Drum sander

[Gerhard]

They did. Well spotted

Didn't have the motor I was looking for tho'!

[scottl1976]

They did. Well spotted

Didn't have the motor I was looking for tho'!

The buggers, will have to look into it!

[Timber_MG]

I saw this linked from your Extremis thread: very impressive work.
It looks like it's built to take some abuse. The advantage of sanding a panel is that a blade will in certain woods tear out some sections, leaving one to sand that out in any event. The large industrial drum sanders are very impressive pieces of kit that will shave a plank down in a matter of seconds but with lighter passes and some experience I can see this thing working well.

[alternativeroute]

The advantage of sanding a panel is that a blade will in certain woods tear out some sections, leaving one to sand that out in any event.

I can vouch for that... I did some oak recently and no matter how light I made the passes with the thickness planer it would tear out around knots...

[Timber_MG]

Imbuia seems to love to tear out. Perhaps the knives need to be extra sharp but sanding down 1mm of hardwood is not to be scoffed at.

[JimGore]

but sanding down 1mm of hardwood is not to be scoffed at

I have one word for you:

RO 150 FEQ.  1mm sanding into hardwood?  No problem.

[Gerhard]

I have one word for you:

RO 150 FEQ.  1mm sanding into hardwood?  No problem.

You'll have to have the hands of a plastic surgeon to get close to the evenness this thing is capable of

@Martin

Yeah, a proper drum sander is an impressive thing. Unfortunately all commercial drum sanders I've seen are very expensive and they are all cabinet types, i.e. big and heavy - not conducive to a townhouse garage. Mine is portable - though not a feather weight I can pick it up.

Another feature that I get - like I mentioned in the Extremis thread - is that this machine evens out the surface over its entire area. A commercial drum sander will have to have a very long feeder table to do the same. Knowing that I'll be able to get the panels perfectly flat makes construction a much less precise endeavor.

I am thrilled to bits with how it came out and how well it works.

[oradba69]

Excellent piece of engineering.
I would love one of those, come now make a price 

[Timber_MG]

@Martin

Yeah, a proper drum sander is an impressive thing. Unfortunately all commercial drum sanders I've seen are very expensive and they are all cabinet types, i.e. big and heavy - not conducive to a townhouse garage. Mine is portable - though not a feather weight I can pick it up.

Another feature that I get - like I mentioned in the Extremis thread - is that this machine evens out the surface over its entire area. A commercial drum sander will have to have a very long feeder table to do the same. Knowing that I'll be able to get the panels perfectly flat makes construction a much less precise endeavor.

I am not in any way trying ot detract from this. It is clearly a robust machine and weight is a good thing in this application. I have only seen the large shop floor type drum sanders with long feeder tables and those take of a couple of mm in one pass with ammeters showing the effort involved. Using MDF as a reference plane will probably give you a sufficiently consistent result without much tear-out.

It's defenitely not the kind of device to have an operator use but I like the ingenuity of it.

[Gerhard]

Thank you Martin.

Louis, the material for the sander set me back around R2,5k. That does not include the drum itself though. It was done for me professionally as a favor so I would not know how much it would cost.

[oradba69]

Thank you Martin.

Louis, the material for the sander set me back around R2,5k. That does not include the drum itself though. It was done for me professionally as a favor so I would not know how much it would cost.

Actually quite a marketable tool if you ask me. Suppose dust is quite a bugger 
I should not have a problem getting the drum made up (cousin has engineering shop). What would you change with your 2nd go at it?

[ghostinthemachine]

Actually quite a marketable tool if you ask me. Suppose dust is quite a bugger 
I should not have a problem getting the drum made up (cousin has engineering shop). What would you change with your 2nd go at it?

Guess one can make a plexiglass canopy with vacuum hose to contain the dust.

[Robert_E]

This sander looks like an excellent idea.

(I would add a finger guard over the pulleys though.)

[Gerhard]

Dust is indeed a bugger. A big one .

What would I change? The most important thing is that I would balance the drum. I never thought of that originally. I guess I can still have that done but I don't know where. ATM the drum vibrates too much for my liking. Results could be better I think if the drum is perfectly balanced.

The second thing would be to come up with a trick to handle the dust. With a width of nearly 500mm one would need something special to get enough extraction across the entire width of the drum. It also needs to be removable so that you can get access to drum for replacing the sand paper.

Depending on what one wants to sand down one can make the drum wider. One can probably go to 600-700mm with the motor (0.75kW) I used. Wider will probably require a stronger motor but then you are going to wrestle the machine too much to prevent it from pulling you across the table

Another important thing is to have a very solid surface to work on. One that does not bend under the weight of the sander or any down force you apply.

The sander has done the job I built it for quite well. I will definitely use it again in future. But I am probably not going to put much more (if any) effort into improving it. If I were going to use it often then I would have the drum balanced at least...