Logan 1875 rebuild

Hey Brian, Thanks. This was one of the options that was discussed. It is certainly a good method. There may actually be just enough material on the bull wheel to allow for machining a step, or shoulder, to make locating the red hot ring correctly in the axial sense. The downside is having to get the tolerance for the interference spot on and the fact that all the teeth have to be cut from scratch. The ring material would be good in cast iron because cutting the teeth would be very smooth. Cast iron could be difficult or expensive to find although I think Durabar has a line of very thick wall tubing. They will sell directly if you approach them in the correct manner (and you're lucky-I happened to call on the day a big customer changed requirements and they were left with some surplus bars that I could use) and be prepared to pay a minimum. They might refer you to one of their distributors who will cut to size, you never know until you try. Cast iron is really messy-no wonder the 19th Century was.....

Cutting the teeth from steel would be more problematic depending on the grade of material and the machinery available. I think it's just a matter of weighing the options and matching available skills and machinery to the job. This is the kind of stuff that keeps things interesting.
Regards, Geoff Morgan
 
Hi Kevin
It may be worth thinking of useing a good quality Aluminum for the ring ,Quite strong enough for this job I think, easy to work, and shrink fit. I have used alloy for change gears with great results.

Another method of fitting could be locktite you will have a large contact area thats good for locktite.

Brian.
 
All I can say is WOW! The help on this site is amazing! At the risk of offending anyone I have already begun the process of pinning the two one tooth breaks and will pin the two tooth break as well. The four tooth break at the present time I am working on machining a piece of cast (as the original gear is) to dovetail in and then braze. I really want to try this my self for the education of it. I will try to take photos and post my progress. It may be slow as along with work it is presently lambing season and that occupies much "spare" time. Thanks to all of you who have offered thoughts, ideas and help. I may have to ask more questions after I goof this repair up.:biggrin: I have throughly enjoyed this site and hope to be able to contribute back in the future.
 
Re: Logan Bull Gear

I obtained my Logan 10" about 25 years ago. The machine has what I consider a design flaw in that the slider rod that changes the head drive from back gear to straight drive has a very small leaf style spring that can (after much use/old age) allow the shaft to vibrate and engage the back gear at inappropriate times resulting in teeth (generally on the bull whee) being shred. the same ends.
Best of Luck, Geoff

Geoff.
I recently had a Logan lathe that had the back gear engaged when the " sliding Rod " was pushed in as you describe above.... THIS IS BACKWARDS !!!!! The back gear should only engage when the Rod is OUT...
It appears that the ecentric can be installet owo work either way... BUT YOU HAVE SEEN THE PROBLEM OF HVING IT BACKWARDS !
Joe
 
Re: Logan Bull Gear

Geoff.
I recently had a Logan lathe that had the back gear engaged when the " sliding Rod " was pushed in as you describe above.... THIS IS BACKWARDS !!!!! The back gear should only engage when the Rod is OUT...
It appears that the ecentric can be installet owo work either way... BUT YOU HAVE SEEN THE PROBLEM OF HVING IT BACKWARDS !
Joe
I did not realize that the rod could be installed in both operational modes, it never occurred to me that the eccentric could be rotated to accommodate the opposite operation. It did not matter in my case because the damage to the bull gear was already done when I acquired the lathe. About two teeth here and another single tooth here and maybe another single tooth there. I "pegged" the teeth in to start with and then about two years later (prior to internet) I learned that Logan was still supplying parts and I purchased a bull wheel. Luckily the back or layshaft was not damaged. I then made a block that attaches to the headstock that utilizes a locating pin. Now it would take a blow from a big hammer to force the bull gear into back gear without deliberately pulling the pin. I could still relocate the eccentric without further modification, but things are fine for the time being. I like the Logan. My only complaint is the same with most of the 10" lathes that I have used (Yes, including the Southbend 10H) is the cross slide screw and nut are on the light side and wander a little. These screws require a lot of attention and inhibit threading to a certain extent. One has to be diligent to keep the play to a minimum and replace the screw and nut frequently. I think the next time I will make an adjusting screw nut so has to compensate for wear.
Thanks, Geoff
 
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