| <"Really tight" isn't necessary - "properly aligned" _is_ necessary;
| because the pocket hole screw's threads _should_ all be in the part
| screwed "to" - this is controlled by setting the drill stop collar
| correctly and using screws with the proper thread length. Clamping
| the parts "firmly" is adequate.>
| I checked all of this , but it seemed that the alignment results
| were still
| inconsistent. What I'm making is boxes about 12" X 18". I want the
| and bottoms to extend slightly beyond the sides. The only way I
| can do
| this is to put a shim under the part that is being drilled into
| first with very
| firm clamping (not "tight", exactly, as you say) and I'm getting
| good results though not perfect. It seems to be the slight
| variance in the final amount of torque that makes the difference,
| even the shallowest angle is still an angle and will tend to shift
| the pieces.
This might be the wood's way of telling you that it'd prefer to be
doweled and glued.
| <You can buy Acme threaded rod stock>
| This is good to know, but which elf presses the swivel pad onto the
| end of the rod?
The cold elf holds the rod while the hot elf pops on the pad. :-)
| Maybe a machinist friend of mine has an acme tap. If they used the
| thread on
| 1930s cars anywhere he probably does. Then I could buy cheap clamps,
| cut away
| the body and make my own plates.
I dunno - perhaps. I think Acme threads have been mostly reserved for
machine tool adjustments and clamping devices. My 3/8" Acme tap set me
back about $65 (as compared to $4 for my most recent standard thread
tap). You might be able to find a better deal on eBay...
I disassembled a HF 3/4" pipe clamp this morning. The crank handle
with threaded rod separates easily from the pad casting when a
retainer pin is popped out. If you can find a matching nut, then you
might be able to braze the nut on a (predrilled) mounting plate; and
you could probably make a swivel pad out of aluminum or even wood -
reattaching it to the rod with the same pin.
On the third hand, you could consider installing a Propel nut
(available from LV and other places) where the mounting plate would
go, and use a 1/4-20 allthread with a threaded knob and jam nut on one
end and a "make-do" wooden or plastic pad on the other. This is
probably the least expensive way to find out if your clamping strategy
will work the way you want it to.
DeSoto, Iowa USA