3D Printing a marker?

[emisnug]

What are people's thoughts on printing a marker out of resin? Some of these machines can print to tolerances of 0.0011 inches - something like 0.02mm I think. That seems like a small enough tolerance for manufacture - at least small enough so that it can be compensated by with O-rings.

Reasons behind asking is that when I've been bored I've designed a couple of markers & bolt systems. Since I don't have any metal working tools (Would need at least a lathe and a 3 axis CNC milling machine, along with a few thousand quid), and I've made a couple of gearboxes via 3D printing before, it seems like a more cost effective method of making a complex shape (i.e a marker or a bolt system).

Thoughts? Or am I just crazy?

 

[Random Invert]

Would it be strong enough to take a beating? or handle the the compressed air?

I'd like to see a weight comparison with a 3D printed bolt over a delrin bolt.

Fancy making a mini bolt and I'll try it for you? can send a spare as a template.

 

[renie]

you could make a spoolvaled gun i suppose as they tend to rum on low psi but, you would more than likely need a metal reg housing to drop the pressure down 1st.
also plastic doesnt hold screw threads very well but if its just for prototyping it would be possible i suppose

 

[Tom]

Low pressure air in paintball is still at high pressure
3d printing will be great for prototyping
You could try making a whole marker and seeing what it can do
But be careful

 

[CraigofScotland]

Not sure it would hold up.

The layers arnt particularly strong, you can usually just slide them apart.

Have you done any airflow calculations with your bolt design, any fluid dynamics? I done a little on them last year for my dissertation, was quite interesting to note the turbulance. Was only basic calculaions as the dissertation was on air pessure effect on recoil of a paintball marker, but I put it in to pad it out

 

[Missy-Q]

Extremely bad idea.
McGyvering a peice of resin, and then filling it with high pressure air, and then holding it up to your face = problem.

If you're going to do it, please have someone record it on tape.

 

[emisnug]

I've given it a fair bit of thought and to start out with I'm making a bolt engine for my DM7. Well, the bolt first, then the housing. Then a Hyper reg. Provided, of course, that it doesn't all go horribly wrong. Making a whole marker prototype would be awesome but also a bit costly. If I get enough money I might have a crack at it. But first things first - the bolt for the DM7.

Soildworks says it should hold up under roughly 850PSI when made out of acrylic resin (closest I could find to 3D priting material) before deforming. So, once I am convinced that I have got all of my guesstimations right, I'll get the bolt printed, then make a video of it, as well as test firing it. If it all goes wrong, at least it'll be funny to watch. (I'll put it in a ransom rest before I put it near my face)

 

[Missy-Q]

What if you get some grit on your tank reg-seal and this causes reg-creep?
Happens all the time.

 

[upzii]

Excellent idea !

However as a Gas Turbine engineer who deals in material science I request that you please don't test anywhere near me

Your main problem will be surface finish (as i'm sure people more involved in working out airflow will tell you that bad surface finish causes for less laminar airflow) and the second that ties in with the first one is friction. Brass, Aluminium and Delrin are all used because of their low coefficient of friction.

Your going to have to machine the parts you make aswell (i suggest using a dremel with a rotary burr with a small diameter as you cant really use a grinding piece on delrin or resins as it will just clog and then burn. If u have any machining questions on the CNC machining side of things give me a shout.

Cheers, Pete


PS Try and get your hands on NX8 PLM Software (Simulates materials better than most others due to the Siemens Data base)

 

[emisnug]

Ooh, a gas turbine engineer! That must be an interesting job

Also, you're right, I've been told a fair few times that surface finish will be a large issue for me. As far a laminar airflow, the DM7 bolt in itself provides quite a rough flow. There is an eddie behind where the air enters.

Also, as far as bolt materials go, Aluminium is the most cost effective material that has a low friction coefficient. That being said though, I could always lathe a bolt out of PTFE. If I remember my chemistry correctly, that has a friction coefficient around the 0.1 mark? (PTFE printing. I need to look that up.) Or CNC it. How much would it cost to borrow a CNC machine for a day I wonder? Or perhaps my university has one I can use... hummm...

Pete, that software looks amazing. How much does it cost?