After that, I found I can extrude PLA at 180°C at about the same rate as ABS, although other folks on the forums use lower temperatures.  I tried increasing the temperature as high as 200°C to see if the filament would come out thinner, but at that temp bubbles appeared in the filament like it was boiling in there.  But 180°C did fine.

I just printed a few calibration blocks and a few portions of my new replacement pool filter basket using my Filastruded PLA on my Mendel Prusa with a .35mm nozzle.   I had trouble with jamming until I raised the print temperature all the way to 220°C.  Now it seems to get through a whole print alright.

Thanks Everybody for the advice!

The fix is a bigger washer or a harder material for the thrust plate. The CNC shop used plywood that was softer than what I used during testing - I never saw this problem personally. I've since switched back to metal thrust flanges.

SABIC MG94 natural ABS is what's provided with the kit. I recommend it for the initial purge as it's characteristics are most repeatable and known which makes troubleshooting easier.

bubbasnow, I ran it around a half hour of the 8-hour cleaning time before the problem happened, and got a good 30 feet or so of filament.  Do you think PLA and ABS should be extruded at the same temperature?  People print ABS at a higher temperature, so you would think it should be extruded at a lower temperature too,  It comes out quite runny and free-flowing at 160°, so I didn't dare go higher and risk it pouring out as a liquid.  On the other hand, ABS is supposed to have a lower coefficient of friction, which should let it flow with less pressure.  I'm using the brass nozzle that came with the Filastruder kit.  I don't see a filter on it.

elmoret, I have Serial No. 536, so it's Revision 1.3.  Sorry if I used the wrong word; maybe it's not ramen.  It's filament with irregularities.  Here's what came out right from the start in this photo (#1 below).  Some of it for a few inches is very smooth and crystal clear (hooray!), but everywhere there is a kink in the filament I can see a small dark piece of debris inside.  I gather from the forums and instructions that this is normal for the first 8 hours of operation, the "purge" process.

The instructions Version 1.3 recommend using clear ABS for the 8 hour purge.  With the kit I received a bag of white plastic pellets labeled only, "Ziploc®".  They look like white ABS, but I know better than to heat a plastic if I'm not absolutely certain what it is.  I checked Filastruder.com/products/filastruder-kit and it says "over 90% of the testing has been done with ABS", but Nylon and TPE also work great and "PLA requires a little more care.  The Filastruder extrudes it fine..." I just have to put it through a drying process first.   A challenge?  Sounds great.  Being careful is what I do best.

Here's a photo of the white plastic and the (vacuum-sealed until I opened the bag) clear PLA from OSP. (photo #2)

Good to hear about the safety feature.  I love safety features.  It's what I do for a living.  That means the pin slipping is just a symptom of the problem.  And the pipe bending was a symptom.  The root cause was the auger not turning freely in the pipe.

If the auger not moving freely in the pipe is usually caused by improper assembly or improper operation, then I'll fix both and make the root cause go away.

I disassembled everything, straightened the barrel, and started over.  Here's another interesting thing I found in disassembly.  (Photo# 3,4) One of the washers is pressed all the way into the plywood thrust block.  Let's fix that by filling in the hole with another washer. (Photo #5)

That would be caused by too much pressure in the extrusion chamber pushing the auger back into the thrust bearing.  Wikipedia says t takes more pressure to extrude PLA than ABS, so it would be expected that the chamber pressure would be higher.

Filastruder.com says the Filastruder can process PLA as long as it's dried well.  I'll do more research to see how others had success with PLA before I try it again.

For now, I'll get a pound of clear ABS and run it through to see whether improper assembly was the issue instead of overpressure.

Thanks for the advice, Everyone.  I hope I answered all the questions, if not in the same order.  I'll post my results with ABS and do more research on how folks get success with PLA.

It looks like you have a fairly ancient kit - shipped 9/18/2013. I think that's a v1.2 - Can you confirm?

There shouldn't have been ramen, though that's dependent on how you set up the filament guide. It is not "standard", though it is going to be dirty on the first purge depending on how well the barrel was cleaned after deburring.
The pellets shipped with the kit are ABS, not PLA. They should be extruded at 180C, not 160C.
The pin slipping is by design, to save the motor from overload. If it is slipping, either the unit was assembled incorrectly or is being operated incorrectly (wrong temperature for the resin being used)
The barrel is very strong - I have run one 1500 hours without damage. It is only damaged if allowed to stall, due to mis-assembly or improper temperature.

As for your last question, no this is not happening to everyone. It has happened to a few users, usually due to a mistake during assembly or mistaking ABS pellets for PLA (or extruding at the wrong temperature for other reasons).

My questions for you:
Can you post some photos of how you assembled it?
Were you sure to keep the thrust bearing compressed while mounting the uprights?
Are the uprights currently parallel?
How was the thermocouple installed?
Where did you get the PLA pellets from?
Why didn't you do the initial purge with ABS, per the instructions?

The motor shaft had smashed the 3/32"dowel pin to a metal mush, allowing the motor shaft to spin inside the hex socket.  Also, the nipple (the barrel of the Filastruder) is visibly twisted and bent.

Any suggestions how I can fix this?

I'll try tomorrow to heat it up again and separate the damaged nipple from the auger to see if the auger is still straight.  I think I need a much stronger nipple (barrel) and a hex socket with a set screw to withstand the massive forces the motor seems to produce.

And is this happening to everyone or just me?

Thanks for any assistance.