Help needed: Loading mechanism (modeling+machining)

A place for general potato gun questions and discussions.
PotatoEnemy17
Specialist
Specialist
Posts: 100
Joined: Tue Apr 10, 2012 6:33 pm

Wed Aug 22, 2012 10:16 am

The bb's coming out of the mag on their own is easily solved:
Attachments
A small dent opposite to the magazine.
A small dent opposite to the magazine.
MagDent.PNG (14.81 KiB) Viewed 2816 times
User avatar
Lockednloaded
Staff Sergeant
Staff Sergeant
United States of America
Posts: 1566
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Been thanked: 7 times

Wed Aug 22, 2012 10:20 am

You should probably have a detent to keep your BBs from rolling out the barrel if you aim downward, and also, why not just use a commercial factory made air cylinder? They come in every size imaginable
Jackssmirkingrevenge wrote:Setup.png
Shouldn't the hose the the loading cylinder come from the chamber so that it's not extra pilot volume?
I love lamp
User avatar
jackssmirkingrevenge
Five Star General
Five Star General
Posts: 26204
Joined: Thu Mar 15, 2007 11:28 pm
Has thanked: 572 times
Been thanked: 345 times

Donating Members

Wed Aug 22, 2012 10:27 am

Lockednloaded wrote:Shouldn't the hose the the loading cylinder come from the chamber so that it's not extra pilot volume?
?

The pilot volume is exhausted into the loading cylinder if I understood correctly.
hectmarr wrote:You have to make many weapons, because this field is long and short life
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Wed Aug 22, 2012 11:17 am

One spring in the magazine will only feed about 6 BBs.
Do you plan on multiple springs and how do you plan to hold the springs together?
Last edited by dewey-1 on Thu Aug 23, 2012 2:01 pm, edited 1 time in total.
User avatar
Lockednloaded
Staff Sergeant
Staff Sergeant
United States of America
Posts: 1566
Joined: Thu Sep 03, 2009 9:38 pm
Location: Texas, USA
Been thanked: 7 times

Wed Aug 22, 2012 1:25 pm

jackssmirkingrevenge wrote:
Lockednloaded wrote:Shouldn't the hose the the loading cylinder come from the chamber so that it's not extra pilot volume?
?

The pilot volume is exhausted into the loading cylinder if I understood correctly.
Just read through the whole thread :oops: , I thought it was supposed to be hooked up like POLAND_SPUD's semi, but now I see it's a different design...
I love lamp
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Wed Aug 22, 2012 3:35 pm

This is hooked up like POLAND_SPUDS semi :)

I see some animations are in order

Mag spring wise, I have a bench grinder, so even if I didn't buy them closed and ground flat, I can grind them myself. I plan on stacking 4 in the mag.

I guess I've been more unclear about my design than I think I have. As my paintball tank fills my QEV, it also charges the air cylinder which is emptied into the barrel as the QEV fires.

As for the bb being pushed from the mag to under the loading piston, even if this happens it will be trapped between the edge of the mag and the loading piston stick, the bottom of my loading piston will be conical so it pushes the bb back into the mag. Remember my mag spring(s) aren't very strong.
Lockednloaded wrote:You should probably have a detent to keep your BBs from rolling out the barrel if you aim downward
I will have a detent, not shown in this diagram.
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Sat Aug 25, 2012 6:08 pm

PaperNinja;

Now that you understand how much a custom machined part costs, you need
to discuss your designs in your own thread to prevent cluttering of the machinist thread.

You are asking for help but you are spoon feeding us with one piddly part at a time.
You need to supply an overall sketch of the design. Any purchased parts with part numbers would be helpful.
Goats spudz
Specialist 4
Specialist 4
Posts: 458
Joined: Tue Aug 02, 2011 12:31 pm
Contact:

Sat Aug 25, 2012 6:10 pm

And use a ruler on your drawings! :D
Where's my Chuck key?
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Sat Aug 25, 2012 6:36 pm

I'll have an animation soon :)
I'll also make sketches for the details of my system

I'm going to do the modification you suggested, or at least try to :lol:.

I'll also provide part numbers for the rest of my loading mech. It'll take me a while to do all this though :)
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Sat Aug 25, 2012 9:55 pm

Ok, here's a very bad version of what I call an animation. I made the drawings in Paintbrush (for mac), then strung them together in iMovie, then uploaded to youtube... :/

I know it's really weird but I couldn't figure out how to do it better.

I know I accidentally forgot the big spring in the air cylinder for the first few frames.

I'll give more physical drawings and mcmaster part numbers for what I have/plan to have tomorrow... right now I'm tired xD

Anyway, here ya go

[youtube][/youtube]

I made this unlisted, not public. It should work but if it doesn't please tell me.
User avatar
Mr.Tallahassee
Specialist 3
Specialist 3
Posts: 364
Joined: Sun Jul 10, 2011 2:35 am

Sun Aug 26, 2012 1:30 am

I find it funny how I pulled that animated design from the picture posted by PotatoEnemy17 at the top of this page without reading any other part of this thread. :lol: That would probably work nicely though. The chamber pressure acting on the air cylinder could even be used as somewhat of a detent if done right.
Sarcasm is the body's natural defense against stupid.
Petitlu wrote:My balls are made of lead and weigh 22g but I can make heavier or lighter ...
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Sun Aug 26, 2012 6:27 am

Hmm I never thought of it being used as a detent, that's clever, though I already have a detent. (mcmaster #1368A11)
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Sun Aug 26, 2012 6:07 pm

awright, some confirm this is gonna work :)

I haven't placed the order yet, but I have it ready. This is gonna be expensive so I really want to get it right.

These are all NPT, and I'll be drilling into the MIP so a BB can fit.

(all from mcmaster.com)

I'm getting air cylinder 6498K111

I'm getting various air fittings to connect it to my QEV

I'm getting nut 98892A400, which I will melt into rubber to make the loading piston, then I will screw the loading piston onto the air cylinder rod.

I'm getting 4757T151 1/8" male tee to make the body of my loading mech.

I'm getting 4568K371 (1/8" threaded pipe, 7" lg), 50785K161 (1/8" threaded cap), and 9657K68 (springs) for the actual magazine.

50785K91 (coupling) to attach the magazine to the tee

9171K61 for the mod that dewey suggested a little while ago (I think in the machinists thread), to mount the air cylinder onto the tee

And lastly, 2521A663 (a 3/8 - 24 tap) to mod the previous part.

Please (if anyone actually has time to go through this xD...) let me know if this will work!

I'm pretty sure it will though.
Last edited by PaperNinja on Sun Aug 26, 2012 7:02 pm, edited 1 time in total.
User avatar
dewey-1
Sergeant 3
Sergeant 3
Posts: 1298
Joined: Wed Mar 28, 2007 10:24 am
Location: NE Wisconsin USA

Sun Aug 26, 2012 6:34 pm

I can do preliminary drawings tomorrow morning.

What QEV are you using?
User avatar
PaperNinja
Specialist
Specialist
Posts: 190
Joined: Sun Jun 17, 2012 7:51 pm
Location: Droneland

Sun Aug 26, 2012 6:45 pm

Shouldn't I do the drawings? But thank you.

QEV

Also, do you know what kind/shape of rubber would be good for my loading piston? I have a hunch it doesn't matter, but mcmaster has too many choices :D

btw re-reading my prev post, I saw this... what I meant by "melt into rubber" was, I'll heat the metal, then sink it into rubber, which will melt and lock it in when it cools. (just in case that was ambiguous)
Post Reply