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View Full Version : VERY strange threading problem w/14X40 lathe



torker
10-28-2006, 11:16 PM
Here's a good one for you! I tried threading with this lathe when I first got it.
Something wasn't right but i figured I'd have to tear it all apart to find out what it was.
Finally made up a test bar and started cutting threads.
Tried 8TPI cut 24TPI
Tried 6TPI cut 32TPI (I think)
Tried 4TPI...looked too ugly to even measure
Tried over and over...engaged and disengaged levers/dials to make sure everything was seated. Double/triple checked the change gears. Read and reread the pi$$poor manual.
Came up to the house....pretty fed up.
Emailed Joe Hartson to see if he could figure it out.
My wife casually/jokingly said it sounds like something is in there backwards
Ding! The lights came on...went to the shop tonight...flipped the dial to the opposite position that it SHOULD have been in and sure enough...it started to cut the right threads...6TPI...just right! 4TPI bang on!
Reread everything again....I'm right...they are wrong. This also explains why my feed rates where never correct either. I got the finish I wanted with the dial set opposite of where they said.
I may not be out of the woods yet as far as running into problems but it works for these threads.
I figure the gears must be bassakwards or the dial is labeled wrong. I've looked at pics of similar lathes and they are all labeled like mine.
Gotta go cut some more threads :D
Russ

Evan
10-28-2006, 11:30 PM
Do you have the lathe mounted right side up?

torker
10-28-2006, 11:40 PM
LOL! I think so. The rounded chuck part goes near the top...right? And the lil' leg deals...I figured they go on the seement part :D

Mark Hockett
10-29-2006, 12:26 AM
Russ,
What brand of lathe is it? My Turn Pro had a simular problem when I got it, but with mine it had the wrong thread chart. The thread chart was for a lead screw with a different pitch. The manual had the correct chart.

J. R. Williams
10-29-2006, 12:36 AM
Russ
Check the stud gear on the input to the gear box. On my lathe this gear is changed to cut the coarse pitch threads.

JRW

torker
10-29-2006, 01:21 AM
Mark...this is a "Force" lathe. Imported by House of Tools (fools) in Edmonton, Alberta.
This is their first attempt at a 14X40...it's really a glorified 13X40 I'm thinking.
Some of their early stuff is very poor quality from my experience.
There are several charts on it for metric, standard etc. The gear changes are very dramatic between the different charts.
I just rechecked it again...sure enough the "fine feed" (.008/.002) only works when the dial is backwards from everything they say. This is with an entirely different set of gears (for general turning)
JR...I don't know if that'd be it here. I could experiment I guess but it cuts what I want now. I still have to check the entire range of threads out now I guess (sigh)
Good thing this thing was a good deal. No wonder the previous owner had it for sale!
Russ

rws
10-29-2006, 07:25 AM
My Acer E1440G is the same way. Either the chart is wrong, or the position label is wrong. I did figure out part of it, and have a note pad to keep me straight, but it sure would be nice to have it all correct.

madman
10-29-2006, 07:51 AM
For that model Lathe its normal. It was made in China and they do all there reading from right to left dont they>??? Just do it backwards and enjoy your new Lathe.

Evan
10-29-2006, 08:54 AM
For that model Lathe its normal. It was made in China and they do all there reading from right to left dont they>???

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BillH
10-29-2006, 09:55 AM
Muzzies read from left to right.

BadDog
10-29-2006, 12:14 PM
That would be Arabic languages (and others related); not the religion which spans many different cultures and languages...

wierdscience
10-29-2006, 12:25 PM
Could be the chart is wrong,could be the stud gear is in the "coarse" position.LLathe at work does that,it has a stud gear that has a 72t on one side and a 144 on the other,you flip the thing over to the get the insane coarse threads like 2tpi.

Or,it could be you standing on your head:rolleyes:

quasi
10-29-2006, 03:41 PM
I saw several of these 14-40 " house of tools " lathes at Graham auctions here in Calgary a couple of years ago. According to the auction yardman, they were brought in for sale by " The house of tools" . There are 2 here in town, I assume it was the industrial one, which is in the south end.

The strange thing is, they were all obviously robbed of parts to repair other lathes. None of them had compounds, none of the tailstocks were complete, apron parts were missing on some, gearbox parts on others. There were a couple of 13-40 lathes of different makeand model also, they were missing parts as well. None of the acessories ( steady,follower rest, chucks ...) were with them as I recall.

I think I remember 6 or 7 lathes all together, there was not a complete lathe among them. House of tools has a good warranty policy and stands behind it, but I guess they can't get replacement parts for there own stuff.

I didn't go to the auction . I didn't think I could resist buying them all and trying to make one functional lathe out of them. But on reflection , I could not have, there wasn't a lathe with a compound or tailstock, and I don't think any had a complete apron. I wonder if I bought them, maybe Grizzly would have parts ....

torker
10-29-2006, 04:22 PM
quasi...funny you mention that. My compound is crap. The rest is ok(note small case) after tweaking but the compound needs a lot of work.
I wasn't too impressed with their support for this machine. Their tech guy was supposed to address the problems I had (because the lathe was so new...even at 8 years old). I sent him a ton of info(measurements etc.)...spent a lot of time on the phone with him and never heard back from him or the service guy.
That cost them any further business from me. I used to spend a lot of money there. Equipped an entire cabinet shop with new Delta machines through them in the late 80's.
I've had far better luck with Busy Bees support.
I'm liking this lathe now that I'm getting it figured out but can see it hitting the road as soon as I get it working well.
With the prospect of going into business (soon) I'm going to need a heavier machine. I like that industrial 14(or 16)X40 that KBS sells. 2 1/2" bore...more power, wider bed etc.
Russ

Tinkerer
10-29-2006, 05:05 PM
The instruction to print the chart most likely said "Print in reverse lettering" and they thought that meant the wongway :D.
At least your wife got you going in right way.

nheng
10-29-2006, 05:37 PM
It's pretty easy to remove the groove pins that hold threading charts, nameplates, etc. Once that's done, simply reverse the plate and install new (or the re-claimed) pins.

Seriously though, I wonder if there may be a mirror image of that gearbox out there somewhere. OR, is it perhaps possible that the inner "skeleton", bearings, shafts, etc. for the QC box can be physically installed in reverse? May be far fetched but with the Asian machines, I'll bet it's not impossible.

Den

kap pullen
10-30-2006, 07:33 AM
The metric change gears may be installed in the drive chain.

In that case, the thread dial won't repeat, and inch thread

pitch chart will be off with the actual pitch cut.

That is the situation with my 13 x 40 gap bed China lathe.

Kap

pcarpenter
10-30-2006, 11:54 AM
I have a Chinese 13/40 that is fairly new. I had cut good threads on one occasion, but recently went to cut one and it kept starting in the wrong position when the feed dial was used as directed, completely butchering the threads.

I kept checking my change gear combination and the tooth number combination read correct.....sort of.

As it turns out, the problem was that one of the gears in the drive train is a "double gear" with two different pitches. Flipping this double gear over will cause it to mesh with either of the two diameter/pitches on that double gear and I had the wrong one....which threw everything off. In short, I installed it incorrectly when I got ready to start threading, even though the number on the side of the gear seemed to imply I was doing it right.

Edit-- there are littl pictures of the correct gear train mesh on the pitch chart on the front of the lathe and a careful exam of the picture showed that I was meshing with the wrong "side" of the double gear. The numbers in the chart are important....but so is the picture.

If yours is the (good) sort of lathe that requires no change gear changes at all to go from feeding to threading (I have access to a larger, 14/40 here at work that is like that), you may still find that it is because it has such a gear pair in the works that is actuated by a lever. If it were installed backward, that could sure explain it. Flipping the gear may solve the problem and make your labels read correctly if that is the case.

Paul

BadDog
10-30-2006, 02:36 PM
Actually, you can have a similar problem even on the "good" sort since there is usually a flip gear for doing the ultra low thread pitches (such as 4 tpi). Of course that doesn't screw up the half nut sync with the threading dial. And then there is the 120/127 gear for imperial/metric that may be an issue. My Rockwell 11" can go from threading to feed with no gear changes using the QCGB, but has both the issues I mentioned above (though I don't have a 120/127 gear). Not that this is entirely relevant to the original question, just something related to the "backwards gear" topic...

Alistair Hosie
10-30-2006, 04:04 PM
I always believed theystart from the back of the book to the front and read from right to left seriously thats what I understood to be the way it's done in China .Alistair

Evan
10-30-2006, 05:17 PM
That's how my mother-in-law reads a book. She reads the ending first. She happens to be Scottish. :D

cam m
10-30-2006, 07:12 PM
Rus

I have a 1440 ROC lathe imported by another supplier here in Cowtown (Modern Tool).. The threading looked AFU'd on mine too until I finally sorted out which of the poorly marked/illustrated gears to install in the headstock gear train. I finally stumbled on the translating 100/127 gear for SAE threads in the tool kit full of bits and pieces and deciphered the diagrams. AIR, there was a 100, 80, and 127/100 translator. As delivered, the lathe had a set up back there only Confucious understood why they'd use...

Cam