Calibration

Started by spiyda, August 16, 2016, 05:16:21 PM

Previous topic - Next topic

spiyda

I haven't given up, 

just been to busy with work to get back to it..   :(    :)

spiyda

Unfortunately I had a Z axis crash today...  so its put the calibration procedure on hold for still longer..

It was a bit of a nasty one, preceded by the sound of one phase dropping out, smashing both the nozzle and the reject tray, pulling several cover tapes off and moving everything out of alignment by several thou, requiring recalibrating the tool and camera positions as well as the feeders.

( To be honest it sounded like the end of the world !)

I just dropped in my spare control box and it seems to be OK and that points to probably a  hybrid driver ( I have a couple of spares, but time is in short supply)

Fingers crossed it will be OK for a few days as I have several hundred small boards to populate.

Does anyone know which of the modules in the switch mode style control box drives the "Z" axis ?

Mike

Quick way to check is with power off, unplug one motor at a time until it becomes easier to move the axis by hand.
Check the D connectors, especially the one that goes into the bottom of the unit - I had a contact go bad - it was very visibly burned.
I doubt a hybrid would cause an intermittent fault- connections are a more likely issue.
The IDC connectors on the stepper control boards (and elsewhere) are also a common problem.
ISTR that the DSP boards and ISA carrier boards can have issues - would be worth giving these a good wiggle
 

spiyda

I swapped the boards around and its definitely the driver board somewhere, 1 phase down.
I ran 90 boards today with the Power unit from my second machine without a hiccup.
Got another 150 or so to do over the next day or so..  for which I'm sticking with the pre-calibration dat file

The faulty driver board needs fixing and I have a couple of the hybrid modules but decided to take the easy option

http://www.ebay.co.uk/itm/151701173165 

That will be used to replace the faulty unit, which I'll repair and keep as a spare.

We have a show end of next week, but once that is over I'll be proceeding with the calibration.

ps, with the switch mode psu, moving the stepper motor makes the cooling fan spin...  !



alanambrose

Anyone interested in resurrecting this topic? Seems to me that spiyda was getting fairly close?

From a post way back: Ed: "Ed - a while back i offered to do a training session on how to do the cal.. not a single taker.......i will be selling the equipment for this soon. :) "

Err, anyone know who Ed was?

Alan

p.s. is drawing CAL05 the calibration camera mount? Also, is it possible to say where the various drawings came from - I'm wondering whether any additional information could be obtained from the same source :)

Gopher

I'm pretty sure Ed was in fact David Clements, I can't imagine there were ever many calibration kits in existence and VSMT who took on the servicing was only ever a 2-3 man outfit, David, Darren and I remember one other but not their name.

I would have thought David was well shot of any kit, at the time of that offer RV machines were apparently owned by two types of customer, small OEMs who didn't have the cash to move on, and hobbyist/single person outfits. One group was confident  in their ability to work things out themselves and the other weren't going to invest in a dead platform or perhaps had already gained the knowledge required.

alanambrose

I was havin a poke around in the files and I noticed that the cal grid seems to sit in a maybe obvious way on the bed - spiyda probably figured this out already.

This maybe?

http://anagram.net/nuts/Versatronics/RVxS-grid.jpg

Also, blnkgrd1.sys and blnkgrd2.sys suggest that rvplace holds the grid and cal numbers as 56x56 matrices. I also found that there are 6,272 rows in the cal grid part of rvdata.dat - which also suggests (conveniently) 2 off 56x56 matrices of x,y points. 56 btw is 27.5 inches / 0.5 cal grid spacing (+1 to make it even) and note the first column of the various matrices (blnkgrd1.sys / blnkgrd2.sys / rvdata.dat) is always blank.

Anyone buy that?

Alan

Mike

Quote from: Gopher on November 26, 2017, 03:22:58 PM
I'm pretty sure Ed was in fact David Clements
I believe so. Probably the most unreliable person I've ever had the misfortune to deal with.
He was really pissed off about me setting up this forum...


alanambrose

OK, I don't know exactly what this means and it may well not all be correct, but here is a visualisation of the two cal matrices in my rvdata.dat with the tool etc positions from the same file. It is possible the cal matrices don't start at cartesian 0,0 (as my previous graphic) and it is possible that the rows/columns may be inverted - as I made a guess which may the matrices are serialised into the file. Anyway, FYI:

http://anagram.net/nuts/Versatronics/RV1S_152%20RBMAR07.png

The green lines are the 1st matrix and the red lines the 2nd - if indeed my guess about the matrix dimensions is correct. The overall shape of cal data looks bona fide, but who knows. There looks something fairly wrong in that the cal data spans the whole bed - which is clearly wrong as the arm can't actually do that - but that's as far as I've got so far. Constructive comments welcome.

Alan

alanambrose

Ah think I've figured out the camera positioning - the camera adaptor shown in the CAL05 model mounts direct to the brass bar on the z-axis. The camera is either 15mm or '17.17mm' diameter and is held with the two m3 grub screws. I was expecting it to be another WAT-704 but apparently not as those are 18mm diameter. Of course, it could be some camera + light rig. I think the slots on the CAL05 model, can be sensed by the R-axis zero sensor.

Something like this:

http://anagram.net/nuts/Versatronics/Possible%20camera%20mount.PNG

http://anagram.net/nuts/Versatronics/Camera%20adaptor%20orientation.PNG

Alan

spiyda

Alan,

you are more than welcome to the parts I made / had made to take this further..  ( rotational calibration thingy, camera on mount  and  grid plate with slightly iffy grid print)

I had the calibration routine running through from end to end but ran out of enthusiasm / time to progress.

The machine I was using decided it didn't want to play any more and I switched to my spare machine which is better calibrated.  Having spent quite a lot of time on it, I need to get on and do some new product designing !

contact me if you would like to take it on


alanambrose

Hey Spiyda,

>>> you are more than welcome to the parts I made / had made to take this further..  ( rotational calibration thingy, camera on mount  and  grid plate with slightly iffy grid print)

Thanks that would be great - but I'm hoping we might convince you to re-kindle some interest :)

I think you were nearly there - seems to me there's (a) just checking that the grid is accurately positioned where it's meant to be - if, in fact, that's required and (b) verifying that the resulting cal file is at least as accurate as the previous one.

I'm up for spending some time to finish this off - anyone else? Mike? Spiyda, any chance of finding some more enthusiasm / time for the last couple of tasks?

I've found a camera which seems to the job and have CADed-up Versatronics' mount design, so it would be easy to print it up. I have to get some stuff water-jetted over the next week or so, so could get some cal platforms cut for anyone who's interested.

Alan

alanambrose

OK a slightly different proposal for a possible cal grid position:

http://www.anagram.net/nuts/Versatronics/RVxS-grid%202.PNG

I'm thinking the whole thing is keyed for exact position on the 6mm dowels (which I just discovered come out and could be replaced for this purpose with longer ones). I think they might stick through the 7mm holes in the Cal04 bed and key the cal grid directly or whatever it is mounted on.

Spiyda: anything else about the cal you can think of? Does the cal routine look like it goes through all the accessible points on the grid? In what order?

Alan

spiyda

Yes the calibration grid plate keys to the two dowels...

You need to start the process at the right spot to enable it to complete..
too far in any direction and at some point the camera will try to image off the grid..

If I remember correctly, it starts a few dots in from the left side..  not far from the position the head waits at after finding the switches..

The camera needs to be on and able to be rotated 180 degrees.

then you manually move to the start position, image the correct dot in the cam and set it off on its travels..

at a certain point it will ask for the camera to be rotated. than carry on to the end.

I got to the stage where it was producing a file...   

the next step would be to get a grid printed more accurately, ( the one I had was not 100% so wouldn't be a fair comparison of the files produced)

I think Mike suggested a way to get one printed.

Mike

Quote from: spiyda on December 13, 2017, 09:36:59 PM

the next step would be to get a grid printed more accurately, ( the one I had was not 100% so wouldn't be a fair comparison of the files produced)

I think Mike suggested a way to get one printed.
Photoplots ( or maybe just get a PCB made ?)
I don't know  if typesetting films are still easily available (I used to use these in teh days when PCB makers would take transparencies), but that would probably be another option - they are typicallt about 1200dpi but not sure what the dimensional stability is like.

This is one possible source - my PCB places uses them and charges me £10 per layer for plots
http://www.phillipsdigital.co.uk/