Sanding disc for disc sanders

[Wapiti]

Has anyone out there used the 8" dia aluminum discs available through Woodcraft (I am sure other places sell them also)?
I want to make up a disc sander from a 1725 rpm motor I have in the shop and am on a really tight budget right now. I would like to get the 9" disc sold by Tru-grit but I am not sure I can spare that much change right now ($55).
I want to make something to get me by until I can pick up a reversible motor and get Tru-grit's discs for flat grinding, etc.
The discs Woodcraft sells are only $16, but I wanted to ask if anyone has used them and how they are. Are they just not worth it and should I make the price leap and go ahead and get the one from Tru-grit.

Also, for future reference, what is the best HP for a disc sander? Any other specs I should keep in mind as I plan for building the "better" one down the road?
Thanks to everyone, again.

 

[mikeS]

I got my 8in discs from Sheffield Knife Supply, die cast I beleive, I faced mine with rubber per Barry Jones suggestion, really is great compared to the metal disc alone. My grinder is a 3/4hp. dual shaft, no need for reverse the motor cost me $12 and the discs $15.

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If winners never quit and quitters never win. What fool said quit while you're ahead?

 

[BARRY JONES]

I use the $15 aluminum disk I got from Koval
Knives. Works like a charm.

My motor is a cheap(taiwan made) 1/2 Hp that runs at 1500 rpm. I don't reverse the motor, either.

Tip - don't use a high rpm motor or your rubber disks will fly right off the aluminum disks. Trust me on this one. I had it happen to me.

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Barry
Jones Knives

Do you hear that?
That is the sound of inevitability.

 

[Wapiti]

Thanks for the information and experience; sounds like it isn't crutial to buy the most expensive disc out their (at least not yet).
The motor I have on hand is a "cheap Taiwan- made" motor, 3/4 HP, 1750 rpm. It has been sitting around the shop so I thought I'd make it earn its room and board.
Mike: Dual shaft, huh. That is a trick idea. Did you just mount a disc on each end, don't need to reverse then? Might have to consider that.

Barry (& Mike): Tell me more about the rubber you attached. Where did you get it, how hard is it and just how did you cut it to a nice circle?
I have some 1/4" thick rubber matting that is used as an underlay under carpets in cement floor office buildings. It is pretty firm, is made up of recycled rubber, kind of speckeled looking. I use it for all kinds of stuff from backers for sanding blocks to anti-slide pads for tools, etc. It is great stuff but I don't know if it would work for this.
Thanks.