Gunsmithing Cant get this internal threading tool set up!

[jonaddis84]

I picked up a good laydown internal threading tool and have been trying to get it working for the past day. Its a Kennametal Carbide holder. Dont have the specifics, but the bar has a flat that when you clamp it down in the holder the insert is held on quite an angle. The cutting surface itself though is angled back up so it appears to be level again.

I have tried above, at, and below centerline with this thing and I cannot get it to cut for shit. Even if I just plunge it into a piece of barstock not threading but just cutting a groove, it still appears to be tearing metal and not cutting it, and it leaves a nasty burr on the whole edge of the cut.

Any advice?

Also, just want to confirm that with this type of tool when threading internally, the compound gets turned 29.5 degrees to the left past 90? So when you move the compound the tool is moving TOWARDS the headstock?

 

[Jkob]

Re: Cant get this internal threading tool set up!

It should be at or slightly above center. It is designed to cut only on the leading edge when threading. If you plunge cut with it, the resulting chips will interfere with each other. Also, when threading internally, the compound should be set to cut in the direction of the feed.

 

[eddief]

Re: Cant get this internal threading tool set up!

When I thread internally I feed straight in with the cross-slide and compound at 30 degrees. Threads turn out beautiful, what type of coating are you running on your inserts??

 

[colchester]

Re: Cant get this internal threading tool set up!

Are you sure that the heel of the tool is not rubbing. This can happen if the hole size is below the min. size for the tool. Got a pic of the setup

 

[hero's machine]

Re: Cant get this internal threading tool set up!

It is carbide which often does not like to go slow....I am sure you know that. Have you tried a different cutting face yet?

 

[Hooper]

Re: Cant get this internal threading tool set up!

Have you cut inside threads before?

Tell us how you are positioning the compound feed in relation to the carriage.

 

[300sniper]

Re: Cant get this internal threading tool set up!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 73 fastback</div><div class="ubbcode-body">Are you sure that the heel of the tool is not rubbing. This can happen if the hole size is below the min. size for the tool. Got a pic of the setup </div></div>

without seeing it or knowing more about the setup, this would be my first guess.


for shitsngrins, turn your lathe spindle in reverse and run the tool on the backside of a piece of test material to see if it cuts that way. if it cuts fine, my guess is the tool is too big for the id of the hole.

 

[jonaddis84]

Re: Cant get this internal threading tool set up!

Definitely not too small of a hole, the bar is only 1/2" and Im just trying to nail down my action threads on practice stock. Here is the setup...

I know I really should be running this carbide insert faster, but it will still work around 115rpm right? Just wont leave as sexy a surface finish. Otherwise I will need to try to find some HSS inserts that match these.

 

[jonaddis84]

Re: Cant get this internal threading tool set up!

Just looked at the other side of the insert, it is KC5025, must be the grade of carbide I assume.

If this tool just isnt going to work for me and my slow RPM's, can someone recommend a good insert threader to use? Just spoke with Mike and Warner tool, in about 2mo they will have one that will work great for actions, but thats 2mo away. I guess their current laydown threader will work ok for Remingtons but not many others.

 

[jonaddis84]

Re: Cant get this internal threading tool set up!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 73 fastback</div><div class="ubbcode-body">Are you sure that the heel of the tool is not rubbing. This can happen if the hole size is below the min. size for the tool. Got a pic of the setup </div></div>

without seeing it or knowing more about the setup, this would be my first guess.


for shitsngrins, turn your lathe spindle in reverse and run the tool on the backside of a piece of test material to see if it cuts that way. if it cuts fine, my guess is the tool is too big for the id of the hole. </div></div>

This is what I was doing just to try to get it setup right. Was just trying to use it as an external threader with the lathe in reverse. In this case though I had the compound opposite of what you see in the picture. The threads looked like crap no matter what I did, and when I did actually take them to almost full depth, the profile didnt even look right at all. I WAS running at 700rpm in this case knowing carbide likes fast.

 

[300sniper]

Re: Cant get this internal threading tool set up!

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonaddis84</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 300sniper</div><div class="ubbcode-body">
without seeing it or knowing more about the setup, this would be my first guess.


for shitsngrins, turn your lathe spindle in reverse and run the tool on the backside of a piece of test material to see if it cuts that way. if it cuts fine, my guess is the tool is too big for the id of the hole. </div></div>

This is what I was doing just to try to get it setup right. Was just trying to use it as an external threader with the lathe in reverse. In this case though I had the compound opposite of what you see in the picture. The threads looked like crap no matter what I did, and when I did actually take them to almost full depth, the profile didnt even look right at all. I WAS running at 700rpm in this case knowing carbide likes fast. </div></div>

keep your compound the same way you have it in the picture while feeding in with it on the back side. that way the screw for your compound is always loaded the same way.

i use carmex TiN coated laydown inserts and even turning the spindle by hand, i still get a decent finish. 300 rpm gives a great finish even though i know they should probably be spun faster. i'm not sure if it is the quality of the picture but the shape of your insert doesn't look right.

 

[colchester]

Re: Cant get this internal threading tool set up!

I cant determine the geometry of the insert from the photos. Im trying to see the relief on the insert, is it possible it is set for a LH thread? responding to the question you asked regarding options for internal cutting tools I took a pc of 1/2" hs tool steel and ground a threading tool that is specifically for truing actions. It works very well for me

 

[chakup]

Re: Cant get this internal threading tool set up!

Make sure your passes are clean and deflection isn't causing any issues. Occasionally I'll run the same DOC for 2-3 passes to make sure there's no issues there. Speed will help with the threads, but it should cut fine going slower. Got pics of how the threads are turning out?

 

[cal50]

Re: Cant get this internal threading tool set up!

What material?

If you have too much rake angle the insert will drag instead of cutting. Similar to moving your feed dial in .002 at a time and not getting any cutting action and another .002 move in and you get a big bite out of your part.

I have one of those style of holder and I use it in a boring tool holder with a sleeve so I can set the insert at zero rake angle and on center. If you have the correct grade of carbide for your material you should get even chips with the slightness of movement on normal material.

304 Stainless is gummy stuff and never cuts really well so there are a few special situations to deal with. I set my compound on the other side (30 Deg.) and you should be good in back gears or regular RPM range.

 

[jonaddis84]

Re: Cant get this internal threading tool set up!

Well Im thinking that this tool just wont work as an external threader for some reason.

I decided to see how it would clean threads up and it worked perfect when feeding with the compound. I may have screwed up the first time I tried it earlier on internal and might have had the compound the wrong way.

I think Ill be able to make this one work until Warner comes out with their new laydown tool. Id love to be able to make this one work perfect because I think it was like a $450 piece new!

First action trued...

Action jig I made today...

8-40 Base hole fixture...

Modified 3/8" socket heads, threads are a tight fit into action , tenon is a tolerance fit into the fixture.