Building a disc sander

[kuraki]

I have a 1/2 hp 3ph motor and VFD sitting around doing nothing. I used it to power my 2x72 initially but it was too small. I think I'd like to make a 9" disc sander and power it with that motor and VFD.

I've never really liked or utilized disc sanders in my profession, I see the value in knifemaking but since I haven't used them I'm not sure about features. I'm going with 9" to utilize normal sanding sheets instead of discs. I plan to make a work rest that is adjustable for angle. Outside of that, are there any design considerations those of you who use them often would recommend? Is there value in making the workrest adjustable for height? What about orientation of the disc itself? Would there be value in being able to turn it from a horizontal position to a vertical one?

Any advice would be appreciated.

 

[Jonathans]

I often orient my blade on the disc grinder in a fashion where a work rest (if I had one) would get in the way. I can flip my disc to horizontal and find that useful at times. I do wish I had a foot controlled on/off switch as I find it difficult to get perfect the blade on the disc perfectly flat at the onset of a grind. I REALLY like the Nielsen disc system.

 

[scott.livesey]

all you need is a the disc and you can get started. I use 8" because of there are many disc makers and there are PSA discs made in that size. 9" would work, but I only know of one source. my are horizontal, one is 115v driving a 5:1 gear reducer so the disc is at 325rpm. the other is a 3/4hp fan motor with VFD.
scott

 

[Fred.Rowe]

This link is for photos on my Picasa site which shows some shots of the horizontal machine I built a few years back. The fence is removable. It's a VS machine of 1 hp rating. it is reversible as well. I have had the vertical type as well, but I prefer the horizontal.

Best of luck to you, Fred

https://get.google.com/albumarchiv...Bzp8g5ffRkIVED4LPZjQb?authKey=CPKw0NHR8bertAE

 

[kuraki]

Thanks guys that's good stuff.

 

[ptomli]

I recently bought a 9" and my first mods are adding magnets into the aluminum disk so I can use 6mm thick mild steel plates, and a foot switch.

I used 9 magnets, 10mm dia and 7mm long. Plenty holding force. My first steel plate was cut and lathe turned, which is great. I'm now waiting for 6 more from laser cutting. I glued a 1mm layer of cork onto the plate, and put the abrasive sheet onto that.

I had the foot switch but it seems the VFD will only allow an all or nothing with respect to remote controls. So in order to have a foot switch I'm going to have to create an extension for start/stop and speed. My foot switch uses a 1/4" phono plug, and the socket I have for this had a built in contact, so when the foot switch is not plugged in the other controls can work as normal.