V2 & V3 Drafting project.

[ThunderCactus]

"accepted"

[m102404]

I've got a bag (and probably a bin or two) of spare parts. There's probably enough for at least 2 mechboxes in there. Most of those parts are spares and junk...but there's enough if you want to do some mock ups and fiddling to figure out what's what.

If you come get it, you can have whatever you want.

That said...you may be best off getting a couple of "good" complete mechboxes if you want better measurement specs.

[K3vX]

Originally Posted by Bandit50

Oh well that kind of half of the fun of doing this, measuring and creating parts yourself. Thanks K3vX for some words of encouragement Keep you all posted how the projects going.

I didn't meant to discourage you, if that's what you thought :P

Honestly, if I knew how to CAD (I know how to use 3DsMax, but real cad is leaving me clueless) I'd measure and help you with whatever parts I have laying around here.

[Bandit50]

Honestly, your words are not discouraging at all. In fact they're more of a motivator. Right now money is tight even to order stuff. Most of you have some good points used parts will not be exact and off by a few thousands of an inch.

So, to co-inside with this project. I will just build a good reliable gear box for my A&K Masada and measure the parts as I build it. Two birds, one stone and with the season going to kick off soon. I am sure, I will be in and out of my own gun a few times. Either way, hopefully by the end of this year, the project will be done.

PS. I think my grammar got better and it only took 6 hours of my life to do what no English professor could do, even at the college level.

[SuperCriollo]

The Grimsby library has a 3d scanner. You might be able to use it for the complicated bits

http://www.grimsby.ca/Table/Grimsby-...rary-Services/

[Bandit50]

A viable option, but if I want to go for that exact, Ill just use Coordinate-measuring machine and part of the fun is measuring this

[Kos-Mos]

Originally Posted by Bandit50

A viable option, but if I want to go for that exact, Ill just use Coordinate-measuring machine and part of the fun is measuring this

I did go through a bunch of gears for shits a few months ago.

across 10 gear sets, different brand, I have over .200" if difference in any direction.

The pitch and attack angle of the tooth are also different. Most will work when mix-matched, but be noisy.
ICS gears have a very different profile and will grind whatever is not ICS (including the motor pinion).

Piston heads also vary wildly. That is because the piston itself does not really touch the cylinder walls, it's the o-ring that expands and seals that does.

Mechbox width is somewhat standard, but finish used (especially when anodized) make a noticeable difference (the Modify TORUS has a hard time fitting in some bodies because of the finish).

Really, if you want to improve what is available on the market, you really should first focus on external limit dimensions. A 3D, precise drawing of absolute limits that "fit everything" would be useful, as it would allow people to design 100% new and probably more efficient/reliable internal component.

I was toying with the idea of a high-speed brushless motor, with planetary gearbox to reduce the speed and boost torque. To get the most starting torque, I wanted to fit the motor inside the mechbox, so that is has a very wide body, similar to HDD/DVD drive motors.

[zzzzsleepy8]

Should be pretty easy to get any modern CNC machine shop to CMM measure the gearbox parts for you.

Or use a CNC machine with a touch probe.

[siggypoo]

I wouldn't put too much faith into a 3D scanner; most jolts, including someone walking by in a library, can cause big mistakes in the scanned document.
Out of curiosity, what software are you using for your 3D modelling? I didn't notice.

[zzzzsleepy8]

It looks like autodesk inventor.

Actually, those 3D scanners might be ok to get rough shapes when you calibrate the size of the model afterwards. But more important are location of holes for bearings, etc, and that requires accuracy and precision that probably only a CMM or other metrology instrument can provide you.

[siggypoo]

I just used callipers, micrometers, and some rulers to measure out the parts from my SKS for the airsoft variant I've been working on. Slow and painstaking, but gets the bet accuracy for me.

[L473ncy]

I missed this thread last year, and not to discourage your or anything but I'm thinking if you use a brushless motor you'd increase battery efficiency significantly.

Now the only problem is how to get one to fit inside a pistol grip, how are you going to get a pinion gear on one, and third is how are you going to route an ESC and all that.

[Bandit50]

There are lots of things I can do to improve the efficiency of a standard gear box. I'm just happy lots of people support the idea, and don't want me to get discouraged.

I would more or less like to provide a standard drawing for the community first though, to help teach and provide a reference.

The other end is experimental ideas, and things that I have listed in the original post.

To answer siggypoo's question. It's an educational copy of an Autodesk software(The companion cube in the top right corner should be a dead giveaway), yes I am aware of the licensing and how the legal end of that software works. Hence the none profit part, this is strictly for fun and education for the community and as well as a refresher of some of my coarse material. Nothing more, nothing less.

In addition to this, please keep the love/hate of drafting softwares out of this topic, as that is a topic for general discussion not here.

[Bandit50]

Originally Posted by Kos-Mos

I did go through a bunch of gears for shits a few months ago.

across 10 gear sets, different brand, I have over .200" if difference in any direction.

The pitch and attack angle of the tooth are also different. Most will work when mix-matched, but be noisy.
ICS gears have a very different profile and will grind whatever is not ICS (including the motor pinion).

Piston heads also vary wildly. That is because the piston itself does not really touch the cylinder walls, it's the o-ring that expands and seals that does.

Mechbox width is somewhat standard, but finish used (especially when anodized) make a noticeable difference (the Modify TORUS has a hard time fitting in some bodies because of the finish).

Really, if you want to improve what is available on the market, you really should first focus on external limit dimensions. A 3D, precise drawing of absolute limits that "fit everything" would be useful, as it would allow people to design 100% new and probably more efficient/reliable internal component.

I was toying with the idea of a high-speed brushless motor, with planetary gearbox to reduce the speed and boost torque. To get the most starting torque, I wanted to fit the motor inside the mechbox, so that is has a very wide body, similar to HDD/DVD drive motors.

I completely agree !

[ThunderCactus]

Originally Posted by L473ncy

I missed this thread last year, and not to discourage your or anything but I'm thinking if you use a brushless motor you'd increase battery efficiency significantly.

Now the only problem is how to get one to fit inside a pistol grip, how are you going to get a pinion gear on one, and third is how are you going to route an ESC and all that.

It's been done a few times already, so couple notes;
- brushless motors are quite superior, the builds I've seen typically have a brushless motor 3/4 the size of an AEG motor, giving you enough room for a cradle
- unfortunately you are totally correct about the ESC and wiring, it's a pain to wire everything and takes up space. The builds I've seen are typically on spacious bodies like the AUG and P90. It would also be very possible on most LMG's
- that being said, they're usually on V3 mechboxes that already have cradles


As far as improving AEG's, I do hope you find simple and inexpensive things to improve the design. Otherwise every improvement is just a matter of cost and manufacturing;
- CNC from billet (or rough cast) mechbox shells, instead of just cast
- more accurate parts
- sealed ceramic bearings
- lighter weight, possibly titanium gears, or
- planetary gears, reason being lighter gears and planetaries are easier on the motor during start/stop phases
- brushless motors
- integrated mosfets with button switch triggers instead of ye olde 19th century throw switch. Also reduces trigger pull which in turn reduces trigger response
- PTW style air nozzle. The tappet plate design is flimsy and adds too much unnecessary weight to that system. The "new" (since '08) polyurethane O-rings used in the PTW design to grab that air nozzle have vastly improved life over the old viton O-rings.

And something non mechbox related that would greatly help accuracy;
- significantly more rigid barrel group. The AEG design has a lot of accumulated play in it, and just about every part of the normal M4 hop chamber sucks lol