GTA
Airguns by Make and Model => Hatsan Airguns => Topic started by: WHITEFANG on April 19, 2012, 01:51:03 PM
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Since GENE has suggested to start a new thread on this topic I have elected to honor his wishes. I have gathered up some more parts that may benefit me for the ram project. I fully understand that anyone that takes on this project must keep safety as the utmost importance. Again these guns have huge amounts of stored energy. Even the true tuners on this site undertake educated risks and great responsibility risk when tuning the guns for us. I don't think that any of them will give you the max you could get out of these guns. Just like the tuner for my Super charged Harley truck, he could give me more power and boost but the engine will not last long. He elects to give you the most HE CAN THAT IS WITH IN REASON FOR THE SAFETY OF THE engine. JM2CENTS
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Gene suggested we start a new thread and refrain from large font, etc, and I am OK with that . . . It also means that Gene has been reading all of our thread(s) here on gas ram conversions, which is also a good thing !
Now, I ask that Gene, and all of the other Tuners / Machinists on GTA, actively join in our discussions here, and contribute ideas on how to safely get the best results from our Nitrogen Gas Spring conversions.
They have much more experience and knowledge and it would be unfortunate for us to not have their input !
Assuming they have not all been following our discussions, I'll give a brief summary of the most current items:
1 - We are talking about converting Hatsan model 125 & 135 rifles to use commercial Nitrogen Gas Springs
2 - These units range from 140 bar to 180 bar in pressure
3 - N-FORCER, KALLER, & MOELLER are the companies they are produced by
4 - Specifications:
19 mm diameter x 125 mm stroke
N-FORCER / KALLER "YELLOW" unit has an Initial Force of 202 lb and a Final Force of 260 lb
MOELLER "RED" unit has an Initial Force of 158 lb and a Final Force of 236 lb
MOELLER "YELLOW" unit has an Initial Force of 203 lb and a Final Force of 304 lb
5 - Joao Mello of American Arms has said that he will be importing Hatsan 125 Gas Ram Conversion Kits
6 - There are questions as to which direction the gas ram should face, when installed
7 - We have been using the equation ( ( F1 + F2 ) / 2 x ( L / 12 ) ) x EC "efficiency coefficient" to predict FPE
8 - We were given "efficiency coefficients" of .33 for .177 / .35 - .38 for .22 / and interpolated .37 - .40 for .25
9 - There is also discussion of the advantage, if any, in the 7% higher Swept Volume of the Hatsan 135 over the 125, with the use of the various gas rams mentioned above.
10 - We need your expert advice and the ability to discuss questions and problems with Tuners / Machinists on GTA
THANKS !
Dave
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I have been following Daves research.
but I refuse to get into the details of the mathematics involved, I simply decided to trust all his hard work and effort to choose the best gas piston that he researched, to give us a good power, but not over doing it ,with good rifle integrity and safety in mind from the get go.
I purchased some moller rams for myself and a few other members here and we shall see what the results will be.
I have decided that I will do three gta members conversions for cost of material and shipping.
If the gas rams give us the results we are expected.
I may later do other members rifles on a one at time basis, put on a small waiting list, for 50.00 dollars above the cost of all materials used and shipping
It will include the moller conversion gas ram, and parts i buy or make, possibly a new jm seal if you choose to have one installed,cleaning the receiver, cross hatching , and typical lube tune using j m molly paste and lubricants.
I will not include any trigger tuning / but will offer you the free how to instructions on the Quattro trigger up grade with the longer screws.
It's my intentions to simply get some GTA members something they been wanting for, that they are not able to do them selves.
Hopefully other members will eventually offer the same, that way we can all save money and buy more rifles, and get back to enjoying our hobby.
First things first, let see how this all plays out, looks like my package just arrived from MC Master Carr with my delrin i ordered. the rams will be next they are own there way.
If everything works out we have Dave Tarheel to thank for wanting to get this, long, over due "up grade gas ram conversion available to all members. in fact thank you Dave for your time and energy looking into the post you started.
Mike
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Howl!!
THE FANG
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I put my name down 1st :)
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This looks like a party!!!! At least it is a joint, can I say that? Adventure.
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I put my name down 1st :)
I put my name down 1st :)
nomadic
if your serious send me a pm and I will put you on the list.
Mike
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I put my name down 1st :)
Hows the weather out there in Hawaii? are you past the rainy season yet
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Can you explain the equation please? Thanks
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Can you explain the equation please? Thanks
Sure thing . . . This equation was provided by "Scotchmo" of GTA.
( ( F1 + F2 ) / 2 x ( L / 12 ) ) x EC "effciency coefficient" = FPE
F1 = Initial Force of Gas Ram in lbs.
F2 = Final Force of Gas Ram in lbs.
L = Stroke Length in Inches
EC = "efficiency coefficient" ( value is .33 for .177 caliber / .35 - .38 for .22 caliber / .37 - .40 for .25 caliber )
EXAMPLE: MOELLER "RED" Gas Ram in a Hatsan 125 in .22 caliber ( 120 mm stroke )
F1 = 158
F2 = 236
L = 4.724 ( Determined by 120 mm divided by 25.4 to convert to inches )
TO SOLVE:
Step 1 - F1 + F2 = 158 + 236 = 394
Step 2 - 394 divided by 2 = 197 ( Average Force )
Step 3 - L / 12 ( L divided by 12 ) = 4.724 divided by 12 = .3936666
Step 4 - 197 x .3936666 = 77.55232
Step 5 - 77.55232 x ( EC "efficiency coefficient" )
Step 6 - 77.55232 x .38 = 29.47 FPE
There you go . . .
Dave
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Thanks tarheel
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Thanks tarheel
You're welcome . . .
The equation is much easier to do, than to explain. Once you have done it a few times, you should be able to learn it and commit it to memory.
We owe a debt of gratitude to Scotchmo, for providing us with this equation !
Dave
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I will be following this too. Would be interested in a gas ram mod,to my 125, to up the fpe a bit with the heavier pellets,and smoother shooting.
I am a toolmaker,and had worked with the nitro springs in the metal stamping industry,but am new to how they are installed into air rifles. Looking to learn here!
Are any mods done to the trigger assembly to strengthen it under the higher loads?
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I will be following this too. Would be interested in a gas ram mod,to my 125, to up the fpe a bit with the heavier pellets,and smoother shooting.
I am a toolmaker,and had worked with the nitro springs in the metal stamping industry,but am new to how they are installed into air rifles. Looking to learn here!
Are any mods done to the trigger assembly to strengthen it under the higher loads?
There have been no trigger mods, yet. Frankly, there have been no reported trigger failures or premature parts wear indicated by any owners of Hatsan / Walther rifles that have been converted to Nitrogen Gas Springs.
If and when the need arises, those issues will have to be looked into. . .
Fortunately, at least for the present, everything appears to be fine. Any future trigger issues will have to be taken up with a true "expert", such as Bob, Gene, Ed, etc, etc, etc., as it is VERY dangerous to modify or alter a trigger, unless you ABSOLUTELY know what you are doing !
Dave
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Looks like it may have STARTED!!!! A FULL MOON is coming!!!!
HOWLING
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At what point would you guys think there is to much force on the quattro trigger
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At what point would you guys think there is to much force on the quattro trigger
When it breaks . . . Sorry, I couldn't resist . . . LOL !
Seriously, from the indications, we may likely reach the "Cocking Effort Limit" before we reach the "Trigger Strength Limit" . . . Mike will be working up in increments, being VERY careful at every step. This is a LOT of force we are talking about and it will not be taken lightly !
From my research, I believe that the MOELLER "YELLOW" may be the "MAX LIMIT", or at least the SAFE LIMIT . . . Further testing will either confirm or deny that.
Stay tuned ( pun intended )
Dave
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Any idea of what the final force of the stock spring is?
Thanks
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Any idea of what the final force of the stock spring is?
Thanks
That is a very good question and one I have been asking on different online forums. Unfortunately, I have never gotten an answer.
It may be possible to determine in by measuring Cocking Effort, but we would also have to be able to calculate the "Mechanical Advantage" of the Barrel / Cocking Arm arrangement.
If Mike can provide accurate data on Cocking Effort throughout the range, with a Gas Ram with a "known value", I can compare the numbers on Data for one with a "Nitro Piston", if someone can provide that data . . . That should get us very close to the numbers for a "factory gas ram" . . .
I wish I could be more precise, right now.
Dave
Dave
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Any idea of what the final force of the stock spring is?
Thanks
When someone opens one up, measure the spring.
free length
installed length
wire diameter
outside diameter
number of coils
We can calculate the force. If that spring is from the most powerful Hatsan, then that would be the maximum safe load for the trigger. Assuming that Hatsan has a safe trigger.
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Any idea of what the final force of the stock spring is?
Thanks
When someone opens one up, measure the spring.
free length
installed length
wire diameter
outside diameter
number of coils
We can calculate the force. If that spring is from the most powerful Hatsan, then that would be the maximum safe load for the trigger. Assuming that Hatsan has a safe trigger.
Scotchmo,
I am hoping that we can get Initial Force and Final Force numbers for the Pyramyd Air "Nitro Piston" . . .
Dave
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Any idea of what the final force of the stock spring is?
Thanks
When someone opens one up, measure the spring.
free length
installed length
wire diameter
outside diameter
number of coils
We can calculate the force. If that spring is from the most powerful Hatsan, then that would be the maximum safe load for the trigger. Assuming that Hatsan has a safe trigger.
Scotchmo,
Obviously, we will be exceeding "factory force numbers" with our gas ram conversions. Otherwise, we would not get a power increase.
Just because that is the "strongest Hatsan spring" does not necessarily mean that it is the "maximum safe load" for the Trigger . . .
After all, Hatsan has a "performance target level" for their rifles, not a "maximum performance" effort, when they make them.
Dave
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Htasn 125 TH .25 Caliber (Only) $169.95 + 25.00 Shipping Special offer (expires on Saturday 04/28Th only 3 left first come fist served.
Call before you place the order only 03 in Stock available for shipping.
John Mello: 954 474 3474
American Arms
http://www.american-armscorp.com (http://www.american-armscorp.com)
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Htasn 125 TH .25 Caliber (Only) $169.95 + 25.00 Shipping Special offer (expires on Saturday 04/28Th only 3 left first come fist served.
Call before you place the order only 03 in Stock available for shipping.
John Mello: 954 474 3474
American Arms
http://www.american-armscorp.com (http://www.american-armscorp.com)
What CALIBERS are available ?
Dave
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Using microsaalmos 32 fpe he got from his hatsan I got that the average amount of force between the two forces would be about 213 pounds
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.25 caliber only 3 left in stock.
Joao
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Using microsaalmos 32 fpe he got from his hatsan I got that the average amount of force between the two forces would be about 213 pounds
Are those "Spring" or "Nitro Piston" numbers ?
What Caliber ?
Dave
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.25 spring using the efficiency at .39
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If someone can post a dimensioned drawing of the Hatsan trigger I'll have a look at it for things such as the shear strength of the sear and the sear pivot pin.... No guarantees, but it's worth a look....
Bob
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Htasn 125 TH .25 Caliber (Only) $169.95 + 25.00 Shipping Special offer (expires on Saturday 04/28Th only 3 left first come fist served.
Call before you place the order only 03 in Stock available for shipping.
John Mello: 954 474 3474
American Arms
http://www.american-armscorp.com (http://www.american-armscorp.com)
What CALIBERS are available ?
Dave
.25 Caliber only.
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Obviously, we will be exceeding "factory force numbers" with our gas ram conversions. Otherwise, we would not get a power increase.
Just because that is the "strongest Hatsan spring" does not necessarily mean that it is the "maximum safe load" for the Trigger . . .
After all, Hatsan has a "performance target level" for their rifles, not a "maximum performance" effort, when they make them.
Dave
Because the gas spring has a more constant force, it is possible to get a power increase while still staying under the trigger load produced by the wire spring.
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Someone sounds "POWER HUNGRY". I thought the point of gas spring conversions was to make a smoother shooting gun. I think modifying for the sake of power could just give you a broken gun.
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GarthThomas,
With all due respect , If you read the whole history of how this post came about, safety has been number one, power secondary but a wanted item or we would not be doing these conversions. Also a belated welcome to the GTA forum. Brent
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If someone can post a dimensioned drawing of the Hatsan trigger I'll have a look at it for things such as the shear strength of the sear and the sear pivot pin.... No guarantees, but it's worth a look....
Bob
Bob,
Unfortunately, I don't know of any dimensioned drawings, "factory" or otherwise. I will do everything I can to find out whatever I can.
Thanks for your help !
Dave
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.25 caliber only 3 left in stock.
Joao
You have a PM and EMail.
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Someone sounds "POWER HUNGRY". I thought the point of gas spring conversions was to make a smoother shooting gun. I think modifying for the sake of power could just give you a broken gun.
Gas rams can smooth out the shooting cycle, last much longer than springs, increase velocity consistency over time, be left cocked for extended times, and reduce overall mechanical noise of the rifle.
Gas rams can, and do, also increase power, through the ability to shoot heavier pellets at higher velocities, by using a higher pressure unit, usually with the goal of staying under 950 fps with the lightest pellet to be used. As a result, FPE can climb dramatically.
My personal goal, for me, is to increase power for hunting. My "target" is 950 fps with 18.1 gr pellets and 860 fps with 22.1 gr pellets . . . Quick Math = 36+ FPE or, in other words an increase of 20%, or higher, in overall power.
Dave
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If someone can post a dimensioned drawing of the Hatsan trigger I'll have a look at it for things such as the shear strength of the sear and the sear pivot pin.... No guarantees, but it's worth a look....
Bob
here you go, notice the one piece is missing click on the links under the picture
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Obviously, we will be exceeding "factory force numbers" with our gas ram conversions. Otherwise, we would not get a power increase.
Just because that is the "strongest Hatsan spring" does not necessarily mean that it is the "maximum safe load" for the Trigger . . .
After all, Hatsan has a "performance target level" for their rifles, not a "maximum performance" effort, when they make them.
Dave
Because the gas spring has a more constant force, it is possible to get a power increase while still staying under the trigger load produced by the wire spring.
I am feeling if I installed the M 90-125 red that I would not want to go to the next yellow, judging by the fps I had of 900 , and the cocking force feeling hefty but reasonable.
the trigger sear may very well take a yellow ram and if some one was strong enough they might not mind the cocking effort being hard at that point but I am just saying I dont see any reason to take it to the next strongest ram above the m90 125 red
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If someone can post a dimensioned drawing of the Hatsan trigger I'll have a look at it for things such as the shear strength of the sear and the sear pivot pin.... No guarantees, but it's worth a look....
Bob
Mike,
I think Bob is looking for a "machinist's drawing" aka "blueprint" of the Trigger Pieces and Assembly with exact measurements labelled on them.
He would then use those dimensions to determine the load on each Trigger component by calculating the "leverage" at each segment of the Trigger Assembly, since the gas ram "Force Rates" are known.
Dave
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If someone can post a dimensioned drawing of the Hatsan trigger I'll have a look at it for things such as the shear strength of the sear and the sear pivot pin.... No guarantees, but it's worth a look....
Bob
Mike,
I think Bob is looking for a "machinist's drawing" aka "blueprint" of the Trigger Pieces and Assembly with exact measurements labelled on them.
He would then use those dimensions to determine the load on each Trigger component by calculating the "leverage" at each segment of the Trigger Assembly, since the gas ram "Force Rates" are known.
Dave
gotch ya .
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The most important calculation will be on the sear which releases the piston.... The critical dimensions are the diameter of the pivot pin, how much material there is around the pin (width and thickness) on the sear and on the trigger box (supporting the pin).... plus the area that is loaded where the sear contacts the piston (on both components).... Those are the parts with the greatest load.... IF those have a sufficient safety margin, then it would pay to do similar calculations on the other intermediate levers and pivot pins....
Bob
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The most important calculation will be on the sear which releases the piston.... The critical dimensions are the diameter of the pivot pin, how much material there is around the pin (width and thickness) on the sear and on the trigger box (supporting the pin).... plus the area that is loaded where the sear contacts the piston (on both components).... Those are the parts with the greatest load.... IF those have a sufficient safety margin, then it would pay to do similar calculations on the other intermediate levers and pivot pins....
Bob
Another thing to remember is that we have several different versions of Hatsan Triggers, both Pre-QUATTRO and of the QUATTRO trigger itself.
Dave
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The most important calculation will be on the sear which releases the piston.... The critical dimensions are the diameter of the pivot pin, how much material there is around the pin (width and thickness) on the sear and on the trigger box (supporting the pin).... plus the area that is loaded where the sear contacts the piston (on both components).... Those are the parts with the greatest load.... IF those have a sufficient safety margin, then it would pay to do similar calculations on the other intermediate levers and pivot pins....
Bob
Bob,
I hope we don't have to know the specific alloys and heat-treat-specs ( if any ) of the various pins and components, as I fear that data might never be available to us.
Dave
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If we have to get into alloys to have a suitable safety margin.... then I would suggest we don't.... I will work with the numbers for mild steel....
Bob
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you know it seems to me once the spring or piston is cocked that force now being at a rest while the sear is ingaged simply just stays locked
its designed to do so, it would have to break in order for it to fail, its not going to slowly pop up and skip off its not designed that way.
As long as it has been cocked and no one has touched the trigger so it is in the normal position.
I would say the force we are talking about on the yellow will not bother the sear at all
normally things are designed for much much higher values of strength when it comes to part like that.
I say on some models the rifle barrels cocking arms may bend before anything else would fail.
the hatsan are built very well, same for the wfh.
only thing I see on the wfh if the gas ram was installed would be to hold it right below the safety when you cock it so no pressure is put on the butt end of the stock, especially if it is a older model like mine