Shopsmith Forums

A Learning Process! That is what all of my projects are. It seems that I often learn the same lesson multiple times.:)

twoblocked wrote:Thanks all:

I got the drum within what I would say is 1/100 of an inch. I could not come up with a good way to true it with a lathe chisel fixed to the carriage, and just did it by hand and caliper finishing with sandpaper glued to a board. (I don't know why I didn't think of using the SS 12 inch disc. doh!) I was afraid to sand more for fear of creating an egg shape. Things seemed to be going this way when marking with a pencil and seeing what was being taken off.

If it does not work, I am not out much except time. PVC pipe is cheap and it looks like I will have to buy much more velcro than I need to get the 4 inch wide adhesive backed hook like I want to go with the 6 inch wide sand paper. The hardware can be taken back off. It is a learning experience in any case.

Once I get there, my plan was to take a board (probably MDF) and adhere some sandpaper to it. Then, take that board and clamp it to the main table. Gently raise the main table and move it back and forth until true.

damagi wrote:Once I get there, my plan was to take a board (probably MDF) and adhere some sandpaper to it. Then, take that board and clamp it to the main table. Gently raise the main table and move it back and forth until true.

Thanks!

I was looking things over last night and was thinking of doing something similar with a 3/8 x 3/8 parting tool clamped to the table, but reground as a round nose scraper. I like the sandpaper idea, too. Maybe even better. I'd hate to ruin the drum and have to start over! I wonder about the sandpaper only wearing along one line. Well, I guess you would just move the board when need be. For a 4 inch drum the table would have to be above the drum. Uh oh, there is a cross member to deal with....

Heck, why bother with a sanding set-up on the table when the time to do it is when the drum sander table is installed? I think I'll leave things as they are until I am further along.

OK, here is a reenactment of how I made the drum. I decided to just explain what I did with the aid of picture. This is not a How-To tutorial or an analysis and is certainly not a magazine article. If it seems that I did something odd, just ask why. If I didn’t have a good reason at the time, I can try to make up a whopper!

Here is what I made the drum out of:

A piece of 26 inch long piece of 4 inch schedule 40 PVC pipe.
Three 4 inch circles of 1-1/2 inch plywood.
3-1/2 feet of cold rolled steel round stock.
Two 5/8 inch by 3-3/4 inch hubs.
Two self centering 5/8 inch I.D. ball bearing pillow blocks.
Eight #8 screws.
PVC cement.

First, I cut the circles a little oversized on a homemade bandsaw jig:

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Picture 1

Next, I bored 5/8 inch diameter holes in the circles on the drill press using a Forstner bit and aligning the bit with the center mark left from the bandsaw circle jig.

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Picture 2

Then, I attached the circles to the hubs with screws using the round stock as a guide.

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Picture 3

After that, I mounted each hub (reusing a hub for the third circle) to the headstock and used it as a faceplate to turn the circle to fit snuggly inside the pipe. 4.00 inches worked well.

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Picture 4

Now it was time to assemble the drum. The circle without a hub was pushed into the center of the PVC pipe without cement. Then the round stock was slid through the pipe and the center of the hubless circle. PVC cleaner and cement was applied to the inside of the pipe and the end circles.

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Picture 5

To be Continued...

Continued (there is a 5 picture limit)...

A pipe clamp was used to push the end circles into place:

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Picture 6

After the cement hardened it was time to true the drum up on the lathe. On the driven end, the 5/8 inch hub simply mounts on the headstock the same as it did when using it as a faceplate. The round stock was slid into the drum for clearance from the headstock, but was still well within the plywood circle for support. It was necessary to loosen the screws on the hubs to get the round stock to slide into the desired position. Then the wood screws and the Allen screws were tightened. On the tailstock end, one of the pillow block bearings was mounted to a scrap that was mounted to the legs from an extension table which was mounted to the Shopsmith at as close to the correct height and depth as I could measure.

Using calipers to true the drum with a round nose scraper:

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Picture 7

Using a skew chisel to square the end:

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Picture 8

Using sandpaper glued to plywood to smooth the drum:

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Picture 9