I hope this is going to turn into a 9" wide thickness sander

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MaineGeezer
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Joined: Wed Aug 13, 2014 12:14 pm

I hope this is going to turn into a 9" wide thickness sander

Post by MaineGeezer »

I decided a thickness sander would be a handy thing to have. Ideally, one about 18" wide that can do an entire guitar top or back would be the way to go. Unfortunately, sanders that big cost over a thousand dollars, a bit too much for me. I looked at the Byrnes miniature thickness sander. It costs $350 and can handle stock up to 6" wide. It would do for a lot of things, but it's small. After looking at the Byrnes and at online plans for building a thickness sander, I decided it was feasible. I'm going to build one that can sand up to 9" wide. That capacity will handle guitar sides, half a guitar top or back, or an entire dulcimer top or back.

"Cheap" is a major requirement, which is one reason I'm not building one 18" wide. After digging through my 40 years accumulation of jun.... er, "surplus raw materials," I've manged to come up with a design that should get me a 9" wide sander for about $150.

The sander will sit on top of my table saw and driven by the table saw motor. I'll replace the blade with a pulley and a belt coming up to the sanding drum shaft. That will save the cost of a motor. It will also slightly decrease the materials requirements.

Here's a photo of the base. The two sort-of-I-beam aluminum extrusions were shipping brackets of some kind for one of Digital Equipment Corp's VAX computers, I think. I've hauled them around for at least 25 years. I'm glad I finally found something I can use them for. The milky white plastic plate attached to them is left over from some other project I had, now forgotten. The rest of the sander will sit on top of that. The slab of aluminum sitting on top will become the uprights and hold the shaft bearings. I bought that a couple of years ago for a project that never happened.

I sure hope it works.
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Diane Kauffmds
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Re: I hope this is going to turn into a 9" wide thickness sa

Post by Diane Kauffmds »

I hope it works well. Thickness sanders are very expensive.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
MaineGeezer
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Uprights in place.

Post by MaineGeezer »

The uprights need to get bored out 1.625" diameter to accept the shaft bearings.

The sanding drum will be 3" in diameter, with a circumference of 9.42". The Plan is to use a standard sheet of 9" x 11' sandpaper on the surface of the drum. I probably could have made the drum 3.25" diameter (10.21" circumference) but the cost of materials would have gone up significantly for the increased diameter, with little gain in performance.

Or I may wind a narrow strip around the drum in a helix, as is done with commercial sanders. I haven't made a final decision yet.
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Don't believe everything you know.
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When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
MaineGeezer
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It works, mostly

Post by MaineGeezer »

I've got to the point that it's usable. It works fairly well. The biggest problem is uneven thickness. Since the stock is fed through by hand, rate of feed is variable, and that produces variation in how much gets sanded off at any one spot. Multiple passes help reduce the unevenness. A power feed may be in the works, if I get sufficiently inspired.

Here's a photo of the assembled unit with one of the covers removed to show the drum. I didn't cut the angle on the end of the strip of sandpaper quite right, so there are gaps. I have since made a pattern that I think is correct, so I ought to be able to cut the next strip and get more complete coverage of the drum.

A belt guard, and a proper-sized belt, are on the list.

I made this so it runs off the motor on my table saw, but now that I've confirmed that it works I may see about building a base and giving it its own motor.
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Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
MaineGeezer
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Joined: Wed Aug 13, 2014 12:14 pm

Difficult to get a truly flat surface

Post by MaineGeezer »

I'm finding that it is very difficult to get a uniformly flat surface. Because it's hand fed, there is some amount of variation in the feed rate, and that produces variation in sanding depth. With really coarse sandpaper (e.g. #80) it's quite pronounced.

I may see about coming up with some sort of power feed, but some of the design aspects of the sander interfere. We'll see.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Re: I hope this is going to turn into a 9" wide thickness sa

Post by tippie53 »

what grit are you using.
May I suggest 2 rollers to help hold the work down. A spring mounted rolling pin may work
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
MaineGeezer
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Joined: Wed Aug 13, 2014 12:14 pm

Re: I hope this is going to turn into a 9" wide thickness sa

Post by MaineGeezer »

I've tried #80 and #120. The 80 was quite aggressive.

I was wondering about some pressure rollers. As you suggest, something spring loaded.

One problem that I need to fix is that the part the work slides on tends to flex a bit. (The black slab in the photos.) It's some variety of plastic, 1/2" thick. I thought it would stiff enough, but it's not. I may add something to stiffen it up, like a piece of aluminum angle across its width, or replace the whole thing with a piece of aluminum plate.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
tippie53
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Re: I hope this is going to turn into a 9" wide thickness sa

Post by tippie53 »

You can make a lot of ways to do this.
having something to help hold it down is key also you can try making a sled. that way the sled pulls it through rather than getting pushed and having it bind up.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
MaineGeezer
Posts: 1711
Joined: Wed Aug 13, 2014 12:14 pm

Re: I hope this is going to turn into a 9" wide thickness sa

Post by MaineGeezer »

Update, a couple of years later.

I gave up on the idea of drivng it with the table saw motror. A friend of mine was happy to give me a suitable motor as a way of getting rid of some of his collection of STUFF, and I built a simple wooden stand for the sander.

I've gotten a lot better at feeding at a uniform speed so I get a uniform thickness. A piece can still end up a bit wavy, but generally I do well enough so it's not noticeable, or hand sanding with a sanding block takes care of it.
Don't believe everything you know.
Anything is possible if you don't know what you are talking about.
When things are bad, try not to make them any worse, because it is quite likely they are bad enough already. - French Foreign Legion
warren47
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Joined: Sun Feb 12, 2023 4:15 pm

Re: I hope this is going to turn into a 9" wide thickness sander

Post by warren47 »

I just saw this this morning. With the mention of sanding half a guitar back or top my interest was piqued. I was under the impression that top and back pieces were always glued while thick. Am I missing something?
Last edited by warren47 on Fri Feb 24, 2023 4:37 pm, edited 1 time in total.
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