a project becomes a prototype

[CarvedTones]

I had something of a disaster on a workpiece last night, yet I am oddly relieved about it.

I have had this jouhikko near completion for months:

I have lots of excuses as to why I didn't finish and some have some legitimacy - for various reasons I haven't had much shop time since Spring - but there was also this nagging feeling I had that I really haven't done as good of a job on it as I wanted.

So what happened? I was cleaning up the interior using my router carriage:

with the bit extension and a mortising bit:

and I manged to go through the bottom somehow. I do need to figure out how; I thought I had the depth adjusted properly and the workpiece was well clamped (NOTE - the above is an old photo; I had it adjusted higher than that!).

Anyway, it's not the end of the world. I can cut the bottom out and put a back on it. It's often done on reproductions when period authenticity isn't important.

So now it is a prototype and I feel the odd sense of relief that I don't have to get this one perfect. The guy who wants one is in no hurry and would be happy to be able to try out a test model that he can give me feedback on and that I can make drastic changes to so I can learn how to optimize sound quality.

I think I was trying to make the leap to "Master" too quickly and this mistake is forcing me to do what I should have in the first place - make one just to learn how first.

 

[DavidF]

I have had this happen, and it was dirty collet or scarred bit that caused the bit to come out of the collet very gradually. If the cut was clean it didn't happen but as soon as there was any roughness or vibration it caused the bit to slip.

 

[CarvedTones]

I have had this happen, and it was dirty collet or scarred bit that caused the bit to come out of the collet very gradually. If the cut was clean it didn't happen but as soon as there was any roughness or vibration it caused the bit to slip.

I think that is what happened. In fact, thinking it over I am almost sure of it. I had to go back over some of it to clean up faint lines between passes. Why the alarm bells didn't go off in my head I am not sure. There should never be any lines between passes, however faint! If a pass isn't dead level with the previous one I should turn the router off immediately. :eusa_doh:

This is the latest of a number of little screw ups. but the first I can't fix. Oddly enough, I potentially could properly complete a better one before this one would have been properly completed if I hadn't made the hole, because of a number of minor fixes left to do to this one. I think the biggest mistake I made was cutting the body to shape way too soon. That took using precise jigs to do a lot of the shaping out of the picture. Too much is eyeballed because there is no perfect surface to reference. In some respects, that is period correct. Carved instruments came from billets, not boards. But I want to make use of power tools to get pretty darn close to intended final dimensions before I take over with hand tools to do the final shaping and carving. This occured to me when I was discussing the possibility of using a duplicator to rough out carvings for the side and back. The first thing I would have had to do is duplicate the surface for the carving onto a blank because the shape I have is not repeatable! Well, ehouch beating myself up. I am commited to learning from this and doing a better job on the next one.

 

[DavidF]

It's something we all learn - cut everything first before removing your reference surface, once it's gone, it's gone! It seems to be human nature to see a project "take shape" but it's never the right thing to do.

The next one will be much better by the sounds of it (no pun intended)

 

[McRabbet]

Andy,

You may want to carefully measure the shaft diameter of both your extender and your mortising bit to be sure that you have not put them too far into the collet where either collet is grabbing only the fillet where the shafts transition from shaft to bit or bit holder. I have encountered this problem in the past where the collet has enough depth to allow the fillet below the end of the collet -- a very effective way to avoid this is to drop a hard rubber faucet washer close to the diameter of the shaft size into the bottom of the collet and shafts will not seat too deep -- use two if necessary.

 

[JackLeg]

I have had this jouhikko near completion for months:

OK, I'll be first to ask! What is it!!!! I'm pretty sure that word ain't in the Stanly County library!!!

:rotflm:

 

[CarvedTones]

I have had this jouhikko near completion for months:

OK, I'll be first to ask! What is it!!!! I'm pretty sure that word ain't in the Stanly County library!!!

:rotflm:

An ancient Nordic fiddle. The guy who wants one is into early Northern European music. You would be surprised how many people are into various forms of early music.

 

[Gotcha6]

Now that you've got everyone's curiosity piqued, you gotta show us the finished product when you're done.:eusa_clap