I have a specific question about cutting threads on a Frejoth (Chinese or Taiwanese import lathe). I have set up the gears and the gear box for the desired threads, but I cannot get the threading drive to turn. There is a forward-neutral-backward toggle that works fine to turn on and reverse the feed. I cannot find any way to get the other screw thread bar to be driven by the drive train. I know this sounds very lame, but I just do not see any other toggle or switch that would engage it.
Here is a picture of the lathe:
There are only six toggle switches and all of their functions appear to be accounted for.
I would welcome any advice.
PS-I got it used and have no access to a manual. Grizzly lathes of a similar make have a thread/drive toggle.
If it doesn't turn, its one of the levers on the spindle stock. Without manual, you're lost. Find a similar looking model at Grizzly or whatever or contact the manufacturer and test their customer service for a manual.
With some (or a lot of) luck, you can find the right lever. Look at the markings for the levers. Find one that looks like it is in between the normal distance between all the other markings. Set the lever to this position.
============== If by toggles you are referring to electrical switches this may be what is distracting you as this is most likely controlled by manual gear changes. On many, but by no meas all, lathes there is a three position lever at the headstock. One position causes the lead screw to rotate one direction relative to the rotation of the spindle for right hand threads, one position is neutral where the lead screw does not turn, and one position reverses the direction of rotation of the lead screw relative to the spindle to generate left hand threads. On my Emco compact 10 there is no external lever but you have to open the cover and manually shift positions, and this may be the same for your lathe.
Frequently this is referred to as a "tumbler."
about 1/3 way down the page to see what you are looking for.
For an internal tumbler as used on my Emco click on
and look at page 24
Good luck, welcome to the world of machining and let us know what you discover.
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The photo (from a site in Taiwan) does not have sufficient detail of the headstock controls to enable me to determine their functions.
Look for one which has a marking like:
which is the threading setting. The same control thrown the other way will rotate the feed rod instead of the threading leadscrew. (I seem to remember that on the Taiwanese lathe which I used something like fifteen to twenty years ago, there was a mushroom shaped button down low on the panel which was pushed in to do threading and pulled out to do feeds. I suspect that it is the bottom-most lever on the illustrated machine.
Check whether any of the toggles push in or pull out when in the neutral position. That might be how it switches between threading and feeding, and uses the same lever to switch directions for both feeds and threads.
It looks as though it has a threading chart on the cover to the left of the main panel.
Could there be some gears missing under that cover? That is where you change the gears to do either metric or imperial threads if it is like the one which I used.
Have you tried searching their web site for a downloadble manual?
Anyway, you have what little I can offer without a better photo (close-up) of the controls and the threading/feed charts on the cover.
*Don't* try to e-mail me a photo -- it won't make it through my spam filters unless it is too low a resolution to do me any good. And
*don't* post it. Upload it to the dropbox (see
for instructions) and then post the URL for the photo here.
Did you engage th' half nut? It's th' farthest lever on th' face/front of th' carriage towards th' tailstock on my Central Machinery 12x36. You have to turn th' carriage handwheel a touch to get it fully engaged.
There should also be a *thread or feed* lever on th' headstock... prolly th' lower one closest to th' tailstock end as it lines up horizontally with th' lead screw. My guess is *thread* is in th' up position. Mine has a symbol like this -wwv- for feed, I can't do th' thread symbol in ASCI, but it looks like a bolt with a centerline through it.
Finally, there should be a thread cutting dial you'll need to engage. It's on th' tailstock side of th' carriage and has a worm drive that when turned CCW engages with th' lead screw threads.
If that doesn't work, email 'em: firstname.lastname@example.org or call:
886-4-23816977 and ask for a manual.
Disclaimer: Mine looks *kind of* like yours, but still different enough to not be positive about your settings.
At a guess from the picture and similar looking chineser lathes.....
Two top levers ...... rpm of hadstock
Lever below to left on second row .... forward/reverse direction of lead screw/cross feed in relation to headstock
Next row of two levers control gear ratio's for of lead screw for feed and thread cutting. One lever wil have 7 or 8 positions ( depending on number of threads capable of cutting) The other will most likely have 4 positions ... lets call them A B C D. A and C will be for lead screw and B and D will be for cross feed.
The bottom lever below and to right of oil level sight glass will engage/disengage the lead screw/cross feed