Resin casting stampede gears.

So guys, i had this brilliant idea, and want to know if you guys think it would work. You know how the stampede gears have a tendency to break when overvolted (It's happened to one of mine, and there's a few other cases i've heard of)? What if we resin cast our own? Even if it's not stronger (though i imagine it would be), it means we can replace the broken ones when they break. Otherwise, i'm seriously contemplating casting them in aluminium... Opinions?

Really? How much voltage have you put through it? It seems that it's not the 'voltage' that hurts the gears, it's the spring upgrade <,<. However, the stampedes I have modified have lasted for more than 5-6 wars.

Uh....you know resin is FRAGILE, right? At least FW resin is, which, judging by your avatar, is what you'd be familiar with. If it's fibreglass resin, then sure, it'll be stronger.

littlebro05 wrote:Really? How much voltage have you put through it? It seems that it's not the 'voltage' that hurts the gears, it's the spring upgrade <,<. However, the stampedes I have modified have lasted for more than 5-6 wars.

My one had a 13-14kg spring running at 12v, and a mate of mine had a stock spring running at 16.8v. It's got to do with the amount of torque going through the gearbox which should be independent of the spring and dependent on the voltage.

Brunius wrote:Uh....you know resin is FRAGILE, right? At least FW resin is, which, judging by your avatar, is what you'd be familiar with. If it's fibreglass resin, then sure, it'll be stronger.

Judging by my avatar? right...
I'm not too familiar with resin, i will admit. I had intended on doing more research before implementing this idea, i was just wondering what other people had to say.

Ungodlyfreak wrote:

Brunius wrote:Uh....you know resin is FRAGILE, right? At least FW resin is, which, judging by your avatar, is what you'd be familiar with. If it's fibreglass resin, then sure, it'll be stronger.

Judging by my avatar? right...
I'm not too familiar with resin, i will admit. I had intended on doing more research before implementing this idea, i was just wondering what other people had to say.

Hmm. I thought I remembered the picture from Warhammer or something. My bad.

Brunius wrote:Hmm. I thought I remembered the picture from Warhammer or something. My bad.

Ohhh, right. hahaha, my bad. Yeah, it's warhammer related, but i haven't done any casting with resin yet. Golly i sure feel silly now.

Ungodlyfreak wrote:

littlebro05 wrote:Really? How much voltage have you put through it? It seems that it's not the 'voltage' that hurts the gears, it's the spring upgrade <,<. However, the stampedes I have modified have lasted for more than 5-6 wars.

My one had a 13-14kg spring running at 12v, and a mate of mine had a stock spring running at 16.8v. It's got to do with the amount of torque going through the gearbox which should be independent of the spring and dependent on the voltage.

Mate this is incorrect.

The gearbox re cocks the spring, and the strength of the spring is directly related to the amount of torque required to do so.

Therefore heavier spring = higher torque levels in gearbox, motor, etc.

The increased voltage may also contribute to peaks in torque, partially by compressing the spring quicker and also by allowing the use of even heavier springs.

I have also broken one set of gears, but it was due to incorrect assembly/alignment.

One mod that may be worthwhile would be to epoxy the 2 large gears that slot together to avoid slipping.

I wouldn't think that resin will much good, compared to the standard gears.

If I was to try replacements (which I wouldn't bother with at this stage), I'd go for brass replacements from some kind of specialist supplier, possibly in the US.

There's not much point as after 16.8v, the thing doesn't fire/load reliably in most cases.

oznerfnerd wrote:
Mate this is incorrect.

The gearbox re cocks the spring, and the strength of the spring is directly related to the amount of torque required to do so.

Therefore heavier spring = higher torque levels in gearbox, motor, etc.

The increased voltage may also contribute to peaks in torque, partially by compressing the spring quicker and also by allowing the use of even heavier springs.

I have also broken one set of gears, but it was due to incorrect assembly/alignment.

One mod that may be worthwhile would be to epoxy the 2 large gears that slot together to avoid slipping.

I wouldn't think that resin will much good, compared to the standard gears.

If I was to try replacements (which I wouldn't bother with at this stage), I'd go for brass replacements from some kind of specialist supplier, possibly in the US.

There's not much point as after 16.8v, the thing doesn't fire/load reliably in most cases.

When i think about it, i'd say your right. Oh yeah, i've been doing some research, and i think casting aluminium or getting them laser cut would be the best and cheapest options. I'm leaning toward casting though. If i can get my hands on some casting equipment, i can start casting more than gears. Stuff like plunger rods, heads, trigger catches, hell even entire shells. Just to be completely nuts about things. LOL 30kg LONGSHOT DERPDERP

Ungodlyfreak wrote:

oznerfnerd wrote:
Mate this is incorrect.

The gearbox re cocks the spring, and the strength of the spring is directly related to the amount of torque required to do so.

Therefore heavier spring = higher torque levels in gearbox, motor, etc.

The increased voltage may also contribute to peaks in torque, partially by compressing the spring quicker and also by allowing the use of even heavier springs.

I have also broken one set of gears, but it was due to incorrect assembly/alignment.

One mod that may be worthwhile would be to epoxy the 2 large gears that slot together to avoid slipping.

I wouldn't think that resin will much good, compared to the standard gears.

If I was to try replacements (which I wouldn't bother with at this stage), I'd go for brass replacements from some kind of specialist supplier, possibly in the US.

There's not much point as after 16.8v, the thing doesn't fire/load reliably in most cases.

When i think about it, i'd say your right. Oh yeah, i've been doing some research, and i think casting aluminium or getting them laser cut would be the best and cheapest options. I'm leaning toward casting though. If i can get my hands on some casting equipment, i can start casting more than gears. Stuff like plunger rods, heads, trigger catches, hell even entire shells. Just to be completely nuts about things. LOL 30kg LONGSHOT DERPDERP

Even better? Lonshot full brass breech cast with the metal boltsled. I'd pay hundreds for that.

-James

Hey when you give the foundry plans for the NF make sure you scale everything up by 1000% because I want to spend hours priming it and be able to inflate a dinghy with a single shot.

mister_elliott wrote:Hey when you give the foundry plans for the NF make sure you scale everything up by 1000% because I want to spend hours priming it and be able to inflate a dinghy with a single shot.

Ahahahahaha, nice.

I have modded at least 8 stampedes and not had a problem but i will not run mine above 11.1v.

Some points:

- Fiberglass resin is super hard, hence it will crack/break easily. The glass fiber is what makes it strong and durable.
- You cannot add glass fiber to something that small and expect it to work.
- Casting resin is a bit better as its more flexible but i would not use it for cast cogs either (Same reason)
- The Stampede gearbox is open to the body internals so if you get anything in there (offcuts of plastic from hacking your shell appart or dirt, you will have an increased chance of causing damage to the gears.

Best bet would be to either find a type of castable nylon (hard and flexible etc (I know of none and i cast in resin)) or locate a direct replacement (Broken stampede anyone? lol).

Cheers.

I actually know a bloke with his own foundry who casts alu on an almost daily basis. I will have to rip the g'box out of one of my 'pedes and run it over to him and see what he thinks.
Problems I can see already though is the gears need to be bulked out before the molds are made to allow for shinkage and teeth on the gears will need to be file finished and my not even cast correctly if they are too fine ( I have not had a gear box out of a 'pede as yet).
Cost wise, It will cost $50 just to fire up the furnace as well as molding and material costs so I could get expensive unless I can get several gearboxs molded in one frame it could get very expensive.

Dietzie wrote:I actually know a bloke with his own foundry who casts alu on an almost daily basis. I will have to rip the g'box out of one of my 'pedes and run it over to him and see what he thinks.
Problems I can see already though is the gears need to be bulked out before the molds are made to allow for shinkage and teeth on the gears will need to be file finished and my not even cast correctly if they are too fine ( I have not had a gear box out of a 'pede as yet).
Cost wise, It will cost $50 just to fire up the furnace as well as molding and material costs so I could get expensive unless I can get several gearboxs molded in one frame it could get very expensive.

Will be watching this thread for replies, keep us updated, I'm interested in getting stronger gears, I've already been through one stampede that had one of its gears teeth torn off.

It will take me some time to get all the details sorted between not having a car for at least a month and work but if I can make something happen I'll let everyone know

My modded Stampede had a heavier spring - not sure of the exact strength unfortunately, the eBay seller just calls it a 2x power spring so it's possibly 6kg or so, and I had a 14.7v LiPo battery charged to nearly 16v which wrecked the gearbox 'somehow' - i'm not sure of the exact problem because when I took it out there didn't appear to be any visible damage and the gears span fine, but when I swapped it for a new gearbox and dropped to an 11v battery the gun was functional again...

I put the busted gearbox in the donor Stampede and it no longer works, confirming that the gearbox WAS the problem but I still have no idea what the specific damage was. :S can anyone shed light on that at all?

If your going to make the COGS stronger, then you might need to consider making a metal back plating for the spring to nest on because mines broken and i was using a 12v with a triple shot spring.

Captain Crooks wrote:My modded Stampede had a heavier spring - not sure of the exact strength unfortunately, the eBay seller just calls it a 2x power spring so it's possibly 6kg or so, and I had a 14.7v LiPo battery charged to nearly 16v which wrecked the gearbox 'somehow' - i'm not sure of the exact problem because when I took it out there didn't appear to be any visible damage and the gears span fine, but when I swapped it for a new gearbox and dropped to an 11v battery the gun was functional again...

I put the busted gearbox in the donor Stampede and it no longer works, confirming that the gearbox WAS the problem but I still have no idea what the specific damage was. :S can anyone shed light on that at all?

Are the 2 gears that press together slipping?

This can happen to blasters with heavy springs/high voltages.

If it is, the trick is to glue them together with super strength 2 part epoxy and let it cure for 3 days.

Make sure you clean it properly with metho before glueing and press them into position correctly while the epoxy is wet.

It's worth a go.

I to can say that running bigger springs in these guns burn out the box. I bought one last night, decided to play with it tonight and well, its very dead. I used an 11kg spring in mine, which seamed fine except it just kept on firing. after looking about found some info on upgrading several smaller return springs. I tested what would happen if i used the plunger spring as the breach return spring (the black one u can see through the clear slide) I think at that time I striped the 12 tooth gear in the box. Oh, the plunger spring is a c-836 from bunnings. I have put one into my long shot also and its working very well, I will bulk up the sled tomorrow in that.
The big question is "where do i find another gear??!!"

You guys have asked for it.!!!!
here it is!
http://www.oznerf.com/t4481-nerf-stampede-gears#78124