Machined pengun - Dimply

[inonickname]

I'll draw it for you, give me a minute.

Edit: no, never mind. I dislike your mixing of imperial and metric

If I had a drawing with all one or the other I would

[Ragnarok]

I've hit my neighbor's shed from at least 30m away

He never said it was a SMALL room... :tongue3:

[dewey-1]

LeMaudit, JSR; Yes drawing is in process and indicating potential problems!

The tip of "nose" piece is 15 degrees not 20.

You may have a problem with the O-ring groove/notch on the Schrader valve with 5mm threads. I believe it may not be thick enough. Better machine this piece first, otherwise every thing else is useless.
I recommend 6mm threads. Try M6x1 threads first.

Do your Schrader valves have smaller than 1/8 inch ID hole?
JSR was to verify dimensions I sent him.

[LeMaudit]

The tip of "nose" piece is 15 degrees not 20.

The nose is a bit complicated... to draw
The cone goes from 15mm diameter to 5.25 mm. That's a 20° angle.
Then, it is turn down to 14mm to match the body diameter, which will result in a nice cylindrical junction, and help to have bigger flats to screw it in place with a wrench. The 3D shows that clearly.

I recommend 6mm threads. Try M6x1 threads first.

5mm seemed okay to me... but I made that step 2 with that n mind
And I do have a spare valve ! we'll know soon.

Do your Schrader valves have smaller than 1/8 inch ID hole?

The schrader ID I have is between a #31 drill and 1/8". I would bet 3.1mm.

[jackssmirkingrevenge]

I did not want to post this after realising how creepy it was

So it is... maniac!



I see your point, but filling a small chamber with a shock pump, my bet is that pilot and chamber would equalist between strokes. After all, my cast epoxy pistons perform in a similar manner to your dodgy little presentation

I'm pretty sure oblong projectiles would tumble within the effective range of the pengun, it's not really about accuracy just keeping projectile tip forward.
It would be pretty useless on the ball bearings though.

I think LeMaudit's miniature machining skills are going to cater for a tiny fin stabilised projectile I had done some evaluation of tumbling with unstabilised nails my pengun v2 here.

Edit: no, never mind. I dislike your mixing of imperial and metric

LeMaudit's requirements, having a metric lathe and imperial drill bits...

He never said it was a SMALL room...

Good save, cheers

You may have a problem with the O-ring groove/notch on the Schrader valve with 5mm threads. I believe it may not be thick enough. Better machine this piece first, otherwise every thing else is useless.

I told him to just epoxy it in place, but noooooo....

[LeMaudit]

LeMaudit's requirements, having a metric lathe and imperial drill bits...

Canada is metric... theoretically! In practice, try to find yourself a metric drill bit for a reasonable price... or a threaded metric rod! Yeah, right...

I told him to just epoxy it in place, but noooooo...

I don't remember that!

The video is done, 14mn... for the first step! :-/
And that's after cutting a good 70% on the editing room!

Currently the computer is producing the HD video, then I'll need to upload on YouTube about 1.3GB.... I'll be lucky if this is done today!
But tomorrow morning, hopefully...

[jackssmirkingrevenge]

Currently the computer is producing the HD video, then I'll need to upload on YouTube about 1.3GB.... I'll be lucky if this is done today!

Hmmm... maybe the quality is a bit overdone, considering it's destined for youtube? I know, I know, you're a perfectionist...

[LeMaudit]

I don't know how to make a smaller file keeping the 1920 resolution :-/ Just discovering the stuff ya know... (PowerDirector)

[dewey-1]

Here is the nose piece 3D CAD model.

What is the overall length on the body tube?

[LeMaudit]

Here is the nose piece 3D CAD model.

Yup! That's the idea Nice job!

What is the overall length on the body tube?

Forgot this one! I have updated the drawing; 11cm.

[edit] the MPG4 supposed HiDef result is crappy and full of bad pixels
Right, I try again with MPEG2/DVD quality. Much smaller, and quicker to encode.

[edit again] Yes! "only" 720x480 but it's good quality video.
And "only" 850MB too! Good... uploading...

[LeMaudit]

[youtube][/youtube]

And the cutting plan that I followed step by step:




Don't search this part on the complete plan... this is just a fixture I will need later to machine the real pengun parts... a shiny fixture... yes... still, only a fixture


Alright!
Some of you will find that video too long; I know.

Consider this is intended as a course for JSR and other people interested by miniature machining. To learn, or just to see in details how things can be done.
It is also a way to look above my shoulder (well... above my lathe really) and laught at me!

There will be 12 other steps following.
The last steps will involve the mill + rotary table.

When everything is complete, it is planned to make a shorten video out of this material, 10 to 15mn HD. But not as a machining course, more like a presentation of the miniature lathe and mill for a simple project. This will go public on YouTube. Those longer videos are not made to be shared outside this forum, they are unlisted on my YouTube profile.

I hope you enjoyed the viewing. More to come...

[Gun Freak]

That was pretty cool... Its easy to watch a long video when it is interesting. But what is "zeroing the wheel"?

[LeMaudit]

I'm glad you find it interesting 8)

Sorry, I could have been more clear. It means that you can reset the "zero" on the graduated collar at any position. That makes the following movements much easier, because you don't have to remember a particular value where you starting point was.

Not all the lathes have that capability, it is an option on Sherline lathes. But one that I couldn't live without

[Gun Freak]

Ohhhh thank you for clearing that up, it makes a lOt of sense now, I was wondering how you knew how far you were drilling into the brass. I really look forward to seeing the next videos and the end result!

[FighterAce]

Oh the chatter... why didn't you put the work closer to the chuck?