Machine Shop Activity

I've been making some of the parts for ScopeRoller caster assemblies using a friend's thickness planer, because I can plane Delrin down to .99" +- .007" with it pretty easily. It doesn't do a spectacular job--tending to produce some waviness at the end of each piece (which I then cut into two or three parts)--but I'm using scrap Delrin that I bought for $1 a pound, so I don't much mind.

Last year, I borrowed his planer, and made what seemed like an excessive number of parts, but sure enough, they have all shipped out the door! A customer email today:

The wheels for my GM-8 have arrived (i.e., the "big wheels" version). They fit perfectly and I really like them! They are both larger and stronger than I was expecting. Also, the brake lock works better than I was expecting. Thanks much; I'm very pleased.

Well, last night I tried to do it again, but in the meantime, the part that locks the blades in position had broken, so it really didn't work anymore. I considered buying a used thickness planer off Craig's List for $100, but when I stopped at Home Depot on the way home they had a Ryobi 13" thickness planer for $199. Brand new, with a warranty! I couldn't resist.

And my, does it work nicely! No waviness at all. It produces a nearly machined finish, and the height adjustment is much better than my friend's planer. Each rotation of the adjustment knob is 1/16", and there are 64 divisions on the knob, so that you can theoretically make adjustments of less than 1/1000th of an inch. In practice, because of the coarseness of the thread on the adjuster, and the somewhat approximate positioning of the blades, I don't think it is realistic to get better than 1/500th of an inch accuracy on the cut, with a tendency to leave an extra .002" to .005" in the middle of these pieces--but that's certainly good enough for what I need to do.

The lack of waviness also means that the scrap ends that I used to throw away are sufficiently uniform in size and appearance that, with a little bit of trimming, they become part for another product that ScopeRoller sells.

I've read that Ford was quite specific about the wood, quality, and finish of the crates in which subcontractors shipped engine parts to him. The reason was very simple; having removing everything from the crates, the crates were turned into Model T floorboards. Wood that wasn't good enough was shipped to some cousins, who made it into Kingsford Charcoal. (I think "Kingsford" may have been hyphenated at one time.)

Waste nothing; use everything. (If only there was a market for Delrin and UHMW polyethylene shavings.)

Another nice feature of this thickness planer is that has a 2 1/4" dust exhaust, so I can plug a shop vacuum into the end, turn the vacuum on, and as I plane the Delrin, most of the chips get sucked up by the vacuum. (Not all, but it is still less of a mess to clean up.)

The Central Machinery model 43389 16 speed floor drill press with which I have been so impressed? Last September, the on/off switch broke. I called Harbor Freight, who imports the Central Machinery brand. The switch cost me all of $1, but the shipping came to about $12. I guess that I should have bought more switches. It broke again.

The good news is that it always breaks in the on position, so I can turn it on and off by just plugging and unplugging, while I wait for parts. When they open on Monday, I think I will request three switches this time, to spread the costs of shipping over more switches.