Drum Sander envy

[Gerard Scanlan]

It depends how old the washing machine was. I have understood that the motors for modern washing machines are designed for short running times and so they are not really suitable for a drum sander which runs for extended periods. I am sure there are people on this forum who know more about this than I do. You can always replace the motor at a later date if it turns out to be less than satisfactory. It is not a very tricky job with this design. The motor I got had never been used, the guy had bought it for a self build circular saw and after 25 years of moving around the garage decided to have a clear out. Perhaps you could post a wanted add on this forum? I got a new motor for my bandsaw from a scrap merchants and for the Drum sander I got a giantic nut and bolt for the raising mechanism and the knobs & high impact plastic for the dust hood.
I do not consider myself to have great technical insight. I usually discover why a particular instruction had to be followed to the letter after not doing so. So if you run into problems just ask, I probably made the same mistake and more besides.

 

[naulattaa]

I would love to see some pics of lathe based sanders feeding/height adjustment systems you have built (anyone?). I have 2 lathes so i could use the other as sander...(as its has a nice motor and variable speed)

I haven't figured out how to support the feeding table and make the adjustment system work accurately with such a long drum (was playing with 60cm proto). Always seemed to get tapered results... Also the feeding system might need some thought or it might turn a workpiece into a projectile.

 

[Gerard Scanlan]

I have never seen any lathe based drum sanders. But it sounds possible. The variable speed would certainly be an advantage. The way to avoid tapering is to make the table first and fix the drum in place and then sand the drum with sand paper glued to a sheet of mdf which you feed under the drum in the same way you will later feed the work. If you read this thread and the instructions on the link to the plans it will all become clear. I do like the idea of using a lathe as a drum sander, but unless you are prepared to sacrifice it as a drum sander it could be tricky to set it up accurately each time, swapping from lathe back to drum sander.

 

[kirkpoore1]

I think if you made a drum sander out of a lathe, intending to sand flat surfaces, the table mechanism would be really tricky. On the other hand, if you used it as a very large spindle sander, it could be really useful for sanding large curves. Say, a 6" diameter drum with three grades of sandpaper arranged along it. Hmmm....

Kirk

 

[gasman]

The plans for my drum sander are evolving.... I am basing this on the Pat Hawley one but I think I will make it with short legs so it can go on a bench - maybe add a base later?
I have bought an 1.5HP induction motor off ebay for £16 - picking it up tomorrow. SHould I try to add a variable speed controller to this? Is that tricky to source?
I have also located somewhere on the web which sells 1" pillow mounted bearings for about a tenner each - and also found somewhere locally which has 'steel bright rounds' in all sizes - 3/4", 20 mm, 25 mm, 1" etc. I was thinking of 1" to give maximum stability. Do you think these would be accurate enough? They are probably not as accurate as proper bearing shafts but the guy who owns the place assured me they would adequate for 1000 rpm or thereabouts. What do people think?
Thanks for advice
Mark

 

[Gerard Scanlan]

If you follow the instructions to the letter (in the plans)about the size of the pulley wheels in ratio to the speed of the motor it should run at the correct speed to be both effective and not tear up your abrasive. Someone told me that regulating the speed electronically rather than with pulley wheels would influence the torque (turning force) and so was not such a good approach. Perhaps some one who understands this properly could through some light on it. The pillow bearings are a good price at a tenner. The reason I suggested sourcing a bearing shaft is because the drum runs at about 1400 rpm. I have read since building my sander that it would vibrate less if I had used a proper bearing shaft. It does not effect the working really it just makes it more comfortable to use. The thicker the bearing shaft is the better.

Gerard

 

[gasman]

Gerard what did you use for the drive belt - I was thinking of using something like a cam belt from Halfords or similar
Pillow blocks have arrived and look good. I have made the drum which now requires truing
I will post photos here
Cheers Mark

 

[Gerard Scanlan]

Hi Mark,

Glad it is coming along so well.
I got my drive belt from the company that I bought the bearings and pulley wheels from. I am sure you could use any rubber like belt as long as the profile of the belt matches the pulley wheel for maximum grip. You can see in the pictures the drive belt on my sander has a tapered profile.
I do not remember if I posted where my velcro and abrasives came from so just in case here it is http://stores.ebay.co.uk/Abrasivexpertjohnt1102?_rdc=1

I would recommend not going any finer that 100 grit at the beginning. You can finish a 100 grit drum sanded surface very quickly with 240grit by hand or with an random orbital sander and it takes a long time to put it through the sander with the finer grits and it is trickier to get the feed speed right. With the 40 and 60 grit it is very like having a gentle thicknesser. I read that finer grits were less effective on drum sanders when I ordered my first stock of abrasives and ignored it thinking I knew better. Drum 435mm long and 95mm diametre and you will need a 1350mm length of 115mm wide abrasive. I needed a 1000mm of velcro to cover the drum (it is wider).

Good luck

Gerard

 

[gasman]

Yes I know it is well over a year but I finally finished it. All except the velcro-backed sandpaper. Where do you get yours? and where can you get the velcro backing to stick it to. Also thought about self-adhesive sandpaper - any views on that? I will post photos
Best wishes
Mark

 

[Gerard Scanlan]

Hi Mark,

I wasted way too much cash trying cheaper solutions. The velcro system is definitively the way to go. The abrasives sold by the guy on ebay who sells all this stuff are the best I have ever used. They just go on for ever. If you are sloppy about feeding the timber through the sander you will eventuallly cause nicks along the edges of the abrasive materials and one day it will tear. On a wide sander like yours you can usually reuse a length of it in the centre for less wide stuff. You can also cut up bits you manage to salvage for other disk sanders.
The self-adhesive velcro came from the guy who sells the abrasives that stick to velcro. The link is in my previous post above. Just search for velcro in his ebay shop if you cannot find it straight away. Looking forward to seeing the pictures. Sometimes projects take an age to get finished, especially if you are not printing your own bank notes to fund it. I am just glad you are in the final stretch. Don't forget to hook up an extractor, wear a dust mask and if you are working in short sleeves for a longer period try a barrier cream. This sander realy produces very fine dust even with 80 grit. I would also recommend you get a courser grit too. I have found anything over 180 was just too fine for this type of machine.

Regards,
Gerard