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I'd make doubly sure its not the motor by adding say a 12V piezo buzzer in parallel with the motor
then you will hear the buzzer cut out if it is a supply problem.
It sounds a bit primitive, but it is actually not a half bad way to fault find, your ears will hear a change in tone better than see an LED or meter.
(I have an FET driving a battery powered buzzer for lower power circuits, but a plain old buzzer will be fine in this case as there is plenty of current floating about, you can put some series resistance and it will still work if you want to limit the current)
you should be able to do the same in parallel with the relay coil..  they don't draw much power.

I looked at this as a possible replacement, but I haven't actually tried it..
http://www.ebay.co.uk/itm/161081748554?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

It might be worth one of us getting one to see if it will do the job for future reference

Is there somewhere in the software a means of repeating placement of a single component ad-infinitum ?

I have one component which consistently fails imaging and I need to tweak the cdf..

All I can think of is to create a job with just that component in..

surely there must be a shortcut ?

FWIW these seem to be the right size replacement rubber feet

22mm x 11mm Conical Recessed Rubber Feet
http://www.ebay.co.uk/itm/360718567706?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Mine were perished and falling apart.. 
and it took two goes to get the right size

obviously the feeder heights will need to be reset after fitting.

The belts all seem to be working OK now,
I reduced the tension on many of them and they work better.

as for lubrication, I was thinking more like washing out with solvent then using PTFE dry lubricant...

Even after cleaning out with an airline, I have a few pins that seem a bit slow to retract..
the odd tape does not line up exactly with the others after indexing..

I have enough to avoid using the iffy ones, but it would be nice to have them all working..

Well,

I'm sure most folks with RVs have done this but
I bit the bullet and stripped the offending feeders down (as far as the mechanicals go)
I ultrasonically cleaned the mechanicals that are involved in stripping
and cleaned the moving carriage parts with an air line..
The belts (which appear to be nitrile) were soaked in platenclean rubbed and dried.

I found a variety of SMD parts..  as well as several short lengths of cover tape..!
I think it may have been the cover tape wound round the take up spindle that was causing the issue.
It probably increased the load the friction between the belt and cover tape needed to overcome.

For the moment the feeders seem to be working OK even on plastic tape..

One question..  the pins operated by the solenoids appear to be running in oilite bushes..

After 15 years they may be a bit dry..  has anyone attempted to relube in this area ?

I initially wondered why the LED ring on the static camera needed to be switched on and off in the first place.
The LEDs were not going to wear out faster than the others on the RV..
Then I realised that the light would probably interfere with the "on the fly" imaging on the arm camera


Re oxidized contacts..  a good mil. spec. dielectric grease is your friend here.
I now routinely smear a very thin layer on all pretty much all mechanical contacts.
For plug/socket contacts, it prevents oxidization pretty much in our lifetime.
but I'm probably preaching to the converted..

I am having trouble getting the feeders to drive plastic tape...
I assume this is a lack of friction between the belt and the tape..

I have tried platenclean which helps a bit but I guess I will have to rebelt at least one feeder

Has anyone tried any other belt materials than nitrile ?

Urethane seems to be popular for small drive belts, but I have no idea what the difference in co-efficient of friction would be.

Chris

Thanks...

that makes sense

getting there...    slowly !

Another beginners qusetion !

I have figured out the normal feeders.. using the training manual as a guide..
but can someone explain briefly how to define as a feeder the following

A short length of feeder tape with components.
stuck to the table with double sided tape, or clamped in a simple jig.

Am I right in thinking in terms of a single dimension matrix feeder ?

Simples...

thanks guys.. 

its the obvious stuff that catches me out!

Rather a simple question, but I've been wracking my brains over this..

I've created a transfer file with the components all neatly placed, how now do I now create a new job ?

What I do is a dummy placement (on sticky tape) of a part nearest each fid.....

Thanks Mike, that makes some sense..

regarding adding a new relocated fid camera,
I measured up and it looks like a 1/4" Cmos board camera with a 25mm lens should do the trick.
It will be a little larger field of view, but a longer lens gets harder to source.
front silvered mirrors 1.3mm thick are also easily available..
the existing cameras are powered via the signal cable, so that needs a little thought
                     (edit - actually not the case, they are powered seperately from a 9VDC connection)
I will have a play in the next week or two and report back

If it works it will make aligning to fiducials easy peasy...

I have fitted synchroflex belts for now

http://www.bearingshopuk.co.uk/synchroflex-t25-950mm-24922-p.asp

Synchroflex T2.5 950mm
Belt Width: 13mm

I still have the old pulley in until I source a new one,

the originals are marked     T2.5 950mm  0103

the new ones are marked     234 Synchroflex T2.5 950mm

Only time will tell how they perform

edit   ..

someone asked me how long it takes to change the belts..

bearing in mind I had not seen the underside of the machine before..
its not difficult, just a bit long winded...  it took about 3 hours..  
Now I've done it once, it would probably take about an hour next time

disconnect the cables under the rear
disconnect the upward looking camera and remove
remove the rear black steel bed cover to expose the tension adjustment screws
loosen the tension adjustment screws
tip the machine up (supporting the arm)
undo the bottom cover
cut off the cable ties that hold the loom to the case to give a bit of slack
undo the plate that has the connector socket on it and feed it through the base plate hole
remove the bottom cover
undo and remove the opto sensor board
undo the bracket the supports the wires across the pullies
(the camera wires then either need desoldering or some other means of disconnecting..  I desoldered)
undo and remove the stepper motors and old belts (you have to feed the electrics through the belt, like a crazy chinese puzzle))
fit the new belts (doing the opposite of removing the old ones !)
refit the motors and tension the belts..  nice and tight, you should be able to just twist the belt 45 degrees or so)
reassemble.. with new cable ties at the appropriate point

there is no need to adjust or align anything except the belt tension..

but the tool positions will need recalibrating as the toolholder has to be removed to remove the rear top cover plate

Just a word of caution

As the machines age, the belts will die of old age..

If the belts get this bad, the exposed steel wires will cut into the pullies..

its only a couple of screws to take the front panel off and the belts can be inspected with a flashlight.

If they show signs of deterioration, its quicker and cheaper to change the belts than to try and source and then replace the pulley!

which by the way is
a 24 tooth T2.5 pulley
13.15mm width across the teeth
12mm bore
overall length (with the plain shaft for a grubscrew) of 22mm

One thought I had to potentially get around all of this would be to make a little camera that fits onto the head in place of the nozzle. Or possibly a laser or LED that shines a tiny spot. That way you  avoid all the offset issues.

I don't yet understand the system well enough to work out how I can use the fiducial camera without it being properly set up..
but perhaps knowing what the offsets are at different places on the machine, I can compensate with a second mark on the pcb
so I haven't given up with the existing camera,

From my experience, laser dots are not easy to use or set up..
a pair of fine laser lines from two sources would work much better,
they can be aligned to always have the crossing point in the right place.
still not as easy to see as a properly set up camera...

but you might be onto a winner there Mike..
Cameras are so much smaller these days and a tiny composite video cam would be small enought to fit in the end of the arm..
In fact replacing the existing camera would be an overall mass loss.


How about a small front silvered mirror on the back of the moving mirror assembly...
then the camera on a mount at 90 degrees to the nozzle (exactly opposite the existing arm cam)
It would need some means of putting the mirror in place to view the fiducial
I wish I had access to the software source, all sorts of things might be possible !

(edit)
you could actually use the existing camera, just remount it and add a second fixed mirror,
I checked and there is more than enough room inside the sheet metal "bump stop" that wraps around the head