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Craftsman/Dunlop '49 6" Lathe Chuck Mounting Problem
The plate the chuck mounts to is not perpendicular to the shaft axis.
What is the best way to fix this? Hammering it back doesn't sound like a good idea. I thought about taking the shaft over to a machine chop, bolting a plate to the existing plate, then getting that adapter plate machined flat, then tapped for the chuck. Any other easier/cheaper ideas? I am a beginner with the hands on operation so please use simple words without too many syllables.... One other idea was to fabricate a different chuck mounting in order to use other brand of chucks. Is this a waste of time too? A brief history: I've been saving up for a "real" lathe but do not plan on purchasing for another year. I've been on the lookout for a small bench lathe in order to practice with in the meantime. At a local swap meet last month someone brought this lathe. At least it looked like a lathe under all of the dirt and grime.... But all of the screws felt tight and I couldn't feel any play in the bearings. What the heck. It was only US$25 and the motor alone (1hp GE) was probably worth that much. Plus if nothing else I'll get the education from tearing the thing apart and seeing how everything works. A month of scrubbing, a gallon of acetone, plus paint grease and oil and the lathe looked pretty nice. I took it to the local club meeting and whereas before when I purchased the comments were composed of advice about getting some chain to go along with that boat anchor now many were asking where I got such a nice little lathe g. So I was happy until I started trying to actually machine something today and found the above mentioned flaw. The chuck must have taken a pretty severe whack at some time in its past. The shaft looks straight, it is the mounting plate at the end that is not square as best that I can tell. Gene Horr my name as one word at texas dot net |
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Ah, but this is the cheapo Dunlop model. The chuck does not thread
on. It merely bolts to a faceplate that is welded(?) to the main shaft. That plate itself is not square. Thanks anyway, Gene Horr my name as one word at texas dot net On 16 Aug 2004 03:08:48 GMT, (Fdmorrison) wrote: The plate the chuck mounts to is not perpendicular to the shaft axis. What is the best way to fix this? Make sure the chuck's backplate threads are clean. Run a bent nail or similar in them to clean them out. The chuck's backplate must thread all the way onto the spindle so that it's face "registers" completely against the corresponding face on the front of the shaft (spindle). You must have this full contact for the chuck to run true. For one thing. Frank Morrison |
Ah, but this is the cheapo Dunlop model. The chuck does not thread on. It merely bolts to a faceplate that is welded(?) to the main shaft. That plate itself is not square. Thanks anyway, Gene Horr my name as one word at texas dot net You mean Dunlap? What model is it? All the ones I've seen had narrow threaded spindles. GTO(John) |
On 15 Aug 2004 20:06:37 -0700, jim rozen
wrote: Measure the runout in the chuck backplate, if it's more than ten thousanths or so, you might consider having a new spindle made up. They are straightforward items and if you have access to a slightly larger lathe it is easy to do. That makes too much sense g! Kind of obvious in hindsight, as all great ideas are... I would say it is more than a few thousandths of an inch. GTO(John) wrote: You mean Dunlap? What model is it? All the ones I've seen had narrow threaded spindles. Sorry, Dunlap. I'd have to go get the model number tomorrow but from searching various web sites I got from more than one source that it was the '49 model. From what I read this model was only made for that one year. Both the '48 and the '50 were slightly different designs. Perhaps they went back to the threaded design becuase it was better?.... Thanks, all for the information. I'm leaning towards just making a new shaft (called the spindle?). I was going to buy a three tooth chuck anyway. This would kill two birds with one stone. Gene Horr my name as one word at texas dot net |
Sorry, Dunlap. I'd have to go get the model number tomorrow but from
searching various web sites I got from more than one source that it was the '49 model. From what I read this model was only made for that one year. Both the '48 and the '50 were slightly different designs. Perhaps they went back to the threaded design becuase it was better?.... Thanks, all for the information. I'm leaning towards just making a new shaft (called the spindle?). I was going to buy a three tooth chuck anyway. This would kill two birds with one stone. Gene Horr my name as one word at texas dot net I'm not really familiar with all the different AA lathe models, but I have to think yours was modified or something really weird. They came stock with a 1/2" threaded spindle with a tiny through-hole. Very prone to bending or cracking. First project for folks with these is usually making a new solid spindle. GTO(John) |
That version of the 6" lathe has a small spindle that is often bent by
overpowering the lathe and doing bad cuts. First off, get rid of the 1hp motor and use a 1/4hp motor on the lathe. Then learn to work within the limits of that motor. Second, make up a new spindle using the faceplate and centers so that the upset of the present spindle doesn't hurt the turning. Third, you may want to try whacking the present spindle back towards proper straightness although this will make the spindle a lot weaker than before (bent metal is never as strong as unbent metal). These are really light duty lathes compared to a 10" or larger lathe but some people don't reallly appreciate the need for the smaller cuts and so forth, especially with doing cast iron castings where you really have to dig deep on the first cut to get through the surface of the part. -- Bob May Losing weight is easy! If you ever want to lose weight, eat and drink less. Works every time it is tried! |
On Mon, 16 Aug 2004 03:11:36 GMT, wrote:
||Ah, but this is the cheapo Dunlop model. The chuck does not thread ||on. It merely bolts to a faceplate that is welded(?) to the main ||shaft. That plate itself is not square. Gene Why don't you post a picture to the dropbox? Is it anything like this one? http://metalworking.com/DropBox/Rex_B_small_lathe.jpg Texas Parts Guy |
On Mon, 16 Aug 2004 09:44:39 -0700, "Bob May"
wrote: First off, get rid of the 1hp motor and use a 1/4hp motor on the lathe. Then learn to work within the limits of that motor. g Well, for that part I'm already ahead of you. There isn't a whole lot of tension on the belt. If anything grabs the belt slips right away. I agree the motor is overkill. My thoughts is that it uses a belt for a reason. I had some club member start recommending a tensioning system as the belt is very loose. My thought is that it would sort of defeat the purpose on such a light duty machine.... On Mon, 16 Aug 2004 18:23:06 GMT, (Rex B) wrote: Gene Why don't you post a picture to the dropbox? Is it anything like this one? http://metalworking.com/DropBox/Rex_B_small_lathe.jpg Texas Parts Guy I'll throw some pictures on the web page tonight. I have some before and during and just need to take some "after" tonight. The lathe looks nothing like your link g. Here's what it looks like: http://www.lathes.co.uk/craftsman/img12.gif Looking at the source page it is claiming it as a '48 model, not a '49. Gene Horr my name as one word at texas dot net |
||The lathe looks nothing like your link g. Here's what it looks
||like: http://www.lathes.co.uk/craftsman/img12.gif || ||Looking at the source page it is claiming it as a '48 model, not a ||'49. There is a very active Yahoo group on this lathe. AA and 109 or something similar. Go to Yahoo groups and search on Lathe. Texas Parts Guy |
||Is it anything like this one? || || http://metalworking.com/DropBox/Rex_B_small_lathe.jpg ||Texas Parts Guy || ||I'll throw some pictures on the web page tonight. I have ||some before and during and just need to take some "after" ||tonight. || ||The lathe looks nothing like your link g. Here's what it looks ||like: http://www.lathes.co.uk/craftsman/img12.gif Actually, the compound is the same as on mine. Everything else is different. Probably the same manufacturer - AA - but newer. Mine is ca. 1937. Texas Parts Guy |
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But lots of of folks tweak the small spindles on those
machines, and replace them with exact duplicates. Jim The trick I've seen most done is just making solid spindle for it. Stronger than the original with the oversized through-hole. GTO(John) |
On 16 Aug 2004 14:14:54 -0700, jim rozen wrote:
||In article , ||says... || ||The lathe looks nothing like your link g. Here's what it looks ||like: http://www.lathes.co.uk/craftsman/img12.gif || ||Yep, that's a AA products machine all right. || ||Those are supposed to have a small (1/2-16 IIRC) threaded ||spindle nose. 1/2-24 Texas Parts Guy |
In article , GTO69RA4 says...
But lots of of folks tweak the small spindles on those machines, and replace them with exact duplicates. Jim The trick I've seen most done is just making solid spindle for it. Stronger than the original with the oversized through-hole. The original AA products machines did not have the hole. That was added later, along with the back gears and whatnot. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
On 16 Aug 2004 17:20:47 -0700, jim rozen wrote:
||In article , GTO69RA4 says... || ||But lots of of folks tweak the small spindles on those ||machines, and replace them with exact duplicates. || ||Jim || ||The trick I've seen most done is just making solid spindle for it. Stronger ||than the original with the oversized through-hole. || ||The original AA products machines did not have the hole. That ||was added later, along with the back gears and whatnot. Yep. Mine has a solid spindle with only 1/2-24 threads for the chuck. It appears to also have a recess for a center, but it's pretty well munged. Interestingly, it has a series of belts & pulleys to drive the leadscrew. Might make threadcutting interesting :) BTW, I attempted to build a new spindle from a 5/8 shock absorber shaft. It cut easily, but I could not get it to cut smoothly. Any dea what kind of steel that would be? Any reason it would not be suitable for a lathe spindle? ================================================= Texas Parts Guy |
In article , Rex B says...
||Those are supposed to have a small (1/2-16 IIRC) threaded ||spindle nose. 1/2-24 Thank you, that is indeed correct for the stock version of the machine. My memory error. Jim -- ================================================== please reply to: JRR(zero) at pkmfgvm4 (dot) vnet (dot) ibm (dot) com ================================================== |
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