GTA
All Springer/NP/PCP Air Gun Discussion General => 3D printing and files => Topic started by: Beachman on March 15, 2021, 07:58:38 AM
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I need help making a 3D model of a short piece of pipe! ;D
Especially with the Umarex shell ejecting Winchester style repeater, the more shells you have, the merrier. But also, inevidably shells get lost on the ground. Cheap replacements would be apreciated by many - also the Colt SAA model owners, as it's really nice to load up a large batch of shells with pellets, at a time.
I'm looking for help converting 2D drawings into 3D models, as I'm just old enough, never to have learned technical drawing on computers. :'(
Obviously, it's basically only a piece of pipe. And I can supply a 2D drawing with all "target" dimensions. Test prints will have to decide the final nominal shell inside bore for the pellets, allowing for shrinkage etc.
The idea is that people can either print themselves, or buy prints from the Shapeways Marketplace. Probably in 50-100 shell batches.
Orientation of prints - one probably wants layer-lines to be longitudinal to the inside pellet bore - and sprues and such, are perhaps the biggest part of the job?
As this is a hobby project, I really can't afford expensive professional assistance. (Ten years ago, a design of mine for a company, cost 15'000 USD to transfer my drawings to 3D. :o It was silly, I just sat beside an engineer, telling him what to draw. :'( )
Is anyone willing to helping me? ???
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Anders,
This sounds simple. How many parts? Are you looking for STL printable file format? Or, what format?
Make some sketches and attach them here; or describe them. I will make some files and then see if they work for you.
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I'll second that, post a drawing and it should be straightforward to whip up.
The harder part will be getting the tolerances correct for 3D printing, doubtful it'll be a single print and done. But it could be, part of the fun of 3D printing. :D
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Most 3D printer slicing software gives one the ability to scale X, Y and Z independently. So, such adjustments don't have to be done in the object file.
Inside and outside diameter printer accuracy are often not the same, so at least a test piece to calibrate that is a good idea. One with an ID large enough to measure easily.
That said, if Anders wants a few tubes with the nominal IDs 0.001" apart that would be easy enough.
Considering how long ago Anders made his enquiry, and the zero replies until now, he may have lost interest...
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I have a feeling that those shells may not last long being 3d printed by a hobbyist with a standard desktop printer. It can be done but I suspect the durability to be low and the longevity to last for a few shots depending on how that shell is ejected.
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Matt,
I think you are right. As far as I can tell, the Winchester '94 uses the same cartridges as designated for the Colt Peacemaker. These should probably be injection molded, or turned from solid: www.pyramydair.com/s/a/Colt_Peacemaker_SAA_CO2_BB_Revolver_Shells_6ct/5500 (https://www.pyramydair.com/product/colt-peacemaker-saa-co2-bb-revolver-shells-6ct?a=5500)
I suspect that Anders has abandoned this thread, and possibly the forum, due to the "slow response" to his request. I sent email and PM just after my first post above, requesting his specs to do the designs for him. No reply... According to his profile, Anders has not visited the forum recently.
A case of, "You can take a horse to water, but you can't make him drink".
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It dose happen but if he dose come back to read it he will know.
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Hello!
Thank you for your answers! :D I did not want to bother Matt / "subscriber" with ideas I felt weren't ripe. But I have not abandoned the idea. I'm just the kind of person, who can ponder an idea for a very long time (sometimes many years ;D), if I have a feeling there might be a better way. ;D
There are two main technical considerations to this idea. And lastly, the economy of it all.
1) Printing in a material that will make the rim of the shell sturdy enough for the extraction action on the "Legends Cowboy Rifle". My own thought is that printing in nylon ought to hold up. Aparently, nylon can be pulled to about 25% before it breaks. That ought to be elastic enough. Yet very shape stable.
If printing nylon is like the nylon wheels under my heavy tool cabinet, it is a really tough material. Another common use is cogwheels. When the material is thin enough, one can make single injection mold hinges. I seem to remember having used such when building airplanes as a kid.
Though, I do not know all available printing materials are. And there might be other suitable materials. (I think someone mentioned "PET-G"?)
2) I've been thinking really hard about how to hold BB's, and preferably also pellets, in the back of the cartridge. I've thought thru many solutions, but they seem not to be printable, according to Shapeway's design guidelines.
Also BB's vary a "lot" in diameter. They can be inconsistent within a package, and types and brands differ. The one's I have measured range from 4,36mm to 4,42mm. (And pellets are of course 4,5mm, +-0,02mm depending on specific designs.) On top of that, printing accuracy / shrinkage has to be accounted for. I've been thinking along lines of +-0,15mm, when considering what designs could work.
The most workable, and also simplest design, is to make a BB only shell, that loads from the front, and the BB is then pushed with like a match or other object, to the back end, where it becomes lodged in a taper, not to fall out. So the shell bore is mostly straight from the tip, but then narrows to a taper, to accommondate different actual BB sizes. Pellets would not work in this design.
A variation to a solid taper, would be to have 1 or more "splines" forming the taper, to lessen the power needed to push the BB out of the seat. Imagine the shape of the splines, would be like the tail feathers on a bow arrow. However, if that is printable, I'm not sure about.
The main use and reason for trying to print cheap shells, is not having to worry that much about ejected shells getting lost. And surprisingly, accuracy with the rifle, does not improve when using pellets, so that doesn't make much sense anyway. (According to Hard Air Magazine and the youtube channel "Airgun Detectives", and my own experience.)
Furthermore, the vast majority of Colt SAA's sold, have been BB versions. In fact, Umarex seems to have ceased production of the rifled option. So a BB only shell design, would cover almost everyone's needs. The few who need to shoot pellets in their rifled Colt SAA, will have to stick to the original Umarex shells.
Copying the Umarex shells, is not easy. They hold BB's and pellets with a snippet of "rubberish" tube / hose. Finding the right size tube / hose, and then cutting snippets, isn't easy, and a bit to much trouble, I think. One could perhaps print the tube snippets in another rubber like / softer material. But I strongly suspect that would kill the economy of it all.
"Springy" holder designs, seem not to be printable. I've also considered all sort's of solutions, like using O-rings, instead of a hard to find tube / hose. It would involve making the shell in two or more pieces. The O-ring solution doesn't feel that attractive either.
3) If these printed shells actually would be cheap, depends on printing cost, and how many times they will hold up, before ceasing to work in the rifle. In the revolvers, they could perhaps last hundreds of times of use.
What are your thoughts? :D
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If you are that interested to continue I suggest finding someone who is willing and capable of creating a CAD file for you. The worst thing to happen here is to find out how to not 3d print this part. I would think injection molded nylon will be far stronger than printed as layers go it solidifies then had to be "flash melted" for the next layer to adhere which could cause weakness in terms of repeated forces acted on the part.
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Hi Anders
You came back "with a bang" :)
Printing small details with a molten filament printer is going to be near impossible. Filament printers have very directional strength in the part. This strength is independent of the material strength.
A UV resin printer or SLS might be able to use appropriate material, accurately, to create springy "fingers", without the directionality. The latter two types of printer are more expensive to own and run than a filament printer.
As I was reading I thought of internal O-rings in grooves in front and behind the BB. A pellet could be placed in a tapering seat, formed into the rear of the cartridge, much like a break barrel spring air rifle breech (but, with a shallower cone).
The simple BB only cartridge that taper from a wide front ID, to a narrower rear could work. Depending on the taper, you could just drop the BBs in, or press them very lightly with a little "ramrod".
If all you care about is cheap and functional, rather than "looks like a cartridge case", then other options open up. Either lathe turn or heat form cheap commercial nylon (or other plastic) tubing. Here is such tubing with a 3/16" ID: https://www.mcmaster.com/8547K24/ (https://www.mcmaster.com/8547K24/)
More plastic tubing: https://www.mcmaster.com/nylon-tube/shape~round-tube/material~plastic/id~3-16/ (https://www.mcmaster.com/nylon-tube/shape~round-tube/material~plastic/id~3-16/)
To form a plastic tube section; run it in a lath or drill press chuck and press a smooth tapering tool into the open end (that sticks out of the chuck jaws far enough). The friction will soften the plastic and allow you to form a bell for a pellet and an extraction rim. After rough forming, the rim can be cut to functional size with a conventional lathe tool. If you are using a single action revolver, then the rim just stops the tube from falling through the chamber.
If you are thinking mass production, then such tooling could be automated.
One could cut O-ring grooves on the outside of the nylon tube sections. Even a tapering cartridge case cane be approximated this way, just by how much the O-ring projects from the parallel tube section.
What would be very useful, is a picture or sketch so we can discuss the critical dimensions. Of both the cartridge and the parts of the airgun that need to interact with them. All others should be allowed to "float", unless looks matters more than function and cost.
Don't be stuck on 3D printing. Be stuck on functional and cheap... First, one must identify the real dimensional constraints. Then you can think outside the box.
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If you are that interested to continue I suggest finding someone who is willing and capable of creating a CAD file for you. The worst thing to happen here is to find out how to not 3d print this part. I would think injection molded nylon will be far stronger than printed as layers go it solidifies then had to be "flash melted" for the next layer to adhere which could cause weakness in terms of repeated forces acted on the part.
I can create 3D print files. However, that does not guarantee a strong 3D printed part. So, the goal should not be 3D printing, but functional and cheap.
If this is to be commercialized, then how the "cartridge" looks matters more. However, if you sell them for half the regular price people will buy them because they are functional and cheap...
Any good engineering or invention/cleverness that follows, must be based on real info. Hence my request for pictures/sketches/dimensions.
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I have a peace maker revolver, and I love it.
It's supposed to be a 45, but Umarex used the same cartridge that was used in a 357 replica.
Why don't you just get some 357 cases and make an insert to hold 177 pellets, or bb's ?
I don't have it handy, and I don't have any 357 shells to test fit.
Hunter
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Are we talking about these? www.pyramydair.com/product/gletcher-clt-bb-revolver-cartridges-6ct?a=5576 (https://www.pyramydair.com/product/gletcher-clt-bb-revolver-cartridges-6ct?a=5576)
(https://www.pyramydair.com/images/acc/PY-A-5576_Gletcher-CLT-BB-Revolver_1463686708.jpg)
(https://www.pyramydair.com/images/zoomed/PY-A-5576-zm1.jpg)
Or these: https://www.pyramydair.com/product/colt-peacemaker-saa-co2-bb-revolver-shells-6ct?a=5500 (https://www.pyramydair.com/product/colt-peacemaker-saa-co2-bb-revolver-shells-6ct?a=5500)
(https://www.pyramydair.com/images/acc/PY-A-5500_Colt-Peacemaker-SAA-CO2_1510237217.jpg)
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It looks like there are at least 4 different types.
I D K.
Hunter
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More:
https://www.pyramydair.com/product/crosman-snr357-pellet-revolver-shells-177-cal-6ct?a=7756 (https://www.pyramydair.com/product/crosman-snr357-pellet-revolver-shells-177-cal-6ct?a=7756)
(https://www.pyramydair.com/images/acc/PY-A-7756_Crosman-SNR357-Pellet-Revolver_1487254817.jpg)
https://www.pyramydair.com/product/crosman-snr357-bb-revolver-shells-177-cal-6ct?a=7757 (https://www.pyramydair.com/product/crosman-snr357-bb-revolver-shells-177-cal-6ct?a=7757)
(https://www.pyramydair.com/images/acc/PY-A-7757_Crosman-SNR357-BB-Revolver_1487254829.jpg)
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https://www.pyramydair.com/product/remington-1875-co2-dual-ammo-replica-revolver?m=4309 (https://www.pyramydair.com/product/remington-1875-co2-dual-ammo-replica-revolver?m=4309)
(https://www.pyramydair.com/images/PY-4309_Remington-1875-CO2-Dual_1504817944.jpg)
https://www.pyramydair.com/product/crosman-snr357-co2-dual-ammo-full-metal-revolver?m=3974 (https://www.pyramydair.com/product/crosman-snr357-co2-dual-ammo-full-metal-revolver?m=3974)
(https://www.pyramydair.com/images/PY-3974_Crosman-SNR357-CO2-Revolver_1465498320.jpg)
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Hello,
It seems I may have discarded the copying of the Umarex solution a bit hastily. ;D Thank's 'subscriber', for reminding me to check Mc Master Carr. Because my thinking was that one would hardly find corresponding metric and imperial sizes hose, for Europe and the people still using imperial sizes, for some strange reason. ;) ;D (After all, the metric system was invented and became law 1795 in France. And very quickly also adopted by just about every country. Transition time in the USA, should have passed a very long time ago. ;) ;D The conservative British - well, they just are the way they are. A hopeless case. ::))
Anyway, the closest usable dimension i found in Stockholm, is 8x5mm. Mc Master sells wall thickness 1/16 (x2) and 3/16 inner diameter, which translates to 7,94x4,76mm - really close!
So now the sensible thing, is to make the beginning of the shell bore at the back, just small enough to compress the hose down to 4,35mm maximum diameter. Due to the fact that the print and shrinkage is +-0,15mm, the very beginning at the back, should have a conical start, because minimum entry diameter might become 4,2mm, which could make pressing in the BB a bit annoyingly difficult.
I still think one should skip the pellet compatibility idea. The skirt would likely be quite deformed, because the compressed hose holder, will form a buldge on one side - which is actually what would hold the BB's.
The rest is about nose shape, because it should seal against the rubber packing it presses against in the rifle. (Tracing a photo, and some measurements, should come close enough.)
Inner bore on the rifle shells, is 4,5mm and 4,6 on the revolver versions. On actual prints, I would think minimum bore diameter should be. 4,45mm.
Shapeway uses SLS for nylon. Tolerance is +-0,15mm. A golden metal finish is actually offered. ;D
P.S. I'm not going to enter the "shell" business. This is a hobby to me. Also I'm curios about gaining some experience in 3D printing. (I'm not going to buy one. I use my lathe and mill way to little. I know a 3D printer would end up the same way. They are hobbies in their own right.)
Shapeways still offer their shop idea. I think it's a legacy thing. Every printing company has shifted their focus towards industrial printing. Including Shapeways.
The shop cuts one middleman. And the idea of not having to finance a stock, is realized. If I were to offer for example CNC turned shells, those things would not be true any longer.
And anyway, there is no way to beat injection moulded shells, the way Umarex does it. It's the hand's down best production technique.
I'll be back with a sketch to make a 3D model. Then one can ask Shapeways for a quote, and possibly order testprinting. And hopefully find out that the shell rim doesn't break. ;D
P.P.S. Now I'm actually going to the beach with the rifle. Temperature is OK at 22C / 72F.
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I'll be back with a sketch to make a 3D model
That will be useful.
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F.Y.I.
The smooth bore pistols can shoot BB's OR pellets.
The rifled barreled pistols shoot only pellets.
Hunter
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F.Y.I.
The smooth bore pistols can shoot BB's OR pellets.
The rifled barreled pistols shoot only pellets.
Hunter
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Anders,
I don't see any sketch. Did you post one?
Sent you an email via GTA.
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My previous post should be;
F.Y.I.
The smooth bore pistols can shoot BB's OR pellets.
The rifled barreled pistols shoot only pellets.
Hunter
Yes Hunter, that is of course true. Is it a smoothbore Colt you have? Have you compared precision with pellets versus BB's for this gun? And which barrel length do you have?
Me and another guy in Sweden's largest airgunning forum, we are beginning to wonder if there really is a point putting up the extra money for rifled replica revolvers? I believe the Gletcher Nagant also is (was?) offered rifled or smooth. For the pistol replicas, it's completely pointless. The shoot like &^^& anyway, in my experience.
Personally I have the rifled 7,5" Colt SAA, and the smoothbore Remington 1875. They have very similar bore length. So far, I have only used pellets in both, since the very point to the invention of the pellet shape, is to give a more stable trajectory. Which it is well proven, it does - in "serious" guns. But after all, these replicas are about playing around, hitting cans and such, not competing and counting point results, punching paper.
However, now that everyone agrees the Cowboy Rifle performs equally well precisionwise, using either type of ammunition, the discussion on the revolvers becomes even more interesting.
I plan to do some serious spread tests on paper, comparing pellets and BB's in either gun. I actually plan to test copper (they are relatively very SOFT) plated lead BB's ("Smart BB's") in the rifled Colt as well. Just for testing. That won't damage the rifling.
And after all, rifling was used in old blackpowder guns, even though the projectiles usually were ball shaped. So it might work.
Though the Cowboy Rifle shot lousy with soft actual size 4,5mm Gamo lead balls. With actual size 4,9mm copper plated leadballs, I seem to remember CO2 consumption rose much, and precision did not noticeable improve, so I decided it wasn't worth it. Especially since they are more expensive, and harder to find.
DO NOT USE STEEL BB's IN A RIFLED GUN! Not even for single shot! You will ruin the rifles in the bore! (Just saying, so no one gets a bad idea.)
In fact, I have this completely unproven theory, that shooting copper plated lead BB's, won't wear the bore on a BB gun, as much as steel BB's. So I only use "Smart BB's." A strong reason for me to use soft lead pellets in a BB gun, was also the idea of less wear to the barrel. And they very, very seldom cause ricoshets.
Unfortunately, comparing the accuracy of the Colt with the Remington, isn't that meaningful, because the Remington has such a heavy lousy trigger action, that you just can't compare the two. The Remington will always provide less precision. But as said, one does not buy these replicas for precision shooting.
However these specific revolvers, and the Cowboy Rifle, have such a consistent spread (no fliers), that you can actually shoot quite seriously. With the right size canister, you can compete perfectly seriously with a friend, or test your self. Cans are the same type of targets used in Field Target - they measure "hit - no hit". So as sayed, you just have to choose the right size target. I would say, that for most people, this is 2,5 times the measured spread, when shooting the gun well rested. (I have a semi competition Röhm Twinmaster pistol for precision shooting. It has adjustable palmrest, and a very well shaped grip. The gun stays "glued" to your hand. If it has any spread at 10m, I would say that the gun it self, just slightly widens the hole in the paper target. I like the gun very much, in single action. They aren't made any longer, but if you come across one, I highly reccomend the pistol. It also has 8 shot magazine and DA.)
Other notes. There are very many different shells on the market. Some are interchangeable, some aren't. I saw a compatability chart somwhere. The Remington shells can be used in the Colt, but not vice versa. Do not try using the Remington shells in the Cowboy rifle! The rim has a smaller diameter. And you might damage the rifle mechanism. (If it works att all? I'm not going to try.)
Shells that are loaded in the front/at the tip, are proven to give less power/velocity, because those loaded att the back, actually extend the bore length. Which is a decisive factor. (Look at the ugly long bore, but extreme power "Texan" airrifle.)
I don't write short, do I? ;D
P.S. Today will be another nice day shooting at the beach. :D Sunshine, moderate wind, and 19C / 72F. And some beer at hand. :D
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subscriber,
I haven't posted a sketch yet. ;D There is the question of diameter to the hole for the tube/hose snippet. Compressing it down to 4,30 maximum dia.
I can't se your mail in my inbox? :( I've tried to reload etc. :(
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Anders,
I used the GTA forum "send email" function.
I basically suggested you email me you sketch. Then I could email you a CAD file or print file. I will PM you my email instead.
There can be a few versions with different bb retention tube spaces; but, one has to start somewhere. A design does not go from nothing to perfect in one iteration. So, provide what dimension you know are not going to change.
What I can tell you, is that you have my full attention, now. That cannot last forever. Once I get bored, I unsubscribe from a thread. So, get off your donkey, and work on the sketch. Unless you have decided that you don't need any help.
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I hear you subscriber. ;)