Hypothetical question for the machinists

[KJQ6945]

You're speaking Greek to me CountryBoy, I know less than nothing about that stuff. In looking at it though, is the portion of the barrel that needs to be .725" in diamter, that diameter for 2.4" from the end of the barrel or does that 2.4 mean something else?

You are good. He's talking about the size of paper AE made the prints on. It's bigger than life. Big company, big prints.

I do have a question for you though. What can are you going to use on this? From what I'm seeing from Allen Engineering, they only make one .30 cal can, and it's a direct thread to the barrel, not the muzzle device, like a MK12. Im probably missing something here.

 

[phylodog]

I most likely won't suppress it but I may contact Allen Engineering and ask them about making a can for it. I decided having it look like I wanted was more important than being able to pop a can on it whenever I wanted. I can always pull the brake and put my .30 cal can on it if I want to but I doubt I'll do it much if at all. Wanted a Mk12 Mod 0 since the first time I laid eyes on one, made more sense to use some of what I had on hand for the build.

 

[phylodog]

Well crap. I emailed Allen Engineering about a 6.5 Mk12 can and received a reply within an hour. They offer it for an extra $25 over a standard can. Ugh, more money.....

 

[Bfish]

Well crap. I emailed Allen Engineering about a 6.5 Mk12 can and received a reply within an hour. They offer it for an extra $25 over a standard can. Ugh, more money.....

Hahaha yeah man they are good to work with! Happy to hear that you reached out to them! It's going to be one sweet rifle!

 

[cbhausen]

You're speaking Greek to me CountryBoy, I know less than nothing about that stuff. In looking at it though, is the portion of the barrel that needs to be .725" in diamter, that diameter for 2.4" from the end of the barrel or does that 2.4 mean something else?

Yes, 2.4 ordinate dimension is the distance from the end of the muzzle (0.000). One decimal place means the tolerance is +/-.020" (see table in title block).

As for the sheet size, it's not uncommon for companies to standardize on one sheet size and many CAD systems (maybe SolidWorks here?) will auto-scale the drawing views to the sheet size when placing them using a parent 3D model to create them.

More interesting, though is the .001" concentricity tolerance between the male threaded part and the bore axis? What about the other diameters? If the can fits, wear it.

/CAD geek post

 

[olhorseman]

Yes, 2.4 ordinate dimension is the distance from the end of the muzzle (0.000). One decimal place means the tolerance is +/-.020" (see table in title block).

As for the sheet size, it's not uncommon for companies to standardize on one sheet size and many CAD systems (maybe SolidWorks here?) will auto-scale the drawing views to the sheet size when placing them using a parent 3D model to create them.

More interesting, though is the .001" concentricity tolerance between the male threaded part and the bore axis? What about the other diameters? If the can fits, wear it.

/CAD geek post

I wonder why the drawing is in 1st angle projection? In 40 years of working in machine job shops I probably saw less than a dozen drawings in 1st angle projection. (BTW, by ASME Y14.5 the GD&T standard, the definiition of concentricity makes concentricity almost impossible to check.)

 

[KJQ6945]

Well crap. I emailed Allen Engineering about a 6.5 Mk12 can and received a reply within an hour. They offer it for an extra $25 over a standard can. Ugh, more money.....

HaHa, congrats! I've had my mod 0 for about 2 years now, and I still haven't ordered the can for it.

 

[cayce]

Have you considered a adaptor? There are lots of people making them.

 

[CountryBoy19]

You're speaking Greek to me CountryBoy, I know less than nothing about that stuff. In looking at it though, is the portion of the barrel that needs to be .725" in diamter, that diameter for 2.4" from the end of the barrel or does that 2.4 mean something else?

Your question has already been answered so I'll explain what I meant in English. That drawing is akin to writing yourself a note to get milk on your way home. A post-it note with normal size writing would be sufficient, but you don't do "just sufficient". So you grab a sheet of legal size paper and in text 4 inches tall you write "GET MILK TODAY". Now you have a note that you can't fit in your pocket; had you written it on a post-it all would be good. But now you have to fold that paper over 6 times to get it in your pocket. By that point it's so thick that it hurts to sit on it all day so you pull it out of your pocket and then you forget it as you walk out the door. Moral of the story, a simple post-it note was all that was needed but you went through the extra hassle to do it bigger (and better?) and it came back to bite you.

Haha...

To put it in perspective, I make my living making drawings like that (among other things). I cannot even print a drawing that large. I have to send it to the guy that runs our plotter, in a different building, and have him print it. It's an epic pain in my back side to print something that size. I only do it about once every 3-4 years out of the hundreds of drawings I print every year.

 

[phylodog]

Gotcha, I'm definitely clueless when it comes to such things.

 

[cbhausen]

First angle projection is the standard in Europe. Don’t ask me why, it looks ass backward me.