Disc Sander Question

I just bought a Harbor Freight 10" Disc Sander.

If I place a straight edge across the face of the disc, it's not flat. It is "higher" in the center of the disc, i.e. the straight edge rocks from side to side. With the straight edge held flat against the one side of the face, there's about a 1/16"gap at the opposite edge of the disc.

I'm new to disc sanders, so I'm not sure if this is an issue or not.

Thanks for your comments on this situation.

Reply to
DerbyDad03
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Its an issue. But then its Harbor Freight, I'd return it and bring your straight edge with you if your planning on buying another from them.

Reply to
Rich

----------------------------------- The answer is "Yes" and "No".

You can find disc sanders that are tapered just as you describe and there are disc sanders that are totally flat.

You can even find a 10" sanding disc that is designed to fit a table saw that is tapered on one face and flat on the opposite face.

Supposedly the tapered face is designed to produce a jointed edge.

I wasn't to successful when I tried it, but I'd chalk that up to operator error as much as anything.

Personally I'd take it back to H/F and buy my power tools from somebody else.

Lew

Reply to
Lew Hodgett

Not blaming you for wanting to save some money but you might not be able to find a place that sells lower quality tools. For a sander that size expect to pay in the $150~$200 range for something tollerable.

With a surface like what you described you might be lucky to be able to keep sand paper stuck to the surface.

Reply to
Leon

It's called a beveled disk.

If you think on it, you'll see that the center of a rotating disk moves much less abrasive against the work than the outer edges. The beveled edge evens out the contact. If you push a piece of work against the entire surface, the parts of the work in contact with the outer edges of the disk will have more material removed than the center.

Also a beveled disk allows you to use a disk sander as a joiner.

Reply to
HeyBub

Does it wobble, too? I'd return it.

If you're trying to flatten a surface, it will be a big issue.

Some choices:

1) Return it to HF and measure the other models they have in stock, taking the best one.

2) Return it and try one of their 12" models for $35 more. If you used a 20% off coupon, be sure they apply that discount to the new purchase price.

3) Return it and call Grizzly. Have them ensure that you'll get a flat one if you order from them, then order it there.
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12" I get $191.65 as a delivered price to Oregon. YMMV.

G'luck!

-- Make the best use of what is in your power, and take the rest as it happens. -- Epictetus

Reply to
Larry Jaques

But that only works if you can tilt the disc slightly. I doubt the HF sander has that capability.

I have a tapered disc for my tablesaw. Tilting it to remove the taper so that only a small arc touches the wood, and using the rip fence, I can get a pretty smooth edge.

But unless I've got several pieces to do it's more trouble to set it up than it's worth.

Reply to
Larry Blanchard

No wobble at all. I would have already returned it if it did.

Now I'm really confused. Some say that it's a beveled disk and can be used as a joiner, you say it's an issue if I try to use it to flatten a surface. Isn't a joiner used to flatten a surface (edge) for gluing?

A fine suggestion, if I feel like taking the plastic straps off the boxes, cutting the packing tape, removing the packing foam, lifting the units out of their boxes and taking them out of the plastic bag. Then, after checking each disk - 'cuz I'm a nice guy - reversing the whole process and packing them all up again. ;-)

Why would switching to a 12" model ensure that I would get a flat disc?

That's a bit high for my needs. $89.99 - $20 (on a $100) purchase fit my budget (and gift cards).

As far as what I plan to use it for (mostly rounding the corners on wood (and aluminum) stock) the "bevel" might not be an issue since I'll really just be using the down stroke side of the disc anyway.

I'm really just curious if that's how it's supposed to be.

Thanks!

Reply to
DerbyDad03

HB:

Brilliant observation. Any point on the disc travels and cuts faster as it is more distant from the center, which the taper adjusts for.

An inventory of the varying utility of the disc configurations Lew mentioned would be illuminating.

Regards,

Edward Hennessey

Reply to
Edward Hennessey

How does one use a disc sander as "joiner"? I'm just not seeing that.

Reply to
DerbyDad03

So does everybody else. Never try to do so otherwise.

Hard to say.

The ones with a built in bevel are meant for saws where you can tilt the plate so the "bent" part is vertical; once done you don't have to worry about the board catching the leading edge of the disk (in addition to being able to join). The same holds true with your disk (except for the joining).

I don't buy the idea about the edge being set back so it won't sand so fast...if it isn't touching the wood it isn't going to sand regardless of how much faster the edge is traveling relative to the center. Cute idea though.

The center on mine is slightly higher too but not by 1/16, more like a RCH. If I want to square up an end I pass the wood from right to left; the center sands away slowly (good, doesn't burn the wood as easily) and if there is still wood to sand the edge whisks it off more rapidly but there is less pressure. You shouldn't be trying to take off 1/16 in one pass, though.

Finally, if you just have to have the plate square, set the miter gauge so it is so.

Reply to
dadiOH

In news: snipped-for-privacy@f31g2000pri.googlegroups.com, DerbyDad03 spewed forth:

another option if you truly need it flat is to take the disc to a machine shop and have them machine it flat. It should mill easily, since I'm assuming the plate is aluminum

Reply to
ChairMan

On 3/27/2011 4:32 PM, DerbyDad03 wrote: ...

Simply set up a slight angle and run the opposite edge along the disk against the fence and you'll end up w/ a sanded straight edge on the other side -- a poor man's jointer if lacking one (or the obvious better expedient of a hand plane).

--

Reply to
dpb

It's "jointer", not "joiner". A flat sanding disc will leave arcs on the wood. If the disc is tapered and then tilted so it is vertical, only a small area of the disc touches the wood, thus eliminating the arcs. This gives a smooth edge. A jointer leaves machining ripples on the edge so still needs a little sanding - the disc does not.

That said, it's often easier to sand or plane out the ripples than it is to set up the sanding disc on the table saw :-).

Reply to
Larry Blanchard

With a rigid disc, only the high part ever contacts the wood unless you run it through at an angle corresponding to the taper.

Reply to
Larry Blanchard

LB:

Agreed. Wouldn't that be the procedure? If not--and you are using a flat disc and flat piece of wood--what would the effect of the differential speed of the disc at points progressively further from the center be on the piece sanded?

I have a tribe of different sanding machines but since no fixed-disc, stationary unit is among them, it would be worthwhile to a have the benefit of experienced understanding which relates to my earlier inquiry about the use of discs of varying profiles.

Regards,

Edward Hennessey

Reply to
Edward Hennessey

"It's all in how you use the tool."

Yabbut, first you have to talk the HF knuckledraggers to bring them all down to you to check.

It might not, but the more expensive tools get closer scrutiny at all the Red Dragon Noodle and Machine Tool factories, don'tchaknow?

there.http://www.grizzly.com/products/12-Disc-Sander/G729712">> I get $191.65 as a delivered price to Oregon.  YMMV.

I hoped against hope that wasn't the case.

What does the Japanese translator for the Chinglish translated booklet say about this parameter?

If it's not, get a set of carbide lathe tools and a lathe manual so you can learn how to turn down the center to flat. ;)

-- If the only prayer you ever say in your whole life is "thank you," that would suffice. -- Meister Eckhart

Reply to
Larry Jaques

In their dreams. Move along, nothing to see here.

-- If the only prayer you ever say in your whole life is "thank you," that would suffice. -- Meister Eckhart

Reply to
Larry Jaques

...and then only if it's a flat taper, not a crown.

-- If the only prayer you ever say in your whole life is "thank you," that would suffice. -- Meister Eckhart

Reply to
Larry Jaques

You do realize that I bought a Disc Sander, not a Sanding Disk, right?

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Reply to
DerbyDad03

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