A place in Canada sells a kit. but there are parts in it that I think might not be as sturdy as conveniently possible. I would like to know (from those who have looked into building a shop made unit of this type of sanders) the requirements or desirable features of a drum made of polycarbonate tubing vs tubing of other materials. The seller says it has to do with static electricity buildup.
I am thinking about using a steel tubing, about 26 inches long and may be an OD of 2.5 to 3 inches, as the drum. I will use a pair of shaft collars and then fit them onto the ID of the tubing.
Or I can use a pipe and turn two piece of rounded wood with centered shaft; I would spin on the shaft and turn the pieces of wood to just the right diameter to fit into the open ends of the pipe, and pound the two pieces of wood into the ends of the pipe.
Where is a source for the Velcro backing on the drum? I mean the Velcro onto which the sanding strip sticks. May be it is just like the sanding strip and is therefore just a long strip of Velcro. If that is the case, where is a good source for long strips of Velcro?
I would be using the unit as a thickness sander with very course grit for the most part. I think I would use a 2-hp motor and spin the drum at about 2,000 to 2,500 rpm, for a 2.5 inch or 3 inch diameter drum.
Is there any opinion on the rpm of a 3 inch diameter drum?
Thank you.
Edited 12/9/2006 1:16 am ET by woodenfish3
Replies
I talked to the suppler at a woodworking show (Stockroom Supply) and bought a kit to make a drum sander from him. I was considering building a thickness sander. My understanding is that he did not recommend this configuration. My recollection is that the concern is overheating the velcro with the sandpaper squeezed between the roller and the wood.
Gear
Thank you
I tend to think now (thank you) that the Velcro hookNloop setup is good only for finish sanding with little drag. Thickness sanding would need a better method of stronger adhensive.
I think I would use a strong PSA for thickness sanding.
Woody- opinion on the rpm of a 3 inch diameter drum: you need to establish the surface speed per minute required for reasonably efficient operation. There are fairly large parameters but I would think that you could get away with an rpm as low as 1500 for that diameter.
Using steel pipe as in water pipe with wood as you plan would work, but it would be heavy and there may be a balance problem-might require at minimum a static balancing, or experimenting with various speeds.The speeds you talk of seem on the high side to me, especially as you are wanting to use very course grits. Plenty dust....
Have you thouhgt of glueing up wood hollow square, turning it cylindrical and using purpose-made steel collars screwed at each end to take the dead axle?Would be lighter, and easier to ensure that all is running true.
Thems my thoughts, having built a stroke sander and a few drums that mount between centers on wood lathe etc etc.
Thank you
I think I would use a schedule 80 plastic pipe and use wood ends, or a plastic tubing and use a pair of shaft collars.
What is the disadvantage of using a small diameter drum, say just 2 inches, and a higher speed?
Is it true that onto a small diameter drum the sanding strip (and Velcro strip) would not be wrapped as neatly as with a 3-inch or 4-inch drum?
This is a great forum.
If you mean a heavy wall pvc type pipe it sounds good.
Smaller drum of 2 inches diameter-it just means you have to have it turn faster to sand efficiently. Also I suppose there is less paper so it wears faster-more paper changing. Perhaps it would heat a bit more too.Would the palstic pipe of that daimeter be stiff/strong enough?
Don't know about the Velcro....
Bruce has mentioned his 5" drum turns at 1720 rpm, which is 2252 sfpm-so if you played around with a sfpm range between say 1500and 2000 this would give you a base to work on.The commercial machines can run at higher speeds because the drums will have been balanced, hopefully.
How do you plan to mount this set up , and what are you wanting to do with it?(2 horse motor is some power to handle).Philip Marcou
Mostly to take out imperfections in ripping tear, glueing, and slight unevenness in 4/4 or 5/4 solid panel formed by ripping, jointing, and glueing.
How much power, in hp of an induction motor, is needed to take 1/32 inch off a 30 inch wide solid stock in one pass, using 36 or 60 grit sanding strip? Perhaps it depends a lot on the wear on the sanding strip itself. I don't believe I would need to take more than 1/32 off a stock.
Power? Depends on feed rate to some extent but I guess you could get by with the 2HP motor-not great but would do. Also the wood type is a factor.If you are feeding too slow because of insufficient power there could be burning.
I had thought thatyou wanted a machine for light duty eg sanding thin strips etc. It is now sounding as though it would be more practical to get a commercial machine, so you can be reasonably sure it can do what it is designed to do.Philip Marcou
Since reading the first part of this thread I have given it a little thought. Several questions come to mind.Plastic pipe, the smaller diameter will probably produce higher (drum)temperatures. Velcro backed ROS paper fails when this happens. The aggressive grits your suggesting may cause there to be a flex in the drum when running a board thru.Why not use a pre made sanding belt, The belts will run cooler, pre made belts are more than likely cheaper, The belts are cloth backed, designed to be used on small diameter rollers. In the end it may be faster to change belts than that of a single drum.Just a thought.
Ron
Ron are you taliking of a sleeve or an actual belt? If a belt then he needs a set up that can tension, position and track that belt, and he is talking of something quite wide....A home made wide belt sander is not practical for most folk.
Now that I know what Woodenfish wants to do with my misgivings are reinforced and I agree with what Rick says-a stroke sander would fit the bill and be quite easy to make. I posted pictures of mine not very long ago here http://forums.taunton.com/fw-knots/messages?msg=32823.15 .Philip Marcou
Edited 12/13/2006 1:31 am by philip
Philip, I was talking continous belt. Not a sleeve.
If you have the skill level and the means to build a drum thicknesser than adding a second drum should pose a small concern. Tensioning the paper or belt, is necessary for either drum or belt. Hook and loop (velcro) is expensive and with the idea of removing sufficent material to constitute a "thickness sander". I imagine heat will be present. Can a single plastic drum disapate the heat, I don't know but I think not. Don't get me wrong, it does require some thought on the design, I think anyone who wants to construct such a machine, drum thickness sander, can do a little better.
Dust collection would be better than a stroke sander and a consistant thickness would be easier to maintain with a drum(s).
I do agree that a stroke sander would fit the bill for many sanding operations, how would you maintaine a uniform thickness? Re. "thickness sanding"
Then again, thats why they have thickness plainers.
Ron
The stroke sander is probably one of the least understood tools around. It's far easier to maintain a good flat surface than with a handheld belt sander if you have the proper training to use one. Interesting how many manufacturers still offer them but I bet most woodworkers don't even give them a curious glance. I still favour a stroke sander over a drum sander any day. Even with a widebelt I would still keep a stroke sander as there are many things a stroke sander can do that widebelt can't. We used to sand the dovetailed drawers on out stroke sander to level out the pins and tails. We could sand curved and shaped edges. We even had a graphite mitt to get at odd contours.
I would be a little concerned about how round the sch. 40 pvc is. Most of it that i have turned has been out or round by about .010-.015..I suspose the ID could be supported by pushing a tight fitting piece of wood down it and then screwing it from the outside. I think they make a sch. 80 , it might be better. It might also bow in the middle..I would not even concider a 3" dia as it would lead to a lot of paper changeing IMHO. .02cents Chris
Thanks
I now also think that a tubing is better than a pipe. One with just 3/16 inch wall would be quite strong for a 30 inch stretch.
Yes I agree, but I would automatically turn the thing true because I am me. The larger the diameter the better, but then the complications start compounding-that's why I am back peddling now.
There is a high tech thicknessing sander pictured on the back of FWW #105, just for folks to reference on....Philip Marcou
Edited 12/14/2006 1:16 am by philip
Something for you to think about. My Performax 10/20 drum sander (motor is direct drive to drum) Motor RPM is 1720 drum diameter is 5".
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Here's the website for the sander parts and information:
http://www.stockroomsupply.com/V_Drum_Sander.php
There have been many articles over the years in FWW so that would save reinventing the wheel. With the Performax I don't think you could actually make something better and cheaper. The old standard to make the drums is to stack plywwod discs on a shaft. Plenty of online articles on this. I wouldn't pay for the Moritz sander plans when you can find free versions on the web. Instrument makers used to make their own drum sanders before the Performax and otherd came out. Drum sanders take a lot of hp so 5 hpwould be minumum for a 24". Our 24" widebelt takes 9 hp. Reading the specs on Performax will give you important details on rpms and feed speeds. You might look up stroke sanders in back issues of FWW. That type of machine would be my recommendation for the smaller woodshop over a drum sander any day. Best all around machine for general sanding applications in a woodshop or even custom metal shop. I've put stroke sanders in a few metal shops and the results were better than could have imagined.
I have a mag w/ plans to build your own drum sander. It uses your TS to power the drum and a hand crank to power the feeder. I'm pretty sure it was Shop Notes. If interisted I can check the name and issue. PM me if you want me to do that.
Cheers,
I asked a guy grom work to make a pdf file of the artical, he is not sure if he can. If it works I'll e-mail the file to you. If it does not I'll post the issue #. He has the mag now I did not check the issure # before I gave it to him.
Drum sander
Hi all, I've started building one and have now discovered this group.
The drum is 130mm OD and is a hunk of 5mm wall thick pipe, I've welded 20mm plates in each end with collars for a 40mm shaft. Drum length is 1050 (about 42") and I'll drive it with a spare 7HP motor I pulled off an old milling machine. Drum speed at this stage works out to 1400 feet/min - I'd be interested to hear if anyone thinks that is too slow. The drum spinning on the lathe at 1100rpm sounded true, it runs within 5thou all OK.
Now another query is that I had planned on mounting the motor/drum all above the bench and building a screw-type feeder that would basically be a steel bar pulled equally on both side in towards the drum. The bench for this unit will be 16' long with the drum mounted in the middle.
But, am now pondering the idea of putting the drum under the table and controlling the cut amount by adjusting the roller up or down. That way, it'd be impossible to take off too much material and the safety issues are a lot less.
Purpose is to sand/strip painted doors. I have a 3 phase speed controller so can vary the motor speed down from its stated 1400rpm - I'm not sure if these things will speed the motor up above it's design speed as well....
Be interested in comments.
Drum sander
Posted twice so deleted this copy....sorry.
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