Day 1 Practice - lessons learned. 12/30 update

[accuracyman]

mram10 how far out past the chuck is the material you are threading? Excessive material length can add to chatter if the tennon is not very rigid. Just something to consider when setting up for threading. You are making good progress.... now to tweak your setup and tools and those threads will start to really shine

 

[mram10]

Danny, I’ll go take a pic of my threading tool and post it.
Medic, thanks, I’ll check them out
Gene, I’ll post pics of my setup maybe a video while I’m doing it to help the diagnosis

 

[mram10]

Just knocked this one out. Same as before. Fixed shoulder. Bolt nose recess was too big. Grrrr. No sanding of the threads. Off to help the wife then I will post pics of the lathe setup. These threads were done with just the cross slide.

 

[mram10]

mram10 how far out past the chuck is the material you are threading? Excessive material length can add to chatter if the tennon is not very rigid. Just something to consider when setting up for threading. You are making good progress.... now to tweak your setup and tools and those threads will start to really shine

I’ll take a pic next time. I had about 2 inches from the shoulder to the jaws. Any closer and I was nervous I’d hit the jaws when turning the shank. I’m sure my tools are not setup efficiently.

 

[Curious]

I’m sure my tools are not setup efficiently.

Ive watched this thread with interest, its so hard to offer useful help when we can't really see your set-up or what you are doing but at least your making progress with the help of others.

I read that you have been grinding your own HSS tooling - my advice would be to invest in some indexable carbide tooling to begin with if you want better results quickly. If your tool geometry isn't correct which it could easily not be then the tool doesn't cut, it tears and it also chatters which your threads are showing.

I use a lot of self ground HSS tooling and when its done correctly and honed to an appropriate sharpness it cuts 416 barrel steel very easily and leaves a superb finish but I have lots of experience of tool grinding behind me, remember the surface finish will only ever reflect the surface finish on your cutting tool, if your tool is rough the work will be. Its not unusual to inspect a cutting edge with a 10x jewellers loupe to check the cutting edge is sharp and smooth. These stubs you are practicing on, they may not be free cutting steel, add to that badly ground tooling and you end up finding it difficult to get good results.

Your technique is coming along but choosing the right tooling for the work can make a huge difference to the finish you get and the ease of operation. Stick at it, you will get there!

 

[Someoldguy]

View attachment 1030263 View attachment 1030264 View attachment 1030265 View attachment 1030266 Just knocked this one out. Same as before. Fixed shoulder. Bolt nose recess was too big. Grrrr. No sanding of the threads. Off to help the wife then I will post pics of the lathe setup. These threads were done with just the cross slide.

If I understand what you are saying, you are advancing the threading tool into the work piece using only the compound screw? That is not going to produce a clean cut as you are applying both sides of the threading tool into the work piece at the same time.
When you set your cross slide screw for your initial cut, set the cross slide screw collar and compound screw collars to -0-. Your compound should already be adjusted to 29.5º, as was discussed earlier in the thread if I recall correctly?
After you make your initial pass and check with your pitch gauge to make certain your lead screw settings are correct, return the carriage to your starting point, return your cross slide screw to -0- and advance your COMPOUND screw .005" or whatever you wish to remove and continue as before.
With each new pass, return your cross slide screw to -0- and advance your threading tool into the work piece using only the compound screw. Savvy?
This means the threading tool will only be cutting along 1 edge, and chatter will be negated.

If I mis-read what you stated, pardon my interruption.

 

[ridgeway]

Nothing wrong with feeding entire depth with crossfeed. Utilize entire tool rather than one side...pros and cons to both ways. Regardless what way...as long as the final result works and is correct...

 

[Someoldguy]

Nothing wrong with feeding entire depth with crossfeed. Utilize entire tool rather than one side...pros and cons to both ways. Regardless what way...as long as the final result works and is correct...

Thought it might be helpful to him. Perhaps not.

 

[ridgeway]

Thought it might be helpful to him. Perhaps not.

I never said it wasn't.

 

[akajun]

I still see chatter, you have too
Much overhang on your tool, barrel too far out of the chuck, and or your tool height is too high or low.

 

[mram10]

Boring bar at end. This is out of order. Carbide at 780rpm
Crumby hss cutter that I need to redo used to turn down to 1.065 at 505rpm.
Carbide cutter for shoulder at 780rpm
Carbide cutter at 780rpm for chamfer
New hss threading tool I made tonight. 135rpm. Same number on half nut. Crossfeed only with .002 passes near end going to a couple .001 passes Here ya go guys. I took pics as I was going on this one. I did cross feed only, sorry SOG, I hadn’t read your last post before hand I’ll try it that way next time. I decided to make a new hss threading tool out of 3/8 and make sure it was very sharp and 60deg. Turned out ok, but I’ll get better at making them.

 

[mram10]

Finished piece. Shank is long. Didn’t measure, just trying to get threads down

Needed to get threads sharper. still waiting on parting tool for a nice relief cut

 

[carlsbad]

time to make something you can use. Although not as useful as you would think, everyone needs one of these.

 

[mram10]

Not Carl
What is it? I made a 1/2 13tpi that goes in the back of the bolt for truing the other day. It that what it is?

 

[TRA]

Finished piece. Shank is long. Didn’t measure, just trying to get threads downView attachment 1030305
View attachment 1030307
Needed to get threads sharper. still waiting on parting tool for a nice relief cut
View attachment 1030308

Much Better

 

[mram10]

Much Better

You’re back! I knew you’d come around

 

[Danny1788]

Nothing wrong with a flat topped thread, no need to be sharper if its to the correct depth. But to me your cutting tool looks too big

should be ground like this

 

[Tucker65]

Your work is getting much better and it also looks like you're not hanging your tools out too far. Keeping them close to the tool holders and not having your work stick out too far from the chuck will greatly help with any chatter problems it appeared you were having earlier.

I'm not sure what's going on with the locking handle that locks your your tool post in place. It looks as though it is pointing towards the chuck and would get in the way of your vision or worse yet hit the chuck. I myself would be getting rid of that handle and just put a big nut on that for locking it down.

John

 

[carlsbad]

Making a nut to replace that locking handle would be a good project. Many think the locking handle is an upgrade--I think it gets in the way. I keep a dedicated long box end wrench on the nearby bench to tighten that nut. I try not to adjust it very often--set it square and forget about it.

to machine the nut on your milling machine a hex collet block or collet indexer is the key. Internal threading is a good thing to master and a nut is easier than a blind hole.

--Jerry

 

[carlsbad]

Don't forget to break your corners.