GTA
All Springer/NP/PCP Air Gun Discussion General => 3D printing and files => Topic started by: subscriber on June 14, 2022, 10:03:17 AM
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Some recent projects inspired me to 3D CAD model the Air Arms T200 (CZ200) front sight mount. I then created a version that adds a functional air stripper. See images below, with print file. In this case, a two stage air stripper that looks a bit like a howitzer muzzle brake.
I can create an S200 version without the sight dovetail. Also, I can add .22 versions, with and without sight dovetails. This version is .177.
The print file will generate a threaded hole for the M4 x 0.5 mm retention screw. I left the thread tight, so chasing it with a tap is advised.
The STL print file for the part shown, is the first file in the attachment list, directly below. The part must be placed on the printer platen as shown, or it will not print properly. Turn supports off. Print at 100% density.
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Muzzle brake Version 1, above looked a little dainty in vertical stiffness, so I added material back to help with that resulting in Version 2. See images below
The material I added stays within the original stock part OD and length. So the casual observer might not notice the sight base now incorporates a functional air stripper / brake.
Version 2 lifts the sight dovetail, such that it just falls within the OD of the original sight base OD. That raises the front sight about 2 mm from stock; which should be within rear sight adjustment range.
The stock part and Version 1 of the brake have a flat bottom, to clear the T200's removable air cylinder. I kept that clearance, but added material such the flat is turned into a curve. A small change, but material far from the center line helps a lot with making parts stiffer, to avert potential vertical droop.
EDIT: After struggling to attach the STL file, I managed to ZIP it - posted in reply #2 below.
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V2 STL is 2700 kB. The max is over 3200 kB, but I system states STL is too large. So I will try to compress the file...
Success: ZIP file containing STL is attached.
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Version 3 of this Brake deletes the front sight dovetail. So, V3 turns the AA S200 "brake" into a brake; while retaining the rounded air tank clearance of V2, over the stock flat bottom.
STL for V3 is attached directly below, as a ZIP file to stay below GTA file size limits:
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I created a .22 caliber version of this air stripper for the AA S200. It has a curved air tank clearance cut underneath, and no front sight dovetail. Else, the envelope is the same as the stock "muzzle brake". See images below.
STL file is attached at the bottom of the list of attachments to this post:
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I extended the stock front sight base by 2.5" in length, and 0.275" in diameter. (now, 135 x 32 mm diameter) (stock, 71 x 25 mm diameter)
The added length results in 3" of length projecting ahead of the barrel muzzle. 2.3" of the LDC length projects back from the muzzle to create a small reflex expansion space. This is fed by the air stripper just ahead of the muzzle.
Now, the total size of this LDC may not make it as quiet as some might like. Yet its short frontal overhang and approximate 50 gram weight make it less obtrusive.
Could I have designed a functional 25 mm OS LDC, just by stretching it a lot, and used a greater reflex length? Not in a meaningful way. Not, if I wanted to keep a functional sight dovetail on it. Not if I wanted to feed air to the rear via meaningful passages, into a meaningful volume. Ditto, if you want to be able to remove the air tank, or use an extended air tank. The tank clearance cut being the bugbear.
The images below compare the sight base LDC against the stock T200 sight base.
STL print file is attached at the top of the list of attachments in ZIP format. It is for .177. A version for .22 will follow.
The version of this LDC without a front sight dovetail, does have more expansion volume, and may appeal to people using scopes.
If there is interest in a longer version of this LDC, I could design one that adds an inch front and rear. So, then 4" ahead of the muzzle, and 3.3" as reflex length. The reason for the reflex design is to increase the distance between barrel supports for batter barrel alignment; considering there is no thread and shoulder arrangement. Only a tight fit at two sections, and a M4 screw at the stock grub screw location.
LDC to be printed with its wide end standing on the printer platen.
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Version of the above LDC, with the sight dovetail deleted.
.177 STL attached as ZIP file directly below.
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.22 version of the above S200 LDC. No sight dovetail.
STL attached as ZIP file directly below.
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Notice that all of these designs sport air tank removal clearance cuts:
So, for those that want their 12+ FPE S200 more quiet, I stretched the above .22 version to 7.1", from both ends. From 135 to 180 mm.
The reflex section is 3" long and the section in front of the muzzle 4.1" long.
The STL is attached below as a ZIP file.
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Those look very nicely designed.
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Thanks, Matt
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For anyone interested in printing any of these designs, note that you should turn supports off in your slicer.
Else, unlike the open structures sketched below, supports inside a closed structure are impossible to remove. So, my designs avoid the need for supports:
There are no slopes off vertical by more than 45 degrees, and mostly they are 30 degrees off vertical or shallower. So, no supports are required. In some instances a design ends up with bridges, but I keep those to less than 2 mm.
There is only one orientation that will enable printing these designs to avoid "floating features" (impossible without supports). That is with the front end of the part standing on the printer platen (assuming FDM or molten filament printing). See sketch below.
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Subscriber,
I have been studying this post very carefully. I don't have a 3D printer, so I need to find someone near me to print it. This looks perfect for my CZ-200.
Thanks for sharing your hard work.
Hunter
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Hunter, PM sent.
You did not mention which design you are interested in?
Assuming LDC; what power level are you running at with your CZ-200? The longer design above should take the sharp edge off a 12 to 20 FPE tune. If that does not meet your expectations, I can design you a longer one. Or longer and wider.
What I get out of this, is your feedback on a given design to help further my understanding. Other than packaging constraints unique to the 200 series, a pleasing form factor that is not too bulky, nor too heavy are the main drivers.
As for the inside, I did a number of designs for the .22 Avenger that other people made and tested. I am incorporating what I learned from those trials into may latest designs.
I retain the M4 screw location of the original factory muzzle "brake". That is used to position the devices in the correctly rotational alignment with the air tank. The screw also prevent the device from moving fore/aft relative to the muzzle. There are no other features to set the position on the barrel. Your experience with ease of installation will inform if I need to add a shoulder for the muzzle to stop against.
I have designed in a M4 x 0.5 mm thread, but expect you will need to chase that with a tap, or a screw, before installing on the barrel. I suggest you obtain a longer screw for more engagement in the plastic. Not to torque it hard (don't), but to resist for aft loads that want to rock the screw off vertical. The threaded depth will take a 8 mm long grub screw on the larger than stock OD devices.
The screw won't go into the stock slot in the barrel, if the muzzle is not in the right fore/aft location (+ - 0.25 mm).
To make finding the location easy, wrap the barrel with tape such that the tape edge is the distance from the barrel muzzle shown below. You will need to rotate the device so it clocks with your airtank. That should place the screw in the screw slot correctly. (or dimple, if some barrel variants have a dimple, rather than slot).
You may be able to get away without the crew from just the friction, or added friction, if add on layer of tape. I have designed the ID to be a slop-less fit with the barrel OD, but still be easy to press or tap on (gently). To reduce friction, the barrel channel is relieved, except for the areas highlighted in blue - last image.
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Hunter,
In case you think not having a positive depth stop for the barrel is to amateurish, I created a version of the last (longer) LDC with such a stop feature. See images and print file attached below.
Previously, I decided against it because:
1. The stock "brake" has no such shoulder;
2. the shoulder/s created need permanent internal supports for 3D printing. Such supports take up volume and may interfere with air flow to the reflex cavity.
3. Also, one needs to be careful of avoiding potential over-constraint; where the barrel stop shoulder fights with the retention screw.
To avoid interference, I spaced off the barrel stop shoulder 0.25 mm "deep", so that it would never prevent the retention screw from going home. (based on my T200 barrel dimensions - which may differ from others). Then added feasible internal tapering ribs to enable printing, with least air flow interference.
Anyway, if you prefer the design with the barrel stop, I am attaching the STL print file to this post as a ZIP file.
Of course, this assumes the longer LDC was what you had in mind. No matter if it was not, because this adds a variant for people that might battle to figure out how to simplify installation. If you had another design in mind, and feel it would benefit from a depth stop, let me know.
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Now there is a .177 version of the longer LDC. It has a depth stop for the barrel muzzle. See images below.
STL print file is attached to this post as a ZIP file.
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Here is a version of the long LDC in .177, without the barrel depth stop shoulders.
In theory, the reflex airflow should be less restrictive with the depth stop material removed. Not that I think there would be a problem with the way the depth stop version turned out. The depth stop version (post above) will be much easier to install.
STL print file is attached below as a ZIP file.
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Subscriber,
I cannot locate a M4x.5 tpmm set screw. Everything seems to be M4x0.7.
Is there a reason that you chose M4x0.5?
Hunter
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Hunter,
Thanks for checking the availability of 4 mm grub screws. I chose what I thought I measured on the stock sight screw; else I could design in a different pitch or even diameter.
That is providing the nose of the screw was 4 mm in diameter for a suitable length (or slightly less, to fit into the slot in the barrel).
So, if you tell me which part you are interested in I can give the retention screw hole an M4 x 0.7 thread this evening.
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Subscriber,
Your work is amazing.
It seems that M3 is commom 0.5 thread per mm.
M4 is most common in 0.7 tpmm.
I will need to tap it anyway so smooth bore is ok.
I am interested in "a version of the long LDC in .177, without the barrel depth stop shoulders. "
I have a 177 set to 11,5 FPE. It doesn't make much noise as it is.
Hunter
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Thanks Hunter,
You are the first person to express interest. Your thread pitch challenge amounts to a design verification question, and is welcomed.
When I started with the stock "brake" I thought about using three screws, but got stuck with the stock one. It become my standoff distance reference for the reflex air stripper.
In thinking about just the screw, I realize that I have not accounted for the screw slot depth in the barrel. I want the screw to be just flush with the top of the LDC as confirmation that it is in the slot correctly when assembled. So, the screw will need to be longer by the barrel slot depth. I will go measure the slot depth and update the recommended grub screw length.
I also want to take a look to see if there are grub screws 4 mm noses, that have a larger thread with a coarser pitch. I fully realize that FDM printing is going to battle making such a fine thread.
Something like this: https://www.mcmaster.com/92905A214/ (https://www.mcmaster.com/92905A214/)
(https://www.mcmaster.com/mvD/Library/M1/20220308/828483C9/92905A214_Alloy%20Steel%20Extended-Tip%20Set%20ScrewX.GIF)
https://www.amazon.com/Screws-Point-Socket-Tensile-Grade/dp/B07ZR1DQNL (https://www.amazon.com/Screws-Point-Socket-Tensile-Grade/dp/B07ZR1DQNL)
Now, perhaps that is being silly. That it may force you to buy a pack of screws, when you could get one standard one...
I could also leave the hole unthreaded, for you to tap to M4 x 0.7. Not sure which would produce the better thread. Anyway, I made the thread deep on purpose: Less likely to strip when just snugged down.
I will take some measurements first...
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I will say that horizontal holes even small ones sag with out support. Its not a big deal if finish work is expected to be done. To expect a print with a prefect hole that is parallel to the earth you will be sorely disappointed. I would make sure that hole has a very robust interface for threads to be cut in then some extra material. One issue is that I can make changes with my slicer that will over ride any design, that is why I print 100% infill.
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So, Matt, are you recommending that the threaded hole be left unthreaded so that a tap is used to create the thread? I can add a generous taper to help align the tap. This way, there is no risk of stripping the printed thread.
After aligning and starting the tap, tapping should be done "upside down". This is to minimize chips falling into the LDC. That way, one does not need to struggle with removing them.
There are two important diameters on the LDC: The barrel seat diameter and the through bore for the pellet. The bore is actually stepped, to make it more forgiving of any misalignment or distortion in the LDC. See image below.
I would like the barrel to be snug in the LDC, but not to the point of bursting it. The barrel seat diameter is designed as 14.98 mm. My T200 barrel measured 14.92 mm. So, a nominal 0.06 mm diametral clearance; or roughly 0.001" radial. As 3D printers tend to print holes smaller than the print file instructs, this should provide just a little tension between barrel and seats.
The pellet bore steps up from nearest the muzzle towards the the front end of the LDC. According to my CAD: 6.4mm; 6.6 mm; 6.8 mm; 7.0 mm
If I had absolute confidence in the as printed bore diameter, coaxial alignment and straightness, and lack of future droop, I would make the bore 6 mm in diameter for .177. As a counter point, the Marauder uses 5/6" (7.9 mm) bore baffles; even for .177. So, I would rather err on the side of avoiding clipping, than gain 2 dB in sound reduction.
So, bottom line, Matt; I would prefer whatever settings you use to make the barrel seat (blue high-light in image) diameter close to the design diameter. Or no more than 0.1 mm under the barrel diameter of 14.92 mm. The other dimensions can float, as the bore diameter already has a generous allowance built in. I think that a lack of perfect roundness and texture in the printed part will create a slightly snug fit on the barrel, even if the average diameter is at barrel diameter.
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The S200 long .177 LDC version below has a blank hole that needs to be tapped M4 x 0.7 mm.
I pre-chamfered the nominal 3.3 mm diameter hole, and added a 20 degree per side cone below the outer radiused chamfer to help align the tap from the start. The inside of the hole is also chamfered and rounded to reduce any tendency for the tap to break the inner edge. Be careful not to run the tip of the tap hard into the opposite side. The middle of the barrel bore is approximately 5/8" from the LDC OD.
The STL print file is attached as a compressed ZIP file - directly below.
EDIT: The slot in my T200 barrel is 1.5 mm deep. To reach the bottom of the slot, the grub screw needs to be 10 mm long, to be just flush with the LDC OD. Do not overtighten this screw. It may strip the plastic and will tend to squash the barrel muzzle out of round.
There should be lots of friction between screw and plastic; so it is not coming loose. The screw should be just deep enough to stop the LDC from rotating - so a rotary rocking action of the LDC to the middle of slop, while taking up slack in the screw is the technique I would use for this. Using a grub screw with a nylon pad on its nose may be a good idea to protect the barrel. There are also totally nylon grub screws in the desired size: https://www.mcmaster.com/95862A122/ (https://www.mcmaster.com/95862A122/)
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Do not overtighten this screw. It may strip the plastic and will tend to squash the barrel muzzle out of round.
By "squash", I mean spring it out of round...
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Correct I would not design in such small threads just a hole sized to tap.
As far as barrel fit I would think a snug fit would be ok. Most of the stuff I have done for others are baffles in a tube that is threaded on.
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Correct I would not design in such small threads just a hole sized to tap.
See my last design a few posts up. Just a hole for tapping.
There is a trap when designing small detail: One can zoom in until the detail looks robust. Meanwhile the size is beyond reasonable expectations for an FDM printer.
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Great thread.
I am very interested, already send V2 to the printer company.
It will be great if there is a version of V2, with extension tube moving dovetail further forward as much as possible to extend sight length. 4" more will be great, 6" even better. If it can touch target at 10m, it will be even better ;) ;D
Open ended in front of the air stripper, a tube acting as a carrier for the front sight. I would use it on 200T, for 10m ISSF matches.
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Thanks for your interest, Bogdan
It would be possible to extend the sight mount air stripper, but have three concerns:
1. What is the maximum sight radius allowed for formal competition? As long as that is not exceeded, you can have any length you want.
2. At a given length and depending on the type of plastic, there may be droop over time due to gravity. A longer tube has more potential to bend under its own weight.
3. A longer tube, and especially a larger diameter one will weigh more. That will cause the barrel to droop more under gravity. At some point, the barrel or muzzle device may contact the air tube. Such contact should be avoided as it is likely to cause the barrel to bounce in an unpredictable manner during the shot.
Now, if you don't mind taking a risk of the longer tube drooping over time, that is fine by me. It may help to print it using a plastic with carbon fiber as a filler. Or any other filler known to reduce "creep".
The air stripper OD can also be increased to make the longer tube stiffer.
For reference, the version 2 sight base has a 25 mm OD, just like the standard part. The suppressors on the second page have an OD of 32 mm. I could use that diameter, or something between 25 and 32 mm.
Some of the more recent discussions suggested not trying to print the thread for the retention screw, because it has such a fine thread. To just leave a nominal hole for an M4 thread, that you will need to tap.
You will notice that I increased the rearward length behind the muzzle on the longer suppressor. That was not just for reflex volume, but for for better alignment and stability.
Please consider these points and let me know what you prefer for length ahead and behind the muzzle, outside diameter, and threaded retention screw hole or not. I can certainly place the sight dovetail all the way at the front.
One last consideration; so four: The printer you use need to be able to print the length. The part needs to stand up on its muzzle, so that it can be printed without using so called support material added. Support material in the air stripper channel would be very difficult to remove.
You have not stated caliber, but because this is for target shooting I assume .177 / 4.5 mm.
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Current ISSF rules for air rifle state that total length of the system of air rifle, from the end of mechanism, to the front of apparent muzzle must be less than 850mm.
Length of system on CZ200 is 630mm, with factory front sight carrier. 200 mm extension will be still legal, as per rules.
What I will like to see is just thin wall front tube extension on V2 stripper, with air stripper position in the same place as on V2. And dovetail on front, for mounting sight. That way, excess air will be vented off, and front tube will act only as sight carrier. Suppressors are forbidden here. 32 mm sounds fine, anyway, as well as anything in between 25-32, just sight dovetail should be on same height as original. I plan to replace original tank with quick fill one, but lets make this file as usable as possible for anyone, even if they use back fill tanks.
I ordered V2 printed with SLA, in Polyamide 12, but it also can be ordered in GF32, reinforced with glass fibber. That should reduce sagging considerably.
I am fine with non threaded retention hole. It should make stronger connection.
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And yes, calibre is 177.. 7.5 j version.
Maximum print length is 300mm in SLS, Z axis.
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Thanks for the additional detail.
For clarity; do you want the air tank clearance cut underneath or round?
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Air tank clearance will be better, to be usable for people who remove their tanks to fill them up. Personally, I am fine with either.
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Bogdan,
I decided to start with your more conservative request to see what a + 100 mm extension looks like. Also to get mass properties. I stretched the rear section by 50 mm for better alignment and support. Especially if you want a longer version; which I will be able to do by "stretching" the design, later. As it is, this version is 228 mm long.
I made the outside diameter 32 mm, while keeping the original 15 mm ID from the stock part. I did this to provide a smooth and uniform inner "tube", rather than to optimize expansion volume, as I did for the suppressors.
It occurred to me to add a third air stripper with a longer cone. But you are running at such low power, this will potentially make the tube more flexible, while not gaining any real function.
As the wall thickness seems excessive in some areas, and is not uniform due the air tank relief cut, I cored out sections of the wall, leaving ribs, where I though it could be lighter. Yet, by maintaining the outside shape, the structure should be stiffer than a solid wall of smaller OD.
Right around the air stripper vents I didn't core out the wall at all, as that section is already lighter due to the "windows". Also, being near the "root" of cantilever support, that area should keep its full wall thickness, top and bottom.
I made the two short sections where the barrel will make contact 14.94 mm for best possible alignment. This, while relieving the section in-between to 15.4 mm, for easier installation.
I may want to create a version of this part with the air stripper windows a little smaller top to bottom for increased bend strength overall. And one or two possible refinements.
In any event the design as shown is attached as an STL print file.
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Continued from above...
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Because this is such a long structure, I reduced the air stripper vent windows back to 12 mm height (from 15 mm in the above design).
I also added a bit of material to the wall directly under the front dovetail, as my lightening channels left it a bit thin in the above design. Images below show changes.
STL print file is attached with file name reflecting 12 mm vent window height.
Note that because of the length of this part, it will take well over 20 hours to print when a conventional Ender 3 FDM printer is used. Making the part even longer may require some external removable braces, so it does not rip off the printer platen and fall over.
By the way, the part would weigh 94 grams, if it has a specific gravity of 1 (like water). If the SG is 1.2 for a given material, then it would weigh 113 grams.
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Bogdan,
In thinking about stretching the sight base to any length you want, I came up with a better idea: Print the front and rear as two separate parts, joined by a 17 x 15 mm carbon fiber tube. The tube can be pressed or glued in place. Set screw locations could also be added to the front and rear parts.
The through bore remains 15 mm, just like the stock sight base (except for the air stripper cones, of course).
If you want a version of the rear section that is shorter, I can do that. The one shown is 196 mm long. The front section is 75 mm long. It could also be made shorter, if you prefer.
The STL files for the front and rear sections as shown are attached directly below.
It may be smart to add some external supports to increase the printer platen "footprint" of the longer rear section. I can add easy breakaway supports after you confirm that you are satisfied with the basic concept.
Else, a less elegant design could be configured for printing with the rear section laying down in its long side. The air stripper cones would need to be extensively modified.
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I really like carbon tube version, as well as 12mm port one. I will try to source 17x15 carbon tube here, as a first step.
Adding printing supports will be great, I just don't know how easy they will be to remove, if some fibber reinforced materials are used for printing.
I am waiting a first printout of V2 to arrive here, in day or two, it was amazingly cheap (less than 3$) and I will use it as proof of concept. I would like to test group sizes, and if air strippers have any impact on them.
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Thanks for the reply, Bogdan
The rear section of the CF tube version has a small overhang error that I will fix by adding sloping material. Image below.
If you have two versions of a print file; one with removable stabilizer "struts", and one without, you can decide which you want to print.
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Above overhang fixed. STL file name ends with "fix" - attached
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I found 17 mm OD carbon fiber tube on amazon before specifying the above. In case you can't locate that size, here is a version of the sight base parts for a 18 mm OD tube.
Both STL files are attached.
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While the rear tube adaptor has to resist the bending moment of the parts hang out the front, the front sight base does not need to have a 32 mm OD. The versions below have a 26 mm OD. So, lighter parts:
One has a socket for a 17 mm OD CF tube. The other version is for a 18 mm OD tube. STL files attached.
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By the way, Bogdan; you mentioned SLS printing. For that, a part with break-off supports will not be required. I think you could print the parts laying down in the powder. No need to stand parts on a narrow end.
So, perhaps no need for me to design parts with break-off supports. Such external braces would be for FDM printing. But, FDM printing experts might have a more calibrated opinion than me. All I know is that my designs don't need internal supports, and if these are used, they are difficult to impossible to remove. I don't know if external supports can be added via the slicer, without turning on internal supports.
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Carbon is not available here, but aluminium is, and I found 18/16 tube. Weight is 150 grams per 1000 mm, so it wont be to heavy. Great that you posted files for 18mm tube.
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Hunter and Bogdan,
If you have tried out the LDC and front sight I would appreciate feedback, so that improvements can be made, if indicated.
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I think that it is lost in the mail.
Hunter
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That would be a bummer.
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I have created a round version of the S200 LDC (no airtank clearance cut). It also has an overall length of 177 mm, with a 75 mm reflex length.
The point of this version is that it can be used on any airgun with a 15 mm diameter barrel - including the S200 series, if that has a front fill port air tank. The "why" is slightly larger expansion volume in the same "footprint"; and more symmetrical internal airflow.
Rather than one M4 retention screw, there are three evenly spaced ones. The unthreaded hole diameters are a nominal 3.2 mm, that need to be hand tapped to 4 mm. For grub screws 8.5 mm long. I suggest ones with plastic nose inserts to protect the barrel.
The intended muzzle face depth from the rear of the LDC is 75 mm. Easy enough to establish with a ruler and adhesive tape. Because this LDC is round, the rotation around the barrel does not matter.
The STL print file for the .177 caliber version is attached below as a ZIP file.
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Sorry for late reply, for some reason, I cant get to the forum from my MAC, or iPhone, only from my win laptop.
I printed in 2 processes V2, and there are some issues which can be improved.
First, interface between barrel and front sight mount is too tight. It is impossible to be installed as printed. I reamed it with 15mm forstner drill bit for wood, as I don't have 15mm reamer, and while tight I was able to fit it on. As it is really tight, aligning front sight mount to be coplanar with back sight was a bit hard. Original sight mount have much larger diameter, and it is easier to fit on.
Second, issue is that sight mounting dovetail is too narrow for original front sight. Front sight can be mounted, but lower part of the sight mount is narrower than upper part. It works with original sight mount, but I don't know if it will work with replacement front sight, like AHG Race.
These two issues doesn't preclude use of the sight mount, but they require additional work.
Another possible area for improvement is making a shoulder on the exact position of the muzzle, in order to set worm screw exactly into slot on the barrel. As reamed front sight mount is tight, it is hard to position it where it should be, so that screw gets into slot. It took me few trials before I was able to get everything aligned.
I will wait for some time, before I order longer extension.
Another interesting item for the CZ200 will be sight raising blocks in different heights. Aluminium ones are starting to be quote expensive.
I will follow up with few pictures. I also changed tank, added regulator on my gun, and I was suppressed how consistent velocities become. Extreme spreads for 10 JSB Simply midweight were under 1 m/s, eg 3 fps.
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Thanks for the feedback, Bogdan
I was tempted to PM you to ask about your printed parts.
Pictures will help. Especially of the dovetail interference.
My T200 barrel OD measures 14.92 mm. The stock front sight base ID measures 15 mm. I made the hole in my design 15 mm, and was actually concerned that it would be too loose. The person printing the part usually has some control over printing ID or OD, tight or loose.
I actually offered a stop shoulder for some of my LDC designs. The gentleman who wanted one asked for it not to have a stop shoulder. I can see how a shoulder could help installation.
From my images, the end of the barrel muzzle should be visible in the rear air stripper window (if I remember correctly).
One way to deal with the potential fit problems would be to offer more than one version of each design. Some with a larger barrel hole than nominal, some smaller. The same with the dovetail fit.
If you provide details about raised sight blocks you would like to have, I can create STL files for that.
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Here is some additional info on the problems I mentioned in previous post.
With of the dovetail on the V2 I printed is 9.5mm, eg 3/8. Original front sight mount dovetail with is 11mm.
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Bogdan,
Additional dovetail measurement would be useful. Something like the sketch below.
I get that measuring the angle is tricky. The linear measurements will describe the angle. It is just that I have seen sight dovetails with angles from 45 to over 60 degrees; so would not want to guess.