"Designing" a Paintball Marker with McMaster parts

[hunter47]

Had an idea stuck in my head for actually almost 15 years now but only recently had the knowledge to even think about following through with it.
The ultimate end goal is to design an open source paintball marker that anybody can order from a standard parts catalog and build in their own home!

It started with wanting to make a Tippmann EBolt with a FASOR cylinder from McMaster but has since evolved.



The idea is to take the FASOR cylinder and a Tippmann/BT/inline blow back valve and install it into a 3 piece body with a pretty bog standard stacked FASOR design not unlike some of the contemporary offerings.

I'm anticipating doing something with an A5/X7/FT12 with the original ebolt design just to understand pneumatics more. My engineering domain is electrical, so I'd have more experience designing the control board, which I also need to do!

The end goal is to have:
1. an ebolted tippmann, just like 15 year old me always wanted
2. a cheap to manufacture and assemble stack tube FASOR marker with as many off the shelf parts as possible

At the end of the day this is basically just a Spimmy, but using more common parts.
The body being designed around the requirement instead of shoehorning parts into pre-existing parts should also help.


This is going to be a loooooooong process, but little by little I'll have something!

[XEMON]

Thats exactly how my e-cocker works 👍
timing is super important as the dwell plays a big part of the velocity

[hunter47]

Ah I see, clever. Yep, exactly what I want except all internal.

[hunter47]

Would you happen to have a video of your e-cocker firing? I'm a very visual person.

[XEMON]

It's currently down, I need to finish replacing some of the barbs 😒
I'll put something together for you 👍

[Daltech]

You would hit the proverbial paintball jackpot if you created the design and parts list so everyone could order the parts themselves and make one from scratch. That would be something special. If we can time autocockers and rebuild tank regs out of old ball bearings we should be able to pull off a homemade paintball uhm, I don’t want to use the incorrect wording here, uhm, uh paintball marking tool. Yeah. Or order the parts and package a kit for double the price. I’d pay double just to not have to ever go to the McMastercarr website ever again in my entire life. That website sucks ass.

[hunter47]

You would hit the proverbial paintball jackpot if you created the design and parts list so everyone could order the parts themselves and make one from scratch. That would be something special. If we can time autocockers and rebuild tank regs out of old ball bearings we should be able to pull off a homemade paintball uhm, I don’t want to use the incorrect wording here, uhm, uh paintball marking tool. Yeah. Or order the parts and package a kit for double the price. I’d pay double just to not have to ever go to the McMastercarr website ever again in my entire life. That website sucks ass.

It uh... somehow slipped my mind to not put this in the OP post. I've edited it to reflect as such.
The intent is to design something that would be open source and easily sourced!

Electronic schematics would be publicly available on github, components used would be modern off the shelf so you can just order a couple from JLCPCB.
Valves and cylinder would be sourced from industrial manufacturers (Clippard, SMC, Festo, etc.)
Paintball specific parts like the bolt would be sourced from the common repository of parts.
Anything that needs to be custom machined such as the cylinder hammer and body would be designed for cheap manufacturing from JLC CNC or Protolabs if you want to stay in 'Murica

[Daltech]

You lost me at GitHub. What I’m saying is, I will pay you extra to not go to GitHub. Nobody on GitHub plays paintball, all they care about is hacking scata and reverse shell on your box.

[hunter47]

If you have another fine online repository for me to openly host files I’m all ears

[Daltech]

I was thinking more along the lines of making a marker kit in a box. Like palmers but not put together and you gotta put it together. We are confusing hosting files for the board and the complete marker with all the parts already in a box for sale. My bad 😥. I’m not good at conversations via text.

[RuleOfSines]

Similar concept i did here, though i had a ebolt ram on hand

[hunter47]

Oh nice! I was watching this recently.

[hunter47]

After some digging I'm thinking the relatively recently released Dye Lazarus valve might be a good valve design to design around.
Autocockers have a large following, so even if this specific valve is discontinued, compatible replacements will remain widely available. It's also a well-designed valve.
I need to get my hands on my old paintball gear at my parents' house - I know I have an OG Azodin KP in that bag which would be a great development platform for finding the ram pairing.

I'm also going to coin this as the "In-Temu-dator" since I am reinventing the Intimidator.

[Rainmaker]

I love this kind of thing. Subscribed!

[scottieb]

I've been thinking about a Spyder build where the ram is concealed in the rear of the top tube. The ram would operate the bolt, which is connected to the striker. A 3way will fit in the trigger frame, and possibly an LPR as well. The skeepier the look the better.

[tyronejk]

One potential issue there is getting enough force through the striker since it's off-axis. Pushing too hard/fast could cause binding in the bottom bore and slow down the striker.

[hunter47]

Binding is exactly the reason why I wouldn't want to do that.

[tyronejk]

Cheap != McMaster lol

I like this idea. So many paintball gun components are slightly modified (sometimes worsened) industrial parts. But cost is a big driver and I think the good industrial replacements are going to be more expensive than their paintball equivalents.

[hunter47]

Cheap != McMaster lol

I like this idea. So many paintball gun components are slightly modified (sometimes worsened) industrial parts. But cost is a big driver and I think the good industrial replacements are going to be more expensive than their paintball equivalents.

Agree, I want to approach this less from a cost perspective but from a user serviceability perspective.
Industrial replacements will generally be... general. For instance, a Timmy ram/ram sleeve are custom built (to my knowledge). You have to rely on the used market or get one custom made yourself if you need to replace the bottom tube.
If the design is free and open source, then even if the industrial part goes end of life, the design can easily be changed in the future by anybody.

I've just been looking around and SMC has an interesting offering - unsure if this has the force I need it to have to break the valve open. Again, my engineering domain is in electrical, all I know about physics is F=ma lol




RE: Sell as a kit
(btw I hate the comments format actually, should just be quote replies)
uhhh I'm not gonna do that tbh because that's a lot of work. But I do intend on making this free and open source so long as the licensing is respected then I couldn't care less if someone else started making kits to sell to people.

[tyronejk]

I've just been looking around and SMC has an interesting offering - unsure if this has the force I need it to have to break the valve open. Again, my engineering domain is in electrical, all I know about physics is F=ma lol

Force/momentum to open a poppet valve is hard to figure out. I remember asking around before and the answer I got was "eyeball it". So basically use existing platforms as reference. Luckily, with the Laz valve, there's a lot of references of what hammer/spring combos, operating pressures, and chamber volumes people are using.

It looks like piston speed here is a concrete spec, but piston mass matters too for opening a valve. That will probably have to be a separate component, since it may be hard to get a piston with a specific mass spec'd out.

[hunter47]

Force/momentum to open a poppet valve is hard to figure out. I remember asking around before and the answer I got was "eyeball it". So basically use existing platforms as reference. Luckily, with the Laz valve, there's a lot of references of what hammer/spring combos, operating pressures, and chamber volumes people are using.

It looks like piston speed here is a concrete spec, but piston mass matters too for opening a valve. That will probably have to be a separate component, since it may be hard to get a piston with a specific mass spec'd out.

Yeah, also why I'm sold on the Laz valve.
I will need to make a hammer/bolt carrier anyways to link the bolt to the piston. This will be where I can tune mass.

There's a lot of variables here, though.

My initial thoughts:

1. Know pressure range + chamber volume for laz valve
2. set HPR to floor of range
3. some sort of hammer on rod end, there is a maximum allowable kinetic energy that the piston can handle so I guess it's that number - bolt weight to just max it out.
4. Drive at 0.5 MPa (figured operating slightly below maximum gives me tuning margin)
5. Tune dwell → velocity reaches equilibrium or starts diminishing → minimum viable dwell
6. Raise HPR until good velocity is reached

This is obviously extremely simplified, but I'm interested in hearing if this is a bad plan.

[tyronejk]

Don't forget to consider flow rate to the piston. You can drive it at 0.5 MPa but if you don't supply enough flow, you'll limit the velocity of the hammer.

Otherwise, I think you have all the important considerations listed.

[hunter47]

Holey moley Onshape is a terrible program. Onshape is the reason why the bolt and valve are open at the same time.
I gotta switch to Fusion. I only used Onshape because it ran on my laptop but now that I'm setup at my desktop again this will definitely not work.

Using ZDSPB's autococker bodies for a start. Tried with both the CJP2 and the CJP-Z valves. The CJP2 is a dual action, whereas the CJP-Z is a FASOR design.
I'm liking the CJP-Z form factor more, but I am concerned about the spring return force.

One thing to note is that the cocker bolt requires at least 50mm of travel whereas the pistons only do 15-20mm of travel (15 for CJP-Z, 20 for CJP2), so I'll need to create a lever linkage of some sort. First thought is a 2nd class lever based on the auto-trigger designs of stack tube pumps, mocked up below:

[hunter47]

Nvm on Fusion, it also sucks.
What I really want is NX, I use that at work and therefore I'm used to the workflow.

[hunter47]

I found some other cylinders with similar physical profiles that have a longer stroke (heh) that I’m going to try out tonight to avoid this linkage (although I think it would look super cool)

[hunter47]

Using a IMI Bimba MA-500 with 1" stroke, looks to fit much better and I think I can fashion a bolt carrier/hammer much easier with this cylinder design.
The only problem with this cylinder is that one of the ports goes straight out the back, so the hose routing will be a particularly interesting problem to solve.

I'm thinking I'll need to get a 1.5" stroke model to make this more easily work with a halfblock bolt.
Speaking of... anybody have a 3D model of one?

[hunter47]

Woof... the IMI Bimba cylinder is ~$200 compared to the CJP2 which is ~$50.