Stupid idea for lathe attachment

I figure some of you out there must have done this before!
I just got an Optimum D650 lathe (see link 1), and I?d also like to have
a 12? disc sander in my shop, but in my country (Germany) they are quite
expensive, even used. I?m thinking of trying to kludge one on to back of
the lathe, and mount a tilting table to the back cover (see link 2). This w
ould save space, and I?m not that busy at the moment.
The biggest problem is that the end of the spindle is not threaded, and the
re?s not much to attach to back there. My idea is to mount the disc plate
to a long rod which goes all the way through the spindle bore and is then
held by the chuck. Since the spindle bore is only 26mm, I?d need to make
some sort of adapter ring to make everything stable (See drawing ? link 3
). I feel like this should work, if a bit quixotic. Any ideas on whether o
r not I?m on the right track, or if there would be another way to attach
the disc to the spindle? Ideas on the tilting table? I'm planning on doing
everything with aluminum, since I don't have a milling machine.
Since I must regularly open the cover to change speed and feed rate, the wh
ole business must be easy to remove. The cover is fairly beefy, so I think
with some reinforcement bars I can mount a table which would work well enou
gh.
Thanks for all constructive replies. Please no safety warnings! Also, no. I
don't have to worry about voiding my warranty. The machine is twenty years
old!
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Reply to
lostfrom68jay
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e a 12? disc sander in my shop, but in my country (Germany) they are quit e expensive, even used. I?m thinking of trying to kludge one on to back o f the lathe, and mount a tilting table to the back cover (see link 2). This would save space, and I?m not that busy at the moment.
here?s not much to attach to back there. My idea is to mount the disc pla te to a long rod which goes all the way through the spindle bore and is the n held by the chuck. Since the spindle bore is only 26mm, I?d need to mak e some sort of adapter ring to make everything stable (See drawing ? link 3). I feel like this should work, if a bit quixotic. Any ideas on whether or not I?m on the right track, or if there would be another way to attac h the disc to the spindle? Ideas on the tilting table? I'm planning on doin g everything with aluminum, since I don't have a milling machine.
whole business must be easy to remove. The cover is fairly beefy, so I thin k with some reinforcement bars I can mount a table which would work well en ough.
I don't have to worry about voiding my warranty. The machine is twenty yea rs old!
Is that a speaker hanging in pantyhose?
Reply to
spamTHISbrp
Yeah. Keeps the dust off!
Reply to
lostfrom68jay
I figure some of you out there must have done this before!
-country (Germany) they are quite expensive, even used.
-lathe, and mount a tilting table to the back cover
-busy at the moment.
Maybe you could get some ideas from wood lathes with adapters to turn oversized bowls on the left end of the spindle.
I greatly prefer a belt sander, which removes material at the same rate everywhere. Disc sanders don't flatten surfaces very well because the outside cuts faster. My father had a disc for his Shopsmith. The paper came partly unglued and gouged the edge of the saw table.
I lived in southern Germany in the early 1970's. You have some first-class hobby stores there!
And a milder climate. Ours is like central Russia, +40C in summer and -20C in winter.
jsw
Reply to
Jim Wilkins
I have not doee this, but if I were to do so I would machine the adapter wh ere it contacts the rear of the spindle with a taper. Not a taper that wil l hold by itself, but one to center the adapter. And I would hawe a thread ed section at the other end of the adapter. And use a nut to put a little tension on the adapter. That way you are not depending on the lathe chuck to hold the adapter. Probably not needed, but it is what I would do.
Dan
Reply to
dcaster
I have not doee this, but if I were to do so I would machine the adapter where it contacts the rear of the spindle with a taper. Not a taper that will hold by itself, but one to center the adapter. And I would hawe a threaded section at the other end of the adapter. And use a nut to put a little tension on the adapter. That way you are not depending on the lathe chuck to hold the adapter. Probably not needed, but it is what I would do.
Dan ================== I adapted a larger lathe's longer 5C collet closer tube to mine by making a brass bushing that is a light press fit in the end of the spindle and a close running fit on the tube. A shaft clamp serves as the thrust-bearing flange on the collet closer. You could make a similar steel collar that presses onto the shaft and is retained from sliding by the disc, and turn the outside to a snug or tapered fit into the spindle like Dan suggested.
Threaded rod works well for shafts that require short built-up areas of larger diameter. Jam two nuts together very tightly and turn them to the shape you want. jsw
Reply to
Jim Wilkins
I've chucked up all kinds of wild things on my mini lathe in a pinch. Its always handy to have a horizontal motorized spinny thing in a pinch, but I would have some concern about abrasive grit from the sanding disc getting into the works of the lathe or even on the ways.
That being said, I kinda feel the same way as others about belt vs disc. I have two combo machines and I use the belt parts all the time, but hardly ever use the disc. I do have a tapering operation I do on one of them, but I have seriously considered converting the other over to a buffing wheel with a mandrel.

Reply to
Bob La Londe
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How many times have you had to pull that chuck wrench out of your chest?
David
Reply to
David R. Birch
Very astute observation!
Reply to
Tom Gardner
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? I see a '?' with my system where I would expect a '"' for inches. Did you compose this with a web browser? On Yahoo, I suspect so. Spell out units if using a web browser, as they tend to install weird characters which won't work with a plain text newsreader or e-mail client.
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.
And -- another safety point brought on by your photo of the lathe itself. *Never* leave the chuck key in the chuck -- even just for a photograph. If you hit the power switch, that chuck key gets thrown at a rather impressive velocity -- assuming that it does not simply slam into the ways of the lathe, damaging them.
Is the lathe large enough to turn a 12 inch disk of aluminum? You'll have to saw it to something a bit oversized and turn it down.
Also -- does it have the horsepower to proerly turn a 12 inch sanding disc at the maximum speed which it can achieve.
Anyway -- I would turn a plug which would just barely fit into the open end of the spindle, then drill most of the way through and tap for a large setscrew (say 1/2 inch or so (or 13 mm or so), with a cone point), and then using a hacksaw or bandsaw if you don't have a milling machine, cut through the diameter on the inside end twice -- the second at 90 degrees to the first. At this point, when you run the setscrew into the center it will eventually hit the bottom of the drill hole and expand the plug to grip it firmly into the spindle.
To this you will bolt your 12 inch disk. (Actually -- do this bolting before you turn the disk to diameter, so it will be concentric.
If you punch a hole in the center of the sanding disc (which is moving too slowly to be of use sanding anyway) you can reach through there with the Allen (hex) key to loosen the setscrew and pull off the disc.
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 expanding split grip I described above) and get a used electric motor of adequate size and bore the hub to slip on the end of the motor shaft. Get at least a 3600 RPM (really marked something like 3450 RPM or so) and I think at least a 1/2 HP motor for that large a disc -- and more likely a 1 HP motor. (In Germany, probably marked in KW instead of HP, figure about 0.750 KW is about one HP.) Sorry for the inch figures, but I *think* you used inches for the diameter of the sanding disc, anyway, even though the ID of the spindle is just slightly over 1" (25.4 mm). :-)
If you can't get a motor faster than about 1750 RPM, then plan to add a pair of pulleys and a belt to increase the speed. Mount the motor below a workbench, and the disc above it, so the weight of the motor can put tension on the belt.
Drill the hub underized, and use a boring bar to enlarge to a slip fit on the motor shaft -- a drill bit will typically be oversized.
Sorry! Already typed the one about the chuck key. And I could not let that one go unremarked, anyway.
But you *do* have to worry about abrading the accuracy out of the bed.
Good Luck, DoN.
Reply to
DoN. Nichols
Haha, I saw that too and wondered why.
I figured the pantyhose were a neat solution to hang something like a speaker from an existing nail in the wall.
Reply to
Kennedy
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 near by with a small shop and a bigger lathe, however. The standard disc size he re is 300mm, or 11.8 in.
I agree that having the disc on the chuck side is a bad idea, but if I moun t it to the back, I don't see so much dust hitting the weighs.
Yeah, I have a bad habit of doing this. Thanks!
Good Idea!
At this point I would just break down and buy a sander. Now that I think ab out 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 th at it would be so cool to have one sticking off of the back of the lathe, s aving a lot of space.
Thanks Don, I used to post as Robobass when I had a shop in Brooklyn back i n the '90's. Not many of the old guard seem to still be around! I've been w ithout toys since I went overseas 12 years ago, and am now putting together a proper shop once again.
Reply to
lostfrom68jay
When I had an art fabrication shop in NY me and my co-workers found the 12in. disc sander to be one of the most useful tools. I suppose it depends on what you're doing.
Not anymore!
True, it has only frozen in Cologne one or two days this winter. It's not usually this warm though. Last year my daughter x-country skied to kindergarten for much of January!
Reply to
lostfrom68jay
Well, true on both counts. I make a lot of dust. That was the impetus to co ver the speakers with pantyhose (black would probably look better), but the n you also have a very practical way to hang the speaker. I'm an incorrigib le recycler. All of the cabinets, tables, shelves, and stands in my shop we re collected from refuse heaps, or neighbors planning to toss their stuff a nd me offering to save them time and trouble. In fact, a lot of the fixture s in my apartment are made from found objects. Over the years, I have picke d up a lot of good wood, and some high end Hi-Fi gear which needed only min or repair. Call me a dung digger, but I bet my stereo is better than yours!
Reply to
robobass
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 Googled "Bandschleifer preisvergleich" and see what you mean about their cost:
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The Westfalia MD150 looks decent for wood and the Scheppach 700 for metal or curved wood edges. I have a similar Delta (minus the "Teller") with a 1" belt that I use more than the wider one, mostly for deburring and rounding cut metal edges with the more flexible unsupported area above the platen.
The Guede, Ferm and Berlan resemble the Chinese imports sold here for $50. They are a lot better than nothing, though a 350W motor isn't really adequate for more than delicate finishing.
You do need some sort of Staubfaenger unless you work outdoors, to keep the finer airborne grit off the lathe. Even wood sawdust can quickly cause rust if it's damp.
jsw
Reply to
Jim Wilkins
JSW,
I already have the Westfalia MD150, or at least a version which I got cheap from an Aldi type store. 2 inch wide belt. Very useful. And still works we ll after 10 years regular use! I couldn't pin down your other suggestions, but "Ferm" is a brand which was sold through the now defunct "Max Bahr". B ased on my experience with their biscuit joiner, I would never buy anything with this mark. I think that it is also true in the USA that the machines sold in the big box stores are intentionally made crappy. I don't get it. D o the big retailers want to frustrate you and force you to hire contractors ? It's sort of like restaurants. In Europe, at least, the closer you are to a major train hub, the worse the food is. I want to ask sometimes, "would it have cost you any more money to serve me a pizza which didn't taste like poop?" I just don't get it...
Reply to
robobass
Yeah, black, and cut off the excess, wot? It looks mighty tacky.
Reply to
Larry Jaques
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Reply to
Jim Wilkins
Hey snipped-for-privacy@yahoo.com You wouldn't say "me found the 12in. disc ..." etc. Ergo, don't say "me and my co-workers found..." etc. It is "I found", or, "I and my co-workers found", or, "My co-workers and I found".
You've been watching too much television with bad scripting.
Ivan Vegvary
Reply to
Ivan Vegvary
JSW,
I already have the Westfalia MD150, or at least a version which I got cheap from an Aldi type store. 2 inch wide belt. Very useful. And still works well after 10 years regular use! I couldn't pin down your other suggestions, but "Ferm" is a brand which was sold through the now defunct "Max Bahr". Based on my experience with their biscuit joiner, I would never buy anything with this mark. I think that it is also true in the USA that the machines sold in the big box stores are intentionally made crappy. I don't get it. Do the big retailers want to frustrate you and force you to hire contractors? It's sort of like restaurants. In Europe, at least, the closer you are to a major train hub, the worse the food is. I want to ask sometimes, "would it have cost you any more money to serve me a pizza which didn't taste like poop?" I just don't get it...
==================
I avoided large cities if possible. The Army bases I visited to work on comm gear were either on the edge of town or in remote areas like Vilseck. Generally I could find a good meal in a small to medium town's Gasthaus, or a restored castle's restaurant. I stumbled onto an excellent pig roast in the banquet hall of a castle far off the tourist track where an American GI like me was still a curiosity.
I had a set of the Shell road maps that showed contour lines, buildings, ruins etc in enough detail to plot artillery fire. I bet the Russians had them too.
The exception was when my parents came over to visit. As neither knew German I took them to downtown places more likely to speak English. The Chinese restaurant near the Dom in Koeln wasn't bad. I don't think they really appreciated JaegerSchnitzel or Spaetzle as much as I did.
jsw
Reply to
Jim Wilkins

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