I’m going to write a detailed description of each of the parts I make for my reprap in case anyone wants to follow in my footsteps. If you don’t want to see all the details, just scroll to the bottom to see the finished part.
I’ve made my first reprap part. I’m making the parts out of 3/4 inch Medium Density Fiber (MDF). It has a nice uniform texture which is easy to work with. This is just under 20 mm thick.
I’m making the first three parts each exactly 1.5 inches tall by glueing two layers of MDF. The parts are measured in mm, so I won’t be building them exactly as they were originally designed.
I combined the x-idler-bracket, constraint-bracket and bearing-insert into one part. I think this means I won’t be able to adjust the x-axis to make sure it is level. I’ll wait and see. I started with a 66mm x 50mm block.
I started by drilling a few holes in the block. Each of these holes is either 5.4mm or 8.4mm. In the picture at the right, I picked the corner on the left side near the top as a datum point. I measured all locations from this point.
On the top, there are 4 holes that are used to clamp the y-axis belt. These are 5.4 mm holes that are 12 mm deep. They meet a square hole that is used to insert a nut that a screw meets. The location of these holes in (x, y) are (6, 11), (19, 11), (6, 55) and (19, 55).
Also on the top there is a hole for the x bar idler. In the original part, this is an 8 mm hole, but I only had an 8.4 mm drill bit so I used that. This hole is 35 mm deep. The location in (x,y) is (9, 33) .
On the front, there are two holes that carry the x-axis rods. These are 8.4mm holes that go all the way through the block to the other side. Their locations in (y, z) are (11, 21) and (55, 21).
The remaining holes on the front are square holes. Two small holes are used to hold nuts for the y-belt clamps. I made these using a side cutting bit for a dremel. The best thing I found was to work back and forth clearing the entire area. The holes aren’t exactly square, but I think they will work. This was my second attempt to make the holes. On the first attempt I cleared most the material using a drill and tried to square it up with a chisel. This ended up splitting the block and I had to start over. The location of these holes in (y, z) are (7, 5) – (15, 12) and (51, 5) – (59, 12). The depth of these don’t matter much, except that they go at least 25 mm.
The last hole on the front is a large square hole. This hole will hold the x-axis idler. I made this whit the side-cutting bit as well. The location of this hole in (y, z) is (20,6) – (46,25).
A final hole is drilled through the side. I’m not too sure of the location of this hole. I used the 8.4 mm bit and drilled all the way through. It’s center is about 5 mm from the bottom and about 40 mm from the front.
Update: Below is how I originally made the y-belt-clamps. These turned out to split easily, so I re-made them with a different orientation.
Next, I made the y-belt-clamps. I cut a 25mm strip of MDF. I drilled two holes into the end of this strip at (6, 6) and (6, 18) . I used a 6mm bit to give me some play room. Finally, I cut two 4mm slices off the end of it to get the y-belt-clamps. These are a little wider than needed, I just left the excess on the inside.
The last piece is the x-axis-idler. I used a 5/8 inch and a 3/4 inch dowel to create these. The best thing I came up with was to use a hack saw to cut each section off. I cut a 10mm section of the smaller dowel and two 3mm sections of the larger dowel. I then glued these together in a sandwich. Finally, I drilled an 8.4mm hole through the middle. It took me several tries to get something that was close to square. The picture below has the wrong washer.
