Chandler plans question

Don Harris · #1 05-23-2007, 03:32 PM

I finished making my beautiful templates and then noticed when flipping my "half of the front" template to the other side of the plans that the "center line" does not run down the center of the neck block, and that the way I've made the template, there will hardly be enough room at the top of the neck block for the neck mortice. Any explanation for that...? Matthew or 1st Bass? I noticed that the Amati plans are the same. On the rest of the drawing, the center line seems centered.

Also, I went to Kinkos to make a couple large format copies of the plans to spray adhesive on to plexiglass for cutting out templates and when I put my finished template on the original plans it was about 2.5mm long! Both copies were distorted lengthwise. Argh. I've made adjustments but the only thing is the corner on the upper part of the "c" is a couple mm high (toward the neck). I think I can live with that if the neck block problem is ok.

1st Bass · #2 05-23-2007, 03:56 PM

How far off is it? I only had the William Tarr plans, and they seemed pretty good. One thing is that the front and back are both on the plans, and the lines are not the same...you have to look pretty carefully. I will go back and look, but I suspect you may have lined up on the wrong line, so to speak. At one point I thought the print was wrong, and called Peter-- he explained what I was seeing, and it turned out the print was right-- I was confused.

The neck block on many basses tapers to nearly nothing on the sides at the top. Some basses have a little ledge, and the maker installs a cap there, of ebony or some other hardwood. But I have repaired basses in which the neck block tapered to zero on the sides, and the ribs are all that you see on the outside--and the caps are not needed.

On my bass the little cap rails are about 6mm thick or a little more, at the bottom, tapering to 4, or maybe a little more at the top. But the block is quite massive inside...there is no lack of strength.

I traced my patterns onto large sheets of tracing paper I bought at an art-supply store, and taped end to end to make them big enough. It was tedious, but it did avoid distortion. One thing to bear in mind is that the "standards" are a little more relaxed in the world of basses than they are in violins. Which is a good thing in my case. :-)

**Matthew Tucker** · #3 05-23-2007, 06:11 PM

Yes. The neck block width at the front is a different width to the back. use the wider measurement for the front and the narrower for the back. I made my template to the back size, then when tracing the front outline I made another small template just for the upper bout to the wider line.

A few mm distortion won't matter as long as you are consistent.

Don Harris · #4 05-23-2007, 10:30 PM

Thanks, 1st Bass and Matthew. I'm reading Chandler's book again and see where the front and back are different to allow for the tapered mortice and are drawn on the different halves of the plan. I guess I've already made a nice back template and will make a small one for the upper part of the front outline like Matthew said.

Don Harris · #5 05-23-2007, 10:36 PM

Hey 1st Bass, did you bend the sides on a pipe or use a heat blanket?

1st Bass · #6 05-24-2007, 08:29 AM

I made a bending iron of a 10" section of Aluminum pipe. I capped one end with a perforated plate, and welded a crossbar of aluminum plate inside the other end to fasten in in my vise. I bent a piece of steel wire to make a bracket that would hang from the inside crossbar and support a propane torch to get it hot.

One torch takes about 20 minutes to get it hot, but then will keep it hot just fine-- two torches instantly run out of Oxygen and go out. I guess the perforations in the top need to be bigger, to allow a faster flow of air. :-)

Incidentally, I had a friend mash the pipe a bit in a press, before I did any welding, to produce an egg-shaped pipe. It works well. I made my bendng strap of aluminum flashing with wooden handles.

**Matthew Tucker** · #7 05-24-2007, 02:51 PM

My bending pipe has two 40-watt lightglobes inside in ceramic fittings. Amazingly, it gets hot quickly, evenly, and bends ribs just fine. But I prefer the heat blanket.

Don Harris · #8 05-24-2007, 04:55 PM

Thanks for the info. Matthew, if you did it over again, would you still do the bend right on the mold for the upper and lower bouts, or build a dedicated form to support the whole width of the ribs?

Don Harris · #9 05-24-2007, 10:02 PM

Just about finished with the arching and f-hole templates. Waiting for some rib wood from Orcas Island Tonewoods. Already bought a couple sets of sitka spruce tops for cheap (because of pitch pockets). On one set I can completely avoid the pockets, on the other I'll get some grafting practice. I've been surfacing the bottoms with a hand plane. I'm going to wait a few weeks before jointing them to let them acclimate to the dry Colorado climate. I'm hoping to start on the mold tomorrow.

**Matthew Tucker** · #10 05-25-2007, 05:58 AM

I think bending onto the mold is fine, you just have to support the rib where the curve changes direction. a few cross-pieces are fine. Others use thin metal or perforated metal nailed to the mold, you can allow for that extra .5mm or just ignore it. You need to do a dry run with your clamps to make sure the clamping holes are in the right positions.

JKoehler · #11 01-31-2008, 10:04 PM

Hey everyone. I`m new to the forums and wanted to ask about Peter Chandler`s templates. It`s concerning the template for the back and top, I just want to make sure I have it right. The 1/2 template on the right or treble side is for the back and the template on the bass side is for the top, the very upper portion of the bass side template. I`ve made some violins, and want to get into making basses. It`s the same basic principle, but bigger! I`m really looking forward to starting this project, but I need to get done restoring a 20`s Juzek swell back bass. Thanks.

1st Bass · #12 02-01-2008, 07:22 AM

I don't have the plans right in front of me, but the side that has the button is the back-- the side without is the front.

Which plan did you buy? I sort of wish I had bought them all, but I was so sure that I would not use them all, I only bought one, and now have ordered another. (I used the Tarr model for my first bass, and am using it for the second, but have ordered the Panormo model for a future attempt.)

Chet

JKoehler · #13 02-01-2008, 06:13 PM

I have the Panormo and Gofriller templates. I`m going to keep faithful to the Panormo plans, but maybe change the upper bout a little of the Gofriller. I have a few places I know for wood, but are there wood dealers that sell European hard woods in America? Maybe I will check out Orcus Island and see what they have.