MIMF

OOPS!
multiply by 10.

And I think Mark needs to divide by 10 unless he's doing millimeters and then he's gone too far! It must be one of those days.

Total utter failure on my first attempt to bend sides I broke it. Try again today.

Need to thin curly maple down to .070 or .080" and bend with a sheet metal backer.

Yup, I saw the decimal point infractions too. My particular curly maple at 0.125" does not work with my bending iron. I brought it down to 0.090 and was able to get decent results I'm happy with. This is the first time I used this bending iron that I purchased 2nd hand -- this is the first time I've used a fre-style bending iron It takes over 30 minutes before water will boil off using a spray bottle and I suspect that it does not get as hot as it maybe should. Combination of the wood being too thick and a questionable bending iron. It certainly will not scorch or brown wood. It did however eventually do the job. If this project is successful, I'll probably buy a new bending iron or build one.

Breaking one of my sides leads me to use some mahogany I have on hand for the second instrument. My thickness planer brought it down to 0.100 cleanly but its still too thick. I'll do a little thinning on my belt sander and finish with a scraper. I'm going to try to do a deeper body with the mahogany sides but this'll wait until I get the original first instrument fully constructed. I'm learning the process as I go.

I was fabricating the end block from some scrap and came across a hunk of what I thought was mahogany. Applied it to the band saw and instantaneously got that ugly bitter taste of spanish cedar which was not anything like what I experienced when I was thicknessing the soundboard. It makes me think that the soundboard is actually honduran mahogany as the guy at the mill said it it was.

I've decided to do a teardrop body as it improves the likelihood of success. Today will be making the headstock/top block.

"It makes me think that the soundboard is actually honduran mahogany as the guy at the mill said it it was."

Mahogany will make a much better soundboard I believe.

Too late now, but another good option for thinning dulcimer sides is something along the lines of what is sold as the Luthier's Friend Sanding Station, which is basically a drillpress-mounted sanding cylinder with a bottom bearing and an adjustable block next to it. Very easy to make if you don't want to buy one, and the cylinder/bearings are easy to find. I made one and have used it for dulcimer, mandolin, and violin sides. Not very useful for larger sides, but great for these smaller instruments.

Jim,
How solid is the drum?
I might try that with my Ryobi sander.

The drum itself is some kind of rubber, so when you tighten the bolt, it expands slightly to hold the sandpaper cylinder in place. There is a large bearing on the bottom that you fit into a like-sized hole in a baseplate mounted to the drill press table. With the spindle in the chuck, and the bearing in itsa snug hole, the cylinder is held in place and does not wander at all. You have to make sure your adjustable fence is parallel to the side of the sander, but it is easy to get nice even sides and take them down well under 0.1". If you get a suitable size PVC Y joint and cut away half of it, you have a perfect dust collector for it.

Something along these lines? I started with a similar but smaller version that I used on the drill press with small drum.

It doesn’t show here but there are 3 adjusting bolts on one end. The middle sets the depth/thickness. Top and bottom adjust to keep it Square to the drum.

That is exactly the basic idea. My version uses a sanding cylinder with bearing in a drill press, so both the top and bottom are secured, but a 1/2" shaft on a spindle sander is probably not going anywhere.

Jim McConkey wrote:The drum itself is some kind of rubber, so when you tighten the bolt, it expands slightly to hold the sandpaper cylinder in place. There is a large bearing on the bottom that you fit into a like-sized hole in a baseplate mounted to the drill press table. With the spindle in the chuck, and the bearing in itsa snug hole, the cylinder is held in place and does not wander at all. You have to make sure your adjustable fence is parallel to the side of the sander, but it is easy to get nice even sides and take them down well under 0.1". If you get a suitable size PVC Y joint and cut away half of it, you have a perfect dust collector for it.

Thanks maybe I can mod this garage resident. It looks just like Ricks!
Thanks guys

Stew-Mac carries the drums and sanding sleeves, and you can see what the real Luthier's Friend sanding station looks like here: https://www.stewmac.com/SiteSearch/?sea ... ing%20drum One of these days I need to get around to posting my homemade version.

Amazon, Home Depot, and various other sources also sell sanding drums and sleeves in variety of more economical sets by Powertec, WEN, and others.

Thanks Jim!

The Luthier's Friend Sanding Station sounds like a handy tool, especially for smaller instruments like dulcimers, mandolins, and violins. Having a drill press-mounted sanding cylinder with an adjustable block seems like a practical solution for thinning sides efficiently and precisely.

All of what we have been discussing above is essentially the same thing as a Luthier's Friend, just homemade and FAR cheaper.

Thickness sanding with the spindle sander is a really nifty idea, keen on giving that a try!

I made a jig for my spindle sander that consists of two MDF fences attached with a hinge at one end. The other end has a large bolt through the non-moving fence that serves as a lead advance screw to slowly move the other fence closer to the sanding drum. It is surprising how well this works. I can take a photo if anyone is interested. It looks similar to the Luthiers Friend but I actually built mine before that came out. I use it to thickness the back of pegheads.

Photo please .

Mine looks a lot like Rick’s.