Official Luthiers Forum!

I located a 1 HP motor off a Craftsman 14" band saw today and the output shaft is something strange like 14 mm. Oh the joys now of locating a 14mm pulley/sheave for the output shaft. Only posting this as a warning to watch for the little things.

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Thank You and Best To All

I just download a plan of Pat.. I have a question for the DRUM, can I go with metal (aluminium) drum, that's from unuse photocopy drum, with 11cm dia and 36cm length..

Please take the following only as an observation that I find interesting. It's not something I care about and is not meant to be a complaint or whining. It's certainly not directed at anyone on this forum. It's an observation only that I think others may find interesting.

The Youtube video that Matthias Wandel of Woodgears.ca fame put up of me with my thickness sander is now up over 160,000 hits. As you can imagine, I receive email on a regular basis from all over the world asking me questions about the thickness sander. I always respond to these promptly. The thing that has surprised me is that nobody (i.e. zero) has ever responded to thank me for answering their questions. The only exception to this is when they have further questions. Then they will start by thanking me for answering their first round of questions before asking their new ones.

As I said, I don't care but I am surprised as I always thank people that take the trouble to answer any questions I have sent to them and I notice that most people on this forum do the same. Am I just old and out of touch with what is polite in this age of the internet?

Pat

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

I usually save my thanks for after I've completed a project - like in this thread.

viewtopic.php?f=10101&t=38710&start=25

And I'll do the same after I finish this project.

All I know about life is that we as human beings will see where we're looking and if ever we do something looking for thanks it can be a mighty hard thing to see - depending, again on where we're looking. I'm thinking that sometimes when I respond there's an implied thank you if not an outright declaration of same, but I do have a general 'Thank You' in my signature because I am genuinely grateful for every bit of knowledge shared on this forum.

Thank You Pat!

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Thank You and Best To All

Rather than hunt down a solid sheave with the specific bore diameter, you may be better off using a tapered-bore sheave (2-pc.). That would allow you to use the appropriate bushing. (I know that 14mm bushings are available.)
Of course, this means that the smallest sheave (pulley) you can use at the motor would be slightly over 3" OD, so you would have to use correspondingly larger sheave at the drum.
Bushings run $5-10 each. Nothing to be concerned about if you're saving a bunch on the motor.

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Always have plenty of sandpaper; it's rough out there!

Thanks so much for posting that advice Robert. I'll begin my search today for the parts you recommend. It's been a nightmare trying to resolve this 14mm issue. Again thanks very much for the advice.

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Thank You and Best To All

Public THANK YOU to Robert for some amazing help. He just sent a PM with links to the parts I needed and they are on the way as I type this. Simply amazing world we live in. Thanks again Rob, for the help.

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Thank You and Best To All

Just when you thought this thread was dead, dead, dead ...

I've taken advantage of my copious free time (thanks to COVID-19) to build a thicknessing sander of my own, mostly following the Pat Hawley design (thanks, Pat!). I've got the discs cut out and ready to bore out for the axle holes. But I have two questions/comments:

1. I notice that Pat's plan called for making your own drive pulley, but somebody mentioned that pulleys with 1" drive holes are available. Would anybody know of a source for these?

2. I've decided to go with the Velcro hook-and-loop sandpaper, and there was a mention that this was available from Woodmaster. I went to their site, but I'm not sure about what their products are.

Is this the stuff to attach to the drum itself?

https://www.woodmastertools.com/shop/ac ... ro-mats-3/


And is this the actual sandpaper stuff, with the corresponding velcro?

https://www.woodmastertools.com/shop/ac ... -150-grit/

And I guess I should ask about other suppliers for the Velcro sandpaper and base.

Finally, I want to thank all the people who have participated in this thread. It's been a real learning experience.

1” bore pulleys are available at McMaster Carr, Tractor Supply, and Northern Tool, off the top of my head.

I got my hook and loop paper from Klingspor.

I got my Velcro for the drum at Lowe’s.

Never asked Pat a question but did build a thickness sander based on seeing his.

Thanks Pat, if you’re listening.

I built one of similar design several years ago. The discs were just pressure fit over the shaft. Very tight, had to pound them on and glued them to each other as I went. No way they would ever spin. I also weed pre finished flooring for the table top. I made my dust collector/shield out of 1/4” plexiglass. I like being able to see both sides as the wood passes through. I put a dust collection port top center and it works very well. As mentioned earlier, small steps to remove material is the key.

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Brad Hall
Mystic Dawg Guitars

Well, I'm proceeding with the build ... I have the discs cut out and dry-mounted on the shaft, I have the motor, pulleys, and belt. The bench has been wired, and I'm ready to start actually fastening things together.

My thanks to everyone who has helped me, from Pat on down to those who gave me links to suppliers.

I do have one question before I start actually positioning the drum on the table. The plans don't give a definite dimension to the location of the drum, although from the plans generated from Pat's design, it looks like it's about a third of the way forward from the hinge. Was that determined to be the best position from experiment, or was that just the way it was drawn?

I built mine with a plexiglass hood. The dust port Is top center and very effective. I also feed from the side. Mine is set up at the garage door and I use a large shop fan facing outside while sanding. Dust mask also. I use adhesive backed sandpaper. The mdf donuts were very tight going into the 1” shaft. I did apply glue to each successive face. Couldn’t slip on the shaft if I tried. Nice job on yours.

......after I posted this I see I already posted with a photo. CRS strikes again.

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Brad Hall
Mystic Dawg Guitars

I used 3/4" cabinet-grade plywood, not mdf, since I had it anyway. They slipped onto the shaft a little more easily than Brad's did, but I took a friend's advice and roughed up the shaft with a file to create cross-grooves, and glued the discs on with a marine-grade two-part epoxy, gluing them together as well as to the shaft. I'm convinced that nothin' ain't goin' nowhere.

I'm now at the state where I'm truing up the drum and getting it ready for the sandpaper. But two more questions arise. (I've already PMed Pat Hawley about this, but I thought I'd pick the brains of the hive mind here.)

First, what is the preferred grit for thicknessing softer woods like spruce and cedar? And what would be the grit of choice for rosewood and walnut, which are the two main woods I use for backs and sides.

Second, I was instructed that once the wood has been touched by sandpaper, it leaves enough grit to dull planes and scrapers. I don't mind the planes, since the thinknessing sander was supposed to replace their use, but I do like to use scrapers on sides and especially on soundboards, because they do a better job of "leveling" the alternating soft and hard parts of the wood. Is it still possible to use the scrapers, with the realization that I'll be sharpening them more, or am I stuck with sandpaper for the finishing steps now?

Speaking personally I only drum sand to a maximum of P150, then go to an ROS or hand sand with a block and I haven't noticed any problem with grit left by abrasives in general.
After a brush off I haven't seen or felt anything left embedded in the wood, not at the lowest or highest grits, but I do use branded quality abrasives, not point in using anything less.
More trouble with wood/resin embedded in the abrasives

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I generally use 80 grit on back/side wood with mine (sometimes 60 with cocobolo). I get it down near final and then finish with 100 grit. With spruce/cedar, I use 80 first and final with 100 or 120. Then random orbit 5 inch with 180 or 220 for all woods.

I pretty much just use 80 or 60 grit. I don’t see my shop made sander as a means to get to my surface finish. I only use it to get (close) to final thickness and evenness. All the parts get further scraping g or sanding after they see the thickness sander. Heavy grit allows me to get there faster with less loading.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

Has anyone had experience of that?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

No, this is incorrect. Sandpaper does not leave behind grit that can't be removed either via vacuuming, blowing, brushing, etc. Obviously, you don't want to sand something and then take a plane to it without cleaning off the piece first.

I would like to reaffirm a previous post about dust collection. Please be careful, folks -- dust is a very serious health hazard. This is especially true for luthiers that work with exotic woods. You do not want any of this to reach your lungs. A good dust collector should be the very first tool that you buy and if you have the shop space - you need to be buying a high quality cyclone if you plan on devoting much time to this hobby.

Thanks for the sandpaper advice. I'd heard that bit about sandpaper and scrapers from an old cabinetmaker. It may have been true with earlier types of sandpaper, or with cheaper sandpaper. I'll try the sanding/scraping regimen and see if it really does the damage to the scrapers that I'd feared.

And I built the dust hood and attached it to the dust collector before I even started truing up the drum.

Yes, I remember glass-paper, actually bought and used it one time, terrible stuff.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Pat,
To your point, over the years here and there I have sent materials to people. Sometimes it was wood or in one case I remember I sent a guy some special potentiometers (no charge, including shipping)....Never even got a Thank You- I found it odd...

Well, there's another home-built thickness sander in the world now.

I just applied the sandpaper to the drum, which was trued up both to get it perfectly round and to test the whole drive-train and dust-collecting systems.

I would have tested it today, but I quit working on it when I started to burn my hand picking up a socket wrench. The joys of working in the Sacramento area in the summertime. But at least the air was breathable today.

At the advice of a fellow woodworker who's had a thicknessing sander for twenty years now, I've decided to go with 120 grit sandpaper. He says that if the wood is reasonably well finished to begin with, that's all he's ever used. If he has to take it down a lot, he just makes more passes. (He says that now that he's retired, time is no longer money.) But I can put whatever I want on it and change it out easily, since I've got the velcro backed stuff.

Get some 80 grit too. You'll need it for thicknessing. Resinous woods clog that 120 pretty fast. I take plates down to .125 or less with 80, then smooth it out with the 120 if you want, but usually the RO sander with 120 - 220 works OK to prep it for finishing. I use sandpaper covered, 3/4" sleds (tables), sized for back or sides, to support those thin pieces too. They can be sanded to fine tune the flatness of your drum adjustment.
Yep, the air quality was better here today too, but yesterday was baaad! Wearing a N-95 to work in the yard.