Making a drum sander

[inandout]

Is there any reason why I shouldn't adapt my 12 inch planer/thicknesser into a drum sander by removing the knives and attaching sandpaper to the cutter block Has anyone tried this? On the same theme could you attach sandpaper to a spindle moulder cutter block?

 

[Scrit]

I'll give you several:

1. Your p/t will probably have a cutterblock diameter of 2 to 3in which will mean that you aren't going to be able to wrap a lot abrasive round it. That means the abrasive will "load-up" extremely quickly, clog and then scorch the work. Most drum sander plans seem to talk about 12in or greater diameter drums to overcome this. The trade used drum sanders from WWI onwards, but changed over to wide belt sanders (like a portable belt sander, but with an 8ft long belt). In order to avoid loading up the abrasives trade drum sanders sometimes had as many as six or even eight drums

2. Your cutterblock is spinning way too fast - probably somewhere between 5,000 and 10,000 rpm (even my industrial planer does 5,000 rpm with a 4in cutterblock) - so that will scorch the work as well

3. Your cutterblock will need to have inserts to get you a smooth surface to the drum

4. The feeder mechanism in a planer is at the wrong side of the work - sanders have a belt feed on the underside of the work for smooth feeding, and you do need a constant feed speed for consistent results

5. The infeed roller will mark the face of the work if it is a conventional thicknesser smooth outfeed roller with a serrated infeed roller - they are designed for use with a 0.5mm or deeper cut (which takes the infeed marks out)

If you are still keen I have a few links for home-built drum sanders:

http://www.mimf.com/archives/thickness_sander2.htm

http://www.rockslide.org/drum sander.html

http://www.moritzdesigns.com/sander/sander.html

http://www.nicks.ca/Toolkits.html#sander1

http://www.woodcentral.com/cgi-bin/readarticle.pl?dir=powertools&file=articles_528.shtml

Enjoy!

Scrit

 

[inandout]

Scrit

Thanks, that was very useful, I am glad I posted before trying it, thanks for the links also.

 

[Ed451]

If you want to build your own drum sander, check this out:

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

 

[Shultzy]

As well as Scrit's comments (very informative, as usual) how are you going to get the sandpaper off when you have finished. The resetting of planer blades is also not easy or quick. With sharp blades you should'nt need much sanding. Anyway why would you need a drum sander?

 

[luthier49]

Here`s a mini thickness sander I made using my Carbatec Mini lathe. I made this to thickness musical instrument sides, ( guitars, mandolins etc. ), and to make overlay veneers for the machine heads of stringed instruments. I have a variable speed control for this machine, and you can see some 1mm veneer I`ve made with it on top of the machine. The abrasive is wrapped around the drum and held in place each end with tape.

 

[mrbingley]

I really like the idea of the v-drum sander.
Seems so simple with no complicated settings to manage.
I've got a couple of unused motors sitting doing nothing.
A visit to the scrapyard is on my list

Chris.

 

[Anonymous]

Thanks for the links Scrit - I am tempted to make a steel version of the second one and implement a power feed.....

 

[Scrit]

Hi Tony

I didn't put the full set on last night, but there a couple more which might be worth a peek:

http://www.ukuleles.com/BuildingHowTo/sandthck.html

http://community.webshots.com/album/223700029vUZYCp

The only other link I have, for the V-drum, has already been discussed. Prior to the introduction of the wide belt sander from the USA in the 1950s many machinery manufacturers made wide drum sanders such as this:

Above: White BDA triple drum sander, c.1950

The drums were covered in hard felt to allow some "give" when sanding. To reduce clogging of the papers these machines frequently employed mechanisms to oscillate the drums from side to side in much the same way as you'd see on something like a Volpato edge sander. Ultimately they were displaced by the wide belt sander (again with oscillation). For reference here's a cross sectional drawing of a Sherrill-pattern wide belt sander of the 1950s:

The basic design principles are all there and I've seen industrial drum sanders built along the same lines. I think that is the clearest diagram I have seen on the principles of wide belt/drum sanding and explains the requirements well.

Of course another alternative is to go to the long-stroke sander design like this:

The downside to these machines is that they are fairly big and that the belt on a 6ft machine is about 5 metres long and so costs £20 plus (they are frequently cloth-backed abrasive and you need to buy them in fives or tens of each grit you use). Up until the 1960s it was still possible to buy wheel kits to build these yourself.

Scrit

 

[Scrit]

As a postscript and to add to the body of knowledge on this type of machine here are some photos of a 300mm wide joinery sander with a short belt and overhead feed. These machines are opensided so it is possible to feed 600mm through them in 2 passes although that will leave witness marks which need to be hand sanded out:

I believe that the basic design could be reproduced with a drum in place of the belt (simpler)

Scrit

 

[Anonymous]

I think accurate alignment of the upper and lower sections will be the issue - particularly when adjusting to thickness

 

[mel]

got a few questions myself
1 what speed is best for the sander head ????
2 where do you buy the velcro covered sander "head" in the uk ??
3 is the abrasive "velcro backed" available in the uk ???
4 are the bearings available to order , the type which bolt down . and are they called the same here in the uk ??

thats all that comes to mind for the moment
all replys appreciated
mel

 

[Scrit]

I think accurate alignment of the upper and lower sections will be the issue - particularly when adjusting to thickness

That's the beauty of the sanding drum under table approach - it should be much easier to align IMHO. The feeder doesn't need to be positioned that accurately so long as the feed wheels are sufficiently compliant (soft enough). You can't thickness sand with a Ghermandi-style sander, but it will get you to 120 or 150 grit very quickly

1 what speed is best for the sander head ????

Work feed or rotation speed? I'll try to look up some appropriate values from some of the sanders I have info on and post that.

2 where do you buy the velcro covered sander "head" in the uk ??

I believe 3M (UK HQ Bracknell?) make the hook material used for hook and loop abrasives

3 is the abrasive "velcro backed" available in the uk ???

3M (Scotch), Mirka and Klingspor all do rolls of loop-backed material - although it isn't cheap. Actually the drum sanders like the American Performax range use standard paper-backed abrasive and clip it onto the drum - that is going to be a lot cheaper

4 are the bearings available to order , the type which bolt down . and are they called the same here in the uk ??

Maybe one of the engineers would like to answer this, but I believe that the bearings are called plummer blocks (?). Picador in Sheffield used to make them and Simbles in Watford were a well known retail outlet. Hepco Motion certainly used to sell them as well but I don't know if they're still in the market.

Scrit

 

[Anonymous]

This is what I use, its the most expensive piece of kit in my workshop, but I can honestly say its worth every penny and I would really struggle without it now.

950mm wide, can sand 40-50 small cabinet doors, ie a good size kitchen in 10-15 minutes.

All come out bueatifully flat, god bless machines, for me the most tedious job used to be sanding everything by hand or small belt sanders.

 

[Scrit]

The only problem with them, Senior, is the price...... I used to find it cheaper to buy time on someone else's machine (triple belt CNC jobbie with a cross sanding belt - brilliant machine, but at around £80k I should hope so)

That's not to say I wouldn't like one to replace my Wadkin stroke sander......

Scrit

 

[Anonymous]

Yes its difficult to justify the price but believe me it its worth every penny.
As for using someone elses machine, I have people coming in to use mine.

Once you've got one, you use it none stop, all my frame work goes through it, panels, doors, drawer fronts, skirting, work tops, veneer boards etc it really is endless.

 

[SketchUp Guru]

Just for ideas if you want to build one, take a look at this.

 

[Scrit]

As for using someone elses machine, I have people coming in to use mine.

I used to trade CNC time for it, so it was effectively a no-brainer. But for small shop or home shops a device like that (or for that matter a CNC P2P) is out of the question

Scrit

 

[DaveL]

4 are the bearings available to order , the type which bolt down . and are they called the same here in the uk ??

Maybe one of the engineers would like to answer this, but I believe that the bearings are called plummer blocks (?). Picador in Sheffield

Looks like Picadorstill make them

I still have a grinder I made in the 70's from an old washing machine motor, some angle iron and a Picador shaft.

 

[Scrit]

Blimey, Mel, Grimsby! Looks like you're in luck

Scrit