# Changing gears on Logan 200



## Loganguy (Jan 19, 2014)

The table inside the cover of my Logan 200 (not a quick-change model) shows different configurations of gearing to achieve different threads.  How do I go about changing the gears?  Do I re-arrange the gears that are there, or do I need a set of spare gears?  Also, many of those gears have a small gear and large gear on the same shaft.  The diagram shows only one gear and lists only one number for the number of teeth.  Which gear are they referring to?


----------



## Chrispy (Jan 19, 2014)

Loganguy,
Your best bet would be to find the owner's manual for your lathe. It will show how to arrange the gears, which gears go where, and how much play should be between the gears. If you do a web search I would bet someone has a manual for that lathe in a PDF file. 
The gears under the cover control the speed at which the leadscrew (long threaded rod on the front of the lathe) turns in relation to the spindle. Say you had a 20 tooth gear on the spindle and a 40 tooth gear attached to the leadscrew and meshed with the 20 tooth gear on the spindle. One revolution of the spindle would be 20 teeth that would go by a fixed point. Since that is in mesh with the 40 tooth gear that gear would only move by 20 teeth or 1/2 of a revolution. Thus with that gear arrangement the leadscrew would be going half the speed of the spindle. If I put a 10 tooth gear on the spindle, the same 40 tooth gear on the leadscrew, then the leadscrew would go 1/4 the speed of the spindle. 
You will use those gears on the end to do two things. Cut threads or set the speed at which your lathe bit feeds across your work. When you turn a piece of metal you are basically cutting a "thread" on the work. This thread is so fine (100 threads per inch +) that it practically overlaps itself and gives you a smooth finish. That's why it's a good idea to have a slight radius on the tip of your turning tools. A sharp, pointy tip will leave a finish like a record... Groovy man.
HTH,
Chrispy


----------



## Mister Ed (Jan 24, 2014)

Loganguy said:


> The table inside the cover of my Logan 200 (not a quick-change model) shows different configurations of gearing to achieve different threads.  How do I go about changing the gears?  Do I re-arrange the gears that are there, or do I need a set of spare gears?  Also, many of those gears have a small gear and large gear on the same shaft.  The diagram shows only one gear and lists only one number for the number of teeth.  Which gear are they referring to?



Holler back if you have questions on the info I sent you ... but I think there are a couple pages there that will help things make sense.:clinkbeer:


----------



## Loganguy (Jan 24, 2014)

Mister Ed said:


> Holler back if you have questions on the info I sent you ... but I think there are a couple pages there that will help things make sense.:clinkbeer:



Thanks Mister Ed, that was a great help, 

I see that there is a standard set of additional gears shipped with the lathe. Of course that was a long time ago and they have been lost by previous owners along the way.  I also noticed that the instruction manual said that you must have two gears on each stud; even if one is not in the gear train it is there for a spacer on the stud.  So, I have ordered the particular gears that I need for my current project and will order a few along the way until I get the recommended standard set.


----------



## Mister Ed (Jan 25, 2014)

Loganguy said:


> Thanks Mister Ed, that was a great help,
> 
> I see that there is a standard set of additional gears shipped with the lathe. Of course that was a long time ago and they have been lost by previous owners along the way.  I also noticed that the instruction manual said that you must have two gears on each stud; even if one is not in the gear train it is there for a spacer on the stud.  So, I have ordered the particular gears that I need for my current project and will order a few along the way until I get the recommended standard set.



No problem! I was pretty much in the same position a few years back. Picked up some gears along the way ... enough to cover 75% of the needs. 

If you spend a bit of time sorting through the TPIs you think you might need ... you'll see some gears that you'll need and some maybe not so much. Most general use threading will use Fig #1 (only three gears). So you need a 32, 72, & 16 ... then the appropriate gear from the right column. How many times are you going to cut an 11 1/2 or 7 1/2 or 64 thread? Its possible ... but maybe not probable that you will.


----------



## Loganguy (Jan 26, 2014)

Mister Ed said:


> No problem! I was pretty much in the same position a few years back. Picked up some gears along the way ... enough to cover 75% of the needs.
> 
> If you spend a bit of time sorting through the TPIs you think you might need ... you'll see some gears that you'll need and some maybe not so much. Most general use threading will use Fig #1 (only three gears). So you need a 32, 72, & 16 ... then the appropriate gear from the right column. How many times are you going to cut an 11 1/2 or 7 1/2 or 64 thread? Its possible ... but maybe not probable that you will.




That is one thing that confused me, Fig 1 has only 3 gears and I looked at my lathe and saw a whole bunch more.  I now see how the banjo bracket can be rotated to accommodate various gear combinations.


----------

