A bunch o' pictures from the last couple of sessions:

Marius (we think, it's hard to tell) after spending several hours in the shop doing some precision MDF belt-sanding

Nikola cut all the structural rods.

Somesh worked on breadboarding the new motor control circuits.

Jim and Michael working on soldering up electronics.

Jim, probably destroying the evidence of his latest plot for global domination.

Somesh, with his circuit.

Adam and Branko, plotting something devious, as usual.

A long overdue update

This was intended to be the post for our March 1st build session. I'm a bit late, eh?

So this post is going to cover the work on the session on the 15th also . . .

So here's the short update: We've actually settled into something resembling productivity at these build sessions. A bunch of the guys worked on making more of the misc little pieces out of MDF. We now have enough of them that I'm going to have to sit down at the next meeting on Monday and do some sorting and labeling, just so we know what needs to be done. Unfortunately,we're going to have to start working on the hard pieces now. (The big ones, with lots of angles and holes.)

Michael has been busy working on the various electronics (the AVR programmer and the three optostop boards), and I think they are finished and tested.

Those of us with experience in Pro/Engineer are translating the PAR files into solid models that we can modify ourselves. Adam, Devin, Branko, and I have been working through these at a reasonable rate. We have enough parts that I am starting to build some of the sub-assemblies. (I'll post pictures as they are done.)

Here's the agendas for the last two sessions. I'm going to start posting the session agendas along with the updates, just so that interested parties can figure out what we are currently working on.

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3/15/10 Meeting

Prep:

• Order Pizza & arrange for beer
• Make sure we have appropriate numbers of sketches

Admin:

• C-Rap can
• Set next meeting: 03/29/2010
• Distribute tasks

Mechanical:

• Continue modeling pieces in Pro/E
  
• Modify part designs for work with plywood
• Start building pro/e assembly
• Continue cutting plywood blocks
• Mill vertexes to correct thickness
• Drill out-of-plane holes
• Start making other parts
• Order Bearings

Electrical:

• Assemble and test programmer
• Finalize other board designs in preparation for ordering other boards (Interested in electronics layout? Check this out?)
• Order parts for motherboard

Software:

• Note: Most software stuff tabled until electronics are assembled
• Create sketch outlines

Recycler

• Decide what we want this thing to do.
• Generate potential designs and processes.

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3/1/10 Meeting

Prep:

• Order Pizza
• Make sure we have appropriate numbers of sketches

Admin:

• C-Rap can
• Set Next meeting
• Assign people to tasks

Mechanical:

• Start modeling pieces in Pro/E (up to three people. Perhaps: Ben, Devin, Adam S?)
  
• Cut final rod to length
• Continue cutting plywood blocks
• Cut out vertexes
• Mill vertexes to correct thickness
• Mill out-of-plane holes
• Order Bearings

Electrical:

• Assemble programmer
• Assemble optostops
• Finalize other board designs in preparation for ordering other boards
• Order parts for motherboard

Software:

• Create sketch outlines

Recycler

• Have BrainSturm session to generate design ideas
• Get Cracking

Cool things other people are doing: The Bedwarming edition

A heated bed for makerbot

Another nice heated extruder bed (Makerbot)

Next blog

If you press the "next blog" button at the top of the page, then you get a random post.  Here's what I got in order that I clicked
Shards of My Sanity 

International Tina Turner Fanclub
Real Women Have Curves
Prowling Sheep

I had to stop at the sheep.

Construction begins . . .

In the last week, we got the orders from McMaster and Dell Fastener in. We still need to order bearings, motors, and electronics, as well as a few other things.

So, we started in on the grunt work last night.

There was a lot of discussion about how to proceed. One of the big things was what to do about the problem of engineering drawings. Adam suggested that it was probably worthwhile for us to do our own drawings and assembly for two reasons: First, it gives us a better understanding of how the C-Rap goes together, and second, it allows us to be more consistent in our construction and modification of future versions. Those of us with access to a CAD package will start working on that over the next two weeks.

Once we got that out of the way, we broke up into groups: a few of the guys went down to the dungeon and cut the threaded stud and rod to size,

a few started cutting out corner vertices (we decided that we were going to make as many parts as possible out of MDF)

and Devin started looking at making real parts out of these pesky STL files.

Now that we have an idea what needs to happen for each part we make by hand, I think it will go a bit faster.

The next meeting will be on March 1st. Same time, Same place.

Weather

There was no meeting (or pizza or beer) this week, due to a fairly impressive snowstorm that has blanketed the east coast.

We'll try again next week

Nothing is easy

I had not anticipated the difficulty in getting the parts and information that we needed to get going.

On the ordering side of things, we've found that many of the parts we need are on backorder, and in at least one case are discontinued.

Almost as obnoxious is the difficulty in getting CAD data for Mendel. For some reason, the reprap project uses Art of Illusion (a surface based modeling program) files as the native data format. These files are, so far as I can tell, impossible to import into a commercial CAD package, making measuring and modifications difficult at best. While many parts are modeled in SolidEdge, these models are not kept up to date. We have found several cases where the PAR files do not match the STLs, and since we can't effectively measure the STLs, it is difficult to verify that a PAR file is correct.