I have spent many back breaking hours sanding down hardwood panels that I made by gluing strips of wood together. I have been unsuccessful so far to do this in a way that would require minimal sanding
. I then discovered that there are things like drum sanders. You know, like a thicknesser but with a sanding drum not cutting blades. I instantly realized that this is what I needed and proceeded to try and find one.
I also instantly discovered two things:
- Drum sanders are expensive (unless you want a one-job-Ryobi - if you're lucky it will last for the whole job!)
- Drum sanders are big.
Two things I don't have in abundance...
So what was left for me to do? BUILD ONE
!
The two most important elements of a drum sander IMO are the motor and the drum. The motor as far as its size/strength is concerned. I first tried a 0.33kW motor and it was way too "lig-in-die-broek" (under powered for the non-Afrikaans speaking folk) so I then went for a 0.75kW - which is what you'll see in the pictures. This puppy is strong!
My biggest headache was the drum. I wanted one that is at least 500mm wide (I'll probably not build a speaker that is deeper than 500mm I hope!). The drum sanders I have seen all have drums in the region of 100mm in diameter. I don't have a steel lathe so my options were severely limited. Fortunately my brother has a contact for an industrial engineering shop that his business uses regularly who can build pretty much anything you can draw! So I drew what I wanted and this guy built it! AND, he did for free as a thank you for all the business my brother's company is giving him you see
. I had to pay for the motor tho
. One thing I never even thought of though is the balance of the drum. I never specified that it should be balanced! I discovered that an unbalanced steel drum that weighs about 10kg spinning at 1410 rpm tends to jump around a bit
. When sanding this turns out to be a non-issue but it is something I want to look into at a later stage.
All the drum sanders I have seen are non-portable. They are floor standing machines that take up a lot of space. Mine would be different from the norm. Instead of the wood being fed through the machine like with thicknessers the machine in my case would ride over the wood. While mine turned out bigger and heavier than I had originally had in mind it is still portable and doesn't take up nearly as much space as other designs.
Actually I am lying! My biggest headache was not the drum (after having it made professionally that is) but the mechanism to adjust the sanding depth. As many things in life the simplest is often the best. You'll see in the pictures how I did it and it works very well.
So!
Parts - pre painting
The slots in the 5mm thick motor base plate I cut with a Dremmel - believe it or not! I went through many discs but I don't know how else I would have done it (apart from drilling rows of holes and filing them down into slots - I am not a masochist). The "ear" with the hole in sticking out of the base plate is for tightening the drive belt. It has a threaded hole at the bottom (which you can see in a picture below) that I can put a bolt through (I'll take a picture if you can't figure out how this works
).
Frame base - painted with casters attached
Frame with drum housing attached
Drum fitted to the frame using pillow block bearings.
You can see that the drum shaft even has a slot for a linchpin! Amazing what one can draw on paper...
to be continued...
