Meat Target Posted March 1, 2014 Share Posted March 1, 2014 Just finished up my new rifle compensator this week. Ran over 50 different combination through Solidworks to come up the design. The last few runs took my computer over 24 hours to finish crunching the numbers. With the new trend in 3-gun going toward short and lighter barrels the goal was to make the compensator as small and light as possible but still be effective. My target was to be as good or better than the SJC Titan for recoil reduction and lighter than the Miculek comp. For down force I didn't want to put too much in, so I designed it to be in the middle of the pack when compared to the others. My last comp weighed in at 4.5oz its amazing how much lighter the gun feels just by dropping almost 2 oz off the front end. I am thinking about going from an 18" to a 16" barrel just to drop a few more ounces off. Its made out of case hardened 1018 low carbon steel with a 1mil of cobalt plating. I ran an FEA on the part using the forces from the simulation to make sure the design was strong enough. I would love to make one out of titanium but the machining of it would be tough going without a CNC machine. The angles are a little more complex than they look in the picture and the set up takes a long time using a manual mill. The side ports are fairly large so it shouldn't be too loud. I played around with the baffle angles to try and keep down the back blast towards the shooter, it looked good on the simulations I will find out quick enough. I have a shotgun comp that I built last year that works great but blows your hair back every time you pull the trigger, looks like something Flash Gordon would have on the end of his ray gun. I am hoping to try it out this weekend. If its not too cold out (18 F here in Michigan) I would like to throw on the other comps to run a comparison. Link to comment Share on other sites More sharing options...
michael1778 Posted March 1, 2014 Share Posted March 1, 2014 Interesting looking design. If we are nerding out here, could you summarize how you modeled the gas dynamics of the problem? Did you use a stock industry standard CFD code or a different simulation technique? I'm very curious because it seems like a very difficult fluids problem. I have a bad enough time simulating rocket plumes and wouldn't touch this problem with a ten foot pole! Thanks. Link to comment Share on other sites More sharing options...
polymerfeelsweirdman Posted March 1, 2014 Share Posted March 1, 2014 I would also want to know how you did the anakysis I would like to try and take a crack at designing a comp Link to comment Share on other sites More sharing options...
Meat Target Posted March 1, 2014 Author Share Posted March 1, 2014 Interesting looking design. If we are nerding out here, could you summarize how you modeled the gas dynamics of the problem? Did you use a stock industry standard CFD code or a different simulation technique? I'm very curious because it seems like a very difficult fluids problem. I have a bad enough time simulating rocket plumes and wouldn't touch this problem with a ten foot pole! Thanks. Solidworks Flow simulation solver uses Favre-averaged Navier-Stokes equations with transport equations for the turbulent kinetic energy and dissipation rates. The initial conditions for barrel pressures were obtained from QuickLoad software, propellent gas properties were obtained from military research documents on rifle muzzle blasts for temperatures and ratio of specific heat. If you look at some of my other posts I have links for videos of the simulations I have done on the other compensator if you are interested. Link to comment Share on other sites More sharing options...
michael1778 Posted March 1, 2014 Share Posted March 1, 2014 Sweet. Thanks! Link to comment Share on other sites More sharing options...
bagdrag Posted March 1, 2014 Share Posted March 1, 2014 Not a nerd here (too dumb and simple) but just looking at this brake makes me think of it being kind of concussive to the shooter. In the pursuit of removing rearward recoil, it looks like it would direct a lot of gas back to the shooter. Haven't tried the SJC Titan yet but this is what I've heard as one of the major complaints. Your design does look very effective for such compact dimensions. Link to comment Share on other sites More sharing options...
Nickoli Posted March 1, 2014 Share Posted March 1, 2014 Glad to finally see this thing after hearing you talk about it. Get out there today and test, warmest day we have had all week, and give us a range report. I'm curious to see how it is going to perform. Link to comment Share on other sites More sharing options...
WhoEver Posted March 1, 2014 Share Posted March 1, 2014 Could You make similar simulation from JP Tank? Link to comment Share on other sites More sharing options...
MarkCO Posted March 1, 2014 Share Posted March 1, 2014 Simulations are a good start, but they still have some error and don't tell the whole story. But dang, 24 hours! I thought mine was long at 18 hours, but only had to run one simulation. Link to comment Share on other sites More sharing options...
Meat Target Posted March 1, 2014 Author Share Posted March 1, 2014 Not a nerd here (too dumb and simple) but just looking at this brake makes me think of it being kind of concussive to the shooter. In the pursuit of removing rearward recoil, it looks like it would direct a lot of gas back to the shooter. Haven't tried the SJC Titan yet but this is what I've heard as one of the major complaints. Your design does look very effective for such compact dimensions. The blow back towards the shooter is not as bad as you would think just by looking at it. I have a larger version with about the same baffle angles and you do not notice any blow back at all. Also because of the larger ports the side blast pressures will be a lot lower than the Titan's. From this picture you can see that the gas flow moves back towards the shooter a few inches but then start moving out to the sides. I will find out for sure tomorrow when I try it out. Link to comment Share on other sites More sharing options...
Meat Target Posted March 1, 2014 Author Share Posted March 1, 2014 Could You make similar simulation from JP Tank? That's another comp that I would like run a sim on. My initial impression just by looking at it is that it should work very well, but its way bigger than it needs to be. I know someone that has one that I could borrow to get the measurements off of. Maybe in a month or so I could have something to share on it. Simulations are a good start, but they still have some error and don't tell the whole story. But dang, 24 hours! I thought mine was long at 18 hours, but only had to run one simulation. Yep it just a start, but that why I used the other comps as a baseline so I could narrow down the trial and error part when actually making them. I had the simulation mesh count up to about 700k cells on the final few runs that why it took so long to complete. Link to comment Share on other sites More sharing options...
fastshooter03 Posted March 2, 2014 Share Posted March 2, 2014 That's the old "Master Blaster" that brownells used to sell. Only the MB had 3 ports and came in two sizes. I still have one and they are very effective and loud. Nick Link to comment Share on other sites More sharing options...
TimMc Posted March 2, 2014 Share Posted March 2, 2014 This is very interesting. Will have to watch this. Link to comment Share on other sites More sharing options...
Meat Target Posted March 2, 2014 Author Share Posted March 2, 2014 Just got back from testing out the new comp, works very well. I was hitting off-hand double taps (0.16 - 0.18sec splits) on a 100yard full size steel IPSC target using a 4x scope, cross hairs never left the target (with low mass carrier/buffer and adj. gas block). Back blast towards the shooter is a non issue, I had someone else shoot it and they didn't notice any either. While they were shooting I was standing off to side and didn't notice any excessive noise or blast. Its definitely quieter than the Miculek comp, the bigger ports did help with the noise. I was going to run a comparison with the other comps but it was only 9F out and my fingers were going numb, so I wussed out and decided to hold off on that until it warms up a little. If I really want to "Nerd it out" I could thrown some accelerometers on the rifle and calculate the actual barrel movement with different people shooting the various comps, but I think I already may have my plate full with other projects for this year. Looks like there may be something to this computer simulation stuff after all. For now I am completely happy with the performance of the comp and can't think of anything that I would change other than possibly making a lighter version of it, of course my opinion may change once I start trying out some of the other comps out there and find one that works better. Link to comment Share on other sites More sharing options...
McCringleberry Posted March 2, 2014 Share Posted March 2, 2014 Great information, thanks! Question, on the Rolling Thunder, did you tune it in any way? Benny's instructions are to have a side hole drilled (right side if you are right handed) and shot/tuned until it sits flat as you shoot it. If that didn't happen, I'm sure the simulation will not account for it and will skew the outcome. I know there is a variance there but it really makes a big difference with that comp and having it tuned. Any way, great work and thanks for sharing with the community! Link to comment Share on other sites More sharing options...
Meat Target Posted March 2, 2014 Author Share Posted March 2, 2014 That's the old "Master Blaster" that brownells used to sell. Only the MB had 3 ports and came in two sizes. I still have one and they are very effective and loud. Nick It may look like it by coincidence, do you have a picture of it? I would be interested to see the port design on it. Link to comment Share on other sites More sharing options...
bagdrag Posted March 2, 2014 Share Posted March 2, 2014 Very cool stuff. I wonder how you're comp would perform in Patrick Kelley's testing rigs. Good to know side blast and concussion to the shooter isn't a concern. Link to comment Share on other sites More sharing options...
Meat Target Posted March 3, 2014 Author Share Posted March 3, 2014 Great information, thanks! Question, on the Rolling Thunder, did you tune it in any way? Benny's instructions are to have a side hole drilled (right side if you are right handed) and shot/tuned until it sits flat as you shoot it. If that didn't happen, I'm sure the simulation will not account for it and will skew the outcome. I know there is a variance there but it really makes a big difference with that comp and having it tuned. Any way, great work and thanks for sharing with the community! Tuning the comp by adding a side hole or opening up the top one wouldn't change the total amount of overall recoil reduction much, its more to adjust for individual variations in gun dynamics and how each person holds the rifle. I could add in the hole tuning changes to the simulation and get an idea of what the changes will do but it wouldn't tell you if would work better. The simulations are good for giving an idea on how effective the comps are in using the gas energy available but they can't tell you the last little tweaks needed to dial it in for each individual person. Link to comment Share on other sites More sharing options...
fastshooter03 Posted March 5, 2014 Share Posted March 5, 2014 That's the old "Master Blaster" that brownells used to sell. Only the MB had 3 ports and came in two sizes. I still have one and they are very effective and loud. Nick It may look like it by coincidence, do you have a picture of it? I would be interested to see the port design on it. I'll have to take a pic when I get the chance. The 3 ports aren't as tall and has two top holes. I think it was around an inch diameter. Nick Link to comment Share on other sites More sharing options...
MarkCO Posted March 5, 2014 Share Posted March 5, 2014 The simulations are good for giving an idea on how effective the comps are in using the gas energy available but they can't tell you the last little tweaks needed to dial it in for each individual person. And the differences between the best and the worst in this realm are actually insignificant. If a comp uses 40% of the available energy in a manner that does not benefit the shooter, it will be worse than one that only uses 35% of the energy in a beneficial manner. Don't mix up effectiveness (what a shooter wants) with efficiency (what an engineer might be trying to improve). Link to comment Share on other sites More sharing options...
Tuflehundon Posted March 6, 2014 Share Posted March 6, 2014 Not a nerd here (too dumb and simple) but just looking at this brake makes me think of it being kind of concussive to the shooter. In the pursuit of removing rearward recoil, it looks like it would direct a lot of gas back to the shooter. Haven't tried the SJC Titan yet but this is what I've heard as one of the major complaints. Your design does look very effective for such compact dimensions. I have the Titan and there is no issue with back blast for the shooter. I have RO's a guy using one and the concussion can be felt by the RO, but as the shooter, it's not even noticeable. Link to comment Share on other sites More sharing options...
fastshooter03 Posted March 9, 2014 Share Posted March 9, 2014 (edited) Here's the Masterblaster pics: A little dirty but you can see how it's designed. IIRC it was around $150 around 15 years ago. Pricey but the only thing available that looked like it worked well. I think we had a Clark(AKA rolling thunder type...)but just didn't work well. I think the cost put out of business. Today's machinery should be able to produce this type of brake at a much more reasonable price. But that is up to the seller..... Nick Edited March 9, 2014 by fastshooter03 Link to comment Share on other sites More sharing options...
Meat Target Posted March 9, 2014 Author Share Posted March 9, 2014 Fastshooter03, Thanks for posting the pics of the Masterblaster, your right it does look a lot like mine with the last port cut off, guess I am only 15 years behind the learning curve. Its hard to tell but the ports on mine look just a little bigger. You are probably also right on the cost of manufacturing, it is a difficult piece to make without modern CNC equipment. The could have reduced the cost some if they only did a two port design as the last port doesn't contribute much anyways. Link to comment Share on other sites More sharing options...
buffalo chip Posted March 10, 2014 Share Posted March 10, 2014 I have a tank break for you to test. I would like to shoot your new design. It looks awesome... Link to comment Share on other sites More sharing options...
fastshooter03 Posted March 12, 2014 Share Posted March 12, 2014 I"m sure your design will work well. It may need some top holes but I'm also sure your testing will figure it out. Just make sure accuracy doesn't suffer. Some brake designs can have a negative effect. Nick Link to comment Share on other sites More sharing options...
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