If ever you want to create a working prototype of anything mechanical, I have found that solid hardwood is the very fastest way to temporarily mount parts in a secure and safe manner.
Compared with reconstructing an entire carbon brush assembly, salvaging of the rest of the drill was relatively easy. The plastic case was loose and cracked internally, so I decided I was going to recreate the drill as a fixed motor test stand, with all major parts bolted or epoxied to hardwood
blocks, that are in turn bolted down to a hardwood surface.
The drill head also has a place to mount a carriage bolt, and so with a little careful measuring of calipers I drilled a hole in the wood surface to admit a carriage bolt. The bolt can be a useful adjustment to help ensure that the axle will move freely during motor operation.
I will enclose the test stand with hardwood walls, eventually…
The salvaged front portion of the drill, containing gear assembly and chuck.
The rear mount of the drill motor was salvaged from its original plastic casing.
The drill's motor front and rear mounts are aligned with the rotor assembly using wooden blocks to yield a skeleton view of the lathe's powered headstock.
Both the original carbon brush mount and its reconstructed sibling are epoxied to wood mounts using JB Weld.
The carbon brushes are mounted on blocks and positioned to make contact with the rotor assembly.
Stator windings assembly (center from left) is epoxied to wood mounts with JB Weld.
After the epoxy has dried overnight, the wood posts are fixed to the wood surface plate with countersunk wood screws.
A brief word about countersinking a wood screw:
A fast and easy way to do that is to use two drill bits, one a little larger than the width of the screw’s shaft, the other a little larger than the screw’s head. Most drill bits are rounded at the tip, so the larger drill will create a tapered cone where the screw’s head makes makes countact.
1) Drill smaller bit throughout thickness of mounting.
2) Drill larger bit about three quarters of the thickness.
3) Introduce the screw through the wide side of the surface.
4) The screw will automatically countersink at half its length, allowing the tip half of the screw to “bite” into the object being attached, such as a wood post.
Something I also found that I needed were shims. The force of the wood screws, as applied to the mounting blocks, can cause compression that distorts the dimensions of the parts mountings. To compensate for the compression, shims may be necessary at the rear axle mounting post and at the stator mounting posts. I certainly found that to be true in my case.
Shims are needed to position the rear and stator posts, to ensure that the motor axle moves freely.
The axle movement is not nearly as free as in the original drill. Greasing might help, as would more precise shimming.
Our next step is to test the assembly, and if we are happy with it, then to epoxy all joins.
To test, now all we need, is power…
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I love your ingenuity, but would hardwood really be up to the required safety standards? I do, however, appreciate that the wood is just a temporary measure while you perfect the set-up, prior to doing it in metal.