MadModder

Well excellent news today. Logically I thought reverse the last step and re-replace the 6SC 6100-6B00 card. No - very similar symptoms - X axis going upwards and growling - more head banging. I then took a VERY close look at the wiring and the various connectors that bring signals on and off the board. I then realised that there are two cable forms terminating in 20 pin headers that are both labelled X311 and are bundled together.

Surely not - no - did I put them back swapped - OH YES I DID 

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Reversing the error I'm back to "no unwanted moves upwards" on reset - phew. These cables are from the feedback encoders from the X and Turret servo motors no wonder it didn't know what it was doing. Fortunately their pinouts and voltage levels are identical so no lasting damage done.

Still got the green error light on the Go card 6SC 6100 6B00 BUT using my bodge on the error input line 404 I can jog X & Z in a controlled fashion.

OK lets put the original Go card 6SC 6100 6B00 back - oh ho - green light out system ready and I can jog X & Z without doing the 404 line bodge

Hoo blooming ray 

Back indoor to absorb the relief with a nice cup of tea and quit while I'm ahead !

My guess is it's a Gremlin. Do you have rat trap you can put in the main cabinet at night? Bait it with a working Android cellphone, or a string of series connected incandescent Christmas lights. Bound to be some action overnight. 

After looking at this problem, the adding of 9mm of extra height between the upper frame and the lower frame, I've come to the conclusion that I'm going to have to live with it.  I worked on the rotating assembly for the last couple of days and didn't accomplish much.  Let's look at my version of an 800 pound gorilla.

What you're looking at is the heart of this machine, it's what I call the rotating assembly.  The major players in the rotating assembly are the following:
1) The upper center frame, that's the dark grey piece in the upper center. The dark brown piece is one of the upper frame rails, these rails are bolted to the upper center frame and support everything on the top half of the machine.  Inside this part is where the slip-rings that feed power to the main drive motors live.
2) The slew gearmotor, that's the olive drab object.  It's a repurposed 3D pen extruder drive.
3) The slew motor clamp, it's the dark purple bit.  This keeps the slew motor in place, and allows about 1mm of motor adjustment for pinion mesh.
4) The slew gear pinion is the light purple object in the center.  The slew gear pinion is a modified 14T GT2 timing belt pulley.  Numbers 1-4 make up the top half of the rotating assembly.
5) The slew gear is the cyan colored object behind the slew gear pinion.  Not shown is the slew bearing, it lives inside the slew gear, the inner race of the bearing is clamped to the upper center frame.  The outer race is a press fit in the slew gear.
6) The pinkish object is the slew gear spacer.  The clamp that holds the inner race of the slew bearing to the upper center frame lives in a space inside this spacer.  Six M3 bolts will keep the clamp attached to the upper center frame.
7) The dark green object above the slew gear is the slew gear clamp.  Six M3 bolts will go through the slew gear clamp, the slew gear, and the slew gear spacer, to keep these parts firmly attached to the main frame. (That' the light grey object at the bottom.)

In real life, what you are looking at is MAYBE 100mm wide by 50mm tall.  The slew gear pinion is a modified 14T GT2 timing belt pulley.  I initially thought that I could eliminate the flanges on this pulley and gain about 11mm of space.  Not so much, there are still 2 problem areas. 
Problem area #1 - There is about a 1mm gap between the dark purple slew motor clamp, and the dark green slew gear clamp.  No matter where it is in its' rotation, about 2-3mm of the slew motor clamp overhangs the slew gear clamp.  No extra room here to eliminate.
Problem area #2 - The black object directly below the slew gear pinion is a track plate.  Twice in its' rotation the slew gear pinion will swing over the track plates.  Only about 1-2mm of the pinion will swing over the plate, but it does swing over it.  There's currently about 2mm of clearance, again nothing extra to eliminate.

Like I said, I spent a couple of days working on this and other than making some pretty pictures I didn't get much done. 

Sooooo.... PICTURE TIME!

Ignore the dark blue in the dump bed, I didn't realize I had a surface selected when I exported this image.

This is another, and better, view of what's under the hood in the engine bay an tank areas.  It's a cross-section view with all but about the lower 20mm of the engine bay and tank walls removed.

I just now noticed that the work platform in the foreground is not correct.  The angled part of the platform should be to the front.  This is a 2 piece assembly, and I'm going to have to remember to build them as mirror images, not duplicates like they are now.

Don

Thanks Steve for the kind words.

At last I can report a little positive progress. I've spent the last three days going round a logical loop regarding the Axis Enable Line not being asserted. This involved 'fault' outputs from the internal Simodrive servo drive supervisory card reporting the error (yes I know it's not enabled - is that your error?) feeding into the 810M CNC controller 'PLC' logic where the signal to enable the drive unit emerges. So it's a circular argument and rather reluctantly I decided that somehow I had to break the circle.

It is fortunate that I spent months on end decoding and mapping out the PLC program several years ago - it was a big help.

The method that I chose was slightly risky (*) - remove the 'fault signal' from the PLC and drive it to a clear state to see what happens. Sure enough the 'Enable line' goes to the correct state (24v) and I can jog in X & Z axis's . A slight oddity was that the fault line had to start at 0 v then go to 24 v - presumably to satisfy some sequence needed by the PLC.

(*)  risky in the sense that these are powerful servos reporting a fault so may not behave benignly.

So I deduce that the error is within the Simodrive not the 820T - most likely one of the two dual axis pre-drive cards. There is the supervisory card that I've mentioned (and changed!) that sources the error signal but it has monitoring circuitry looking at the pre-drive cards, the power drive cards and the power supply. Sadly card changing is pretty involved - not only loads of plug connectors but also a fair number of bolted high power connections for the servo motors themselves @ 40 amps. as well as numerous option settings on daughter boards.

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Just need to get down to it

In the last couple of days I've been busy figuring out how I could modify a 13 rpm 3D pen's extruder drive, with a worm gear output for the final drive, into my slew motor.  Also figuring out just how much other stuff I'd need to modify, because SOMEBODY didn't bother to figure this out BEFORE he slapped everything together in the assembly drawings.

Fortunately, none of the modifications were extensive.  The 3D pen extruder has a worm output gear, and a straight cut gear, both are pressed onto what looks to be about a 1.5mm shaft.  What I am starting with looks very similar to this.

I had to order a small gear puller set that will allow me to pull the gears off the shaft, and press everything back together when I'd done with the modifications.  I'll need to make a new output shaft, one that's nearly 20mm longer than the existing shaft.  I've no doubt that I'll need to order some stock to make that shaft.  I also need to go from the 1.5mm shaft to a 4mm shaft, for the 14T GT2 pulley that I'm using for my slew gear pinion gear.  I've got some 5mm stock I'll use for that.

I discovered that some how, somewhere along the line I had changed my mind about exactly where I was going to put the slew motor.  I started out with the planned location being on top of the platform.  I think it probably changed about the time I decided to put a seat, and an operator, and a control panel in the cab.  Because some Doofus didn't 3D model this change at that time, when I got around to it - I was in trouble.  By that time I had received the 14T pulley, which was also about 12mm longer than I was expecting - I can only get rid of about 4mm of that 12.

BUT... I've still got to bury the slew motor gear box, which is 10mm thick, into the upper frame - which is 12.7mm thick.  AND, has 5mm deep wiring tunnels dug right where the slew motor needs to go.  I can sink it about 5mm into the upper frame. but I need to gain at least another 5mm somewhere - maybe more.  I added another 5mm to the height of the spacer ring that positions the slew bearing, modeled the 14T pulley as short as I could get it, and checked the 3D model for interference.  I still had interference between the tracks and the bottom of the slew pinion - so I added another 2mm to the spacer ring.  I now have 1.7mm clearance between the tracks and the slew pinion as the pinion rotates over the tracks.  (That's good enuf for Gub-mint work!)

Between the slew motor debacle, and the GT2 pulley being 12mm longer than expected, I had to add over 9mm to the space between the upper and lower frames.  It's starting to look a little ODD.  I think I can lose some of that extra height by eliminating the upper and lower slew bearing clamp rings, which are both 3-4mm thick.  The upper clamp ring holds the inner race of the slew bearing to the upper frame, while the lower ring holds the outer race to the lower frame.  The rings are each held on by six M3 button head screws.  If I eliminate the rings, and use the just button head screws - and flat washers - to hold the races in place, I can probably lose about 6-7mm of the extra 9 that I added.  Which should help to eliminate the too tall look.  But doing that means I need to change the positions of the pockets for the heat set inserts in the lower frame - which is already printed.  (Nope not changing that one, maybe just the upper clamp ring?  We'll see.)

Don