Attempting to Build a Drum Sander

[Jeff Ransom]

Hello all, I am in the planning stage of building a drum sander. My question is what would be better to use for the roller, something heavy or lite? what I have in mind is a roller from a printing press that is 31" long 3" around and weighs 30 lb (see the attached pic) The base for this machine is the metal table you see in the pic and I will be using a 3/4 hp 1725 rpm motor.

If I use a heavy roller I would think that the momentum once it has gotten up to speed would be more consistent and stable.

Any advice would help Thanks.

[richard poitras]

I just sold my 16/32 performax sander and it had an aluminum drum about 5’’ in diameter so I think the roller you are considering would be to heavy and too small in diameter? But let’s see what others think…

Richard

[Van Huskey]

I just sold my 16/32 performax sander and it had an aluminum drum about 5’’ in diameter so I think the roller you are considering would be to heavy and too small in diameter? But let’s see what others think…

Richard

+1 something lighter and a larger diameter. The larger diameter s more important to me since a 3" ha a lot less sandpaper so changing would be much more often which can be a pain. The heavy wouldn't be too much of an issue as long as it is secured well at both ends, if you are trying to build a teo pass machine like the 16/32 then it could be a serious ssue. but I doubt you are.

[Chip Lindley]

Think BIG! A larger diameter drum (5", 6" or even 8") gives you much more sandpaper area to do work with. You would be happer and get more sanding done, going that route.

If you plan on sanding panels, think much larger than 3/4 hp. (at least 2hp) Drum sanders must overcome much friction, and enertia of the spinning drum is of little help. Sheer horsepower is needed! Continually pushing a lite motor to it's max will soon cause it's failure.

You might as well conjur up your own conveyor system while you're at it. Shoving boards or panels through by hand will become *old* in a hurry.

[Scott Hildenbrand]

I'm not going to say too heavy, because I don't think that has any factor in it.. In fact, a heavier unit would hold momentum more than a lighter one..

However, like Chip says, larger in diameter would be better as you'd get more paper to the part.

Are you planning on having a feed system? If so, you might have a use for those 3" rollers after all.

[Mike Reinholtz]

Hi Jeff,
I'm in the process of building a drum sander as well, maybe we can help each other avoid some mistakes. I've been doing research into how these machines being built and have decided to use 6" machined conveyor rollers for the drums (dual drum machine). To spin the conveyors I picked up a 5 hp farm duty 220V motor and ordered pulleys to match the drum FPM of production units. I ordered a couple cheap conveyors and spun them on a shaft with pillow blocks bolted to my workbench (makeshift lathe) and found they weren't straight enough.
For the conveyor I'm using a 1/2hp DC gear motor, with the right controller these allow for infinite speed control of the belt. These motors are not cheap but can be found occasionally for much less (I found mine at Industrial Liquidators). There are some machines out there that use sanding belts for the conveyors, so I'm following suit and starting with a 120 grit 37"x75" belt. These are widely available online in many sizes and can be had for much less than a rubber conveyor.
I wouldn't worry so much about the weight of the rollers as I would about the wall thickness of the pipe it's made from, if it's thin and defects your surface won't be flat. Also if it's too thin I've heard they expand too much from the heat. As for your motor, unless you are making a really small machine I think you might end up needing something bigger. If you need one, I have a motor sitting on a shelf not being used (either 2 or 3 hp, can't remember).

[Al Deutscher]

Hi Jeff,

I built one of those beasts (sanding/thickening) drum sander. I tried a 3/4 HP 115 VAC motor and found it wasn't enough. I had to go to 1 HP 115 VAC motor at 2450 RPM to sand with my 4 3/4 inch diameter x 27 inch wide drum.

For the drum, I used 3/4 inch MDF glued together with a 3/4 threaded rod through the center. It works well, for me.

Good luck, you'll love it when done.

Al

[M Toupin]

I built a 30" with a 7" drum and 5hp. it works very well and never slows down, but I don't think I'd go much smaller on hp if at all.

The 3" drum you have might be a good starting point for your drum, but as others have said, 6-8" is a much better option.

Mike

[mreza Salav]

I have built one too and is documented here (you can find it).

Do research on the commercial ones and use their experience :)

As for drum size, 3" is way too small. I'd say 5" or so is the good size.
As for motor size, mine is 2HP and I can easily stall it if I take too deep cuts.
I'd say anything below 2HP is not good for anything wider than 15" or so.

If you are going to have a power feed (conveyor) pay enough attention to how to adjust the rollers to control the conveyor stay on track; otherwise it will shift to left or right in no time! Mine works perfectly (I have 4 screws on the four corners of the rollers that I can adjust). This is also used to adjust the tension on the belt.

I'd say, also pay enough attention to the method you are going to secure the sand paper to the drum. You want to make sure it doesn't slip during operation.

good luck!

[Eddie Darby]

You might want to look at a different style of drum sander called the "V" drum sander.
The site has some videos and a FAQ page that will help you.
They use small diameter drums made of PVC and velcro for holding the sandpaper on, so changing is easy.

http://www.stockroomsupply.com/

http://www.stockroomsupply.com/Drum_Creations.php

http://www.theonlinewoodshow.com/show/company.php?number=20102&cat=1

http://www.stockroomsupply.com/infopages/DrumSanderInfo.php

In the FAQ section they talk about using Velcro on a thickness drum sander. There is a bit of a learning curve here as with Dremel moto tools when they first came out, as most people are use to forcing things, and these tools rely on the high RPM's doing the work.

Some people also attach a sanding disc on the end of their sanders shaft.

[Jeff Ransom]

Thank you all for great advice. I really like the v-drum design (thanks Eddie) and the idea of putting a disc sander at the end of the shaft. I guess its back to the drawing board and rethink my design.

Does anyone have a diy disc sander plan or where to purchase a disc that will go on the end of the shaft?

[Eddie Darby]

You are welcome.



Most places that sell disc sanders will sell you a replacement disc.

[Rod Upfold]

In ShopNotes #86 they built a drum sander - it might give you ideas.


Rod

[Scott Hildenbrand]

Might also search Lumberjocks and see what they posted up.. I searched the projects yesterday (since you perked my 6 year old want of doing the same thing) and saw at least 5 that were really well done and 15 or so all together.

[Brian Backner]

One of the things to consider when designing any kind of big sander is heat disipation. Wide belt sanders are probably the champs at this - by running the belt between two (or even three "drums" - the actual drum and one or two idlers) the belt travels through open air to allow the heat generated by the sanding to disapate. Also, by being flexed twice, the sawdust tends to fall off, causing far less loading and therefore markedly reducing belt clogging and burning.

How does this apply to drum sanders? I think one should try to devise ways to handle the heat. The best drum sanders have massive, 6" or even 8" diameter steel or aluminum drums that act as heat sinks to draw heat from the sandpaper. Such a design is almost mandatory as the sandpaper can never flex to shed sawdust. I've seen one or two designs that use a compressed air "curtain" to both blow sawdust from the drum as well as cool it somewhat.

Just my 2 cents.

Brian
Taxachusetts

[Jerome Hanby]

Nick Engler also built one in his book (http://www.amazon.com/Sanding-Planing-Techniques-Woodworking-Companion/dp/0875965822/ref=sr_1_1?ie=UTF8&s=books&qid=1264429159&sr=8-1)Sanding and Planing: Techniques for Better Woodworking (The Workshop Companion) (http://www.amazon.com/Sanding-Planing-Techniques-Woodworking-Companion/dp/0875965822/ref=sr_1_1?ie=UTF8&s=books&qid=1264429159&sr=8-1)

It has an option to be powered on a Shopsmith. I was originally planning on using his plan along with the one in Shopnotes as a guide, but I'm thinking 24" width would be much more useful which would increase the weight to the point that lifting it on to and off of the Shopsmith would become too much of a chore. Plus, spinning that size drum with a 1 1/8 HP headstock might be asking too much. Standalone option opens the door for more features like a powered conveyor belt and multiple drums.


In ShopNotes #86 they built a drum sander - it might give you ideas.


Rod

[Paul Steiner]

Everyone must hate sanding as much as I do, everyone is building a drum sander and so am I. I have the shop notes 86 plans they are really good but... I am not going to use my tablesaw to drive it, and I am wondering about alternatives to making my own drum. Also theirs is only 16" why not shoot the moon and make a 24". I am probably going to adapt the shopnotes plans and have at least a 20".
For drums I am thinking about 2 ideas. 1 is buying a drum kit from stockroom supply. The other idea is cannibalizing drums off old craftsman belt sanders. Currently I have 2 belt sanders thats a total of 2 drums like the attached. The run on 1/2" bearings I think if I can hold everything in place it would work. Please let me know what you think!

[Eddie Darby]

One of the things to consider when designing any kind of big sander is heat disipation. Wide belt sanders are probably the champs at this - by running the belt between two (or even three "drums" - the actual drum and one or two idlers) the belt travels through open air to allow the heat generated by the sanding to disapate. Also, by being flexed twice, the sawdust tends to fall off, causing far less loading and therefore markedly reducing belt clogging and burning.

How does this apply to drum sanders? I think one should try to devise ways to handle the heat. The best drum sanders have massive, 6" or even 8" diameter steel or aluminum drums that act as heat sinks to draw heat from the sandpaper. Such a design is almost mandatory as the sandpaper can never flex to shed sawdust. I've seen one or two designs that use a compressed air "curtain" to both blow sawdust from the drum as well as cool it somewhat.

Just my 2 cents.

Brian
Taxachusetts

Perhaps you will benefit from seeinfg this demo video of the "V" Drum Sander. No Heat!

http://www.theonlinewoodshow.com/show/company.php?number=20102&cat=1&prod=drumdemo

[Greg Portland]

Eddie, you seem to like promoting the V-drum sander on this forum. How does this design ensure even sanding across the surface? This looks like it operates similar to a jointer except the infeed and outfeed tables are not skewed? As we know, a jointer cut does not result in a board with even thickness. With the 'hump' of the sanding drum in the middle of the table would this not cause divots, trenches, etc. in the sanded surface? There is a reason that conventional drum sanders have a feed belt and reference surface. I'm confused about the accuracy that is possible with this DIY design.

To OP: definitely go with a 6"+ drum diameter.

[Brian Backner]

[QUOTE=Eddie Darby;1323537]Perhaps you will benefit from seeinfg this demo video of the "V" Drum Sander. No Heat!

How can you say "no heat?" Sandpaper against wood generates friction and friction means heat. Friction/heat would be directly proportional to a number of things: width and depth of sanding, rotational speed of the drum, stock feed rate, degree of loading (how much sawdust is already stuck to the paper on the drum, grit of sandpaper, and probably a half dozen more things.

IF you're trying to make an argument that sanding with a V-drum generates "no heat," I would like to know what, specifically, about its design and/or use either limits the generation of heat or, alternatively, facilitates such rapid heat dissipation that it's build-up is unnoticeable.

Brian
Taxachusetts

[Frank Warta]

How does this design ensure even sanding across the surface? This looks like it operates similar to a jointer except the infeed and outfeed tables are not skewed? As we know, a jointer cut does not result in a board with even thickness. With the 'hump' of the sanding drum in the middle of the table would this not cause divots, trenches, etc. in the sanded surface? There is a reason that conventional drum sanders have a feed belt and reference surface. I'm confused about the accuracy that is possible with this DIY design.

So after watching the video what they claim is that they keep the drum just bellow the surface of the table. Relying on the "loose" bond created by the hook and loop (velcro) to stand the loops up under centrifugal force and raise the paper above the surface of the table. This explains why they don't worry about the "hump" but it doesn't explain how as the piece exits the paper, presumably thinner then it entered, it would not skew the piece slightly out of square with each pass. I guess you could carefully only put pressure on the in-feed side of the piece but I would imagine that would just lead to snipe instead.

As to the question of heat, he makes the same claim that since the paper is basically "floating" above the roller the airspace between the paper and roller allow the rotation speed alone to keep the paper cool.

I'm not sure this is really the equivalent of a true drum sander. It seems like it may be useful in some sanding applications. I would be very worried about the quality of the results, but I'm new to woodworking so if I was you I wouldn't trust me.

[Jerome Hanby]

Wont swear to it, but I think some of the projects on the v-drum site show the hardware being used for an overhead drum sander...


So after watching the video what they claim is that they keep the drum just bellow the surface of the table. Relying on the "loose" bond created by the hook and loop (velcro) to stand the loops up under centrifugal force and raise the paper above the surface of the table. This explains why they don't worry about the "hump" but it doesn't explain how as the piece exits the paper, presumably thinner then it entered, it would not skew the piece slightly out of square with each pass. I guess you could carefully only put pressure on the in-feed side of the piece but I would imagine that would just lead to snipe instead.

As to the question of heat, he makes the same claim that since the paper is basically "floating" above the roller the airspace between the paper and roller allow the rotation speed alone to keep the paper cool.

I'm not sure this is really the equivalent of a true drum sander. It seems like it may be useful in some sanding applications. I would be very worried about the quality of the results, but I'm new to woodworking so if I was you I wouldn't trust me.

[Danny Burns]

[QUOTE=Eddie Darby;1323537]Perhaps you will benefit from seeinfg this demo video of the "V" Drum Sander. No Heat!

How can you say "no heat?" Sandpaper against wood generates friction and friction means heat. Friction/heat would be directly proportional to a number of things: width and depth of sanding, rotational speed of the drum, stock feed rate, degree of loading (how much sawdust is already stuck to the paper on the drum, grit of sandpaper, and probably a half dozen more things.

IF you're trying to make an argument that sanding with a V-drum generates "no heat," I would like to know what, specifically, about its design and/or use either limits the generation of heat or, alternatively, facilitates such rapid heat dissipation that it's build-up is unnoticeable.

Brian
Taxachusetts

You are correct, all friction creates heat!

[Eddie Darby]

Eddie, you seem to like promoting the V-drum sander on this forum. How does this design ensure even sanding across the surface? This looks like it operates similar to a jointer except the infeed and outfeed tables are not skewed? As we know, a jointer cut does not result in a board with even thickness. With the 'hump' of the sanding drum in the middle of the table would this not cause divots, trenches, etc. in the sanded surface? There is a reason that conventional drum sanders have a feed belt and reference surface. I'm confused about the accuracy that is possible with this DIY design.

To OP: definitely go with a 6"+ drum diameter.

I have a unit and it works great!!! That is why I am promoting this unit, so others can benefit too. I am in no way connected to or receive any compensation for doing so.

Some people have made "V"drum sanders with an off-setting tables like a joiner. I remember Paul Moore mentioning this, but I can't remember the answer except that it was not necessary.

If you look at a #8 bench plane, used for making joints, you will see the same configuration. A straight flat surface with a cutter sticking above it.
The owners of these planes, and manufacturers spend a great deal of time and effort trying to get the sole of the plane perfectly flat. Cheaper planes are cheap because it's less costly to make then flat.

If you go over to Neanderthal Haven you will find a thread dealing with this subject.

http://www.sawmillcreek.org/showthread.php?t=129612

All I know is that things work, and I am not using my sander to hog off huge amounts of wood. I suspect that it is this fact that you are not removing very much wood at all that things work out the way they do.

A jointer however can remove 1/8" to 1/4" with one pass, and now the geometry works against you unless you have the adjustable in-feed table working for you.

I know that the shavings I take when joining a board are in the area of 0.001" or less, so it makes me think how much am I removing with 220 grit sandpaper, that is just touching the board. I"ll have to see if I can measure it. If you watched the videos then you will see that there is an adjustment screw that sets the table height above the drum. You do this adjustment once, and then if you want to take a bigger cut, you change the sandpaper to a bigger grit, and for a smaller cut, you use a finer grit.

The problem I see with this New approach to sanding, is just that, it's New, and just as Dremel tools had to fight an uphill battle when it first came out having to tell customers to let the RPM's do the work, it is the same here.

The Old method is to force the wood between 2 surfaces, which creates enough heat to burn the wood, the New method lets the sandpaper float off the drum, and so you end up "tickling" the wood into submission!



To OP: definitely go with a 6"+ drum diameter.
One of the videos shows Paul Moore using the same piece of wood over the small diameter drum, and then over the larger diameter drum. The result is faster feed rates over the larger drum, so if you are a hobbyist, then a small diameter will do, but for large volume sanding, the 4" drum is the way to go.

[Eddie Darby]

[QUOTE=Eddie Darby;1323537]Perhaps you will benefit from seeinfg this demo video of the "V" Drum Sander. No Heat!

How can you say "no heat?" Sandpaper against wood generates friction and friction means heat.

Brian
Taxachusetts

Sorry about that one Brian, I hope I didn't throw the Laws of Physics out the window with that post, I should have said that there is next to no heat, and that the is No Burning.

Did you see the drum sander removing varnish off a kitchen door?
Across the glued joints?

The old style of drum sanders are trying to in essence force a thick board into a smaller confined space between the roller and the bed, and this is what pinches the sandpaper into the two surfaces, and creates enough heat to burn/melt glues, varnish and wood surfaces.

The Velcro allows the centrifugal forces to lift the paper off the drum surface, and instead of forcing the wood into submission by "brute force", you end-up "tickling" the wood into submission.
The end result is that the wood is happier, and the sandpaper is happier, and your pocket book is happier.

Then add to that the ability to easily and quickly change belts, and vary your grits, and you have a nice machine to use.

Want to remove more wood, just use a larger grit. Want to run several different grits on one drum? Why not.
Need to sand something wide? You don't have to contend with closed ends, so you can double up the width of the drum.

Then if that isn't enough, the dust control problem is minimal at worst, since the drums don't fling dust all over the place.

A real paradigm shift in sanding.

[Scott Hildenbrand]

Well, I'd been watching that method of sanding for a while since I'd first seen it and the concept seems promising. Quite frankly, the small size alone is enough to motivate me to try it out, though I'll end up putting together the parts myself.

[Joe Von Kaenel]

Paul,

Like you, I love woodworking but hate sanding. My Jet 16-32 drum sander saves a lot of sanding with my ROS.

Joe

[Greg Portland]

So after watching the video what they claim is that they keep the drum just bellow the surface of the table. Relying on the "loose" bond created by the hook and loop (velcro) to stand the loops up under centrifugal force and raise the paper above the surface of the table. I'd think that this would still cause a dip if you held the piece in one stationary position. As long as you can keep the piece moving and take minimal passes then it probably isn't a problem (easy to do with small pieces). How does this unit work on a long board (say 8' long x 12" wide)?


As to the question of heat, he makes the same claim that since the paper is basically "floating" above the roller the airspace between the paper and roller allow the rotation speed alone to keep the paper cool.Most modern drum sanders use hook & loop paper for this very reason (plus it slightly flexes the paper promoting flake removal). A larger drum allows more time to cool before it hits the wood again. A wide belt sander has even more time to cool plus it bends & straightens the paper (promoting dust flaking / cleaner & cooler paper).

[Eddie Darby]

The size of a particle on 220 grit sandpaper is listed as 68 microns from this web-page http://en.wikipedia.org/wiki/Sandpaper

Since a particle is embedded into the bonding material for the paper, we will not get 68 microns for scratch depth, but somewhere around half that.
The average human hair is in the area of 40 microns.

68 divided by 2 gives 34.
34 microns is 0.034 mm which in inches is 0.00133 inches.

At some point in running the wood over the drum you will transfer the weight from the 'before the drum' side of the table to the 'after the drum' side of the table, and in so doing the from of the workpiece will drop 0.00133 inches down on the table.
If you wanted to place a 0.001 inch shim under the leading edge, then you could catch the drop, but I think that a little over a thou does not matter.

I somehow don't think this will be a problem, and in practice this has proven to be the case. I wonder how many "V" drum units are out there and no one has had a problem with this.

For really long wood, just make a table surface that is bigger so the the balance of the wood remains on the table and this will keep you from working too hard. If you go with a 4 inch diameter drum, you will be able to move the wood faster as well, which should help on 8 foot long pieces.

[Eddie Darby]

Here is an article by Steve Maxwell on the "V" drum sander.

http://www.erenovate.com/articles/hardware-tools/shop-built-drum-sander-ideal-for-home-workshop

Another review

http://www.woodworkweb.com/Shop-Made-Sander-That-Really-WORKS.html

http://lumberjocks.com/reviews/119

[Frank Warta]

The size of a particle on 220 grit sandpaper is listed as 68 microns from this web-page http://en.wikipedia.org/wiki/Sandpaper

68 divided by 2 gives 34.
34 microns is 0.034 mm which in inches is 0.00133 inches.


I guess I have a couple problems with this math, the first is that the FPM of the drum is likely to be many times that of the feed rate of the wood. So assuming 1750 RPM for a 2" roller you have something like gives you more then 1800 FPM for the sand paper. Since you might move the wood at something more like 40 or 50 FPM that means that you're getting something like 36 times more sand paper travel then board travel. So you end up having to multiply by quite a bit.

My other concern would be that since drum sanders are often used with much coarser paper, even in the video he mentions the use of coarser paper, you'd be applying that multiplication factor to a larger initial value as well.

So all of that to say, I don't doubt for speeding up general finish sanding tasks it's probably fine, but if you were trying to clean up tear-out or other surface defects you're likely to be using something more like 100 or even 80 grit paper, and you may still be right in that because it's still a fairly small amount of total wood removal it may not matter. For what it's worth I'm not trying to be difficult or argumentative but as a newbie these kinds of details still seem important to me.

[Eddie Darby]

Have you seen the all the videos?

I ask because FPM has nothing to do with how much is removed with this sander. Once the section of wood has been sanded, it is done, and no matter how fast or slow the drum is or your feed rate, no more wood is being removed.

During one demo Paul Moore just stops and takes his hands off the wood, and the wood just sits there. The set-up of the sander is such that the drum is below the table top surface, and the sandpaper is just above the table top surface due to the centrifugal forces.

The wood is only being barely contacted by the sandpaper. Thus very little heat, and longer abrasive life.

If you have tear-out, then use a bigger grit to remove more wood, and as you get closer to the finished dimension, you start to use finer and finer grits. This is something that drum sanders that have tedious sandpaper changes are not good at doing. On 1 drum you can attach more than 1 grit, so you can just shift over to the next higher grit when it's time, and you don't have to even stop the machine.

If you are concerned that the 80 grit sandpaper is going to cause problems, just turn the wood around and sand in the other direction every other pass.

BTW 80 Grit is 190 microns, and half that is 95 microns which is 0.00374 inches. So you are leaving somewhere around 4 thou deep scratches.

[mreza Salav]

I don't see a reply to this concern:

A v-drum sander (like a jointer) cannot give you an even thickness across a board. The drum sander I built is a priceless tool to me when it comes to sanding the pieces that come off the bandsaw for bent lamination. They cannot go into the planer (too thin) and you'll need an equal thickness across the board.

v-drum sanders are an easy solution for those situations that you already have a uniform thickness and only want to take one lite layer off by sanding.

Just as a jointer cannot do the job of a planer, v-drum sander comes short in certain situations....

[Randal Stevenson]

I don't see a reply to this concern:

A v-drum sander (like a jointer) cannot give you an even thickness across a board. The drum sander I built is a priceless tool to me when it comes to sanding the pieces that come off the bandsaw for bent lamination. They cannot go into the planer (too thin) and you'll need an equal thickness across the board.

v-drum sanders are an easy solution for those situations that you already have a uniform thickness and only want to take one lite layer off by sanding.

Just as a jointer cannot do the job of a planer, v-drum sander comes short in certain situations....

I asked about this at the woodworking show a few years back (haven't been able to make it back). To use as a thicknessing sander, you have to use a couple of pieces, the thickness you want to make the board. These act as fences, which the board goes in between, with (they recommended) something like a plywood sled, over the top. When your sled is riding the fences, you have achieved the thickness you want. No, it isn't designed as a thicknessor, and the salesman recommended, using a planer first, and then final sanding it (on solid wood), where as he recommended this for things like cabinet doors that have a bit of a seam, etc.

In my view, the V drum sander is good for quite a few things, and it would make me seriously consider skipping any "bargain" open end type sanders (Ryobi, Jet,Performax), and only consider something like a Woodmaster or Timesaver (the last way out of budget/shop constraints).

So the original poster should really have a better idea of his needs, take our opinions, and direct specific questions toward the companies, and owners of those machines.