tyandnan
noticing nice landscape pebbles
Member since April 2014
Posts: 96
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Post by tyandnan on Aug 16, 2014 17:43:05 GMT -5
Hi all,
I recently found an old lortone sa - 8 arbor on craigslist for $75. It didn't have a motor, but it came with a couple of the cheaper 8" drums (not the really nice expando's, but the two-piece metal drums with a rubber insert). It has a polishing wheel on the right side as well. I'll try to get a picture up later.
I found an old furnace motor for free. It is 1/3 horse power and runs just over 1000 rpms. First, will a furnace motor this size work? Second, what RPM's should I be shooting for? The arbor has 3 different pulleys, and the motor currently doesn't have a pulley, so I can buy what I need to get the right speed.
There is a little rust on the machine, but not too bad. What is the best way to prep the machine for a repaint, and what paint is best to use?
I think that's all to get me started. I'll have plenty of questions on wheel options and what not in the future. . .
Thanks in advance, Tyson
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milto
starting to spend too much on rocks
Member since January 2010
Posts: 162
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Post by milto on Aug 16, 2014 18:45:23 GMT -5
The speed is 1750 RPM, and it is odd to have a furnace motor running 1000 RPM, as most are 1750. 1/3 HP is usable, the wheel that will draw the most are the lower grits (80-100). Good luck, the bearings are replaceable, just don't buy them from Lortone as they are available much cheaper.
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tyandnan
noticing nice landscape pebbles
Member since April 2014
Posts: 96
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Post by tyandnan on Aug 16, 2014 19:25:09 GMT -5
The speed is actually around 1050 or something lower than 1725. Couldn't find any free 1725s.
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Post by Peruano on Aug 16, 2014 19:25:41 GMT -5
Find yourself a pulley chart to calculate what size of pulley to use on your motor to generate that 1750 prefered for the business end. I'm going to guess that the major stress on an arbor is the start up and a capacitor start motor would be preferable especially if you are tending to the smaller power end needed for the wheels. If the wheels on the machine are the thumpers (slot in the wheels so that belts of different sizes can be clamped in), you will probably want to change to expandos (closed belts that are tightened on the rubber coated wheels when the centrifigal force of the wheel expeands their size. Easy smeezy for changing and cheaper than diamonds when you have a limited number of wheels to use for the entire process. Enjoy the rebuild but realize that the spacing on the wheels may change slightly if you change them due to hub thickness, so you may have to space the arbor differently as you reassemble. I've been thinking about these issues as I'm planning the rebuilt of an old Highland Park arbor. I hope I have not mistaken any of your questions. Tom
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Aug 16, 2014 23:24:01 GMT -5
I have a couple of those split drums too. The max. speed is supposed to be 1750 R.P.M., so figure your motor pulley diameter using the diameter of the smallest of the three on the arbor. I did a rebuild on one of those for a friend some time ago, made a pivoting motor mount to tension the belt, and it also slid sideways to provide proper belt alignment. Moved it sideways with a ball-ended tube sorta like a floor shifter on a car, and had one hole in the slider housing three holes in the sliding bar to drop a positioning pin in. Sandblasted the metal and painted with Hammertone paint.
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tyandnan
noticing nice landscape pebbles
Member since April 2014
Posts: 96
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Post by tyandnan on Aug 17, 2014 1:51:33 GMT -5
So I want to shoot for a 1725 speed then? And said blasting is the best way to remove old paint/rust? I haven't figured how I will mount the motor yet, so I appreciate the ideas. Also, this motor does have a capacitor' so I should be okay in that department.
As far as the arbor and pulley system, I believe it is still functional, but I will have to see when I get the motor hooked up.
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Post by johnjsgems on Aug 17, 2014 20:30:42 GMT -5
1/3 hp should work. Try what you have before buying another motor. Most furnace motors have an external run capacitor. The motor mentioned is a motor with a start capacitor (in a metal housing attached to motor). With 8" wheels it would be nice to have the starting torque of the capacitor but maybe not necessary with only two wheels. If you have to replace motor try to find a 1/2 hp. If your furnace motor says "continuous air over" or words to that affect it won't work. Many residential furnace motors are multi speed and will have a black wire for high and red for low. His drums are Lortone Exact Span, not split drums. Exact Spans are close to being as bad as split drums. They are a non standard size and nobody makes diamond belts to fit. Worse thing is you have to pull center apart to change belts which would be tiresome with one drum. Kingsley does carry the Exact Span size belts which are a little smaller than standard. If it is your only unit I would put an 80 or 100 grit 8" diamond wheel on left and 8" X 3" expando on right.
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Post by johnjsgems on Aug 17, 2014 20:35:35 GMT -5
Finishing depends on condition. If you have a sand blaster and metal is in good shape that works. Lortone uses such thin metal I would be really careful. I usually wire brush and clean it as well as possible and then spray with several coats of hammer tone paint. It can go right over rust and bumpy finish hides any surface pitting or flaws. Auto parts stores have a product called "Rust Stop" or something like that. Spray any bare metal/rust and it turns black. Then paint over.
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gemfeller
Cave Dweller
Member since June 2011
Posts: 3,805
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Post by gemfeller on Aug 17, 2014 20:59:33 GMT -5
Finishing depends on condition. If you have a sand blaster and metal is in good shape that works. Lortone uses such thin metal I would be really careful. I usually wire brush and clean it as well as possible and then spray with several coats of hammer tone paint. It can go right over rust and bumpy finish hides any surface pitting or flaws. Auto parts stores have a product called "Rust Stop" or something like that. Spray any bare metal/rust and it turns black. Then paint over. I used that procedure on a couple of Lortone arbors except I painted with epoxy paint. It held up very well but the only color I could find was kind of a sickly yellowish cream color. But function trumped appearance and I cut a lot of stones on those. I retired them when I bought my Genie. BTW, I still have them and would make someone a nice deal if they'll pick them up from me -- no shipping (southern CA, Ventura County.) They might need bearings and I think I have those too. PM me if interested.
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tyandnan
noticing nice landscape pebbles
Member since April 2014
Posts: 96
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Post by tyandnan on Aug 17, 2014 23:47:41 GMT -5
Awesome advice. I will look into it all here and see what I can do.
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Post by Rockoonz on Aug 18, 2014 1:15:37 GMT -5
One of my first arbors was a Lortone SA8 that had rusted pinholes through the base pan I used a POR15 like product, forget the manufacturer.
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tyandnan
noticing nice landscape pebbles
Member since April 2014
Posts: 96
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Post by tyandnan on Aug 18, 2014 9:01:47 GMT -5
The motor says "air over motor", so I guess that means no go?
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Post by johnjsgems on Aug 18, 2014 20:31:35 GMT -5
"Air over" means the motor relies on the heater's blower air to cool the motor windings. It has no cooling fan built in. They won't run long without a good air stream blowing over them. I guess you could run a powerful fan but finding the right motor would be better.
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quartz
Cave Dweller
breakin' rocks in the hot sun
Member since February 2010
Posts: 3,341
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Post by quartz on Aug 18, 2014 23:22:51 GMT -5
I've put a car alternator fan on a couple air over motors, and they work great. I screwed them to the pulley, being careful about proper rotational direction and accurate centering.
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QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,632
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Post by QuailRiver on Aug 19, 2014 2:48:58 GMT -5
Continuous Duty rated 1/3 hp 1725rpm motors are pretty common. They were used on old clothes washing machines and are still used on a lot of hobby grade wood working equipment (drill presses, lathes, jointers, belt sanders, etc), squirrel cage fans, and industrial pedestal fans. I have found used ones for $10-$20 (including the squirrel cage fan) at local auctions. Or if you want to spring for a new one Zoro Tools has several models starting just under $100. A 1/2hp motor will work just fine too. www.ebay.com/sch/m.html?item=221492462594&ssPageName=STRK%3AMEBIDX%3AIT&_ssn=zorotools&_from=R40&_sacat=0&_nkw=1%2F3+1725+motor&_sop=15Check all grinding wheels and sanding drums you will be using to see if they have a Maximum RPM rating on them and never operate the machine faster than that rating. A grinding wheel or a sanding drum breaking apart at 1725rpms can be serious shrapnel. Also if the Lortone machine arbor has a three step pulley then, it works out best to put a three step pulley on the motor as well so when you change speeds the belt will track smoothly. Larry C. Larry C.
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