would be appreciated.

[adrianm]

Presumably the preview in VCarve is correct?

As you say the SBP code looks fine. The only values changing between the first and second pass are the Z ones.

Most likely cause is going to be something binding on the machine or missing steps from being pushed to hard.

[bill.young]

Hi Jeffrey,

It looks like you're losing position as it cuts along the right-hand side in the first pass, but measuring those parts might help show what's really happening. The y-axis length of the body of those blocks should be 7"...is the right side of the block shorter than that, or the left side longer? What speed are you cutting at?

You might try removing the bit and turning the router off, and then re-running the file and listening for any odd sounds. You can generally hear if you're missing steps, which should show you where the problem is.

Bill

[aileron]

Thanks for the information. With both your comments. I was able to deduce what was wrong. The only problem now is how to fix it.

I could feel the machine grinding or skipping or something like that when it ran at the extreme X and Y position when it was cutting the far right corner.

So I decided to do a test.

I zeroed the machine, drilled a hole at the 0,0 xy position a tenth of the way down and then moved the machine to its extreme edges 6,8 xy with the GOTO command where it once again made a funky grinding sound. I then moved the machine back to zero and drilled another hole. Its off by roughly .33 an inch from where the machine had zeroed itself. It obviously does not zero in the y position correctly and then skips at the extreme edge.

See pictures:
http://i476.photobucket.com/albums/rr129/aileronster/IMG_3094_zps6bd262ec.jpg

http://i476.photobucket.com/albums/rr129/aileronster/IMG_3098_cropped_zps6b3f4d0f.jpg

I gather I need to add an offset to the y position in the handibot.sbd file. I just don't know how.

Thanks for all the help...

Oh and I was running the machine below what I have read should be the speeds this machine should run at: 1.7 inches per second and 10500 rpm per the feeds and speeds calculator. I inputted that into the end mill information on the tool path side of VCarve Pro. Plus added that bit for simulation in the preview mode on the ShotBot 3 control software. I also know it correctly added that into the .spb file as well.



'&ToolName = "HandiBot 1/4" Straight (48-005)"
&Tool =2 'Tool number to change to
C9 'Change tool
TR,10500 'Set spindle RPM
C6 'Spindle on
PAUSE 2
'
MS,1.7,1.0

[bill.young]

Hi Jeffrey,

Try slowing both the move and jog speeds down to 1, zero the x and y axis with the c3 command, and then run the same test.

[bill.young]

Also the rpm setting in the sbp file doesn't control the speed of the router on the Handibot...it's controlled by the dial on the top of the router. Set that to 4 or so and you should be good.

[srwtlc]

I don't know anything about these HandiBots, but do they have a mechanical stop at the max travel and if so could it be set too close to the travel extents so that it causes lost steps when driven to that point?

Or, your xy homing offsets are wrong and your xy 0,0 are getting set out further from the 0,0 limits.

[aileron]

Set speeds to 1 on move and jog, zeroed C3 command, and while it was noisier and slower, it did the same thing. :(

Thanks for the heads up on the 4.

[Brady Watson]

What are the dimensions of your part? It is imperative that you do a C3 or zero out the Y to make sure that you hear NO "grinding" aka stalling noises from hitting the far extents of the machine. Measure your physical part & then check that it matches the programmed path. Also make sure that if you are using a larger diameter bit than the project recommended that there is enough extra room to get around the profile of the part without exceeding the machinable area of the tool.

If you are encountering stalling when air cutting, it isn't going to get better when you turn on the router to cut. Back up to VCarve Pro CAD and check dimensions...and then check your bit diameter you spec'd out in CAM when you made your toolpath. The bit diameter could be the difference between hitting the stops & cutting your part.

I don't have a HB here, and not many here do either. Here's the spec sheet - which was a pain to find (marketing - Hellooooo):

https://s3.amazonaws.com/ksr/assets/000/704/278/aea0bf2c2d0e494108ed7ac4cd476cb2_large.png?1372348 143

-B

[bill.young]

These "F" pieces have the same Y-axis dimension as the ones you successfully cut before with "S" on them, and from the piece of code you posted they are cutting in the correct place in the workspace, so I think Scott is on the right track...that your Y-axis zero has gotten out of whack.

Before we get much further can I suggest we move over to the Handibot forum ( http://handibot.com/forum/ ) to continue this conversation? My guess is that not many over there check this forum, and this may be helpful to other Handibot owners that might not look here.

Of course everyone here is welcome to join in over there!
Bill

[aileron]

I followed the custom 3 program where it loads XYzero.sbp program which then loads my_variables.sbc file. From within that last file I was able to change the XYOffsetY from 0.5 to 0.15. Of course I commenting out the original and copied it once more to make my change just in case I need to revert back at a later date.

Shown below:

'&my_XYzeroOffsetY=-0.5
&my_XYzeroOffsetY=-0.15

Its now working, and I do understand that the smartest approach is probably to figure out where the absolute data is found and modify the absolute data for the table itself. Once I understand how that is actually defined and works I will tackle that approach.

As for taking this to the Handibot website forum. I would love to do that, but I don't like using my full name (they don't allow you to modify it) or even my real name online. From my perspective its just asking for trouble with the amount of information that is out there about an individual and clever people with too much time on their hands and ill intent.

Thank you for everyone's help. :)