Crosman Air Pistol Owners Forum

Crosman air pistol - General => Crosman air pistol - General discussion => Topic started by: mr007s on September 26, 2012, 11:23:07 PM

Title: Need a Measurement
Post by: mr007s on September 26, 2012, 11:23:07 PM
 Need some help guys. A member here has one of my caps made for a 2400KT, one that has the rod in the end of the cap to push the powerlett against the valve. The air tube on this model is 1 5/8" longer than a 2240 so it stands to reason the rod would be that long to take care of the extra length. I have sold a few of these and always fab the rod to extend from the face 1 5/8 inches. For reasons we cant figure he has a leak issue with my cap but not the stock cap.
If those of you that have a model Crosman with the long tube and a stock cap could post a very accurate measurement of the rod it would help a great deal. I am having the cap returned to me for evaluation but would like to have measurements from several guns to verify that the length I am using is acceptable.
Thanks guys for any help you can provide, I appreciate it.
Title: Re: Need a Measurement
Post by: Crosshairs on September 26, 2012, 11:59:02 PM
I check two guns and i get 1 5/8". And one of them is yours.
                                           Mike
Title: Re: Need a Measurement
Post by: 1377x on September 27, 2012, 12:06:14 AM
ask the buyer if he has some duct tape.have them build up the tape on the bottom of the cart.if that seals it,have them send you back the cap with the cart with the built up tape.better yet if they have some washers that fit the id of the tube with the id hole smaller than the rod put one in if it seals then you know how much more rod is needed.
have them send back the problematic cap for inspection
Title: Re: Need a Measurement
Post by: chongman on September 27, 2012, 12:19:42 AM
I measured the stock Crosman rod  and got  1.564".  Your tri-wing rod is 1.624". No leaks  :-*
Title: Re: Need a Measurement
Post by: arkmaker † on September 27, 2012, 12:28:42 AM
Quote from: chongman on September 27, 2012, 12:19:42 AM
I measured the stock Crosman rod  and got  1.564".  Your tri-wing rod is 1.624". No leaks  :-*


1.564" on my stock cap as well, which confirms Chongman. If your cap rod sticks out .062 longer there should be no problem with the cap. Front valve seal may be shot??
Title: Re: Need a Measurement
Post by: 0351_Vet on September 27, 2012, 12:40:23 AM
1.566 & 1.567 on the other, is what I got,
so we are in the ball park for factory stuff.  :-*
Title: Re: Need a Measurement
Post by: 0351_Vet on September 27, 2012, 12:41:32 AM
BTW 007 - I need one with the rod in SS Long. (When you get a chance).  :-*
Title: Re: Need a Measurement
Post by: mr007s on September 27, 2012, 12:50:43 AM
Quote from: 0351_Vet on September 27, 2012, 12:41:32 AM
BTW 007 - I need one with the rod in SS Long. (When you get a chance).  :-*

Hey Vet, I can help you first of next week. Pm me with which and what you need and we will proceed.
Title: Re: Need a Measurement
Post by: 0351_Vet on September 27, 2012, 12:52:23 AM
Quote from: mr007s on September 27, 2012, 12:50:43 AM
 

Hey Vet, I can help you first of next week. Pm me with which and what you need and we will proceed.

Will do....Thanks  :-*
Title: Re: Need a Measurement
Post by: mr007s on September 27, 2012, 12:56:47 AM
Quote from: arkmaker on September 27, 2012, 12:28:42 AM

1.564" on my stock cap as well, which confirms Chongman. If your cap rod sticks out .062 longer there should be no problem with the cap. Front valve seal may be shot??

Yes Art, I am wondering if he has valve seal issues as well. But his stock cap works and seals without a leak. He has to really crank down on mine he says. I make the rod from 3/8" diameter stock. Wonder if I should go up to 1/2" for more contact with the cart?
He is mailing the cap back for my inspection.
I think I will start going with 1.565 to 1.6 for the next couple caps and see if any issues arise.
Title: Re: Need a Measurement
Post by: eric on September 27, 2012, 01:08:58 AM
Quote from: 1377x on September 27, 2012, 12:06:14 AM
ask the buyer if he has some duct tape.have them build up the tape on the bottom of the cart.if that seals it,have them send you back the cap with the cart with the built up tape.better yet if they have some washers that fit the id of the tube with the id hole smaller than the rod put one in if it seals then you know how much more rod is needed.
have them send back the problematic cap for inspection
a dime or two should work if the seal isn't shot .....
Title: Re: Need a Measurement
Post by: arkmaker † on September 27, 2012, 01:24:28 AM

He has to really crank down on mine he says.

Makes me think even more that the seal is brittle. The rod may have shifted slightly also. If that is the case, then it could be pushing the cart to one side so that the tip of the cart is hitting at an angle. Hence the leak and him cranking down harder in order to make the seal all the way around??
When you get it back the simple test for that would be to roll the shaft on a table with the cap hanging off the edge. If it is crooked, you will see the cap wobble a bit as you roll the shaft.

Title: Re: Need a Measurement
Post by: mr007s on September 27, 2012, 01:40:24 AM
Quote from: arkmaker on September 27, 2012, 01:24:28 AM
He has to really crank down on mine he says.

Makes me think even more that the seal is brittle. The rod may have shifted slightly also. If that is the case, then it could be pushing the cart to one side so that the tip of the cart is hitting at an angle. Hence the leak and him cranking down harder in order to make the seal all the way around??
When you get it back the simple test for that would be to roll the shaft on a table with the cap hanging off the edge. If it is crooked, you will see the cap wobble a bit as you roll the shaft.

I will do that. When the rod is installed I check alignment with a dial indicator to make sure all is straight. If it is crooked now it will probably have been bent. The rod is coated with red loc-tite and pressed in place .300" deep when they are assembled.

Is the stock rod 3/8" OD? 1/2" OD?
I am thinking a 1/2" would contact more area of the cart and stabilize it better.
Title: Re: Need a Measurement
Post by: arkmaker † on September 27, 2012, 02:04:34 AM
.312" diameter and cupped on the end
Title: Re: Need a Measurement
Post by: mr007s on September 27, 2012, 02:15:13 AM
Quote from: arkmaker on September 27, 2012, 02:04:34 AM
.312" diameter and cupped on the end

Thanks Sir. I also cup mine.
Title: Re: Need a Measurement
Post by: 0351_Vet on September 27, 2012, 02:54:50 AM
Quote from: arkmaker on September 27, 2012, 02:04:34 AM
.312" diameter and cupped on the end

You beat me to it...photos and all. Great job.  :-*
Title: Re: Need a Measurement
Post by: 1377x on September 27, 2012, 04:09:47 AM
this is the first i have heard about an issue with one of your caps
i am interested in the outcome im thinking of adding a 2400 to the arsenal.
Title: Re: Need a Measurement
Post by: eric on September 27, 2012, 04:17:32 AM
Quote from: mr007s on September 27, 2012, 01:40:24 AM
I will do that. When the rod is installed I check alignment with a dial indicator to make sure all is straight. If it is crooked now it will probably have been bent. The rod is coated with red loc-tite and pressed in place .300" deep when they are assembled.

Is the stock rod 3/8" OD? 1/2" OD?
I am thinking a 1/2" would contact more area of the cart and stabilize it better.
i might use grease or something to allow the gas cap to turn more freely when pressure is applied rather than have the two pieces be/act as one
Title: Re: Need a Measurement
Post by: Fronzdan on September 27, 2012, 04:18:42 AM
I got 1.565" length and 0.309" diameter.

Title: Re: Need a Measurement
Post by: mr007s on September 27, 2012, 10:59:10 PM
Thanks for all the helpful info. I will make the next couple rods 1.575 to bring them more in line with the factory cap. Decided to stay with 3/8 Diameter instead of going to 1/2.
Title: Re: Need a Measurement
Post by: BDS on September 27, 2012, 11:22:55 PM
1.565" on mine!

Your adapter with .060" length of "squish" of the cartridge to seal s/b fine?