Friday, February 20, 2009


So on the way out the door this morning, I felt compelled to mount my finished collet holder on the mill. Four hex-head cap screws to secure the holder into its new, freshly painted frame, two to hold it onto the mill. Annoyingly, I found that the paint I put on last night had not quite dried, so my wrench left a few circular divots. Grumble. Will I never learn to be patient?

Then I found that the mounting surface - the casting which makes up the mill body - is not perfectly flat, so my base plate doesn't and won't lie flat unless I drill and tap another hole. Well, I just might.

The thing wiggles just a little - not as much as it did when sitting on the original bent 'L' bracket of 1/4" aluminum - but it bugs me that it wiggles at all after all the effort I went to. Functionally it doesn't matter that it wiggles, it just bugs me. I may modify it to get the wiggle out. I'm hoping most of the wiggle is due to the base plate not lying flat and therefore being able to bend in and out a bit at one end.

Castings aren't perfectly flat? WHO KNEW?? Ah fuck it, I'm still pleased with how it turned out. I'll put up a picture later maybe.


Next thing I'll be working on (aside from a pile of household chores which have been neglected due to both of us feeling oogy for weeks) is the insulating bushing for the copper pipe fittings which will make up the mounting for the Jacob's Ladder for the steampunk/Mad Scientist light switch box. I needed a chunk of 2" diameter x 1.5" long PVC from which to turn this thing. I didn't have any round plastic bar stock that big, but I did have a scrap of 0.5" thick PVC, so I cut out three ~2" circles from it and glued them together. I used primer on the surfaces (softens the surface a bit) before the PVC glue. Then I stuck it in the bench vice for three days.

The $64,000 question is how long it will take for the solvents in the areas away from the edges to diffuse into the plastic and eventually make their way to the atmosphere. I know that the primary solvent in PVC glue - tetrahydrofuran - is an astonishing solvent with great penetrating ability, so it is my fervent hope that I won't have to wait a month to start machining this thing. But PVC glue also contains acetone, MEK, and maybe one other solvent, and I've no idea how long it will take for them to be gone.

The last thing I want to have happen is for me to stick this thing in the lathe chuck, start turning it into an actual cylinder, and have it fly apart because the glue hadn't dried. In theory, once the glue (which after all is just PVC dissolved in solvents) has dried, it will all be one big solid chunk of homogeneous PVC, minus bubbles which I tried hard to avoid while assembling the pieces. Hmm. Maybe I should wait another week. I wish I knew of someone who has tried this trick...

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