On 2014-01-24, wrote:

My first question is "can your lathe produce sufficient speed for
a sanding disc to work well?". It looks as though your maximum RPM is
2200. Normally, the speeds are significantly higher. Is that 12 inch
diameter?

Good points. The machine is 750 watts, and yes, 2200 rpm max. I can
turn a max of 14.5cm radius, so the disc could be up to 11.4 in. I have
a guy nearby with a small shop and a bigger lathe, however. The standard
disc size here is 300mm, or 11.8 in.

Hmm ... can you handle a short workpiece at a greater diameter?
Is the 14.5 cm radius based on clearing the carriage, or on just barely
clearing the ways?

It doesn't look to be a gap-bed lathe, so that is not an option
to get a bit larger diameter workpiece in there.

Second -- how are you going to keep the sanding dust from
rapidly abrading the ways of the lathe? I would put a disc sander as
far as possible away from the lathe or any other precision machine
tools. The grit from the sanding disc is *very* bad for the ways.

I agree that having the disc on the chuck side is a bad idea, but if I
mount it to the back, I don't see so much dust hitting the weighs.

Sanding dust goes *everywhere*. If you are going to be sanding,
cover the ways, carriage and tailstock with newspaper wet in oil to trap
the dust -- and do as much as you can to keep the dust from getting
inside the headstock covers, as you will abrade the threading gears as
well.

And -- another safety point brought on by your photo of the
lathe itself. *Never* leave the chuck key in the chuck -

Yeah, I have a bad habit of doing this. Thanks!

Turn back a bit behind the square end to be a press fit for a
compression spring -- two diameters -- one to allow the spring to move a
bit, and one closer to the T-handle to trap the spring. Push on a
spring which is long enough to push the key out of the socket whenever
your hand is not on it -- and make a tube to hold it the rest of the
time -- someplace easy to reach, like the front edge of the table it is
mounted on. Easy enough to bolt something onto the perforated angle
iron which is supporting the table top. Or ever thread some coat-hanger
wire through two holes to make a complete loop plus a bit before turning
into the holes.

Some chuck keys (such as my Bison 6-1/4 inch one) come with such
a spring. I've left mine in place, though some pull them off.

[ ... ]

The cover is fairly beefy, so

[ ... ]

Again -- I would not put sanding operations this close to the
precision machine surfaces.



Better to go ahead and make the disc and hub (without the

[ ... ]

At this point I would just break down and buy a sander. Now that I
think about it, by the time I add up the hours and Euros to do any of
this it seems to not pay off. I can get a lower end machine for about
$240. It's just that it would be so cool to have one sticking off of the
back of the lathe, saving a lot of space.

I've got a three-wheel benchtop bandsaw which includes a
mounting for a disc on the fastest running hub -- and that might work
well, as there is not as much precision machinery in the bandsaw. :-)

A pity that you can't find Harbor Freight there. Yes, they have
really poor quality -- but also very inexpensive. I got a little
disc/belt sander from them about a month ago. I had to pull it apart
and properly re-align it so the disc plate did not bind on the guard.
And do a little work to minimize the wobble of the disc plate. But for
less than $30.00, it was worth it.

And in their monthly flyer, they've got a 6" disc, 4" belt for
$59.99 (regular price $99.99, but I don't think *anyone* pays regular
price. :-)

Is there some importer there like Harbor Freight?

Thanks Don, I used to post as Robobass

I recognize that name. Welcome back!

when I had a shop in Brooklyn
back in the '90's. Not many of the old guard seem to still be around!

Nope. Only those who are willing to keep a really active
killfile. The political junk from trolls has been chasing off most of
the better regulars.

I've been without toys since I went overseas 12 years ago, and am now
putting together a proper shop once again.

I'm sort of putting my shop back together after a fire badly
smoked it and rusted a lot of things. Since the shop has been cleaned
out and re-drywalled it I've been setting things back up and using
something called Evapo-Rust (which is actually carried by Harbor
Freight, and does the job without containing hazardous chemicals. I've
been de-rusting BXA sized toolpost tool holders, and smaller ones for
the little Emco Compact-5/CNC lathe (Dickson style), as well as various
other small tools.

Good Luck with re-building your shop,
DoN.

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