Mini Lathe and Change gear calculators

[jcmullis2]

If the factory included true transposing gears this would be simpler, but they cost-cut.
Something to check carefully before buying
-Mark

As beginners most of us don’t know very much about any of the intricacies of mini lathes. We read the product description and specs and look at the pretty pictures. All of which is communist propaganda BS. The description says the lathe can do metric and imperial threading. I’m sure it can but not with the gears and charts provided. If they had included 2 additional gears the lathe should cut all the common imperial and metric threads. The retail cost of those gears is about $10. Theres no cost to include accurate charts. I would have gladly paid an extra $100 and been happier with my lathe. It doesn’t make sense to me unless they’re playing a sick joke on the consumer.
im sure there’s thousands of others that’s had the same problem because I bought mine from amazon and they have them on eBay too. Of all those owners only 1 posted a gear chart. Nobody seems to want to help out the next fella anymore. You ask for help and you get told that you shoulda checked into that before buying or do some head scratching and figure it out buddy. I get it, the mindset of most is forget the next guy. He’ll have to figure it out the hard way. I was raised to treat others the way you would want to be treated so it’s gonna take me a little while to adopt these ways.
I appreciate your advice and next time I buy a lathe I’ll check carefully. Until then I’ll use the gear chart the one fella posted that covers the common threads. Smdh

 

[jcmullis2]

Depending on your project? Trying to get the perfect pitch may not be necessary. Yes, I understand that perfect is best but sometimes you can fudge it. You could have gears now that will get you close within a few percent? And not all thread calculators on the net will do the best for you. You need to learn your lathe and gears that you have, sit down and do some head scratching.

I agree that learning one’s equipment is paramount. However complex gear configurations with thousands of possible permutations isn’t something you can pick up through trial and error. Some people don’t have the capacity to do the math. How do you suggest someone who lacks the mathematical skills learn those things? I bet if you’re chart was wrong or absent you couldn’t figure it out either. It’s not realistic to think many can and probably why every lathe comes with a threading chart. Even lathes with gear boxes have charts. I was fortunate enough to find a accurate chart by someone with a lathe like mine. The gears needed for imperial threading will be here soon enough and my problem is solved. I thought someone would share with me and everyone to follow how the LMS gear calculator applies to lathes with more than just 4 gears. That way I could use it for uncommon threads and so could others for years to come. Instead of finding people with something to contribute I get guys that don’t know but feel the need to post something. I appreciate your comments and hopefully so will the people to follow.

 

[Jim F]

Another thing to consider is a ELS, that would solve your problem.

 

[royesses]

Try this calcululator:

CGTK - Mini-Lathe Change Gear Calculator

Here is a little graphic I made up showing the change from 3 to 4 gear setup:



Roy

 

[jcmullis2]

Try this calcululator:

CGTK - Mini-Lathe Change Gear Calculator

Here is a little graphic I made up showing the change from 3 to 4 gear setup:

View attachment 348134

Roy

I have 5 gears and a spacer so this setup doesn’t appear relevant to my situation. However, I’ve been looking at the problem all wrong. The gear calculators are giving me configurations that only have 4 gears and this is showing a 3 gear setup. It just occurred to me that just because I have more gears doesn’t mean I have to use them. I can arrange my gears in 5,4, or 3 gear combinations. I might give it a try if I don’t get my new gears soon. Like I mentioned before, I got a chart from a guy with a lathe exactly like mine. It has gear combinations for ALL of the usual metric and imperial threads. It requires gears that I don’t have yet but I ordered them a week or two back and they’ll be here soon.
Is it common for others to give you crap about buying a Chinese machine when you ask for help? I have thick skin so I’m okay if that’s the case. I just wanna know if that’s what to expect in the future.
I appreciate your help with everything. You got me looking at this gear stuff in a different way.

 

[Jim F]

I have 5 gears and a spacer so this setup doesn’t appear relevant to my situation. However, I’ve been looking at the problem all wrong. The gear calculators are giving me configurations that only have 4 gears and this is showing a 3 gear setup. It just occurred to me that just because I have more gears doesn’t mean I have to use them. I can arrange my gears in 5,4, or 3 gear combinations. I might give it a try if I don’t get my new gears soon. Like I mentioned before, I got a chart from a guy with a lathe exactly like mine. It has gear combinations for ALL of the usual metric and imperial threads. It requires gears that I don’t have yet but I ordered them a week or two back and they’ll be here soon.
Is it common for others to give you crap about buying a Chinese machine when you ask for help? I have thick skin so I’m okay if that’s the case. I just wanna know if that’s what to expect in the future.
I appreciate your help with everything. You got me looking at this gear stuff in a different way.

It is rare here.
I get crap for having a C model SB9.
It doesn't bother me, I am OK with change gears.

 

[royesses]

You should not get crap about a Chinese machine here. The members here understand that not everyone can get a high end machine due to various reasons. It is more important to be machining and learning here. We help each other here. I hope you get the gear situation sorted out.

Roy

 

[jcmullis2]

You should not get crap about a Chinese machine here. The members here understand that not everyone can get a high end machine due to various reasons. It is more important to be machining and learning here. We help each other here. I hope you get the gear situation sorted out.

Roy

Well I suspect hassling one another is all in good fun. I was aggravated and I’m sure that I took it wrong. I wanted an old American lathe but there was nothing within 500 miles that met my needs and fit in the allotted space.
My son printed one of the two gears I needed to begin verifying the threading chart I found and I was able to verify a few of the threading pitches on that chart last night. He was working on the stuff to print the other gear earlier so my threading issues will be over when he prints that gear. I’ll just use the printed gears until I get the metal gears I ordered. I have a metric threading dial and after some head scratching I figured out how to use it with imperial threading. Now I can disengage my half nuts and not ruining my work piece if I want to. I’m not able to use it like the threading dials on a imperial lathes but I can use it to do everything I need.
It’s safe for me to say that my lathes threading problems are over. I now have a $1k lathe that I can thread and chamber barrels thru the headstock or between centers. It’ll pay for itself with just the few barrels that I have needing to be replaced.
I appreciate everyone who tried to help me with my threading problems and I look forward to sharing what I learn with others.

 

[Jim F]

Are you using the Oxtool and Abom79 method ?

 

[royesses]

Well I suspect hassling one another is all in good fun. I was aggravated and I’m sure that I took it wrong. I wanted an old American lathe but there was nothing within 500 miles that met my needs and fit in the allotted space.
My son printed one of the two gears I needed to begin verifying the threading chart I found and I was able to verify a few of the threading pitches on that chart last night. He was working on the stuff to print the other gear earlier so my threading issues will be over when he prints that gear. I’ll just use the printed gears until I get the metal gears I ordered. I have a metric threading dial and after some head scratching I figured out how to use it with imperial threading. Now I can disengage my half nuts and not ruining my work piece if I want to. I’m not able to use it like the threading dials on a imperial lathes but I can use it to do everything I need.
It’s safe for me to say that my lathes threading problems are over. I now have a $1k lathe that I can thread and chamber barrels thru the headstock or between centers. It’ll pay for itself with just the few barrels that I have needing to be replaced.
I appreciate everyone who tried to help me with my threading problems and I look forward to sharing what I learn with others.

That is great news!
Have a Merry Christmas
Roy