Monday, January 9, 2017

DIY Drum Sander v1

I like watching YouTube videos that show how to make your own jigs, and even full fledged tools, for wood working. I don't have a large collection of woodworking tools, and I can't afford to buy everything that I want, so I find myself dreaming of making some of the things I want, and these videos make me think that I can.

One of the tools I covet is a drum sander. I certainly can't afford to buy a drum sander, so I considered trying to make one. I had grand ambitions, and even selected some plans to purchase to start my project, and bought a couple of the critical components. And I was almost ready to get started when I stumbled across another video that featured a much simpler solution. So simple in fact, that I wanted to smack myself for not thinking of it myself.

So here is my first attempt at building a drum sander.

I intend to use my ShopSmith Mark V as the power and the frame for the sander. So I need to build a drum and a deck which will become accessories for the ShopSmith.

I started with the drum. I like the idea proffered by Stumpy Nubs of using interchangeable drums rather than trying to peal the paper off of one drum to change the grit. So I made a drum out of very cheap and easy to use PVC pipe. I'm pretty sure I used 2 inch (inner diameter) pipe. I also made sure I used the kind with the thick walls, so that the pipe would be nice and stiff.

I turned two wooden plugs on the lathe that would fit into the ends of the PVC pipe.

One end would have a piece of metal rod sticking out the center of it. This rod would be gripped by my Jacobs Chuck on my ShopSmith, which would power the sander.

 The other end would have a small divot in the center, and would sit on the live center of my tail stock

 The fit of these plugs was VERY snug. Still, I used a small screw to make sure it didn't spin or come loose. I had to countersink the screw head to make sure the surface of the drum stayed nice and even and smooth.

 I bought a long 80 grit sanding belt on clearance for $1.75. I cut the belt and wrapped it around the pipe and held it in place with electrical tape. When I was happy with the fit, I unwrapped half of it and attached it to the pvc with spray adhesive. Then I wrapped it back up with tape to make sure it stayed put, and then I did the same to the other half, from the other end. Once glued, I wrapped it all tightly with electrical tape until the glue was good and set.

Next came the deck. I set a piece of 3/4 inch plywood on the ShopSmith to get my size and spacing.

 I used a series of stacked wooden blocks and a pivot screw to create friction locks that would mount the deck to the way-tubes of the ShopSmith.
 This is a fairly simple setup. The blocks are stacked to the thickness of the way-tubes. Then the top block is attached with a screw on one end so that it can pivot on that screw and swing out under the way-tube, locking onto it.

 With the main deck now locked onto the way-tubes, I could start working on the tilting top deck. This would be attached to the main deck with a couple of heavy hinges at the front edge.

When in use, the top deck would be raised up close to the drum. The work piece would be slid along the top deck, under the drum, and fed through by hand (very carefully). The distance between the drum and the top deck would determine the thickness of the work piece, working sort of like a thickness planer.

 To set and hold that distance, I used posts made from 5/8 inch threaded rod, and a nut. The nut sets the height by determining the length of the rod from the top deck to the main deck. The excess rod pokes down through a hole in the main deck. 

 The top of the rod rests in a little pocket on the underside of the top deck. It is made from hardwood (oak) and reinforced with a metal washer, so the rod doesn't wear away at the top deck. In these pictures you see me using two rods. I thought this would give me greater stability, but it just made it impossible to adjust the deck height evenly, so I later switched to just one rod set in the center.

 Here is the finished sander. It is crude, and may need some refining, but it does function. I need to make some adjustments to get the top deck to rest perfectly parallel to the drum, so it sands perfectly evenly all the way across. I think that will involve putting some thin shims under one of the hinges, but I haven't got that far yet.

 I also think I'm going to double up the material on the top deck to make it stiffer. I thought 3/4 inch plywood would be stiff enough, but with only one support in the center, I am now getting a little bit of flex across its width. That might also be caused by some play in the hinges, though they are about as tight as I could hope for. Maybe I should replace them with a length of piano hinge. I will update when I get it all tweaked.

Tuesday, January 3, 2017

Rose Quartz and Jatoba Wand

Just a quick pic of my latest wand. It is a short wand, made of Jatoba wood (Brazilian Cherry) with a polished Rose Quartz point at the tip.

I was originally trying to make a full sized wand, like my usual (around 16 inches or so long), but I had an issue during the turning. The wood blank split on me just as I was finishing up the handle. I managed to salvage the handle , which will become a 2-part wand, and this was the left over part, which would have become the shaft. I decided to salvage the broken piece and make it into a smaller wand. Later, I added the quartz tip.

Jatoba wood is very beautiful, but seems a bit brittle and splintery. It seems to crack easily. I will have to keep that in mind when using it in the future.

Wednesday, November 16, 2016

Wood Turning FAIL and recovery (or, Turned Segmented Bowl v1.0)

The turned wooden bowl I posted last week was the first one I finished, but not the first one I started. I had originally started a much more elaborate design for my first piece, but I got impatient waiting for it to glue up, so I started turning #2 first. As it turned out, #1 was a little too ambitious, and suffered from a lack of planning.

I literally just started cutting up pieces into strips and gluing them together. I knew it would be made of layers of rings, and those rings would probably have something like 8 segments each, but that's about all the planning I had put into it. My first ring I made turned out way larger than I thought it would be and had to be cut down. Then I just started slapping things together.
Some of the rings were octagonal and some were square. Some were cheap reclaimed pine, and others were reclaimed oak. The sizes of the rings were haphazard, and at one point I had to make an extra ring as a transition because the sizes were too far apart. I planed to let the sizes of the rings  dictate the shape of the bowl.
I figured out during glue up, that I had not planned on how to clamp an octagonal ring of wooden segments. I made due with electrical tape stretched around the rim.

Then, lots of sanding to even up the faces and hide the crimes. I had to add some super glue to some of the joints because I had gaps. I guess my chop saw is not calibrated very precisely, because the angles didn't quite meet up as the should have.

Then the rings were glued together into a cone type shape of sorts. It was around this time that I got impatient to get my bowl turning on, so I started turning the simpler blank (#2) that I started gluing up while I was struggling with the rings.
After attaching to a glue block for mounting onto the lathe, the turning began. Right away things were off to a rocky start, with the whole rig being unbalanced as hell. I worked quickly to turn the protruding corners off the rings just to get the table to stop shaking.
 The rings were far too disproportional from one another. The transitions from one ring to the next were very hard to smooth out, and I had many instances of tare out, some very violent ones that sent large chunks of wood flying into me. The edges of the rings wanted to catch on my chisels, and I came much closer to being injured on this project than on any lathe project previous.
Just as I was getting the transitions under control, I had a blow out. I stopped the lathe to check my progress, as I often do, and noticed that one of the segments had been cut all the way through in spots. FAIL. I unmounted the piece and tossed it in the scrap bin.

But wait! I think we've established what a cheap bastard I am, and how I can't let anything remotely usable go to waste. So I rescued the failed piece from the scrap bin and decided that since only the top ring was ruined, I could probably cut off that ring and replace it with a new top ring.  So I re-mounted the piece to the face plate, and started parting off the ruined top ring.
Then, once the top ring was off, I decided that I was too lazy and impatient to make a new top ring. I would just try to turn what was left into a bowl. Even without the top ring, it was almost as tall as the bowl I just finished yesterday.
The turning was problematic, I'll tell you that much. I had a lot of bad catches- a lot of gouging and chip out. And the transitions from ring to ring were tough to smooth out. This bowl would have benefited from some better planning, that's for sure. And sharper tools (I'm bad at sharpening, and sharp tools are the key to good wood turning). And I burned my fingers pretty good being impatient with the sand paper. You see, I'm to lazy and impatient to change the pulleys to adjust the speed of the lathe, so I sand at the same speed I turn, which is much too fast. This whole project had me impatient and frustrated, and I kind of rushed through it. Maybe that's why it encountered so many problems.
Anyway, the final product turned out to be acceptable- nice even. I think my next bowl will be a little less ambitious and better planned out. I obviously need more practice with bowl turning before I start doing anything fancy.