Shopsmith Forums

Hi folks,
I haven't used the disc sander function much as I have had a stand along unit. Trying to wean myself off of other machines I am ready to move forward. My disc is aluminum from my greenie. I think I have see the steel discs are better and then there is the how to fasten the sandpaper issue.

I know you guys have probably already beat this one up before but help a guy out and I will send some business Shopsmith way.

Bob

I have two 500s, one with steel and one with aluminum disc. The steel is heavier, but to tell the truth I don't have a preference. Grit and speed seem to influence cutting action more. I buy 12" sandpaper discs with peel-off paper cover glued backs. I have also used rubber cement.

Having started with aluminum disks, I prefer them. Lighter, less inertia coming up to speed, but my favorite 'attribute' is the slightly tapered outer circumference.

The ribs on the backside however really stir up the air(and dust).

Other than all that, they are functionally equivalent.

Guys, since I'm currently without a disc, which should I look for, the ER/early MkV disc, made out of aluminum, or the later steel disc. Which one is less prone to warpage?

Or, should I just continue to buy up Craig's list stuff, and see what happens?

No, I don't want just one disc, but a few, so I don't have to keep changing paper.

Currently without a sanding disc, since someone STOLE
all my ER stuff. (Search " rusober " as a "member" here, and you'll see what I'm talking about. He's got ALL my old stuff, and paid exactly SQUAT for it. I
however, paid HUNDREDS for it.) In fact, he charged my old slumlord $500 for my old ER.) (Yes, "slumlord is a glorification of his "true" calling.)

steve

skou wrote:Guys, since I'm currently without a disc, which should I look for, the ER/early MkV disc, made out of aluminum, or the later steel disc. Which one is less prone to warpage?

Or, should I just continue to buy up Craig's list stuff, and see what happens?

No, I don't want just one disc, but a few, so I don't have to keep changing paper.

Currently without a sanding disc, since someone STOLE
all my ER stuff. (Search " rusober " as a "member" here, and you'll see what I'm talking about. He's got ALL my old stuff, and paid exactly SQUAT for it. I
however, paid HUNDREDS for it.) In fact, he charged my old slumlord $500 for my old ER.) (Yes, "slumlord is a glorification of his "true" calling.)

steve

I only have gut feel, but I think the cast aluminum ones are less 'warp' prone.

There are three versions on the cast aluminum disk - early 10E(3/16" setscrew), late 10E(3/16" hex setscrew) and Mark 5(5/32" hex setscrew). The 10E versions have a different pattern on the back.

There are other sized disks. I believe a 10E 9" and a Mark VII 10"(with conical like backside).

JPG40504 wrote:Having started with aluminum disks, I prefer them. Lighter, less inertia coming up to speed, but my favorite 'attribute' is the slightly tapered outer circumference.

The ribs on the backside however really stir up the air(and dust).

Other than all that, they are functionally equivalent.

I agree 100% with JPG with four comments/questions.

1. Aluminum disks run cooler (not that there is a big difference with Steel.

2. The slight outer circumference taper is a plus except it is hard to keep the sand paper stuck down on the taper. Any suggestions for how to keep that stuck down?

3. It's hard to find aluminum disks on e-bay/craig's list that run true (don't wobble a bit) Beware!

4. My first aluminum disk that came with my brand new Mark 5 in 1975 has machining spots on the back which I presume were done for balancing. Is that common? I've never seen another disk machined like that.

Rick

I use spray on adhesive to attach my sanding discs. I get it at craft stores for ~$6/can. I've also used rubber cement in the past.

As far as the steel vs aluminum argument, I'll add that there are also 2 versions of the steel disc arbor. The newer version is longer and allows use with the latest version of the lower blade guard for dust collection purposes.

rickm808 wrote:4. My first aluminum disk that came with my brand new Mark 5 in 1975 has machining spots on the back which I presume were done for balancing. Is that common? I've never seen another disk machined like that.

Rick

My '78' Mark 5 with original aluminum disk has injection sites, but only the faintest of machine marks that might have been for balance.

I never thought about the fan effect from the ribs, but have noticed that the ribs can trap fine dust/resin which might throw balance out over time if not cleaned, like a saw blade's teeth.

I also never noticed the taper before - thanks for the insight on this. I don't have a clue how you would securely mount sandpaper to the tapered edge. For an edge I use a French wheel on my Delta lathe which cut lips nicely. If you are unfamilar with this tool, check out:

https://www.google.com/search?q=french+ ... 14&bih=652

Years ago when I was in graduate school I worked in a pipe shop where I learned how to turn briar pipes and cut mouth pieces. The French wheel is a must for this kind of work.

My '57 Greenie has an aluminim disc. I have never noticed it not being flat. Is that something that happened on a regular basis due to heat? My "80s model didn't come with a disc so maybe I will buy a steel disc and try both.