30mm optics with minimag???

[Wildcat]

Could a new head be made that would fit the 30mm optics on a minimag w/sammich? /ubbthreads/images/graemlins/smile.gif I tried just slipping the head of my blaster jr on my minimag. More out of curiosity than anything I guess. Has it been done before?

 

[Chop]

Does anyone know what the thread size and pitch is on the head of the Mini M@g?

 

[XtremePyro]

The threads on the bulb end of a 2 AA mini mag are
20 TPI and the major diameter is around 0.682- 0.685
or a hair under 11/16" or 17.40 mm

 

[Crux]

XP - While the MM threads may appear be 20 TPI, look closely! There are four of them at 90degrees and each is 5 TPI. I'm sure there is a name for this thread, but I'm an E.E. not an M.E.
Anyone care to fill us in?

Best regards, Crux

 

[Lux Luthor]

A custom made head would probably be the way to go. The BJ head is a behemoth compared to the minimag body (and heavy as heck). If you trim down the 30mm optic, and leave just a small lip, you could get it down to the diameter of a Legend LX, or even smaller. That would be a nicer match.

Something like a larger PR-T head with proper threading for Minim@g would be sweet.

 

[tvodrd]

It's called a 4-start thread. They are special and very difficult to machine. Best is to have a cu$tom tap ground- wild guess ~$250! The advantage is fast pitch, but much smoother than a single, high helix angle thread.

Larry

 

[IsaacHayes]

the 2C nexstar will fit 30mm optics. Not sure if you remove the large lip or not off of them...

 

[Chop]

tvodrd,
That kind of shoots holes in my turbo head idea. I have some 1.3" reflectors coming in from Carley and wanted to turn a nice turbo head for the MM. I kind of thought that the threads would be a hurdle. I'll have to think about it somemore.

Anyone have any ideas?

 

[tvodrd]

Chop,

I just got home and had a chance to take a closer look. I think that you could rethread the 4-start to a fine pitch 11/16, like 11/16-32. It would be a lathe job, even with a die from Travers. It wouldn't look pretty, but would probably be functional. If I had a junk mag tube, I'd give it a try for you- think I have an 11/16-24 die, but finer would be better.

Larry

 

[XtremePyro]

Crux,

By george your right. I remember reading about such threads
but this is the first time Ive ever seen them.
I bet that would be aggrevating to cut on a lathe.
Of course I'll have to try it out /ubbthreads/images/graemlins/smile.gif
Im thinking you could index the start of each of the 4 threads
with each of the jaws on a 4 jaw chuch.

Tim

 

[tvodrd]

XtremePyro,

You usually cut one by indexing the gears in the headstock. I will spare you (and me /ubbthreads/images/graemlins/grin.gif ) the details. I'm rusty so check Machinerys Handbook.

Larry