Thickness sander

[Doug Shaker]

I've started to think about thickness sanders. I am thinking I would like one, but I have a bunch of questions.

What is the most useful size? The price goes up as the bed gets wider, but when is more width just a wast of space and money?

Has anyone tried building one? I have plans from an old copy of Fine Woodworking for building one, but does this really yield a useful tool? Or is it just a stop-gap measure that I will want to replace when I have the cash to buy a commercial unit?

Any thoughts?

[Charlie Schultz]

Moved to "Tools & Jigs"

If you haven't already checked out the library, there's some food for thought here: http://www.mimf.com/ksearch/ksearch.cgi ... y=50&all=1

[Bob Gramann]

I built one. It was manual feed and required a fair amount of effort to use it. I replaced it with the 18 inch open ended Delta 31-255x many years ago. It's not perfect, but it's pretty good. I can get reliable, repeatable results with it. I use it all of the time, mostly for plates, sides, and braces. I could get along without it using hand planes instead, but If I didn't have it, I would buy it again. I run 100 grit paper in it and just take my time rather than making the deep scratches that result from more aggressive paper.

[Doug Shaker]

I guess I should specify that I am primarily interested in thickness sanders from the viewpoint of a builder of flat-top acoustic guitars.
I would use it mostly for soundboard, back, side, and fretboard dimensioning.

[Bob Hammond]

The other specification is the price range. A commercially built sander can be a significant cost but it can be a good investment if the volume of work justifies the cost. If the volume is low and/or the cost of a commercial sander is prohibitive, it's possible to build a sander than produce acceptable results at the expense of the time to build it and the time and effort that is spent operating it.

[Michael Imbler]

Doug, I have the 10/20 size, and find it adequate for the classicals I build. With unlimited space and money I'd probably spring for the 16/32 size, but really with a little set up, the 10/20 is fine. You just have to run the back and top through twice as many times as you are doing 1/2 of the width each time through,
Mike

[David King]

If I had to start over again I'd probably get the 16" Jet/Performax/Shopfox. It's nice to have a little extra width as you can loose 3" on the right if the paper starts to overlap as it gets loose. The overlap will burn the crap out of your wood.

[Nate Scott]

I built mine a few years ago in order cut costs and because I wanted to make it wide (24" drum) and to include a few other customizations. Without a power feed, it does require a little more effort and technique, but I don't mind it. I just go slow and feed at a consistent rate. With no power feed it's also possible to push stuff through at an angle, which seems to cut more aggressively. I use the sander a lot - more that I predicted, and I'm happy with how it works. I occasionally think about adding rollers to keep the stock flat on the table (wide thin tops can lift at the edges a little), but so far it's not been an issue.

I would build it again if I needed one.

[Bob Hammond]

Before I forget, I saw a vid of an industrial sander that has the belt's path is skewed from the stock feed path. This prevents lines/gouges from a defect of the belt (or does it just spread it across the entire surface?). I think the offset was adjustable from 0-10 degrees. I suppose that this could be designed into a shopbuilt machine, but the initial setup could be tricky.

Nate, I think that a bicycle chain & weight system that draws a sled through the sander could relieve some of the effort and also provide a constant rate of feed. I'm thinking that the chain would be an endless loop that runs in a groove, and the sled and weight would hook onto the chain for each pass. This system would do away with a fussy belt and roller feed.

[Paul E Buerk]

I seem to remember this topic coming up before, so it might be worth a trip through the archives. I'd just emphasize the need for dust collection as a requirement, not just a nice to have.

I've got the Delta, and it's a solid OK. The 18" Width works well for me, allowing me to run the entire top or back through. I don't particularly like the table height adjusting drive and find myself contemplating replacement of the belt system with a chain and sprocket. It's not a huge deal, but it does require occasional checking and adjustment to make sure that everything is still aligned properly.

If the Grizzly units had the drums similar to the Delta, then I probably would have gone that route. A double drum 18" closed end might be the ideal, but I didn't find one out there.

[Bob Gramann]

The open end allows you to run a back through sideways (in two passes) to rough off material. Running sideways generally keeps the oily woods from gumming up the paper.

[Nate Scott]

Good thought on the chain feed, Bob. It could be designed to still allow manual feeding for things like shaping bridge wings.

I agree that dust collection is not optional on this one.

[Bryan Bear]

Keep in mind that I am a hobbiest with limited production. I made a thickness sander several years ago and if it disappeared, I would make a new one. It was dirt cheap to make and I could choose the size and set up. The manual feed is tedious and it takes a long time to use but the results are accurate. Never having used a commercial sander, I suspect the time needed to thickness a plate would be similar (you can only take off so much in one pass). A manual feed is certainly more taxing on your mind though. You can't just put it in and meet it on the other side over and over again. You have to push and pull it through taking care to keep the feed as consistent as possible and ensure that you aren't sniping the ends. That really adds to the tedium. After a while you get used to it and you develop a bit of technique.

[Clay Schaeffer]

I have a Ryobi 16/32. I bought it used several years ago. It has some minor problems with the switch, and putting paper on is a bit of a pain, but for my level of woodworking it has been a reasonable investment.
If I had to buy something new (@$1000+) I would seriously consider making one.

[Gordon Bellerose]

I built one. It was manual feed and required a fair amount of effort to use it. I replaced it with the 18 inch open ended Delta 31-255x many years ago. It's not perfect, but it's pretty good. I can get reliable, repeatable results with it. I use it all of the time, mostly for plates, sides, and braces. I could get along without it using hand planes instead, but If I didn't have it, I would buy it again. I run 100 grit paper in it and just take my time rather than making the deep scratches that result from more aggressive paper.

I have the same sander, and it works very well for me also.
There are some woods that it is better with than the planer.

The open end means that you can sand things up to about 34 inches wide. Delta claims 36, but that might be stretching.
With an 80 grit paper you can really hog off the wood. I use mine with up to 220 grit, but mostly with 120.

[Martin Keith]

+1 from me on the Delta 18/36 - I consider this one to be the only small thickness sander worth having.

The Jet / Powermax and other comparable units all suffer from the same design issue, which is that
the drum assembly travels for making thickness adjustments. This makes it basically impossible for it to be rigid enough to sand to any kind of tolerances. I've read many reviews of the Jet / Powermax units where folks said they had to adjust the drum-to-table parallelism PER SPECIES depending on how hard the wood is, and how much they were cutting per pass. This, to me, is inexcusable. Having the drum and motor traveling up and down seems like a recipe for non-rigidity.

By contrast, the Delta houses the drum in a welded steel box frame, and moves the conveyor up and down. That's much better, but even the Delta has visible deflection on the outboard end when taking a reasonably heavy cut. I've used 2 of these extensively and they both have the same issue.

My solution is to close in the open end with a 1/4" thick aluminum plate.
I bend it to a mild "Z" shape to accommodate the offset between lower base and upper arm,
and bolt it to the sander with ten 1/4"-20 bolts and nuts, tightened hard.
See pics.

The plate was a bit fussy to make but can be built with just a drill press and bandsaw if necessary.
I bent the plate using 8/4 mahogany as a platen and a 3/4" aluminum rod as a fulcrum, and then deflecting it with 6" C-clamps. Works great and is very controllable. The hardest part is spotting and locating the clearance holes for the factory bolt heads, but even that is not that bad.

The only downsides - you need to remove this plate if you ever change the conveyor belt, but that only happens every 6-8 years unless you abuse it. I never sand anything wider than 18" so it will never be an issue for me. But, if you had to, you could just take off the plate and do the job, then replace it.
10 nuts/bolts is not that big a deal to take on and off. Also, you can't peek into the end to spot how far the drum is from the part when adjusting for your first cut, but that's a small price to pay.

The advantages: the machine gets MUCH more rigid and sanding accuracy is considerably improved.
Both sanders I've modded have been quieter and seemed to have more available power - I think some HP was getting lost to flexing the arm back and forth. I put a dial indicator on the arm before and after, and even without a part in the machine the arm was vibrating quite a bit - .010" to .015" of horizontal movement. Couldn't easily measure the vertical axis. After installing the end plate it went down to about .001 - .002". Big difference! The parts come out flatter and more even side-to-side.


This has really improved the Delta machine and I now feel I'm doing about as well as I can without going to a widebelt. The materials are cheap and you can do the mod in about 2 hours if you plan ahead.
I definitely encourage anyone with the Delta sander to consider doing it.

Cheers!
Martin

[John Steele]

I have a Royobi 16/32 that I purchased new years ago. Besides the overall PITA of changing paper, it has filled many trouble free bags on my dust collection. I believe the feed belt is about ready for replacement. Prior to that I had a shop made. The power feed proved to be a major benefit.