Video of impulse ram 98: https://vimeo.com/418455605
Ever since I was a young man in 2003, I was fascinated with the e-bolted 98. Seeing guys from tippmann effect going toe to toe with the big boys always blew my mind. At the time it was hard to justify spending $300 on a GTA kit or psychoballistics kit and I never got around to it. Fast forward 15 years and I have an original factory GTA ebolt 98 and just couldn't bring myself to hack it up trying to make a fast 98 with eyes and matrix parts.
There are a few options out there for sourcing an electropneumatic 98 ram:
1:buy a ram from a kit. This is usually expensive and they are uncommon. Expect to spend at least $80 IF you can find one. Then invest more time and money in making the ram air returned to make the ram capable of more than 13 or so BPS.
2:get a machinist to make you one. This is also an expensive process and I messaged a few people about it who claimed to be making some. Unfortunately, nobody would make me one.
3:Retro fit a ram from another marker. I chose this option.
Remembering how large in diameter an impulse ram was, I figured it was a good start. Found one on ebay for $13 shipped and went to work.
First thing I had to do was block off two holes the ram uses for air forward stroke and air return stroke in the impulse body. There are two at the bottom of the ram and two at the top. I only need one hole for each. Drilled and tapped the top holes for 10-32 and put plugs in them. Drilled and tapped the bottom holes for 10-32 so I could use standard cocker barbs/qevs.
Second issue was trying to figure out how to secure the ram in the body. I've seen guns in the past use screws to secure a ram housing in a body such as the ICD BKO, alien interceptor, alien remains. I drilled and tapped two holes on the right side of the ram for 10/32 threads so I could use two machine screws to secure it. [IMG]
upload pictures[/IMG]
The impulse ram is slightly smaller than the inner diameter of the 98 body, So I made a round spacer out of aluminum. Think it was 1/16'' flat stock and I bent it around a socket to get it perfectly round. Used a couple 114 o-rings around the ram on either side of the spacer to keep it from shifting and also help pinch the ram in the receivers. With just the o-rings and no spacer, the ram was held in the receivers very tightly and wouldn't move. This is ideal because I really wanted to limit the stress on the screws securing it in the body. [IMG]
upload pictures[/IMG]
To decide exactly where I wanted to mount the ram in the body I placed a valve body in the receiver and set the ram so that at the end of it's stroke, it would be holding the valve pin fully open.
I removed a bunch of material from the inside of both receiver halves to I could fit my board and solenoid and QEVs/barbs. I had several 2 way solenoids laying around and considered using an intimidator noid, but the cyclic rate of a humphrey noid is about 23 bps and the physical dimensions of the noid make it a tight fit. Used a mac 43 noid instead. The mac noid is the 4.7 watt variant and draws a massive amount of current. Most boards will simply shut off when they try to fire it. Only boards I know of that will run it are 07 ego boards and 05/06 ego tadao boards and some others. I used a 16v 2200uF capacitor to store energy for the solenoid. I have a good supply of dm4/5/c boards kicking around and was going to use that to drive the solenoid. I used a scenario dreams DMT chip. Here's the first testing of the board, solenoid, capacitor driving the ram. I used a QEV on the forward stroke of the ram to help move air from in front of the ram faster so it would have more energy going forward, thus striking the valve with more force and allowing a lower operating pressure than if using a barb. Using an old palmers rock LPR to feed the noid.
After determining that the system was going to work, I set about getting my linkage right in the body for the front bolt. Drilled a hole in the top of the aluminum impulse hammer making sure that it wasn't going to hit the top of the plastic valve body when wide open, then bent a shorter linkage rod out of some brass rod. Mounted everything up and it started looking like a functional gun! [IMG]
upload pictures[/IMG]
Test firing the setup proved to be a great success. LPR is at 160 due to the low mass of the hammer as opposed to 110 psi on the GTA e-bolt with the same valve setup. At first I was a bit concerned with the high pressure, but after some speculation on the high operating pressure of the impulse, shocker, and countless other guns that don't use LPRs, I determined it would be just fine. Here it is firing over a chrono using a huge .695 barrel and tiny .680 paint. https://vimeo.com/343868945
If anyone has any questions, pm me or post here. Glad I took the time to not only build this funky thing, but share it with you guys on the forum. With everything going to facebook now, it's very hard to find any information and special projects and builds are usually lost forever after the first month of viewing. Hopefully this post will be accessible for a long time and will serve others well.
Ever since I was a young man in 2003, I was fascinated with the e-bolted 98. Seeing guys from tippmann effect going toe to toe with the big boys always blew my mind. At the time it was hard to justify spending $300 on a GTA kit or psychoballistics kit and I never got around to it. Fast forward 15 years and I have an original factory GTA ebolt 98 and just couldn't bring myself to hack it up trying to make a fast 98 with eyes and matrix parts.
There are a few options out there for sourcing an electropneumatic 98 ram:
1:buy a ram from a kit. This is usually expensive and they are uncommon. Expect to spend at least $80 IF you can find one. Then invest more time and money in making the ram air returned to make the ram capable of more than 13 or so BPS.
2:get a machinist to make you one. This is also an expensive process and I messaged a few people about it who claimed to be making some. Unfortunately, nobody would make me one.
3:Retro fit a ram from another marker. I chose this option.
Remembering how large in diameter an impulse ram was, I figured it was a good start. Found one on ebay for $13 shipped and went to work.
First thing I had to do was block off two holes the ram uses for air forward stroke and air return stroke in the impulse body. There are two at the bottom of the ram and two at the top. I only need one hole for each. Drilled and tapped the top holes for 10-32 and put plugs in them. Drilled and tapped the bottom holes for 10-32 so I could use standard cocker barbs/qevs.
Second issue was trying to figure out how to secure the ram in the body. I've seen guns in the past use screws to secure a ram housing in a body such as the ICD BKO, alien interceptor, alien remains. I drilled and tapped two holes on the right side of the ram for 10/32 threads so I could use two machine screws to secure it. [IMG]
upload pictures[/IMG]The impulse ram is slightly smaller than the inner diameter of the 98 body, So I made a round spacer out of aluminum. Think it was 1/16'' flat stock and I bent it around a socket to get it perfectly round. Used a couple 114 o-rings around the ram on either side of the spacer to keep it from shifting and also help pinch the ram in the receivers. With just the o-rings and no spacer, the ram was held in the receivers very tightly and wouldn't move. This is ideal because I really wanted to limit the stress on the screws securing it in the body. [IMG]
upload pictures[/IMG]To decide exactly where I wanted to mount the ram in the body I placed a valve body in the receiver and set the ram so that at the end of it's stroke, it would be holding the valve pin fully open.
I removed a bunch of material from the inside of both receiver halves to I could fit my board and solenoid and QEVs/barbs. I had several 2 way solenoids laying around and considered using an intimidator noid, but the cyclic rate of a humphrey noid is about 23 bps and the physical dimensions of the noid make it a tight fit. Used a mac 43 noid instead. The mac noid is the 4.7 watt variant and draws a massive amount of current. Most boards will simply shut off when they try to fire it. Only boards I know of that will run it are 07 ego boards and 05/06 ego tadao boards and some others. I used a 16v 2200uF capacitor to store energy for the solenoid. I have a good supply of dm4/5/c boards kicking around and was going to use that to drive the solenoid. I used a scenario dreams DMT chip. Here's the first testing of the board, solenoid, capacitor driving the ram. I used a QEV on the forward stroke of the ram to help move air from in front of the ram faster so it would have more energy going forward, thus striking the valve with more force and allowing a lower operating pressure than if using a barb. Using an old palmers rock LPR to feed the noid.
After determining that the system was going to work, I set about getting my linkage right in the body for the front bolt. Drilled a hole in the top of the aluminum impulse hammer making sure that it wasn't going to hit the top of the plastic valve body when wide open, then bent a shorter linkage rod out of some brass rod. Mounted everything up and it started looking like a functional gun! [IMG]
upload pictures[/IMG]Test firing the setup proved to be a great success. LPR is at 160 due to the low mass of the hammer as opposed to 110 psi on the GTA e-bolt with the same valve setup. At first I was a bit concerned with the high pressure, but after some speculation on the high operating pressure of the impulse, shocker, and countless other guns that don't use LPRs, I determined it would be just fine. Here it is firing over a chrono using a huge .695 barrel and tiny .680 paint. https://vimeo.com/343868945
If anyone has any questions, pm me or post here. Glad I took the time to not only build this funky thing, but share it with you guys on the forum. With everything going to facebook now, it's very hard to find any information and special projects and builds are usually lost forever after the first month of viewing. Hopefully this post will be accessible for a long time and will serve others well.
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