Repair/Restore Logan 820 lathe

vincent52100

Registered
Registered
Joined
Mar 26, 2014
Messages
211
Finally got my lathe into the basement. I’ve started cleaning and reassembling it. I have found the problems with the gearbox. When I got it both gears on one lever were missing. I think someone crashed it. There are two bad gears in the gearbox. Can someone tell me how to remove the lead screw from the gearbox. I’ve removed the set screw from the collar but don’t want to break something trying to separate it. The S/N is 33206

00A5C224-5512-498D-BE4F-D38C83A72293.jpeg

C9405C85-794B-48AA-AF78-1DE436763A3A.jpeg
 
I could be off in left field with this suggestion as I've never run a Logan. But on an Atlas, you move the carriage up or down the bed until the half nuts are approximately in the center of the lead screw, close the half nuts, and either remove the right lead screw bearing or at least remove the bolts holding it to the side of the bed. Then you use the carriage feed handwheel to walk the lead screw out of the GB. If it takes more force than you feel safe in applying to the handwheel, rig up something to pull on the right end of the lead screw while turning the handwheel. This should walk the lead screw out of the GB. Then open the half nuts and extract the lead screw.
 
You need to remove the nut on the end of the lead screw, remove the gear and key, and it will pull out. It's a lot easier if you remove the gb and screw as an assembly and seperate them on the bench.
 
Thanks! I have the assembly on the bench. I’ll get them apart and see how much damage is done. I can see four gears are bad or missing. Hopefully that’s all.
 
Started work on my gearbox this evening. It looks like I will need five gears. I’ve taken some pictures of the bad gears.
I’m not sure if I have the numbers right but I tried to make a list of the gear numbers.

Gears on lever
LP1014 (LP1300) 40T
LP1016 (LP1131) 22T
Gear Box
LP1002 (LP1137) 32/16T

The serial number is 33206 (Model year 1945?)

I’m hoping that I will be able to find the parts used. The rest of the gears look pretty good. I haven’t cleaned them yet but I don’t see any nicks etc. The same is true of all the other gears.
Does it look like I’ve got the right numbers?
I’ve also put in some pics of the other gears.
Thanks for the help.

6229E594-BD09-4FD8-A90D-2505A7A436B1.jpeg

8C9D5C4B-F560-49CD-A142-2BB7DA6D4905.jpeg

7F72778F-4552-4265-91F5-2F2F451F4080.jpeg

94B5F777-7CD3-4089-90E3-8B7064BA887D.jpeg

0EC28F9A-74E4-485E-AF32-0CCB28FF236C.jpeg

212A341D-AC4C-48BE-A3F8-DB0C33E48249.jpeg
 
Logan was able to sell a nice lathe for a low price because the majority of the non-cast iron parts were available off the shelf from other suppliers. The gears came from Boston gear. Once you get the dimensions of your gears (DP, ID and width) find the matching Boston Gear part number then search for them Amazon and MROsupply. You will likely find brand new gears for the price of used.
 
I’ve noticed that on the Logan site that it looks like there’s two different part numbers. For example part # LP1014 (40 tooth gear) also cross references to LP1300. Is there any difference between them? Thanks!
 
There are two different quick change gear boxes used on the 820. The LA-24-1 gear box was used on serial numbers 46561 and below (which is what I believe you have). The LA-1240 was used on serial numbers after 46561.

LP-1130 (old LA-497) is a 40 tooth gear with an OD of 2.625" Width 0.495" and Bore of 0.438" (with bushing) used on LA-24-1 Gear Box
LP-1014 (old LA-1213) is a 40 tooth gear with an OD of 2.1" Width 0.370" and Bore of 0.375" (with bushing) used on LA-1240 Gear Box

LP-1300 (old LA-470) is a shaft for the gear stack on the LA-24-1 gear box

I'm not 100% sure which 32/16 gear you need but for the LA-24-1 gear box I believe it is either one of these:

LP-1137 (old LA-500-A) 32/16 teeth OD 2.13/1.13 Width 0.592" Bore 0.563
or
LP-1134 (old LA-502-A) 32/16 teeth OD 2.13/1.13 Width 0.530" Bore 0.563 (with bushing)

This information came from a combination of the Logan 800 series manual, Current* Logan Catalog and the Logan Web Site

*Well as current as I have which I got from Logan about 7 years ago.
 
Last edited:
Back
Top