Raspberry Pi First Impressions

It's my Pi!

The long wait is over and I finally have my hands on an actual Raspberry Pi. Initial impressions was that I'm really nervous about getting this protected and supported in a case. It's no more vulnerable to abuse than any other PCB, but a case will give me some peace of mind.

Getting the SD card was easier than I thought it would be, and the instructions at http;//raspberrypi.org/downloads were clear and easy to follow. One caveat, however: they don't explain that the partitions need to be adjusted after you dd (the command for copying the image onto the SD card) the image onto the card. It gives you a filesystem partition of about 1.7 GB and if you have a 4GB card, a bunch of it is going unused if you don't fix it. I used gparted on an Ubuntu computer to move the swap partition to the end of the unallocated space and then grow the filesystem partition to fit. I'm pretty sure it would be a bad idea to change the start point of the filesystem partition, and I didn't. 

It was a little dicey on first boot. I was a little dissapointed because it didn't sync up with my plasma TV via HDMI right away. I got some horizontal lines going across the screen. Information to help me troubleshoot this issue is hard to find, and the search function on the Raspberry Pi forums is, as one element14 user put it, "about as useful as a fish on a bicycle." I punted and switched over to the RCA output and that was no problem. Then I tried HDMI on the presentation projector, and that was fine too. 

Getting the audio to work was a small saga, which I can not now relate because the file containing my notes are on the Raspberry Pi.

I have two more units on order with element14, which I'm happy to see both have delivery dates now. This first one was from England through RS Components. I'll have it a whole month before the first one from Newark element14 gets here. I registered interest with RS in the first hour of the announcement, and at element14 about 9 hours later. Not sure how that 9 hours really accounts for a month's worth of delay. I suspect things are just especially slow at element14. 

This is a repost of my article on WixsonIT. Follow updates there.

Enclosure Dissaster!

The Hains printer in the semi-finished enclosure at the Makers Guild Meeting.

The the enclosure for the Hains /was/ in final stages, needing just windows, front door(s) and lots of work on attaining the piano finish that I want for the case exterior. The rough edges of the particle board, especially around the openings for the windows, is giving me fits. And I am a bit stuck about what to do about the front door. Fourteen inches is too wide for a door, I think, but dividing the door into two seven inch doors means that there will be an obstructed view from the front when the doors are closed. Plus, figuring out how to lock the doors when they close in the middle like that is challenging. I've decided to use t-nuts instead of printed trapped nuts for the screws that hold the case on to the base. T-nuts are awesome, and will give a nicer, cleaner profile on the inside of the case. They will also be less hassle than would be designing then printing up the bits I need for the trapped nuts.

Note: I said /was/ in its final stages.

I was in such a rush to get the enclosure finished before the expo at the KIA that I was slapping layers of paint on it right up until the night before. The paint wasn't completely dry, so the case got stuck to the base. In short, I busted the top of the case hammering on the underside to get it unstuck.




In my rush to repair it I fail to think things through sufficiently and break the case in two more places.







Yeah, so.... I think it's salvageable, but it's going to take some thinking.

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RepRap SitRep

The Hains is due for a rebuild, adding longer leadscrews and the MakerGear Z-axis stabilizer clamp (a.k.a., lower-z-bar-clamp, right and left), and replacing the fender washer pulleys with printed ones. Before I dare tear down the Hains I have to first get the Desmonda working. For the Desmonda the rods are all cut, parts are all gathered, the heat core just needs it's final cook to be ready for assembly into the hot end, and construction of the frame has begun. I still think that if it weren't for the fact that I'm trying to figure out the exact length the rods need to be to use acorn nuts on the ends I could get it done in a day.

By the way, so far I've figured out that the triangle frame pieces for a Prusa should be exactly 370mm long, the x/z axis crossbars at the top need to be exactly 440mm long, and the x-axis crossbars (4) need to be exactly 282mm long. Still working on the lower z-axis bar, lead screws and drill rod. I'll be posting an updated instruction set for cutting the bars when I get them all sorted.

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Location:Glenwood Dr,Kalamazoo Township,United States

Wood Shop Buyout

 This weekend I bought out a woodworking shop. It wasn't planned. I just sort of happened. Someone Desi knows told her he couldn't work any more because of his health and needed some money for medical bills. He produced a list of his tools and Desi brought it home to me. Thanks to Zim and his truck, I was able to go out Saturday and take the whole lot off his hands.

I paid $1,750 for the whole bit, which is too much, but it was for a good cause. By my guess I would have paid $2,370 for all those tools new. Some of the tools are decidedly not new. The old table saw and sand paper of dubious value notwithstanding, I paid 80% of what it would have cost in a raid on Lowe's.

So, now I have a nearly complete woodworking studio. The highlights are: table saw, 3 routers, rotary cutter, jig saw, joiner, miter saw, and compressor with nail and staple guns. I have a complete inventory drawn up. To finish it off I would probably need a planer, drill press, band saw, and lathe.

Printing Colbert is Hard

This is supposed to be the bust of Stephen Colbert, but it kind of reminds me of that scene from Total Recall. Travesty, both the movie and the print.

I've been troubled by this issue from the start. All my big prints have failed in similar fashion, most regrettably the Makerbot plates for Mendel parts. Small prints are no trouble. It seems happen most during the travel phase of the print, as it moves any long distance without extrusion. I've tried a lot of things, including slowing the entire print, travel and all, down to a crawl.

The famous Art of Failure article describes this problem as an issue with insufficient current. I've been playing with the current on the motors a lot. I turn them up until they stutter from too much juice, and I can't seem to make any headway.

I have to solve this, though, because students are going to want to print some largish things.