Drum Sander envy

[Gerard Scanlan]

I would love a drum sander but they appear to start at around 600 pounds. The smallest size Jet would be more than adequate. Why are these machines so expensive? Has anyone tried using a bobbin sander with a fence or do they wobble too much. I have seen a fair number of people have built their own. Seems like a considerable undertaking. Someone suggested that I mount a hand held belt sander on a drill sander. Can anyone suggest a cheap, effective and not to difficult to construct alternative? I want to finish bandsaw resawn stock and inlay work.

 

[TobyB]

I have been using a Carroll drum sander in my pillar drill for this sort of work and it's excellent. A cheap pillar drill, new or SH, even if it was a bit wobbly for accurate drilling would still work OK perhaps? I built a table and fence quickly out of MDF. Just a thought ... not a "proper" drum sander ... but effective ...

 

[Gerard Scanlan]

I am currently building a drum sander. Frame is complete (solid oak) hope to finish feedtable this weekend. Then all that remains is the drum. I have all the parts just a question of putting it all together. I am surprised about how easy it has been to do up until now. I will post a picture when it is finished. I will also know by then if I would recommend anyone else making one.

 

[Gerard Scanlan]

Some pictures of my now completed Drum Sander.
I am struggling to find the right abrasive loads for the sander.
I have tried paper backed and linnen backed abrasives but they both shear off at the brackets after 10 minutes of sanding.
Any ideas where I am going wrong?
I could go down down the expensive Hook and Loop road but CSM will not supply outside the UK and it also means I can never use anything else.

 

[Webby]

Maybe the roller is to small in diameter....hence the tear off ...i am no expert mind :lol:

 

[Gerard Scanlan]

Thanks for your suggestion Dave.
However I built the sander to the dimensions that many other people have used before me and no one has every suggested that in retrospect they wished that the drum had been larger. It is 95mm in diametre and 435mm wide, the plans asked for 3 3/4 inches so I am not far away from that at all.

 

[Bigdanny]

would glueing a soft rubber over the roller help. I wouldn't think would need to be very thick, just something to smooth the irregularities from the plywood. I have seen quite a few home built models made using mdf which might give a more uniform smooth finish after its sanded. Does running it in reverse make any difference?
At some point I want to make one of these also, so am interested to know what your solution is.
HTH Danny

 

[knappers]

Can I just ask a stupid question? As you feed the wood under the roller, what's to stop it getting fired out the other end?

Thanks

Si.

 

[Gerard Scanlan]

Stupid questions are always welcome because they are sometimes not as silly as you think. I hold the wood back slightly as I feed it over the table and under the roller, once it is almost all the way through I catch on the other side and ensure that it finishes the passage at more or less the same speed. I assume this is the same for a planner/thicknesser. It only gets launched at the last centimetre or so because the rest of the time the friction of the whole surface on the table is far greater than the friction across the drum. The sander is one supposed to take off a small amount at each pass.
The plywood is completely smooth, as easily as smooth as mdf would have been, it just doesn't look it because of the dark and light strips caused by the end grain being intermitently at 90 degrees to the piece adjacent to it. This is not the cause of the abrasive load tearing. The original 1950's plan I used suggested plywood. I don't really see how running the drum in the other direction would stop the abrasive from tearing as it would actually increase the load on it.

 

[Chems]

It can only really be down to using the wrong sort of paper? Your clamps look far better than the commercial offerings so no reason why they shouldn't work. It that paper actually designed for drum sanders or is it just a roll of normal sand paper?

Nice build btw, I like the way you've put the motor on a hinge as a tensioning method.

 

[Gerard Scanlan]

I have tried using linnen backed sanding belts from belt sanders that are really heavy duty and they just tear away too! The remains of the sandpaper that can be seen on the drum lasted longer! CSM sell sticky back velcro and velourbacked paper abrasive for drum sanders but they don't ship outside the UK. The German brand they sell Hermes is only sold by a wholesaler for industrial users in the Netherlands. Minimum order 500 metres.

 

[JakeS]

I have tried using linnen backed sanding belts from belt sanders that are really heavy duty and they just tear away too!

Could it be that your drum is rotating too fast? From what I recall the write-ups I've seen of drum sanders all seem to suggest that the drum should rotate fairly slowly (compared to most power tools), I would have expected this would be the reason why.

 

[Chems]

If its any help for your testing I can re-ship you the velcro stuff. With the velcro having support all over it may fair better.

I think what Jake says might also be a factor.

 

[Gerard Scanlan]

I am starting to think that the speed the drum is rotating might be the problem. Thank you for the offer of reshipping. I can get my Dad to send me the stuff. It is just a bit of a hassel that it will take a week or so every time I need new supplies. I also noticed that sanding belt suppliers often sell off belts for machines that are no longer being made and I thought to myself that is a cheap source of abrasives. More money to spend on wood I just was keen to know if anyone else who has built one of these contraptions ever encountered any problems and was the velcro road the only one that really worked. Obviously the grip the velcro would provide will likely hold it in place and the slight cushioning effect will no doubt help to prevent the paper tearing away. Of course it might be handy if someone with a commercial drum sander could tell me how fast the drum rotates. Might be in the manual.

 

[deserter]

Does your belt oscillate at all, I know on the one at work the belts have to oscillate otherwise they run off to one side and tear on the side mechanisms.
I'll check the speed of the drums tomorrow but we also have speed settings for the feed rollers.
Another question would be do you have adequate extraction for it? When the belts clog they get hot very fast causing them to tear at the seams when the glue warms too much.

 

[Gerard Scanlan]

No this is a drum sander designed in the 1950's so it just spins like a bat out of somewhere. No oscillation involved. I am considering trying a smaller pulley wheel on the motor spindel to see if that corrects this problem. I have a feeling that the frightening rate at which it hurtles is part of the problem. Too slow is just going to take an age to sand stuff so it would be useful to know what speed commercial beasts work at and then I can buy the correct size of pulley to get near that. There is no dust sprayed around it all gets extracted and the abrasive looks unused when it tears off.

 

[Chems]

The jet sanders are 1725RPM according to their website. Make yourself a little speed controller for the motor to slow it down would be the easiest way.

 

[Gerard Scanlan]

I have ordered a 63mm pulley wheel for the motor spindel. That should slow the drum up to about 1800 rpm. I can collect the pulley wheel on Tuesday, so as soon as I have installed it I will post the results. Might be useful for anyone else who is thinking of building one. In retrospect I think that a sander with a 20 cm drum would have been quicker to build and it would certainly have taken up less space in the shop and been nearly as useful. The size I have built is popular with instrument builders. Even with the tearing sanding belts I have managed to use it on box lids and thinner material for drawer bottoms so the width of the drum is not wasted but I have noticed that I have been using it more for narrow planks.

 

[Chrispy]

Can you increase the friction between the drum and the paper, so as to take some of the strain off of the end clamp, I imagine when you are using the machine the paper is being stretched as it slips around the drum under load so if you can stop that happening it should help.

 

[Gerard Scanlan]

I think that is why the hook and loop (velcro) abrasive is popular with lots of people who build one of these sanders because it grips the drum over its entire surface. Perhaps sandpaper glued to the drum underneath the clamped on abrasive would have the same effect.
As soon as have installed the new smaller diametre pulley wheel I will try a few experiments.