The steamer is just a 6 foot length of 2" inside diameter black plastic drain pipe with some 1/4" wooden dowels used to support the work piece.
The form for bending the bridge consists of a set of small blocks screwed to a piece of wood along the curve that will be the eventual shape of the bridge.
After about 40 minutes the bridge is taken out of the steamer. clamped to the blocks and left to cool down and dry out for several hours.
I lust after your Powermatic jointer...
ReplyDeleteI've been going over the soundboard section of the instruction manual. I've found a discrepancy in order. Marking out in the SB section spends a lot of time on the bridge and makes an off hand remark that the tuning pin hole positions will be determined later. Well... The case assembly section had the wrest plank drilled long ago using the pin centers denoted on the drawing. Hmm.
ReplyDeleteI think that you may have misread that section - the holes for the tuning pins have, indeed, already been drilled in the wrestplank - it is the pins in the nut that get get marked and drilled later.
ReplyDeleteIt's certainly always possible I misread, but I looked it over again and think I read correctly. Here's what it says:
ReplyDelete"3. Marking out
Using the drawing as a pattern
In this step, the drawing serves as a pattern for positioning the bridge and nut, and for marking the placement of the ribs. The position of the tuning pins, bridge pins and hitch pins will be found later, also by using the drawing."
No matter and anyways since I'll be using my drill press to make the tuning pins holes, they'll be drilled before I glue the wrest plank to anything.
Regarding your bending jig - did you use it, and steam, for the other bentside pieces too? If I can remember them all, the hitchpin moulding, the false inner veneer cap moulding, the outside bottom moulding and the lid's endgrain hiding strip all have to follow more or less the same curve.
ReplyDeleteIn addition to the bridge I steam bent the case outside bottom moulding, the lid moulding and the inner veneer cap moulding.
DeleteThe bentside hitchpin moulding supplied with my kit was already bent, and I did not steam bend the the cypress inner veneer itself - that was easy enough to just bend and clamp in place as it was being fitted.
The lid and outer bottom case mouldings are easy to bend and I did use the same jig that I used for the bridge since it was close enough to being the right curve.
Bending and fitting the cypress cap moulding was the single most difficult thing that I had to do in building the entire instrument. The moulding is wider than it is high and you are trying to bend it around its larger dimension. It doesn't want to do that and it will twist if you try to bend it in the kind of jig that I used for the bridge - and just after twisting it will break ...
In the end I made a special jig just for the cap moulding. The jig consists of a piece of 1/4" thick MDF which has been cut to match the bentside curve. A second piece of MDF is glued on top of this so that it overhangs the first piece by about 3/8". The purpose of the overhang is to stop the moulding from twisting.
I still have it somewhere - I will take some picture of it so you can see what it looks like.