rimcanyon
Diamond
- Joined
- Sep 28, 2002
- Location
- Salinas, CA USA
My 1949 10EE originally came with a Monarch collet closer, as did the 59. The one on the 49 was not included with the lathe, so I decided to use the 59 collet closer on the 49 since it is a mfg. lathe. OK, this is where the fun begins:
The Monarch collet closer attaches to the spindle using two dog point setscrews that anchor in holes in the spindle. On the 49, those holes were about 1” from the end of the spindle. On the 59 they are about 4” from the end. I am using a late 60’s spindle on the ‘49, which has no holes, but I wanted to include the info about the 49 because I think it is a clear indication that the design changed between 49 and 59.
The lever for the collet closer pivots on a cast piece that attaches to the upper headstock cover. On the 49 the pivot piece was about 4” wide; on the 59 it is about 3 ½” wide.
The pivot pin for the 49 was originally a single long pin that was removed from the top. The 59 uses a pair of pins inserted from top and bottom and held in place by setscrews.
The lever for the closer is angled up on the 59; it is horizontal on the 49.
I believe that the 49 collet closer is identical to that used on a round dial machine, based on my recollections of owning a 43 round dial 25 years ago.
So as to fitment of the 59 collet closer, I ran into some issues, some I haven’t solved yet.
The closer was a tight fit, I used all thread to bring it home, but it works well. I have tried it with several different 5C collets using a Monarch 5C nose piece. The Hardinge collets seem to have full threads from the start; with those I get about 5-6 threads of engagement. Some 5C collets have slightly tapered ends, i.e. the first couple threads are low. So with those I get 3-4 threads of engagement. What is a good target for this value? I still have some room to pull the closer in tighter, but the end of the draw tube is currently flush with the end of the spindle. This may not be a useful observation, since some 5C spindles have more of a flat on the end than others. I would be interested to know whether the draw tube is flush, recessed, or stands proud of the end if you have a lever collet closer. This is in the relaxed position.
The angle of the collet closer handle introduces a clearance problem on the 49. I.e. with the handle horizontal as the original was on the 49, the grease fitting for the lower cam follower runs into the knob for the middle headstock cover. So I can either re-drill the pivot piece holes in the top headstock cover and angle the pivot upwards for clearance, or I can move the grease nipple for the cam bearing. The new McGill cam bearings come with a pair of small tapered plugs, so they allow you to plug both ends and allow grease to come in through the center drilled hole in the shaft, so changing the location for the grease fitting is feasible. The original cam bearings have a grease fitting in the end opposite the bearing and no plug at the other end, so I assume Monarch thought that some grease should escape to lube the slot on the collet closer.
I hope all this is clear. Would be interested in others’ thoughts about this. Have any of you gone through this before and installed a later model Monarch lever collet closer on an early machine?
-Dave
The Monarch collet closer attaches to the spindle using two dog point setscrews that anchor in holes in the spindle. On the 49, those holes were about 1” from the end of the spindle. On the 59 they are about 4” from the end. I am using a late 60’s spindle on the ‘49, which has no holes, but I wanted to include the info about the 49 because I think it is a clear indication that the design changed between 49 and 59.
The lever for the collet closer pivots on a cast piece that attaches to the upper headstock cover. On the 49 the pivot piece was about 4” wide; on the 59 it is about 3 ½” wide.
The pivot pin for the 49 was originally a single long pin that was removed from the top. The 59 uses a pair of pins inserted from top and bottom and held in place by setscrews.
The lever for the closer is angled up on the 59; it is horizontal on the 49.
I believe that the 49 collet closer is identical to that used on a round dial machine, based on my recollections of owning a 43 round dial 25 years ago.
So as to fitment of the 59 collet closer, I ran into some issues, some I haven’t solved yet.
The closer was a tight fit, I used all thread to bring it home, but it works well. I have tried it with several different 5C collets using a Monarch 5C nose piece. The Hardinge collets seem to have full threads from the start; with those I get about 5-6 threads of engagement. Some 5C collets have slightly tapered ends, i.e. the first couple threads are low. So with those I get 3-4 threads of engagement. What is a good target for this value? I still have some room to pull the closer in tighter, but the end of the draw tube is currently flush with the end of the spindle. This may not be a useful observation, since some 5C spindles have more of a flat on the end than others. I would be interested to know whether the draw tube is flush, recessed, or stands proud of the end if you have a lever collet closer. This is in the relaxed position.
The angle of the collet closer handle introduces a clearance problem on the 49. I.e. with the handle horizontal as the original was on the 49, the grease fitting for the lower cam follower runs into the knob for the middle headstock cover. So I can either re-drill the pivot piece holes in the top headstock cover and angle the pivot upwards for clearance, or I can move the grease nipple for the cam bearing. The new McGill cam bearings come with a pair of small tapered plugs, so they allow you to plug both ends and allow grease to come in through the center drilled hole in the shaft, so changing the location for the grease fitting is feasible. The original cam bearings have a grease fitting in the end opposite the bearing and no plug at the other end, so I assume Monarch thought that some grease should escape to lube the slot on the collet closer.
I hope all this is clear. Would be interested in others’ thoughts about this. Have any of you gone through this before and installed a later model Monarch lever collet closer on an early machine?
-Dave
