User:Thav/mendelBuildLog

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This is a build log for Thav's first Mendel build. Parts were procured over a range from July 2010 to January 2011. Build is taking place in Raleigh, NC.

Parts

RP

My main bot plastic parts were provided by Steve Degroof on a Darwin. The parts required a bit of cleanup, but appear as if they will work.

Vitamins

Purchased from Berrybros on the reprap forum link in November 2010. All hardware parts were included in this kit except for the mudguard washers and jigs. Found some mudguard (fender) washers at Ace Hardware locally, 3/16"x7/8" that seem to work well. M4 washers were extremely tight fitting, taking a lot of force to get down on the screw. This is extremely frustrating, so I would recommend that after you check your rods for straightness that this is your second quality check for vitamins. Jigs were cut from plywood to length, along with some of the measure distances.

Thin Sheet

Opto flags were cut with aviation snips from some left over pieces of straight aluminum duct I had.

Thick Sheet

I got a quote for 4.5mm aluminum to be water cut for all the thick sheet parts for $150 US. I decided this was too much and bought a 2'x2' piece of birch plywood from Lowe's hardware. These were fortunately stacked flat and I was able to find a very flat piece. I printed templates of the thick sheet DXF and attached them to the plywood with spray adhesive. I cut the parts out on my bandsaw and drilled holes on a drill press at work.

Electronics

Purchased a set of Camiel's Gen 6 electronics second hand. Includes optos.

Motors

Purchased a set of 4 NEMA 17 steppers on ebay.

Shaft preparation

These came with gears that required some effort to remove, see below.

ThavMotor1.jpg ThavMotor2.jpg ThavMotor3.jpg ThavMotor4.jpg

Got it! Thanks to NewPerfection Forum post

I had these steel wrenches around from these bicycle shaped planters I have.

ThavMotor5.jpg

I used them to get some support under the gear. The vice is NOT clamping the body of the motor, just supporting the wrenches

ThavMotor6.jpg

Then you just get your punch in there on the shaft and punch away. On one I sort of shattered the lip on the pulley, making it hard to get the wrenches to catch, but it still worked out fine. Remember to give your motor a soft landing spot!

ThavMotor7.jpg

Windings

These motors appear to be unipolar with 6 wires.

Wire number Wire color Stepper hookup
1 Black not used, center tap A
2 Red A+
3 Yellow A-
4 Blue B+
5 Orange B-
6 White nut used, center tap B

This results in a positive going command from pronterface to spin the motor counter clockwise, looking down on the shaft.

Firmware

Running Sprinter firmware built from git at commit f8c17d3b4..., compiled with arduino 0022 and using pronterface using the install script from the wiki, ended up with git commit edeb4339...