Sophomore Questions as Shop gets Busy

[DaveTooley]

CNC expensive to repair? Tell me ain't so.
Haas supports their machines. Mine is a 2009 model. I guarantee you not much has changed with the core systems in that machine. There are what I call Gen 1 machines that are old. Then Gen2 which I think is the sweet spot. Handwheels, door override function, chuck guard or full enclosure. Then the current Gen3. only full enclosure , no handwheels

 

[LVLAaron]

Got one on a heavy 10 so you dont need alot

I've seen a lot of back and forth about it, but don't personally know anyone with one. I've mainly seen "it's too heavy for the headstock" and "it's difficult to use a parting tool" with it.

I love the idea behind it. If I had a dedicated chambering machine it would have one.

 

[Dusty Stevens]

I've seen a lot of back and forth about it, but don't personally know anyone with one. I've mainly seen "it's too heavy for the headstock" and "it's difficult to use a parting tool" with it.

I love the idea behind it. If I had a dedicated chambering machine it would have one.

I dont use it. Too far from the headstock and making bushings for each barrel sucks. There is a severe chance for chatter so the parting tool concern is valid. Itll pull the barrel right out and break your tool before you can stop it

 

[INTJ]

I am not sure the bushings are a terrible idea. I personally know three long-time, highly respected machinists (guys whose names you'd recognize) who use them. Their chamber runout is the same as those of us that use outboard spiders. The difference is they are able to chamber barrels twice as fast when using a manual machine.

I am going to be shown by one of them how it's done.

We all know the outboard spider is easy to learn and works very well. In a low production environment or as a hobby it is the best choice. I might even argue it's better for a BR rifle. However, these guys that use bushings makes rifles that shoot as well as anybody's. It just is harder to setup, perhaps requiring a higher level of machinist skills.

 

[LVLAaron]

What kind of bushings are we talking about here?

 

[Judd]

What kind of bushings are we talking about here?

Supports the outboard end of the barrel, slides around the barrel and locks on the taper (I’ve seen some thread the muzzle first and then thread the bushing onto the barrel) but requires the spindle to be machined or validated as true.

 

[Dusty Stevens]

Actually im talking about the bushings that have to match the taper of the chamber end. The muzzle kinda flops around in the spindle and is not held or theres no point in having the tbas. It is similar to chambering in the viper fixture but harder to hold the barrel. Probably the biggest issue is being that far away from the headstock. Machinists know the closer you are to that bearing the better everything is

 

[INTJ]

What kind of bushings are we talking about here?

Delrin bushings. They are machined to fit in the spindle and have o-rings on the outside diameter. The hole in the middle supports the shank or muzzle.

I would only use them in the 1440GT to thread the muzzle on short barrels. Then I can put on my barrel extension and use the spider. However, the guys that I mentioned like big heavy lathes with long headstocks, so everything that extend into the headstock is supported by a bushing.

 

[Dusty Stevens]

Delrin bushings. They are machined to fit in the spindle and have o-rings on the outside diameter. The hole in the middle supports the shank or muzzle.

I would only use them in the 1440GT to thread the muzzle on short barrels. Then I can put on my barrel extension and use the spider. However, the guys that I mentioned like big heavy lathes with long headstocks, so everything that extend into the headstock is supported by a bushing.

Thats just like indicating the OD on the outboard end. Here is the instruction manual:

https://www.tiptopwebsite.com/files/ssgcustomrifles.pdf

 

[dnellans]

I spent 25 years running a wire EDM. A lot of that time was spent straightening out reamed holes. So, I don't buy the line that a reamer will follow the existing hole without a pilot. YMMV.

I want to hear more about this!

 

[INTJ]

Thats just like indicating the OD on the outboard end. Here is the instruction manual:

https://www.tiptopwebsite.com/files/ssgcustomrifles.pdf

That is my thought as well. It's not really lining up the bore. That said, the guys the use them get the same chamber runout as those who dial with an outboard spider.

 

[Dusty Stevens]

That is my thought as well. It's not really lining up the bore. That said, the guys the use them get the same chamber runout as those who dial with an outboard spider.

When i adjust mine with the muzzle held it does not actually get the bore straight. Its like its not strong enough to bend the barrel into alignment and you can only adjust it in the same plane you would with a 4 jaw or adjust tru chuck. Thats checking it with an indicator rod, gordy rod or long stem. So it negates using the axial alignment part of it, and it puts you that much farther from the spindle. I guess its all in how much time you put into testing your setups

 

[Alex Wheeler]

I almost bought a trubore chuck. But decided not to. I want one of the places I dial to be directly under a jacking screw. Dialing away from one makes you chase it and the less parts involved the better. I just couldn't see how it would improve my work or speed. You can actually chamber a barrel pretty quickly if your brain is thinking of the next step before you get to it and no one is interupting you.

 

[Alex Wheeler]

I'll tell you how you could double production tomorrow. Show up at 2am. I used to do that when I was a mechanic. Everyone is sleeping, zero distraction.

 

[Walt Krafft]

^^That is why I worked midnights for 25 years. The company owner would leave me all kinds off goofy stuff to do. One time I ended up writing a cnc program to single point a thread in a sine wave profile. The thread form looked like a light bulb thread.

 

[LVLAaron]

I almost bought a trubore chuck. But decided not to. I want one of the places I dial to be directly under a jacking screw. Dialing away from one makes you chase it and the less parts involved the better. I just couldn't see how it would improve my work or speed. You can actually chamber a barrel pretty quickly if your brain is thinking of the next step before you get to it and no one is interupting you.

Same. I hadn’t thought about that with the TBAS.

 

[X Count]

Delrin bushings. They are machined to fit in the spindle and have o-rings on the outside diameter. The hole in the middle supports the shank or muzzle.

I would only use them in the 1440GT to thread the muzzle on short barrels. Then I can put on my barrel extension and use the spider. However, the guys that I mentioned like big heavy lathes with long headstocks, so everything that extend into the headstock is supported by a bushing.

It's twice as fast because they are only radially indicating one location. Using a spider your chasing back and forth indicating 2 or 3 locations to balance radial and axial alignment as best as possible. The muzzle will only be as good as how concentric the barrel OD is to the bore which may be fine on good barrels but not so fine on others.

 

[INTJ]

It's twice as fast because they are only radially indicating one location. Using a spider your chasing back and forth indicating 2 or 3 locations to balance radial and axial alignment as best as possible. The muzzle will only be as good as how concentric the barrel OD is to the bore which may be fine on good barrels but not so fine on others.

It's not the dial in. I usually take 5-10 minutes to dial in. I can't remember if I posted on this thread or my other recent thread, buts it's all the double checking and hand-fitting I do. If I were to make fewer passes and cut to the numbers, it would speed me up. I will start incorporating that, but I am not sacrificing quality for speed. The owner is very onboard with that.

I am not showing up at 2 AM. We are expanding our space again, and talking about walling off the area where we have the lathes. I don't think people who don't machine understand how much it slows you down when you keep getting interrupted.

Adding the second lathe and lathe operator will double our production. We will have one setup my way--dual spiders--and the other likely set up with the bushings.

The guys that use the bushings get the same chamber runout as the outboard spider guys.

 

[Dusty Stevens]

The guys that use the bushings get the same chamber runout as the outboard spider guys.

If you check it in the same setup as you chambered it in that is possible. But if you take this purely out of proportion drawing as to how the bore wanders then think of how you could possibly get a chamber running straight with the bore without moving the muzzle youll see just how that will go. Does it matter to them or you? Thats up to you to decide. Always gotta be devising new methods. Using a bushing in the spindle is the same as chambering between centers. It sure is fast

 

[INTJ]

If you check it in the same setup as you chambered it in that is possible. But if you take this purely out of proportion drawing as to how the bore wanders then think of how you could possibly get a chamber running straight with the bore without moving the muzzle youll see just how that will go. Does it matter to them or you? Thats up to you to decide. Always gotta be devising new methods. Using a bushing in the spindle is the same as chambering between centers. It sure is fastView attachment 1389226

I don't disagree. I can't see how a bushing could make a good of a chamber as a spider.

I personally will only use a bushing for threading a muzzle on a short barrel. Then I add my barrel extension and cut the chamber the right way.

I am sure the bushing guys will say all that matters is the throat being dialed in true, and when they prebore they make the rest of the chamber straight.

So with their setup, with the muzzle fixed, they can get the throat dialed to be concentric with the spindle, but there will absolutely be runout at the breech. I am not sure if it's .0005 or .005. However, when they cut the tenon then the threads will be true to the throat, and when they prebore, the prebored section is also true with the throat.