7 replies to this topic

[ravetrooper]

CALLING ALL STAMPEDE EXPERTS!

I finished the internal mods for my first Stampede (almost) and I'm painting it this week. Sadly I ran into the dreaded bump-fire or "Runaway Stampede Syndrome" and did a ton of research and troubleshooting until I found a fix. As of now, it is working fine. I ended up finding the actual cause and it is the plunger/breach assembly recoiling and pushing the white piece (pictured below) into the trigger button which puts it in the nearly endless cycle. I "fixed" it by placing an extra spring in the trigger button so the recoil doesn't push it as easily.

My questions are:

A. Why is the part that collides with the plunger assembly even there? and

B. Is it somehow essential for blaster function? or

C. Can I just cut it off and leave the rest intact?

Even though it's working right now I feel like this could potentially be a permanent fix. (Once I put this back together I never want to have to open it again )

Here is the piece of which I speak.

Edited by ravetrooper, 09 March 2015 - 10:52 PM.

[snakerbot]

B. Is it somehow essential for blaster function?

Yes. That switch getting pushed by the plunger tube is the cycle control. Without it, whenever you release the trigger, the blaster wouldn't complete a cycle. Basically, when you first pull the trigger, that switch closes, which starts the motor moving. The plunger tube then pushes that white piece, so that even if you let go of the trigger, it will finish at least one cycle. Once it's done firing, the cycle spring around the breech pushes the bolt back which opens this switch and stops the motor. You need that piece.

[Aeromech]

This image shows the location of two springs you will need to replace with stronger ones in order for the stampede to function at higher voltages and RPMs. That is all. This is the solution.

EDIT: All the parts that you mentioned are there for a reason and if you play for it long enough you can discover the functions for yourself. Every part does something .

Edited by Aeromech, 10 March 2015 - 09:38 AM.

[MAV13]

Don't cut it off, it will work without it but you will have to manually time your shots. First try replacing the spring on the switch, then shave it down until the problem goes away rather than cutting it clean off. You can retain the ability to single shot properly while eliminating the runaways.

[ravetrooper]

Thanks so much for the responses everyone! I had already replaced the springs mentioned and I'm glad to know what that piece does. I guess it should be fine then

[racer188]

I'd like to add one more thing of concern for the Stampede. On mine I discovered there is one more spring that causes the bump fire even after replacing the one on the switch and the catch spring.

I used this, Blasterlabs

This spring is hidden underneath the slider where the catch is. The original one was way too weak.

Here is the link that explains it, link

Bump fire is now 100% gone on my Stampede. Mine is shorten, brass (angel) breeched, gears reinforced, and running off 4 trustfires.

Edited by racer188, 10 March 2015 - 11:58 PM.

[ravetrooper]

I'd like to add one more thing of concern for the Stampede. On mine I discovered there is one more spring that causes the bump fire even after replacing the one on the switch and the catch spring.

I used this, Blasterlabs

This spring is hidden underneath the slider where the catch is. The original one was way too weak.

Here is the link that explains it, link

Bump fire is now 100% gone on my Stampede. Mine is shorten, brass (angel) breeched, gears reinforced, and running off 4 trustfires.

Yes, I forgot. I found and reinforced that one too. The ballpoint pen sized spring right?

[racer188]

Yes, I forgot. I found and reinforced that one too. The ballpoint pen sized spring right?

Yup that's the one.