cutting threads
- Thread starter mike4517
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You don't need a thread dial if you never disengage the half nut. I have a thread dial on my lathe, but I prefer to just stop the lathe at the end of the cut, back the tool out of the work, and reverse the motor. I rarely use the thread dial.
Chuck
Chuck
I took instructions that I got here and went into the shop and had a talk with the lathe, he was real understanding, I said tonight I have learned from reading and asking question about threading and you are going to help me learn the rest, we got along great the short cut of 1/2 rod did not want to get along, but after about 15 of them in the trash can I got it, cut fine thread and course and I finally got it, I can say that is the most rewarding thing that I have done on the lathe, the 14X40 HF lathe is great, after all that talking want to say thank to those who have help make it plain, I am not scared to do that now, but still have a lot to learn and I am sure I will mess some up, love this hobby, Lathe Nut
rake60
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There was a time that I dreaded seeing a print at work with thread specs on it.
Then one day I just decided to dive into like I actually knew what I was doing.
I worked with the best information I had and expected to junk a few parts in the
process. The threads turned out to be within tolerance...
Single point threading on a manual machine isn't easy, until you do it a few
times.
Personal safety first!
If it doesn't feel safe to you don't do it until it does!
Machine safety second.
Stopping a cut by stopping the motor isn't an instant STOP.
If you're afraid you'll crash the machine practice the cuts well away
from the chuck until you are comfortable with your reaction time
for stopping. It is safe and it works quite well.
But it IS something that takes some practice to be safe.
Rick
Then one day I just decided to dive into like I actually knew what I was doing.
I worked with the best information I had and expected to junk a few parts in the
process. The threads turned out to be within tolerance...
Single point threading on a manual machine isn't easy, until you do it a few
times.
Personal safety first!
If it doesn't feel safe to you don't do it until it does!
Machine safety second.
Stopping a cut by stopping the motor isn't an instant STOP.
If you're afraid you'll crash the machine practice the cuts well away
from the chuck until you are comfortable with your reaction time
for stopping. It is safe and it works quite well.
But it IS something that takes some practice to be safe.
Rick
B
Bogstandard
Guest
Both Rick and myself, plus a few others, have said a few times on here that if you can get single point threading under your belt, the world of model engineering opens its doors.
With just a couple of well ground tools, you can save yourself a fortune not having to buy expensive taps and dies. In fact you can make your own special taps and dies.
If you are afraid of running into the chuck, there have been a lot of designs over the years for an automatic carriage stop. Some of the bigger lathes have it built in by the manufacturers. These designs are usually very easy to make and fit, and usually consist of a few levers, a cam with pawl and a spring load to disengage the half nuts. I don't have a plan to hand, but I am sure that when I clean out my deep storage area, I should be able to find one.
Mike,
Does your machine have half nuts?
If it does, I would try to find thread indicator to fit your lathe. Or if not available maybe some of the whizkids we have on here now, can give some idea what the calculations are to make a basic one.
OK, you can do the job without one, but realistically, one is needed if you are going to be doing thread cutting in any quantity. OK to do manually, occasionally, for say a left hand metric on an imperial machine. But to do it all the time like that, you need to be a masochist, with a tendency for self flagellation.
John
With just a couple of well ground tools, you can save yourself a fortune not having to buy expensive taps and dies. In fact you can make your own special taps and dies.
If you are afraid of running into the chuck, there have been a lot of designs over the years for an automatic carriage stop. Some of the bigger lathes have it built in by the manufacturers. These designs are usually very easy to make and fit, and usually consist of a few levers, a cam with pawl and a spring load to disengage the half nuts. I don't have a plan to hand, but I am sure that when I clean out my deep storage area, I should be able to find one.
Mike,
Does your machine have half nuts?
If it does, I would try to find thread indicator to fit your lathe. Or if not available maybe some of the whizkids we have on here now, can give some idea what the calculations are to make a basic one.
OK, you can do the job without one, but realistically, one is needed if you are going to be doing thread cutting in any quantity. OK to do manually, occasionally, for say a left hand metric on an imperial machine. But to do it all the time like that, you need to be a masochist, with a tendency for self flagellation.
John
B
Bogstandard
Guest
What machine is it Mike?
John
John
Way back in the day when machinists made there own tool bits out of old files and worked by light from a skylight or a small oil lamp (those are not exaggerations either) they use to put a chalk mark on the gear mounted on the feed shaft and another on the bed of the lathe, when these lined up you engage the half nut and so on. Primitive but it works.
B
Bogstandard
Guest
Mike,
Because your lathe is fairly old, and most probably made for war work, it was most probably never fitted with a threading dial.
Because you should have a 1" x 4TPI leadscrew, you would need to find an 8 toothed gear with the pitch of the teeth at the same pitch as the leadscrew, it wouldn't need to be the same thread form just the same pitch (tooth tip to tooth tip). If you could find one of those, it would be dead easy to rig up a threading gauge.
Sorry I can't be of any more assistance, I have already looked thru my collection of old gears and there was none that were suitable.
John
Because your lathe is fairly old, and most probably made for war work, it was most probably never fitted with a threading dial.
Because you should have a 1" x 4TPI leadscrew, you would need to find an 8 toothed gear with the pitch of the teeth at the same pitch as the leadscrew, it wouldn't need to be the same thread form just the same pitch (tooth tip to tooth tip). If you could find one of those, it would be dead easy to rig up a threading gauge.
Sorry I can't be of any more assistance, I have already looked thru my collection of old gears and there was none that were suitable.
John
B
Bogstandard
Guest
Are you going to the Thundersprint at Northwich on the same weekend as Harrogate
http://www.thundersprint.com/Latest News -2.htm
I managed to get the Saturday off to get to Harrogate. My friend is displaying his classic racing Ducatti. I have been making bits all today to get him road and race legal.
John
http://www.thundersprint.com/Latest News -2.htm
I managed to get the Saturday off to get to Harrogate. My friend is displaying his classic racing Ducatti. I have been making bits all today to get him road and race legal.
John
B
Bogstandard
Guest
Stainless front wheel spacers, and repairing the crappy Mazak fuel taps. Had to drill them apart, and rather than being rivetted together, modify them so they could be stripped down for cleaning, plus get all the faces perfectly flat so that they don't leak any more. The worst job I have done for the damned thing was to make some connectors for the taps to tank. Only about 3/4" long, but wierd superfine metric, cast Mazak LH thread in one end and the same thread but RH in the other, joining in the middle. I made them out of bronze.
The problem is that the bike I think is from the late 60's early 70's, so all the parts are now specials or unavailable, and cost a fortune. Hence this is where I come in. Available and free. But that's friendship.
John
The problem is that the bike I think is from the late 60's early 70's, so all the parts are now specials or unavailable, and cost a fortune. Hence this is where I come in. Available and free. But that's friendship.
John
I'm just lurking and eagerly trying to soak up the wealth of information on here ;D ......... threading still seems like a dark art to me 
, but I'll get there given time, first though I'll be happy to make a little swarf before too long.
But, engineering aside for a moment ......... Motorbike racing just happens to be the one sport I love ;D ;D .......... sorry to any football fans .......... so Mike, what do you race
Dave
, but I'll get there given time, first though I'll be happy to make a little swarf before too long.But, engineering aside for a moment ......... Motorbike racing just happens to be the one sport I love ;D
;D .......... sorry to any football fans .......... so Mike, what do you race Dave
Hi dave
I race allsorts i am looking after a young lad called jay dunn we are at oulton park british super bikes this weekend
http://www.jaydunn.co.uk/
my next race is in belgium on a vincent
Mike
I race allsorts i am looking after a young lad called jay dunn we are at oulton park british super bikes this weekend
http://www.jaydunn.co.uk/
my next race is in belgium on a vincent
Mike
