pipemakersforum.com

hey guys my shaping disk has some pretty bad wobble to it It is a 7 inch gator grinding disk backer pad and I am just using 36 grit fiber sanding pads from lowes. the sanding pads are always curved when i get them and I am guessing this is what is causing the wobble. I think the fiber disks have actuallu bent my grinder backing pad out of shape. I was just wondering if you guys have the same problem and if a better brand of sanding pads or backing would help. thanks

My sanding pads needed to be clamped to a flat surface for a day before I could use them. After a day or so of clamping to a flat surface, there was only a little bit of wobble, which has fixed itself with use. Also, to get them to work on the arbor of my motor, I machined a bushing to eliminate the wobble.

Alright so there will always be a little bit of wobble?

watching videos and stuff of people shapping it always looks like there disks are spinning so true, but maybe its justbecause they are moving faster. I also have my sanding disk going at about 1750 rpm should i speed it up?

My disc runs true after the clamping and a couple hours of use. 1750 is a fine speed to work with.

Alright sounds good ill try that. What kind of disk are you using

I'm using the Harbor Freight version. I wouldn't assume it's anything different than what you have except for the bushing I made.

Usage will help flatten it. Use a chunk of hard wood and bear down on it against the disc. That will get it hot. Get some small clothes-pin type clamps and use them around the perimeter of the disc when you aren't using it. This will help keep it flat.

I made my backing disk from aircraft aluminum. I just use a washer and spray adhesive to keep my sanding disk/wood chipper in place. Don't have to flatten the disk. 1/8" sheet doesn't even know the disk is adhered to it.

andrew wrote:I made my backing disk from aircraft aluminum. I just use a washer and spray adhesive to keep my sanding disk/wood chipper in place. Don't have to flatten the disk. 1/8" sheet doesn't even know the disk is adhered to it.

Is your disc tapered or flat? Surgery on the sanding sheet is normally required if the disc is tapered.

For you carvers who really want to get after it, pick up Tim West's 7" high-speed-rated & balanced Briar Evaporator:

http://www.jhlowe.com/machine_parts.htm

It's counterintuitive, but the faster a disc spins the less resistance--"tugging"--there is of the work. At 5000+ rpm, it's like passing a block into a science fiction "disintegration field". Whatever enters simply disappears.

As for how to spin one that fast with your current motor, just rig a belt /pulley multiplier.

LatakiaLover wrote:For you carvers who really want to get after it, pick up Tim West's 7" high-speed-rated & balanced Briar Evaporator:

http://www.jhlowe.com/machine_parts.htm

It's counterintuitive, but the faster a disc spins the less resistance--"tugging"--there is of the work. At 5000+ rpm, it's like passing a block into a science fiction "disintegration field". Whatever enters simply disappears.

As for how to spin one that fast with your current motor, just rig a belt /pulley multiplier.

+1

I use a 36 grit 7 inch wheel at my lathe's top speed (which is "only" 4000 rpm) and I find it to be smoother and much more precise than at lower speeds. Also, at that speed a slight wobble actually becomes a non issue and tends to all but magically disappear.

For a many years now I have done all my shaping at 3000rpm, to being with just because it was convenient but now I much prefer it. You need a steady hand and practice though as at 40 grit the wood disappears fast!

I remember way back somebody (Rad, maybe?) said to wet it and then glue it on. Haven't tried it myself, but worth the try.

I actually just turned mine up to about 3000 rpms and the first time I touch the wood to it the sanding disk is pulled right up against the backing pad and the wobble is pretty much gone


Sent from my iPhone using Tapatalk

It's like the difference between whittling with a dull knife versus a sharp one. Counterintuitive maybe, but there's much more control, you don't have to press as hard, things are less likely to grab and slip etc. Glad you got it sorted.