02GF74
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posted on 30/1/07 at 07:54 PM |
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technique for putting on a thread squarely
well you can all
the process of making metric studs hasn't been too successful.
I am find the thread is not on squarely, although each successive attempts is a bit better.
I have tried usinga drill press - bolt in chuck and the die on the vice to start the thread and that was no good; also using set square which was a
it better but still out.
Last thing I'll try is to put the headless bolt into a cordless drill and "drill it" into the die at very low speed to start it
off square.
So any tips/advice before I spend mega bucks!!!
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Danozeman
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posted on 30/1/07 at 08:10 PM |
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Taper the end and take it easy with a steady hand..
Dan
Built the purple peril!! Let the modifications begin!!
http://www.eastangliankitcars.co.uk
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02GF74
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posted on 30/1/07 at 08:14 PM |
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I did taper the end using file on drill; I do have spare metal so can make it almost a cone; will give that a shot.
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SeaBass
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posted on 30/1/07 at 08:37 PM |
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What sort of quality of split die are you using?? I'm lucky to be consulted on what we should be buying engineering tool wise at work. I always
opt for either Presto or recently Goliath seems a balance between quality and price. Many cheaper taps and dies are effectively made from toffee IMHO.
How long a thread are you cutting?
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907
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posted on 30/1/07 at 08:40 PM |
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Have you seen those round spirit levels, about the size of a 50p, like the ones you get in a camera tripod.
Usually about a quid in a cut price tool shop.
Stick one (double sided tape) on the top of the die holder.
Square up the bolt in the vice and watch the bubble.
I agree with the start taper btw.
Or...
Buy a lathe.
Paul G
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Shaw
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posted on 30/1/07 at 08:44 PM |
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Are you using a die nut or a die in a propper die holder.
I hane always found using a die nut to be a bit hit or miss.
you could thighten two nuts together on the imperial end and try tightening it into the die held in a vice carefully?
Yes buy a lathe!
[Edited on 30/1/07 by Shaw]
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owelly
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posted on 30/1/07 at 08:51 PM |
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Die nuts are for when you already have a thread.
If you have a good quality die in a matching holder (stock) it should be possible to screw the middle screw (on the stock) in as far as possible and
then screw the outer two screws in just to hold things. That should start your thread nice and square. Then slacken the middle screw and tweak the
other two for the next pass. Do this until the thread is correctly formed.
http://www.ppcmag.co.uk
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02GF74
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posted on 30/1/07 at 09:04 PM |
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Apex, UK split die.
Putting on 15 mm thread.
The die holder comes from a JCB Argos (read cheap but reasonable qulity) and is a very tight fit - I am wondering if it is not seated squarely?
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Mal
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posted on 30/1/07 at 09:25 PM |
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Die in Holder
Owelly described how to expand and adjust the die to size the thread.
With the 3 screws backed off the die should be a slightly loose fit in the holder
to allow the tapered centre screw to open the split and expand the thread.
If the die is a tight fit in the holder with the screws backed off there is your problem.
Mal
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02GF74
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posted on 30/1/07 at 09:41 PM |
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ok then, seems like a new die holder is required.
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NS Dev
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posted on 1/2/07 at 08:18 AM |
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unfortuantely the only way i can EVER get completely square threads is to thread in the lathe, even using the die stock. You push it up with the
tailstock to keep it dead square.
Retro RWD is the way forward...........automotive fabrication, car restoration, sheetmetal work, engine conversion
retro car restoration and tuning
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02GF74
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posted on 1/2/07 at 01:34 PM |
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wasnlt sure whtehr to start a new thread about starting a new thread
got a new die holder. it has an additonal disc attached with 3 fingers that are adjustable, the idea being they slide along the rod to keep the die
in the right place.
will know this evening if it is any use.
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JB
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posted on 1/2/07 at 04:27 PM |
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Square Threads
Taps. I always start the tap in the drill or lathe. In the drill I put the tap in the chuck, the work clamped on the table or in a vice and turn the
chuck by hand whilst just putting a little downward pressure on the chuck.
The process is similar in the lathe, do the turning by hand until I have lots of threads engaged and I am fed up of turning the chuck by hand.
I never cut external threads because they are awful and I will buy good quality bolts and design around those. However if you must then the correctly
sized bar is critical and as Mr NS says a lathe is about the only way, but you should be able to do the same in a drill press.
Hold the bar vertical in a vice on the drill table, put the die and holder onto the bar, then just use the chuck to apply enough pressure to keep the
die square. You will adjust the chuck to give the most surface area on the die. You will have to work out how to apply pressure on the chuck with the
handle and turn the die holder at the same time.
John
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02GF74
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posted on 2/2/07 at 02:16 PM |
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thinking of throwing the towel in on this; did fancy die holder is useless; did the drill chuck thing again and got 1 good thread out of 7
attempts
just can't believe how difficult it is?!?!?!?
if I had no choice, I could use my studs but I want the to go in with no wobbling, tis a right bu88er .
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David Jenkins
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posted on 2/2/07 at 02:23 PM |
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Some grades of stainless can be very chewy to machine or drill - at a guess, you've encountered an example!
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02GF74
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posted on 2/2/07 at 02:59 PM |
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dunno, after recommendation on here agaisnt using stainless, I went for the locost BZP bolts- easy to cut but not so to get it right.
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gazza285
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posted on 2/2/07 at 03:41 PM |
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Why do you want metric studs anyway, it's not like UNF studs and nuts are rare or expensive. If you cut a new thread on a BZP bolt you'll
removed the zinc plateing and increase the chances of the nut rusting on again anyway. Think I paid pennies at an autojumble for studs and brass nuts,
and I'm sure I've seen them at my local factors.
DO NOT PUT ON KNOB OR BOLLOCKS!
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