Milling and mounting for a red dot

[T-DOGG]

Think I'm going to do a few more optic cuts on a couple of guns eventually, but do some more practicing beforehand. Upgrading my pseudo mill to see just how much use I get doing milling operations until I decide I need a real mill. Ordered a 2-axis DRO kit, a digital depth gauge made for a drill press and some actual machinist jacks. Last night I reinforced the column by bracing it to the wall. Much better, but now the stuff on the wall vibrates depending on press rpm. Oh well.

 

[T-DOGG]

Ended up installing an Ade 1 degree delrin shim on the Tanfo Witness instead of the modified EGW plate. This brought the optic down lower, giving a co-witness of the irons and it looks better overall.

 

[russc2542]

What gun?
Just wondering how prevalent this is.

Now I’m going to check barrel at lockup to bottom and top of slide on a few various pistols.

Same one. CZ P01.

All my CZs (and clones) have a short little nub in front, big ol' sight in back. RAMI, P01, 97, IWI Jericho, and a Tanfo Mossad. I took out some calipers and did some math and they come out to 1 degree downward tilt of the barrel vs the lines of the slide. You can see in many of the pics in this thread the difference but here is one with a quick reference line.

 

[SmileDocHill]

Wow, 1 degree doesn't seem like much to make that big of a difference. (I just outed myself as a non-machinist).
As a rifleman, I guess it's 60 MOA though, which does drive home the significance... I heard that in a class once

 

[T-DOGG]

Wow, 1 degree doesn't seem like much to make that big of a difference. (I just outed myself as a non-machinist).
As a rifleman, I guess it's 60 MOA though, which does drive home the significance... I heard that in a class once

I thought the same initially as well. I assumed you just milled them all flat/parallel and the optic had enough elevation to adjust. Learn something new every day.

 

[55fairlane]

Wow, 1 degree doesn't seem like much to make that big of a difference. (I just outed myself as a non-machinist).
As a rifleman, I guess it's 60 MOA though, which does drive home the significance... I heard that in a class once

So for all of you non-machinist out there , your favorite tool maker & mathematical manic will help you.....so what is 1 degree, well simply 60 minutes. Let's lookmat it this way, if you look at the geometrical drawing of 1 minute, that minute looks like a piece of pie, with the pointy end at your muzzle and the wide end at the target.

So if we look at the math, (and I won't bore you with that math, Google it if you must know the formula) 1 degree @ 100 yards will be 60 inches wide!

So now let's refine this (and make it more user friendly) 60 inches is a lot of area, so to make adjustments finer(for "dialing something in" ) optics companies have given us ½M.O.A OR ¼ M.O.A adjustments, but what is a M.O.A, well minute of angle, we have simple refined the angle in to minutes, and the are 60 minutes in 1 degree. So now let's look at 1 minute or angle, remember we are still looking a pie shaped wedge, at 100 yards that 1 minute is 1 inch wide. So we refine our adjustments even more (on our optic) to ¼ minute of angle or 15 seconds.

So what's in a degree, if we look at your handgun, 1 minute up/down , side to side at 25 yards 1 minute is 15 inches!

Now that your head is ready to explode, there is duct tape in the lobby, Thank you for coming to my lecture on mathematics and other boring things that really are important.

Aaron

 

[ditcherman]

So for all of you non-machinist out there , your favorite tool maker & mathematical manic will help you.....so what is 1 degree, well simply 60 minutes. Let's lookmat it this way, if you look at the geometrical drawing of 1 minute, that minute looks like a piece of pie, with the pointy end at your muzzle and the wide end at the target.

So if we look at the math, (and I won't bore you with that math, Google it if you must know the formula) 1 degree @ 100 yards will be 60 inches wide!

So now let's refine this (and make it more user friendly) 60 inches is a lot of area, so to make adjustments finer(for "dialing something in" ) optics companies have given us ½M.O.A OR ¼ M.O.A adjustments, but what is a M.O.A, well minute of angle, we have simple refined the angle in to minutes, and the are 60 minutes in 1 degree. So now let's look at 1 minute or angle, remember we are still looking a pie shaped wedge, at 100 yards that 1 minute is 1 inch wide. So we refine our adjustments even more (on our optic) to ¼ minute of angle or 15 seconds.

So what's in a degree, if we look at your handgun, 1 minute up/down , side to side at 25 yards 1 minute is 15 inches!

Now that your head is ready to explode, there is duct tape in the lobby, Thank you for coming to my lecture on mathematics and other boring things that really are important.

Aaron

Love it want more!!
I had done the math, but didn’t know the terms.
I’ll absorb this for a bit first…

 

[T-DOGG]

 

[T-DOGG]

Added a quill lock with a brass tip to the press tonight. I shaped the brass tip to match the contour of the quill for a better bite. I like repurposing things. Like an old header bolt from my car days and an old brass punch I don't use. The threads are 3/8-16, to help put some America into this Chinese drill press. And also because I couldn't find a M10-1.5 nut in my bin.

 

[55fairlane]

I like repurposing things. Like an old header bolt from my car days and an old brass punch I don't use.

I like to machine things.....like the morse taper floating (chamber) reamer holder

Wanna see more??

 

[ditcherman]

I like to machine things.....like the morse taper floating (chamber) reamer holder

Wanna see more?? View attachment 256448

Interesting, because it’s a reamer you want it to float?

 

[SmileDocHill]

So what's in a degree, if we look at your handgun, 1 minute up/down , side to side at 25 yards 1 minute is 15 inches!


Aaron

I think you meant to say 1 degree at 25 yards, not minute. So as not to confuse others... he's saying at 25 yards 1 degree is 7.5 inches. If you consider 7.5" from bore axis in all directions you get a cone with a diameter of 15" at 25 yards.

 

[55fairlane]

I think you meant to say 1 degree at 25 yards, not minute. So as not to confuse others... he's saying at 25 yards 1 degree is 7.5 inches. If you consider 7.5" from bore axis in all directions you get a cone with a diameter of 15" at 25 yards.

You are correct on my 1 minute vs 1 degree misquote.

 

[55fairlane]

Interesting, because it’s a reamer you want it to float?

Floating vs ridged.... floating....this type of tool holder allows for both axis and radial runout. This floating set up will keep our finished hole or chamber "true" to the centerline of the finished hole/chamber. The holder allows the to tool to follow the bore, regardless of angler or radial misalignment (runout).
A ridged tool holder will not allow for that compensation causing the finished hole/chamber to be out of spec. Hole out of round, hole tapered, hole not I the correct location.

 

[Lpherr]

Floating vs ridged.... floating....this type of tool holder allows for both axis and radial runout. This floating set up will keep our finished hole or chamber "true" to the centerline of the finished hole/chamber. The holder allows the to tool to follow the bore, regardless of angler or radial misalignment (runout).
A ridged tool holder will not allow for that compensation causing the finished hole/chamber to be out of spec. Hole out of round, hole tapered, hole not I the correct location.

Eccentric threaded holes.
Aren't those for adjustment?

 

[ditcherman]

Eccentric threaded holes.
Aren't those for adjustment?

Oh hi there you know about “farmer tolerance” too?
These guys that talk in tenthousanths can really be bothersome.

 

[cedartop]

I have to laugh looking at what you are all getting done with the equipment you are using. We have all of the fancy stuff at work and still have guys whining to no end about how that can't do this, that, or the other.

 

[Lpherr]

Oh hi there you know about “farmer tolerance” too?
These guys that talk in tenthousanths can really be bothersome.

I only work up to thousandths.
Anything above that, is anal for what I work on.

 

[ditcherman]

I only work up to thousandths.
Anything above that, is anal for what I work on.

Well, I’m trying to shed my farmer ways and listen in thousandths.

 

[55fairlane]

Eccentric threaded holes.
Aren't those for adjustment?

You can not thread an eccentric hole, thee entire hole is out of round. Normally you "turn " the shaft off center creating a cam or eccentric