Aluminum Classic valve?

[steveg]

the typical modern, good quality cnc lathe or mill
is capable of +/-0002" positioning and +/-0001" repeatability.

what that means is that if I command a diameter of
1" than what will happen is a size between .9998" and 1.0002"

repeatability is when I repeat the same command the next
time it will be within +/-0001" of what happened the last
time.

This precision can be about halved with the installation
of feedback scales.

Oh and CP one of the most accurate lathes that can be had
is a manual lathe.

CP do you remember the brand of lathes and mills being used?
professional curiosity.

[nerobro]

So logn as you get the hole centers right and lengths right. you sould be ok. IIRC the powertube spacers are changes in .005" and I"m sure the on/off position is somewhat floatable. Probally as much as 1/16" of an inch. that's .0625"... (my guess judging from teh shape of the back of the sear.... of course moving the on/off will affect trigger pull... more or less leverage)

o-rings hold the on/off, and powertube bits in place... so you have several thou to play with.

[magmonkey]

I am probably opening a can of worms by typing this but here goes

When I was in trade school I had no money but loved

automags.... so what to do? I borrowed my friends

micromag and reverse engineered it, I built the body, grip

frame, asa,power feed,ball detent and yes the air valve.

the only bought parts were the grips and sear It was a

general pain in the butt but I did it because I wanted a

high end

marker and could not afford one at the time. the "gliney

mag" is still in service but it now has an retro valve in

it, although the one I built still works.

I showed the marker to tom at skyball and he complemented

my work, I told him it was a one off deal and I would

never sell it (I didn't make it to step on toes, I made it

because I was poor and cheap, plus it cost me more in time then I could ever get for it)

it was one of the coolest projects have

undertaken.... My advice Learn as much as you can doing

small projects, there are alot of things that could have

gone wrong but luckily didn't.

Gliney the mag monkey
Destructive customs

[Python14]

POST PICS!
I want to see.

[cphilip]

Originally posted by xen_100



I would like to see some proof of that... 1/1,000,000 of an inch? come on? there is nothing on this earth that could repeatably mill or lathe something to that close of a standard. all you have to have is a VERY slight amount of wear on your tool and it will go out serveral 1/10,000ths of an inch. I think that is a little exagerated.

we're not talking about tolerances thatr are that close anyway. if they were an air valve would cost alot more than $300!

They threw that number out as the maximum capability of the machine. I didn't say it has to meet that for our stuff but its incredibly small when you want it to be and even a 100 thousanths or 10 thousanths ( have to ask Tom what he shoots for here) is something like more like what we are looking for.

Your not thinking about the whole set of other things that magnify any mistake. One part can start adding up as you move down the line. No its not an exageration its a statement of what they CAN do. Things have to be perfect to achieve it. No hand chucking is going to do it. And its going to take more than a set of calipers to measure and align those. So no hand lathe is going to be able too get in those numbers with repeatability. Sorry but its not possible without the right tools. Not that WE need to get there but we do need close tolerances for repeatability.

FYI...We saw some small pins you could not even see the threads on. 100 per inch. they were about the size of a sear pin. I could not believe they were threaded. But if you held em up close you could see the little fine lines. Amazing.

I will have to look the name of these milling machines up as I do not recall from memory. Maybe one of the others will pop up and remember it. But they are special ones. Capabilties far beyond what we need for these but still well within what we need cranking them out.

And you guys are on the right track with the spacers and all. They are to take out tolerance variants and wear. But in order for them to do that they have to be very close to start with. And stay within the 5 one thousanths of an inch your given to adjust them with. Now remember that is after quite a few parts are lined up and all the play they may introduce. Remember each part that wears or oxidizes magnifies the mistake to the next part down the line. And not always linear. When you go from the length of the power tube to the on off pin and how big around the valve body is and how it sits in the rail and then down to the position of the sear pin in the rail to the length of the trigger rod. All them things in line and some give and take and the next thing you know you can exceed that if your not carefull. If it all is close then you can adjust that last little bit out. If its too far from that then you cannot. So its critical that all of them are so close to start with so there is no more than .005 to adjust out.

the "Timing" of a mag is all in the little things that makes them fit together. In say a Cocker its in all the rods and things you can adjust poor tolerances out with. With a Mag you need to be pretty darn close to start with. So that is why Tom is so fussy about it.

Think in those terms about what I was pointing out to him when I was cautioning him about what he was into. He may still want to try. But he needed to realize that it was not just reproducing the same valve in Aluminum either. It would need to be changed in some places.

[Russ]

Phil, welcome to my world

My guess is that what you saw wasn't a milling machine (aka milling center), but a turning center, a machine that makes round parts, but also has the capability to mill the workpiece...

Was the name of the machine japanese?

[cphilip]

Your probably right Russ. I am not up on the different terminologies of them. It will do all the cuts at once including all the inner ones. With out ever letting go of the piece. Cuts and mills all that stuff in the centers and holes and all in one pass with mutilple tasks. Multiple tools and such moving in and out. And starts the next one as it feeds the bar stock in. Whatever you call one of them things. I think it was said that those guys Tom uses has the largest concentration of them in one spot anywhere. They are complete little set ups. I do not recall the name but I think I made a note of it somewhere in my notes.

[steveg]

Mori Seiki , Okuma, Nakamura , and Mazak are the popular
ones.(from Japan that is)

[cphilip]

Mazak sounds familiar but my old age is kinda making me unsure....

[TheJester]

you might not want to jump into something that big right away, you're 1st time on the machine you'll be lucky to hold +/- .005 tolerances. i'm not sure about the tolerences of the mag valve, but i've been doing it for a year now and i still can't always get with in +/- .003, i try, but mistakes happen

[cledford]

Phil,

It was Mazak - I've got some pics around here I'll try to find.

-Calvin

[steveg]

A Mazak then, so unless it has the optional Fanuc control
then it probably has the standard Mazatrol, which under
the hood is a Meldas (Mitsubishi) control.

anyhow standard Meldas and Fanuc controls have a least input amount
of .0001" or .001mm (which is actually smaller
by 2.54 times)

standard lathes with +/-.0002" positioning are good enough
for airplanes, and even space program parts, as well as
nuclear, infact these lathes are even used in bearing manufacture
to rough the parts to size before final grinding.

But a millionth..., no. definatly not at only $250 000

so if a standard lathe is good enough for the space program
odds are it's good enough for mag parts

feel hit over the head enough yet Phil?

and I still know that a good machinist with a good Hardinge
manual lathe can do better that almost any CNC lathe.
just a LOT slower

[steveg]

http://www.llnl.gov/str/April01/Klingmann.html

now This! is a lathe that can cut to a millionth of an inch

[dansim]

ive seen magmonkeys micromag at aone 1, and it was very impressive

[cphilip]

Well I am not certain of the capabities of these things for sure or wether we were discussing their measuring capabilities when that number came up. I know it came up in conversation but I will not attest to it as the cutting number. I know it's small as heck though. The only one I can find any real numbers on was in One 10 thousandths of an inch from a model made in 1994. Repeatabilities show in that number. And I not sure which model it is they use. They had several models of them there. Some better and newer than 1994 for certain. All the numbers we throwing around are small as heck! But most of them are hard to achieve when human error is inputted as well as inexperience.

All I remember was I was mighty impressed with them numbers.


The machine is here but not sure which ones as they had several