GTA
Support Equipment For PCP/HPA/CO2 and springers ,rams => 3D printing and files => Topic started by: subscriber on November 27, 2023, 05:37:14 AM
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GTA member jolofree asked about a muffler for his Marauder:
https://www.gatewaytoairguns.org/GTA/index.php?topic=182738.msg156492161#msg156492161
I made some suggestions, and what panned out was this: A 32 mm OD x 140 mm long 3D printable LDC in two versions. One version has a 13/16-28 male thread, and is intended to replace the stock Marauder shroud front endcap. The other version is identical in all aspects, except that it has a 1/2-20 female thread.
The latter version would require a thread adaptor to replace the stock front shroud endcap; such as this one: https://donnyfl.com/products/marauder-mrod-1-2-x-20-unf-adapter-with-thread-protector
After thinking about what jolofree had asked about keeping his stock Marauder baffles, I decided to design only an external add-on. At first my thinking was that integrating the internal shroud baffles into the external muffler would better align the parts. But keeping them separate would keep the platform closer to stock.
Using the DonnyFL adaptor might be the more robust option with respect to the thread, but the direct mount might be the cheaper option. I might even suggest getting both.
Both STL print files are attached in the same zip file, below. The parts need to be positioned with their threads uppermost on the printer platen, to print the cones inside correctly. Anyone is welcome to print these parts for themselves or anyone else. I have confidence that the 1/2-20 thread will be usable directly off the printer; but the 13/16-28 thread may require some iterations to get it just right.
If you are unable to print these parts for yourself, and don't know anyone that can print them for you, I can recommend someone.
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In case you want to print just the 13/16-28 male thread to prove it good first, here is just that aspect as a part STL:
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Yes Sir, These designs look great. The size is perfect.
I have ordered the adapter from Donnyfy, the threads on it are 1/2"-20 so I will need the design with the female threads to match that.
Could you please advise how to best contact Bob or Mike to get this done?
Also I was advised by a member on Air Gun Nation to look into installing t 'Depinger' in the Marauder.
I'm not sure exactly what that is, where to obtain one, and how to install it.
Do you think that would make the Marauder have a quieter shot signature?
Thanks, I really appreciate all your help with this. j
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John,
The 1/2-20 adapter is more versatile for any future bits you might want to try. So, good choice.
You can PM Bob and Mike here:
Bob: https://www.gatewaytoairguns.org/GTA/index.php?action=pm;sa=send;u=67950
Mike: https://www.gatewaytoairguns.org/GTA/index.php?action=pm;sa=send;u=19269
A depinger goes into the airtube, so to install it you must depressurize the airtube first. Failure to do that is likely to throw the front cap of the airtube (the one with the foster fill fitting on it) forcefully enough to cause damage or injury.
Depingers come in many forms. Some are a partition in the airtube with a small hole in it. This is a flow restrictor placed about midway in the airtube to damp pressure waves that bounce in the airtube on the shot. Others are an actual bottle brush that does the same thing. Installation instructions are included with the depingers that are sold.
Depending on when your Marauder was made, it may have Crosman's version of a depinger. Anyway, what they are, how they work, and how to install them is covered by many threads and posts. This google search string points to such posts on GTA:
https://www.google.com/search?q=site%3Awww.gatewaytoairguns.org+depinger+marauder
And yes, if your Marauder does not have a good depinger, it will be making a loud pinging sound on every shot. That is, if it is a stock unregulated version. Marauders were available with regulators from Crosman to keep the velocity more constant over so many shots, but at a lower power level than the unregulated ones. There, the regulator acted as a depinger, but if yours lacks a regulator, then a depinger will help reduce the noise.
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John,
You had a question about the "front barrel mount drilling" on AGN. Drilling it out to flow more air tells me that the person suggesting that modification was referring to the air stripper/diverter; that is pressed onto the muzzle end of the barrel. This part:
(http://img.photobucket.com/albums/v722/wtani/IMG_7372.jpg)
Here is a discussion about drilling out the vents on the Marauder air stripper - although I think one does not need to go quite that large on the holes: https://www.gatewaytoairguns.org/GTA/index.php?topic=42482.msg396424#msg396424
(http://i1320.photobucket.com/albums/u532/scott_schneider1/IMG_1185_zps171026af.jpg)
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This one is nicely done:
(https://www.gatewaytoairguns.org/GTA/index.php?action=dlattach;topic=42482.0;attach=55022;image)
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Yes that's it. I think I'll give that mod a try. Thanks!
And I cant srr sent messages, Did you receive my message about the shroud threads?
They are 8mm or .315" and virtually the same maybe one more thread in the shroud.
JF
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John,
I just saw your PM about the shroud endcap thread length being 8 mm. I have updated the moderator thread length and the thread test piece. Version 2 STL print files with 8 mm long threads are attached below:
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Hey Subscriber, toyed around with these for the Marauder Pistol yet? That could be quite useful as many have added an extension to reduce the report.
Casey
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No, Casey, I have not.
Care to be more specific?
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Yes, I was wondering about a shroud mount extension for the P-rod. I am not up to speed with the design side of printing, but I currently run both a pair of FDM printers and a resin printer. I can get you more specific measurements if you don't have them. I have printed both your M-Rod extension which works fantastically and showed a 5 -6 db reduction on my 25 making it even more friendly.
Casey
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The important detail is the thread designation: Diameter and pitch.
I assume perhaps incorrectly that the moderator for the PROD should be smaller than that for the MROD? Please advise, unless you want to leave that up to my discretion. OD and length (or range of dimensions) you are looking for .
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Okay, sir, it looks like from my thread gauges and caliper that it's a .68" diameter 24 tpi SAE for the threaded part of the original shroud end cap. Its outside diameter is .75" and the depth of the threaded side to engage in compression on the factory baffle stack is .36". I have attached a couple of pictures. As for sizing, I am experimenting with your LDC Bore Clearance Study pieces, and that diameter is fine in my opinion. Perhaps a simple endcap to 1/2-20 adapter to provide the proper host fit. If you feel up to it perhaps also a complete thread unit like the above in the same 1" diameter for those who would prefer a complete one-piece solution as well.
Images:
(https://i.postimg.cc/3yRFxW9y/Shroud-Cap-01.jpg) (https://postimg.cc/3yRFxW9y)
(https://i.postimg.cc/Ty4qLGHt/Shroud-Cap-02.jpg) (https://postimg.cc/Ty4qLGHt)
(https://i.postimg.cc/K3XPffbL/Shroud-Cap-03.jpg) (https://postimg.cc/K3XPffbL)
(https://i.postimg.cc/624VCSkt/Shroud-Cap-04.jpg) (https://postimg.cc/624VCSkt)
Thank you,
Casey
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Thanks, Casey
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Casey,
I design two variants of .22 PROD LDC. Both have an OD of 1", and are 4" long ahead of the shroud, after mounting. One version is cylindrical; while the other tapers up from 3/4" at the very back end, to better match the shroud OD. Internally, they are identical. See attached images below.
The attached ZIP file contains the STL for both cylindrical and taper LDC versions.
Note that you need to rotate the part in your slicer, so the threads are uppermost - see last image. Else internal baffle cones will be unsupported; and the part unusable. Print at 100 % infill, with all supports turned off.
I suggest that you first verify the thread fit by printing just the rear inch or so, using the cylindrical version for a broader connection to the platen. If the threads are too tight, use the slicer to scale the part to 99.5% in the X and Y axis. Leave the Z-axis at 100%, or the pitch will be off and cause the thread to go over-tight before fully screwed in. If the thread is too loose, print the X and Y axis at 100.5%.
I expect the thread to screw in somewhat tight the first time, and then loosen up after that to a just snug fit. This is when printing the STLs directly, without scale adjustment, although it depends on you printer, material, slicer and settings. So yours may or may not need intervention.
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Thank you kindly, sir, I will get them printed and provide feedback as soon as I can test them out. I appreciate your time and assistance, sir, it's great to find others who think alike.
Casey
P.S. I have had great success with your designs and my printer,slicer, and settings seem to be right on point thus far. Again I will provide feedback as soon as I can.
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Casey,
In case you find the threads on the above version of LDCs too tight, you might try Version 2. Version 2 has more relief in the threads, intended to screw on easier.
If you have not yet started printing the first version, I might suggest you try version 2, first.
ZIP files contains version 2 STLs for both taper base and cylindrical LDC versions.
Image below is of superimposed thread profiles, for V1 and V2; to show where material has been removed from thread-form:
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I will try v2 of the tapered extension. I have however already printed and tried v1 of both. I forgot about the pull-off fill cover, so the tapered version is best for those who do not wish to unscrew their extension to refill. That said both screw on smoothly and tighten as expected. I used .16mm and .12mm print modes to check and see if I needed the additional quality/precision of the .16mm print level. The .12mm is fine and saves a bit of time, I may try .2mm to speed things up a bit more. Both versions of the extension, tapered and straight quell the last bit of pop exceptionally well for a short 4-inch extension. I am more than pleased with the results and would recommend these to anyone wanting just a bit more quiet from their Marauder Pistols/Carbine. Perhaps we should create a new post to share with more of our air-gunning brothers and sisters.
Picture of the tapered model:
(https://i.postimg.cc/TwhmpZGD/Tapered-Extension-01.jpg) (https://postimages.org/)
Thank you again, and I'll get a v2 printed to test for you as well.
Casey
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A couple more things. I will perform some actual DB testing with and without the extension to get a rough number for those interested. I will also shoot a couple of groups with and without to see if any difference is visible in group size and POI. More to come.
Casey
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Thanks for the feedback, Casey
I am glad that the fuller thread-form versions works for you. I expect that then the V2 might screw on with some play at your print settings. Even so, they might help someone struggling with Version1.
Your results make me wonder about the print settings John is using in this thread:
https://www.gatewaytoairguns.org/GTA/index.php?topic=209016.msg156539630#msg156539630
Feel free to start a thread in the PCP gate about your PROD, posting your results and impressions of this LDC. Post a link to the section of this thread where the PROD LDC project starts:
https://www.gatewaytoairguns.org/GTA/index.php?topic=211473.msg156539885#msg156539885
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By the way, the PROD LDC could have been designed longer. I chose 4" because it is a pistol and adding too much length would not appeal to too many people. If you want a longer version for less pop, speak the word.
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Thank you sir. I will start a new thread for my P-Rod and link this thread so other can benefit from this work as well. If you would like to stretch the unit a bit more I am happy to print it and test it out. I will also print and post results for the V2 of the 4" along with some decent DB level readings so all may compare. I am using a phone program, but I have a calibrated mic to go with it. That said, all first test are done with the phones built in mic to ensure they are a safe level for the good mic. I will PM you with another idea we might also collaborate on. I'm still a beginner with 3D design, but I'm learning.
Thanks again for the assist and the design work sir, very much appreciated.
Casey
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Casey,
I have taken the 4" LDC version with the conical rear and stretched it via a "natural baffle increment". See image comparison below, with the 4" version at the top. The longer version just happens to end up at 150 mm; or just short of 6".
Truth be told, it looks a bit skinny for the 1" OD, but if it works better and does not clip from "whip", or break off, then it would be a viable option.
Clipping is not likely, unless the LDC attaches visibly skew, as the bore is generous for .22, and tapers larger towards the front.
The STL for the V2 version with more thread relief is included in the attached ZIP file.
Suggestions for printing these are the same as for the above versions.
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So, I thought there might be interest in a PROD LDC that looks like a longer shroud: I took the "4 inch" version and reduced the outside diameter to more closely match the shroud OD. See images below.
The ZIP file contains two STLs. The V2 file has the same relieved threads as do the earlier LDCs above. Version 1 has the slightly tighter threads. I did not convert the 150 mm long LDC version, as that seems too skinny to me.
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Al, since I was the one who asked Subscriber for the P-Rod LDC/Extension I would like to publicly state that I have printed every version, tested them and they work fantastically. I prefer the V2 with the taper in the 105mm length, but the straight version that matches the shroud diameter works just as well, and takes the last bit of sharpness out of the P-Rod. I have printed the one I use most in both PLA, (first test) , PLA+, and finally one in PETG. I also have carbon fiber filament so if I ever do have any issues I can make one from that as well. I tend to stick to the matte finish PLA+ and PETG, but the few parts I have printed in CF come out fantastic looking. The sound is great, as is the look. Thank you Subscriber for the great addition for the P-Rod shooters that want that last little bit.
Casey
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By the way, the PROD LDC could have been designed longer. I chose 4" because it is a pistol and adding too much length would not appeal to too many people. If you want a longer version for less pop, speak the word.
Not longer but shorter! For pistol field target. Ill need to measure though. Longest is 15" total of barrel with any attachments from breech.
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Brandon,
Go ahead and measure.
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I did, and there is no extra room so its just for home use and not comp. I appreciate the files and willingness. They work great!
Thank YOu
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Brandon,
Are you saying that you don't need a custom length design after all? If I misinterpreted that, please be specific.
Thanks for coming back to the thread.