- Joined
- Oct 18, 2016
- Messages
- 2,872
The screws on mine have never loosed up. Not that it couldn't happen but I wouldn't bother.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Saving a Logan 825
- Thread starter bhusted
- Start date
I want to replace my spring and would like to know if you have found a replacement as mine is very weak.I still need to source a spring small enough for it before I put the pin back.
Thanks!
- Joined
- Oct 18, 2016
- Messages
- 2,872
Backgear latches and springs are also available from Logan. Not as cheap of course.
- Joined
- Dec 25, 2011
- Messages
- 10,552
And it is pretty unlikely that the originals were 3 mm diameter. Given that 3 mm is 0.1181", they are probably 1/8" nominal diameter Measure the wire diameter of the original and try to match it in a 1/8" diameter compression spring.
On another subject, in an effort to see whether or not the manual that we have answered one of your earlier questions, I looked up the spindle pulley and small spindle gear in the Logan 800 Series manual that we have in Downloads. According to the manual, the 800 Series all use a flat belt for the spindle belt. What's the deal?
And on a related subject, another member made the comment that he had never loosened the screw marked "OIL" in his machine. That screw should be removed and several squirts of SAE 20 ND applied either daily if the back gears are often used, before every back gear usage, or at least monthly.
And as to the use of the second screw, according to the 800 Series manual (but see my second paragraph), the second screw should have all of the threads removed from the nose, which fits through a hole in the reduced diameter of the small spindle gear that fits into the pulley.
On another subject, in an effort to see whether or not the manual that we have answered one of your earlier questions, I looked up the spindle pulley and small spindle gear in the Logan 800 Series manual that we have in Downloads. According to the manual, the 800 Series all use a flat belt for the spindle belt. What's the deal?
And on a related subject, another member made the comment that he had never loosened the screw marked "OIL" in his machine. That screw should be removed and several squirts of SAE 20 ND applied either daily if the back gears are often used, before every back gear usage, or at least monthly.
And as to the use of the second screw, according to the 800 Series manual (but see my second paragraph), the second screw should have all of the threads removed from the nose, which fits through a hole in the reduced diameter of the small spindle gear that fits into the pulley.
Thanks for the info about the second set screw. The hole for that screw has threads that go all the way through the bearing on mine. Perhaps someone tapped it the rest of the way at some point in its life. Before I install the pulley I think I'll run the screw all the way in to just before It gets to the bearing with some loctite. I'm aware of oiling the backgear bearings on the spindle through the oil hole.
Since the hole for the spring is 1/8" I needed a spring that is under that size and 3mm springs are plentiful and inexpensive. Since I have no original to go from from for the backgear latch, I took a guess with a couple of different wire sizes and will see what "feels right". It's not a critical spring rate, so I figured it couldn't hurt. I'll report back with what I decide to use when they arrive.
From the manual I downloaded from VintageMachinery.org for the 825, it is meant to be mounted on a special cabinet with the motor down in the cabinet. There are 2 v-belts that run to a jack-shaft with a flat belt to change speeds and then another v-belt to the motor. Since I have none of that arrangement, I've elected to run a 3/4hp DC motor. Hopefully it works out well. I think the 800 model has a flatbelt on the spindle with the motor mounted behind.
I have been trying to take advantage of some of the nice weather we have been getting and have not spent a lot of time working on the lathe. I did accomplish another small repair today and finished reassembling the QCGB levers. I never did get the spring handles off, so I had to paint around them.
I also made a small repair to the scroll? for the halfnuts. The connection from the shaft to the plate that causes the halfnuts to move was loose. From the factory it seemed like the shaft had a partial D profile and had been peened into the hole on the plate. Over time this connection had worked loose. Probably fully functional, but I figured I should address it while I had things out. Originally I planed to weld it, but was concerned about the distortion from the heat. I chose to try a 'dutch key' I think it's called. I drilled and tapped the intersection of the shaft and plate for 8-32 and installed a set screw. The connection is solid now and if it works loose again, I'll just weld it.
Thanks again for all of your help. I think the next big assebly will be the apron. I've also got some machining to do for a carriage locking nut to make thanks to some drawings from Nogoingback. I'm still looking for any information on the banjo support (LA-510-A) if anyone has a photo or basic dimensions. I know the bolt through the slot is 7/16-14, but not sure on the length of the slot or the location of the pin that goes into the banjo.
Since the hole for the spring is 1/8" I needed a spring that is under that size and 3mm springs are plentiful and inexpensive. Since I have no original to go from from for the backgear latch, I took a guess with a couple of different wire sizes and will see what "feels right". It's not a critical spring rate, so I figured it couldn't hurt. I'll report back with what I decide to use when they arrive.
From the manual I downloaded from VintageMachinery.org for the 825, it is meant to be mounted on a special cabinet with the motor down in the cabinet. There are 2 v-belts that run to a jack-shaft with a flat belt to change speeds and then another v-belt to the motor. Since I have none of that arrangement, I've elected to run a 3/4hp DC motor. Hopefully it works out well. I think the 800 model has a flatbelt on the spindle with the motor mounted behind.
I have been trying to take advantage of some of the nice weather we have been getting and have not spent a lot of time working on the lathe. I did accomplish another small repair today and finished reassembling the QCGB levers. I never did get the spring handles off, so I had to paint around them.
I also made a small repair to the scroll? for the halfnuts. The connection from the shaft to the plate that causes the halfnuts to move was loose. From the factory it seemed like the shaft had a partial D profile and had been peened into the hole on the plate. Over time this connection had worked loose. Probably fully functional, but I figured I should address it while I had things out. Originally I planed to weld it, but was concerned about the distortion from the heat. I chose to try a 'dutch key' I think it's called. I drilled and tapped the intersection of the shaft and plate for 8-32 and installed a set screw. The connection is solid now and if it works loose again, I'll just weld it.
Thanks again for all of your help. I think the next big assebly will be the apron. I've also got some machining to do for a carriage locking nut to make thanks to some drawings from Nogoingback. I'm still looking for any information on the banjo support (LA-510-A) if anyone has a photo or basic dimensions. I know the bolt through the slot is 7/16-14, but not sure on the length of the slot or the location of the pin that goes into the banjo.
- Joined
- Dec 25, 2011
- Messages
- 10,552
OK. Under drive certainly explains the pulleys. The 800 Series manual that we have doesn't seem to have any photos of the underdrive version.
On the motor question, I think that I would consider a DC gear motor in order to try to keep the motor RPM up. The spindle pulley is already about as small as you can go so you can't run a smaller pulley on the motor. TANSTAAFL certainly applies when trying to run a DC motor too slowly. Besides possibly not having enough power at the lower end, you also may not have enough cooling.
On the motor question, I think that I would consider a DC gear motor in order to try to keep the motor RPM up. The spindle pulley is already about as small as you can go so you can't run a smaller pulley on the motor. TANSTAAFL certainly applies when trying to run a DC motor too slowly. Besides possibly not having enough power at the lower end, you also may not have enough cooling.
I managed to get the headstock reassembled. The rear bearing was replaced and the main bearing was cleaned and re-lubed. Getting the dust shields back into the casting was probably the worst part of this process, but I'm happy with the results. The backgears are not installed because I still need to attempt a root canal on one of them.
I've also disassembeld the apron and in the process of cleaning and prepping for paint. I've ordered some replacement bushings for the the traverse wheel shafts. I'm a little surprised that there isn't an oiler for the bearings. I'm thinking of drilling and installing a ball oiler on the casting where the hand wheel shaft goes. What do others think? Sacrilege or improvement? I have some spare oilers because I had to order a pack of 10 for the one I needed to replace in the tailstock.
I've also disassembeld the apron and in the process of cleaning and prepping for paint. I've ordered some replacement bushings for the the traverse wheel shafts. I'm a little surprised that there isn't an oiler for the bearings. I'm thinking of drilling and installing a ball oiler on the casting where the hand wheel shaft goes. What do others think? Sacrilege or improvement? I have some spare oilers because I had to order a pack of 10 for the one I needed to replace in the tailstock.