ultraking

Which leads me to my next question, what kind of weight do you think these E-maxx's could carry. I know you say that it could be torqued down, how hard is that to do? Again, RC Super N00b (although learning very fast through this process). We have found some cameras through a security company that will do about a three mile range, and even 1 mile or more through steel in buildings. The downside is that the transmitter ways about 2 pounds. From the performance specs I've seen I dont think a couple of pounds in the chasis would be a big deal, but what are your thoughts. What do you think the max weight we could get away with would be? We are in the process now of seeing if we can get a couple of these donated from Traxxas so we can get started with testing, so in the meantime, I will continue to count on you guys. We talked to the Chief and the SWAT team commander yesterday and they are starting to get pumped about the idea since it looks like its gonna happen. As I said, we are a small town, so being able to do something like this on the cheap that might be able to make our officers safer is just plain awesome, not to mention the cool factor. I know I'm rambling, but when you think about the weight issues, try to think about the roll cage too and how that will factor in to overall performance. Even if this thing only does a top speed of 5-10Mph, that is more than sufficient. If it went faster than that, I'm sure we would put some sort of dampener on it anyway, so that is just fine. Thanks guys, I will keep you updated and do some pictures once we get started.

ultraking

And another thing we have been thinking about. Obviously the E-Maxx is very stable, I watched the video on the 2coolRC site of the on-board camera on an E-Maxx where the driver flipped it off a ramp and it rolled back on its feet, but how could we design the rollcage or mod it to where it was almost impossible to be left upside down or immobile. There has a to be a way to ensure that 99% of the time this thing is gonna stay in the upright position and ready for action. What are you thoughts on this?

aliens8mycow

Weight shouldn't be a huge factor. Some of the custom all aluminum conversions with jumbo tires weigh in around 14 pounds. If it ends up getting heavy, there are better brushless motor choices out there with all the torque and power you'll need. There are also 'wide' conversions that will make the truck about an inch or two wider that would aid in stability. I don't know the best companies to look at for those, but there are a lot of maxx guys around here, and I'm sure someone will chime in.

Gearing for torque is about the simplest of all the customizations ahead of this truck - simple change of gears at a cost of about $10. The maxx has a 2 speed transmission, too (I think), so you would have the ability to have a 'crawler' speed and with the push of a button shift into a higher speed.

Speedmunkey

A buddy of mine is building/testing an E-Maxx based crawler right now. He is running a 55 turn lathe motor and has MASSIVE gear reduction on the thing. If the tires could get enough traction the thing could easilyy drag 50-60lbs..

another item for the shopping list:
Beadlock wheels

I'm not saying you'll be rock crawling, which is the primary use for the wheels, but they'll let you easily replace your tires in the future instead of buying new wheels or trying to remove the old tires and reuse the rims. A worthwhile useage of money.

As for your self-righting idea, I think we can draw from the world of Battlebots for that answer. An extenable rod could be used to flip the truck back over. I've seen it work for a 40-50lb battle bot, no reason it won't flip a 15lb E-Maxx over as well.

Also, I agree on the airplane radio. With items such as the righting rod, a camera swivel, tear gas dispenser (I LOVE that idea and I'm not joking. Imagine carrying a TG canister or a flashbang into a situation, popping it off in perfect sync with your team moving in? Yeah, I can see that being a VERY good thing.) you are going to need more than a 3 channel radio system.

Something that crossed my mind is noise. Electric trucks aren't NEARLY as loud as nitro, but they still make noise. I wonder if you could insulate the transmission and motor area to supress the noise? Hearing it from 10' away shouldn't be a problem, but 30-40' away would be.

I suggested the steel body as a joke initially, but after thinking about it, I think bullet proofing it would be a wise thing. Can you imagine some thug taking shots at our little rover? It's gonna need some kevlar! Otherwise, you might have a rover down after it's all over. I know a guy locally that is making oval racing bodies out of 1/8" lexan. I'll talk to him and see if he can handle 1/4 or 3/8 and do something custom. Worst case, we put lexan plates directly onto the rollcage. Anyone know of lighter bullet resistant material?

ultraking

All very cool ideas, but remember, cost is still an issue, unless somebody is willing to donate time and parts. We do have a web site though and we could be putting some sponsors and that type thing on it if they are willing to contribute to the cause. Not to mention that I'm sure there are some RC magazines and things like that out there that would probably be intersted in doing a story on this if it comes out right. Just food for thought.

ultraking

All of that is very cool, but keep in mind, there is a cost ceiling on this project, so we have to stick to the mission with as low a price as possible. If it was up to me, we would mount a SAW machine gun on it and shoot stuff up, but again, there has to be limits (unfortunately). I will entertain any possibility of modding the body so it is more impervious to harm though, we dont wanna have to rebuild this thing every time it goes out on a mission, but I believe we will be able to insure it as a piece of police equipment when it is done, so that should help.

Speedmunkey

The guy I'm talking about would be cheap actually. He carves a body out of wood and uses that in his vaccum mold. All he'd need to do is for an existing body is pour one full of plaster, then he'd have an instant mold. $100 at most I'd say, and with 1/4" or 3/8" lexan, you won't ever need a new one lol!

The bar would be fairly inexpensive, probably $1-200for the pneumatics involved.. I say we let Sleepy design that one

A decent 5 channel radio is less than $200, a 6 channel is about $250..

The roll cage should be about $200

Beadlocks are a BIT pricey, so we could scrap those if you can't swing em. Just add lots of CA glue to the budget..

Rccarfreak33

sleepy23
sorry to get of toic but haha yea i remember that seen in badboys 2 this is just like it but i thik it was a txt-1 instead of an emaxx.

ultraking

Wow, those actually sound like decent prices Speedmunkey, I have passed that on and it might be doable once we get going on this!

sleepy23

My Feedback: (1)

pneumatic bar....piece of cake, maybe 100 bucks worth of materials (depending on donations). the only thing is you will have to carry atleast a small paintball gun air tank, those little cartriges wont get it done...

the more i think about the emaxx, the more i realize that with the mods needed, its almost a waste of money to buy a new truck, just really only need a roller. i would remake the chassis out of aluminum and skin it with kevlar. you need aluminum a-arms, if upping the weight, might want to redesign to do dual steering servos. unless you just had to have 2 gears, i would replace the gearbox with a gear reduction unit.
and finally, i dont think i would try to much of it without having a cad design

Speedmunkey

I dunno, you can do MOST of the stuff to a fairly stock E-Maxx. Throw on a steering servo with huge torque, like the one Cen uses in their big monster truck (like 200oz of torque) and it'll turn anything you want. Heck, that would probably steer my Chevy out in the parking lot lol

ultraking

So, you're saying I should use the E-Maxx? Once again, sounds awesome, but I only break open computers, not RC Cars. Of course, maybe we could buy you a plane ticket.... :-) I wish I knew how to do all that cause it sounds like it would be really cool to do that!

aliens8mycow

I'm sure you could use the same type of soundproofing insulation that audio installers put in cars - might even be able to line the inside of the body with it?

And back to the brushless motor system. What's the cost on the novak? About $275 or so? How about going with a more powerful system to offset all the gear reduction? Mike over at rc-monster.com would possibly help out on this one. You can get the warrior 9918 for about $250 and a Feigao motor (8L or 10L -- long can for torque) for about $80. That's listed price, which isn't much more than the novak, and if he'd 'help out' a little bit, well... that would be good. I think I would trust that system with my life long before I'd trust the novak brushless (I'm a little biased, though)

Speedmunkey

Agreed, especially if we could get some sponsorship going.. You seem to know the guy, make it happen

Hey Ultra, Sleepy and I live about an hour apart. I'm sure if you shipped us the parts, we could make most of this stuff happen for you.. I can't speak for Sleepy (though I know his answer, I'm sure) but I'm all for seeing this come to life. Make sure you include a few extra flashbang grenades for us to practice with!

studysession

I have been monitoring this thread closely. Need to watch where this conversation leads and goes. I have already deleted posts from this thread already. Do not talk about explosives or weapons of any kind and stay off the topic of asking for money and sponsorships. Thank you.

Speedmunkey

Study, how is anything being discussed here a TOS violation? I too have been watching this thread closely, and I've seen nothing remotely out of line. Lighten up man, we are trying to help the guy with his project.

aliens8mycow

Do you have any ideas, study? You do a lot of brushless motor work, custom milling, etc. How about some input from an expert, here?

aliens8mycow

Even though we seem to be pushing the limits of what we're allowed to talk about here, I'd like to take the opportunity to mention how nice it is to be a part of such a huge group of folks with a combined wealth of knowledge and experience. It's pretty cool that someone from totally outside the rc world would find rcu on the net to seek advice on such a great project.

ultraking

And not only that, you guys have totally exceeded any expectations I have had about what I would find here. It would have probably taken months of research to find what I have gotten from here in just 2 days. Pretty cool!

Revs

This project sounds awsome, unfortunatly i run touring cars so i have little to offer, but i think the idea is awsome, I too think this is a great community and look forward to seeing some plans or ideas drawn up, Just a thourght, the suspension will it cope with the extra strain? even at low speeds? and the transmission, loads of lube or grease between gears would keep it quiet and corectly shimmed gears, mayb some type of sealent on the diffhousings as well.
I would have thort that it would have been okay to talk about weapons and explosives becasue they are being used for good and they help take some of the edge of the thread and make it more enjoyable to read.
I also think this should be made a sticky, as its a good example of every one coming together to contribute there ideas and ultimatly make some thing worth while.
Tom

Speedmunkey

Ultra, RC is filled with people from all kinds of backgrounds. Sleepy over there is a mechanical engineer, and I'm a mechanical designer. We apply our own brand of geeky-ness to this hobby, and it usually turns out to be rather interesting.

Ya know, to be honest, I'm not sure what all everyone does for a living.. Sound off boys! What do you guys do?

Oh and Revs, no actual weapons were being discussed.. Only crowd control devices a SWAT team would utilize. I think it was a knee-jerk reaction to seeing the word "grenade" appear on a public forum. Flashbangs are used by SWAT teams to distract the bad guys so they can do their thing. It isn't an explosive device, more like a glorified firecracker. If that isn't allowed, then RCU has my sincere apologies. I thought we were having an serious conversation about potential design elements for this rover and not watching Spongebob...

45mph pede

Everyones talking about electronics here... so being me we HAVE TO talk about looks. Im thinking black bead locks, with m2k's all around. Black body (out of cevlar) for weapons reasons then put some nice white stickers and paint it up like a police car Maby even get a light bar?

I agree all alum. with bead locks, and a brushless motor will be awsome. I do have a question though.

Is this thing sapost to be quiet and like creap up on someone, or is it going to be a 'delevery truck' to like delever phones to the bad guy. Because that will change the set up dramaticly.
-Wes

sleepy23

My Feedback: (1)

i was bout to sound off that me and speed were mechanical guys..... i know there is atleast one more mechanical guy here. I pretty sure i have run across an electrical guy or two on the boards also. i have a ton of ideas bouncing around right now in my head, however, some of them would require alotof fabrication and design time. I dont think the overall cost would be that much more...but anyways. i got to thinking that along with the rotating camera, it would be nice to have a light afixed to that. with the brushless, the issue of power is going to come up, i would recomend a lipo battery to run this creation. also with an emaxx chassis, you only have so much room to add stuff, after that you are going to start packing on top heavy weight.
just from my design and project management experience, it would be very benefitual to develop a bit of a spec for the vehicle. for instance,:speed,ground clearance, runtime, options( camera, mase, etc..), bulletproof..

just some food for thought

Speedmunkey

agreed, right now we have a moving target and we're shooting ideas at it like beanbags lol

Pede, depending on how high the camera is mounted, the body might have to be totally clear.

oatmealman

My Feedback: (1)

i went to this carrere day thing and the fbi was there he let us try on bullet proof stuff,it weighted like 3-4 lbs at max and it was a full vest,it could stop bullets pretty good i think the guy said the things that could blow throw were a 50 cal machince gun(well i wonder y maybe because the bullets as big as my turds[&:]),and it couldn't stop a sniperrifle bullet from a 1/2 a mile away unfortunatley[&o]