16 February 2012


I received a surprise parcel on Saturday from Mr Sum, just one day after he sent it. The postal service obviously doesn't loose all of his parcels it seems, they must be losing their touch.  The parcel contained most of the missing parts for my SumPod and an incomplete hotend v2.  It would be so much easier to tell with a picklist what parts are missing - at least at Ikea you know what you're supposed to have and tell what's missing (and the customer service is a lot better too).

Over the weekend I built the supplied parts into my SumPod and loaded the SumPod Sprinter firmware.  After double checking connections, I excitedly powered up the SumPod to test the three axis of motion and experienced a sinking feeling, not the light-headed, vomit inducing miss-typed dd or clicking hard drive variety, thank goodness, just a 'frustrated this should work, here we go again' feeling in anticipation of the inevitable fault finding.  The stepper motors were 'spazzing' (a well known technical term) and would turn when a finger was prodded onto pins of the Pololu driver - a fault finding technique I recommend (after discharging any static) to indicate floating pins with a little capacitive coupling.  I was concerned the Pololu drivers had been damaged having missed the tell tale 'magic smoke' while reassembling the electronics and connecting it to the SumPod.  Had rousing them from an extended slumber damaged them?  Who knows, they had been in a box on a shelf since mid October...

I powered off and went in search of answers.  Official SumPod documentation is still incomplete.  I checked the SumPod forum (made more difficult by Richard's refusal to re-enable my forum account so I can post, apparently I am a negative poster on my *own* blog) and the usual blogs, and a big thanks again to http://renaissance-engineer.net/ for the guides.  However in true fault finding fashion I reverted to the last known working state (nice when possible) using vanilla Sprinter (remember to set motherboard to type 33).   Adjusting the positions and connections of the endstops (with a little focused swearing and guidance of the RepRap wiki - you all know the address!) all was well and the motors behaved as expected.   Phew!!

For those following the build connect the endstops as NC, position them thus:
X (on the right facing out) and Z (at the front facing down) endstops under the print bed.
Y (facing inward) behind the carriage.
The connections to the RAMPS board are all minimums and will home successfully using ReplicatorG.  Ensure the connections are S and -, not on the lower pin which is used for powering opto endstops.

I'm considering augmenting the standard endstops and having both max and min limits on all axis.  I'll detail this in a later post.

Emailing Richard about the remaining missing parts, it is clear that he believes he has supplied all of the necessary parts, multiple times and that I have "misplaced" them.  There are images in the Wiki that show the parts of a SumPod hot end V2. I know that I have not received them. I believe we all got an email from Richard Sum in December saying we would be receiving the new hot ends ...

So, I have a working SumPod sans a complete hot end (oooh and the experimental dual extruder that I paid extra for waaaaaay back last year) and the wait is getting beyond frustrating.

For Richard's benefit cos I know you stalk me here and I love you for it (since I get a nice email after each blog post), I am not in the habit of playing sock puppets or posting in the third person.  My name is not Karl and nor do I post as Karl (for anyone not aware or not yet been accused of being Karl, check out the comments on this recent HackADay article).  Now hurry up and send me my missing kit because then I could complete my SumPod and tell my blog readers all about it.

Night night
SumPod Guinea Pig signing off

1 comment:

  1. Hey man. Im Mike, the guy who created the (now unofficial since Richard pulled the link) Sumpod Wiki @ http://sumpod.jumpwiki.com. Ive created a user forum to complement the wiki which is unbiased, uncensored, and definitely wont "ban you" ;). Id love your help in populating it with some posts. The forum can be found at http://sumpod.proboards.com/ and is also linked from the WIKI. Cheers!