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I am definitely interested.  Perhaps you can reach me on heaton.steven@googlemail.com

Mentioning you are placing hard made me think that if the stepper pinion was loose on its shaft, then it could slip when placing resulting in the offset that you see. The offset would be cleared if the machine was re-homed.  I can't see how the pinion is fixed (I couldn't see a grub screw) so it may be press fit.  Just a thought.

Asuming the mechanical movement is free, could it be an intermittant connection to the stepper motor ?

I had a similar problem with a different make of machine.  The z axis would occasionally move up and down wildly crashing the head, then it would go back to normal but be offset from its expected position. 

I found the fault in the end when it acted up whilst the machine was parked and I wiggled a few connectors and it fixed it.  I presume the stepper coils were energised to hold the z position, but the break in the feed to a coil caused the stepper to move 1/8th of a turn back and forth.

You might investigate a stepper coil becoming open circuit when hot, connectors dirty, or abrasion at the point the wiring passes through the arm joints.

In the PCB image, I am not certain the connectors on the right are for the steppers, so DYOR there.

The one with the silly name is possibly Ploopy Feeder:

https://www.youtube.com/watch?v=qa37CS5gLkE

Feeder comms info is here in case you have not seen it:

http://electricstuff.co.uk/forum/index.php?topic=237.0

I've done some simple tests with my old pnp machine (Mechatronika M10) fitted with one lane using a Dima Optimat feeder, using a optical sensor (RPR-220) to detect the pick head and then advance the tape by 1, 2 or 3 steps for 4, 8, or 12mm taps.  A stepper motor presses down on the top lever which advances the tape and operates the take up spool simultaneously.

If you plan on decoding the incoming RS232 I would think you could fairly easily operate any stepper motors, solenoids, etc required for any type of feeder you can get hold of.  The height and physical envelope is likely to be the limiting factor.

Steve.

Perhaps an email to CSsupport@cyberoptics.com ?

Steve.

Thank you both.  I managed to home the machine this morning.  I can now let go of the Emergency Stop button.

Below are my findings for anyone who has not seen their machine working before purchase.

Steve.

I am understanding like this :

So more like the attached image ?

Does it matter the angle of the forearm ?  Closer to the midline or away more from the midline ?  Or doesn't really matter.

I will give this a try tomorrow.  Thanks for your help.

Steve.

I bought an RV1s about a year ago and have found some time to bring it back to life now.  I have not seen it working.

The problem I have is with the homing the arm for the first time.


I have run armtest.exe and found the following (see also image attached, arm.jpg) :

>>

Analog input 6 (X Res) reduces from 255 to around 6 and the tick in box 6 appears when the forearm is rotated around its elbow and the angle between the forearm and upper arm is approximately 135 degrees.

Analog input 7 (Y Res) reduces from 255 to around 6 and the tick in box 7 appears when the arm is rotated around its shoulder and the angle between the north-south axis of the base and the upper arm is approximately 20 degrees, with the elbow to the left of the line.

>>



My problem comes when I run RVplace and open the file Demo-pcb.job.

The machine finds the limits for the Z and rotation axes successfully, but I am having problems with X and Y.


With the upper arm starting in the E-W direction and the forearm in the N-S direction, the homing movement commences clockwise at the shoulder (away from the Y limit switch position) and has to be stopped before the elbow hits the back of the cabinet. 


1. I would like help with confirmation that the X and Y limit switches (optos ?) are operating in the correct location when running armtest.exe (in my attached image arm.jpg) ? 

2. If this is all correct, am I starting with the arm in the correct position (arm position 1 in the attached file park.jpg) ?

3. If this is all correct, surely the should the arm should not commence rotating at the shoulder clockwise (away from the Y limit switch) ?

4. I have tried starting with the arm in position 2, and in this case it finds the Y limit successfully.  But I don't think this starting position is correct.  And what the arm does afterwards is worrying me and I have to emergency stop it.


I would be grateful for any help with this as I am struggling with the fundamantals.

Many thanks.



Further to the above, I have removed the baseplate front cover and see that each pulley has two areas with slots.  Each pulley has a single slot, and also two slots about 5mm apart further around the pulley.  This means that during armtest.exe there are two positions where the limit switches are activated.  I have added a drawing (limits.jpg) if this helps.

I purchased one (the buyer offered at £40 each).  Unfortunately I received the PMM-MD-53030-10 (opto-input) rather then the  PMM-MD-53031-10 (COMS input) version.

The seller accepts the mistake and has accepted my return, but I am tempted to keep the module for the spare power hybrid.

BTW I cannot identify the optos on the pcb, so I suspect they are encapsulated in the smaller hybrid module adjacent to the input connector.  The input connector for the step pulses is different also between the two versions of the module.