Can't Thread Finer Than 28TPI on LMS3540/Sieg SC4 Lathe?

No problem, Stu. I didn't say what my idea was, only "I have an off the wall idea to try and will update here if it works. "

The open door is a little spooky, but thankfully it's still a bit far from the controls, and you ride the control panel on the lathe while threading.
 
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MontanaAardvark I didnt know you were a member of this forum. My name is Brandon. I messaged you on Youtube then through email. Sorry I have not replied. I have been pretty busy. Glad you got this figured out as did I as well.
 
Hi Guys,

Many smaller lathes use a banjo arrangement to allow different sized gears to be used. Normally you would try and keep everything inside the cover. Running a lathe with those gears exposed like that is very bad practice. Sometimes you have to use a smaller gear as a spacer. Or use one as an idler.

Unfortunately some manufactures don't include all the gears that you may need to cut some threads.
 
Hi Guys,

Many smaller lathes use a banjo arrangement to allow different sized gears to be used. Normally you would try and keep everything inside the cover. Running a lathe with those gears exposed like that is very bad practice. Sometimes you have to use a smaller gear as a spacer. Or use one as an idler.

Unfortunately some manufactures don't include all the gears that you may need to cut some threads.

I'd be more than delighted if someone could show me how to thread those finer pitches while keeping everything inside the covers. User 9t8z28 has said he thinks he sees how by making a different banjo - or making a series of them.

Unfortunately, there is no "customer service" help to call for these lathes. I bought it from Little Machine Shop and asked them in addition to posting here back on July 1. LMS told me nothing. They didn't comment when I sent that picture of how I did it.

In the mean time, I use a temporary cover over the gears. I don't wear long sleeves in the shop, and the only thing it needs to do is block me from bumping into it. While threading, I'm watching the cutter with magnifiers on and my hand on the stop button.
 
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Hi Guys,

I'm sure that I've seen somewhere that someone had made a new banjo/banjo's for his lathe. I know that there is at least one design for a replacement banjo for my lathe. The slot is about 12 mm (1/2") too short to fit certain gears. To be honest, I don't remember what the gear size was, other than it was one in the chain. I do remember that in order to use the 127 tooth gear, you can't close the cover, but it doesn't protrude like the one in your picture.
 
Hi Guys,

I'm sure that I've seen somewhere that someone had made a new banjo/banjo's for his lathe. I know that there is at least one design for a replacement banjo for my lathe. The slot is about 12 mm (1/2") too short to fit certain gears. To be honest, I don't remember what the gear size was, other than it was one in the chain. I do remember that in order to use the 127 tooth gear, you can't close the cover, but it doesn't protrude like the one in your picture.

As I pointed out in the original post and the video (post #6), I was able to thread 28 TPI, but when I went to 32 TPI the 80 tooth D gear pushed the 127 tooth C gear into the bushing on the drive and kept A and C from meshing. When I went to the 100 tooth D gear for 40 TPI, that pushed the C gear so far out that it hit the plastic enclosure on the left. It wasn't within two inches of meshing.

Like I said, if I'm being stupid, I want to fix it. I'd love to see how to get threading to work without the gears hanging out beyond the cover.
 
Hi Guys,

Many smaller lathes use a banjo arrangement to allow different sized gears to be used. Normally you would try and keep everything inside the cover. Running a lathe with those gears exposed like that is very bad practice. Sometimes you have to use a smaller gear as a spacer. Or use one as an idler.

Unfortunately some manufactures don't include all the gears that you may need to cut some threads.

I believe MontanaAardvark and I both have the full set of available gears to thread any TPI from 4-80 and .2-8 metric. I know I do and then some. I have more gears than are needed. Maybe they accidentally gave me 2 kits. Anyway, the only way to thread these finer TPI’s is to do exactly as MontanaAardvark did. I am working on a solution so that we can keep the banjo inside the cover. My idea is to use an idler that will be a part of the banjo but will be adjustable the same way the banjo is. Another option is to relocate the plastic box that has some kind of electronics in it. If this was out of the way the 40 tpi gear set would fit inside of the cover, but I am not sure on the 32 that MontanaAardvark had to cut. I would preferred to make another banjo rather than relocate the electronics box

BaronJ, I have never heard of an issue where the banjo was not long enough. In regard to seeing someone make a longer banjo for their lathe; yes I saw it as well on youtube but its for a 9x or 10x lathe. I can’t remember which one it was. The banjo is almost identical but there are a few slight differences. Let me see if I can find the link
 
EDIT: I posted right after MontanaAardvark and he states that relocating the electronics box would not allow the 32 TPI gearset to fit on the inside of the cover.
 
What kind of lathe do you have?
Hi Guys,

I'm sure that I've seen somewhere that someone had made a new banjo/banjo's for his lathe. I know that there is at least one design for a replacement banjo for my lathe. The slot is about 12 mm (1/2") too short to fit certain gears. To be honest, I don't remember what the gear size was, other than it was one in the chain. I do remember that in order to use the 127 tooth gear, you can't close the cover, but it doesn't protrude like the one in your picture.
 
Here is the Youtube video series by Dans-Hobbies. Its titled “A better lathe banjo”.
This mod is for a Harbor Freight 8x14.
 
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