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Malibu
10th November 2006, 08:27 PM
The new toy in the workshop... but not finished yet.
Based on Sturdee's pictures and some scans I had through e-mail. All made of pine, except for the motor mount plate which is oregon and MDF and the braceing made of hardwood scraps.
The drum is 725 wide and has a usable width of 700mm and a maximum depth of work is 150mm. A 110mm diameter steel tube on ply bosses with taper locks holding onto a 25mm shaft and self-center bearings. It seems to run fairly true, but maybe about 1/4mm off center (Bent tube?)
Solid as a rock and I can take 4mm swipes with 100 grit paper. The paper is too fine, so I need to get down to 60, or 80. The taperlocks make changing the drum a breeze, so I can have various grit drums if I need them for fine work.

Picture 1 shows the table adjustment handle and the bearing support unbolts to change drums.

Picture 2 is the cantilever setup that changes the height of the table. Braced with some good chunky steel angle iron.

Picture 3 is the business end. A .55kw, 3 phase motor and a 6.5 to 1 ratio bearbox. It's driven from a 240V inverter, so I can do nifty things with it. Ramp up in 10 seconds for a slow start and ramp down in 2 seconds for a quick stop.
I'm overdriving the motor at the moment, but I might end up changing the pulley ratios to drop the motor revs down a little. I'll put a motor speed control dial on it when I get the chance and maybe a fwd/rev switch.

Picture 4 is a general shot... yet to be done is dust collection, vee-belt guard and a little trimming up. On this end of the sander, I plan to put a 17" face plate sander and work a flat belt sander into the deal as well.

All up, it sands like a beauty and I'm really happy with the way it all turned out. A bit of bracing is needed on the table, but that might be tomorrow's job. Cost so far is about $60 for the pine.

Sturdee
10th November 2006, 10:49 PM
Looks great, I'm sure you will get lots of use from it.


Peter.

contrebasse
11th November 2006, 12:25 AM
Malibu, haven't you got anthing better to do? :-)

what's the drum made of?

Malibu
11th November 2006, 09:57 AM
Ahhh... holidays! It would seem that's there's nothing to do but stay down in the workshop for days on end. Now it's a clean up time down there.

The drum is a piece of American steel conduit that I pilfered a few years ago because it looked like it might come in handy one day.

Peter, what grit did you find is best on your sander? I've used 100 because that's what was on the shelf at the hardware, but as per a discussion elsewhere here, it seems 80 is the best 'general' grit and would have gone with that for my first drum if the choice was there.

After playing around with it a little, I'm not real happy with the 1/4mm out of round, so I might modify at a later date and use a wooden roller, or fix some wooden slats to the steel drum and true it on the machine. Something to ponder over for another day :)

Sturdee
11th November 2006, 11:58 AM
I use 100 grit as well, but I believe 80 is better.

The reason I use 100 grit is because it was $10 for a 100 metre roll of 70 mm wide cloth backed sandpaper. Cheap enough.:D :D :D

Peter.

junkboy999
12th November 2006, 01:30 PM
Look good Malibu

It is built like a tank, should get quite a few good year of use out of it.

A agree with Peter and use 80 the most. My secound working drum sander uses a single sheat of standard paper so I can easly pick the grit. 100 is great for close to finishing sanding, but clogs to fast. 60 Grit just makes to many heavy snading marks that you'll have to snad out later.