Quick Change battery Tray
 

Yeah, this idea has reared its ugly head yet again. This past weekend At the track I realize that most conventional battery containment systems have become a pain to racers who wish to perform battery swaps and run longer mains without losing much time compared to the nitro's. The past day I have been trying to think of something that would be quick change (less then 10 seconds) and eliminate the hassle of plugging in the batteries you are swapping in.

Secondly it has to be able to handle the abuse of racing. the jumps, tumbles etc. So the hold down system must be sturdy.


So My idea is this.
- Base the design off of Team Novak battery trays and Mike's 2s Hardcased lipos.
-Cut a holes in the chassis the same size and shape as the batteries
- Flip the trays upside down so that packs are bottom loading
- Incorporate Male bullet connectors into the battery tray so that when the battery is inserted it automatically connects to the speed control wiring. without the need to plug anything additional in.
(any ROAR battery with 4mm bullets would work. see here, reedy, Rc-monster)
- The doors i have mocked up have a beveled edge which would line up with a beveled edge made into the chassis to keep the door from moving without the need for another quick release fastener.


There are only a few things that are holding me back.
-What quick release mechanism to release the battery doors
-Machine work on the chassis
-Battery selection


Plans and updates
-Now that i have something to look at. I thik it may be easier to mount the tray to the chassis by the sides and leave the front/rear open for the quick release mechanism.
- The quick release mechanism is to be a dzeus fitting- They are quarter turn quick release fasteners used on aircraft and race cars- they are plentiful at my house :)
- Now that my dad has seen me and my truck race hes taking the whole rc thing more seriously(finally) and Im in the process of talking him into getting me a hand mill :yipi: He is the one that sparked the "Trap door" Battery tray idea.


Ill stop blabbing, here are the pictures!


http://i152.photobucket.com/albums/s...dedchassis.jpg
http://i152.photobucket.com/albums/s...oorandtray.jpg
http://i152.photobucket.com/albums/s...sisanddoor.jpg
http://i152.photobucket.com/albums/s...aysonedoor.jpg

I think that this would weaken the chassis too much - The key is the locking mechanism...

Mike and I had discussed ideas and he was working on something - The issue is by the time you build it electric classes will be out with 12 min mains and hence no need for battery swap...

I hear you on that, but my car has a giant composite brace spanning the entire car. i dont think strength will be a problem, and not all mains are the same... Just because i run electric doesnt mean I shouldnt be able to run 30 minute mains or enduros dont you think?

I hear you but the question is with so many e's coming from OEM's without this technology - races are likely to be to the common denom i,e, around 12 mins

This is one of those great ideas that seems so simple and yet so hard to carry out- I get 'engineer's block' with stuff like this sometimes.

My old Hornet had a bottom access for the pack and I miss that simplicity, it would really help if mfr's would standardize cell/pack size like back in the day. Not that they were much more standard, there was just a lot less choices haha. 6 cell 1200 mah Ni-Cad baby! Hump packs, the memories...

Sorry.

The simplest way to add some rigidity back to what you propose is to do a 2 level chassis, or add some bends/angles to the edges wherever material is lacking for cutouts.

I think you already knew that, but a chassis with a channel type center (Revo) would obviously be much easier to do that with. You might consider side loading with a vented box like the E-Revo if your body would allow.

the design seems entirely too complex. all you'd need is two male plugs mounted standing straight up on the chassis, soldered 90 degrees to the wire, then push the battery upside down onto the male bullets. have fixed sides and spring loaded holding tabs on both ends. done.

http://home.comcast.net/%7Etruerc/re...eady_packs.htm

the hard case 6000mah one.

what about a trap door like on the e-revo and savage?? just put the bullets in the tray and it plugs right in when you insert it...

The best thing I could think of with all the quick change battery threads is a hardcase pack (or something similar) that had indentations on it that would clamp onto the chassis.

Pick up a regular TV remote. Take off the battery cover. Imagine the cover is the battery and the remote is the chassis. One end of the battery slides in and the other end clamps on. You may be able to incorperate the leads with this too if you are creative...

Thats the general idea from the beggining.

Thinking all this though- this is definately not the best idea for the job...

Sure would be cool as hell.

....Back to the drawing board.

Make a locking mechanism on the battery and battery tray along with bullets. Where ya go. One tab would be the best imo, just slide one end in and snap the other along with the bullets.

look how it's done on a cordless drill.

what about the way that the batt doors on the $20 wallmart RCs are closed?? hinged at one end and a lock at the other.

from talking with around i hear that Tekno and Losi are both working on quick-change battery trays for 1/8. not sure how for along they are but i know it is in the works.

i think the trap door chassis is way too comoplicated also and too much potential for issues. you would be better off putting a door on your body if you really want to go that route but most likely no matter how this is done you would be using some type of clip so you might as well just undo your front body clips of your body giving you access to your trays and then use a system like the soldered 4mm standing male connectors like already mentioned.

i have thought alot about a quick-change tray also. a couple of weeks ago the rocky mtn nitro challenge was at out track and the mains were 30min. the nitro guys were pitting at least twice and some even a third time at then end where as a 5000mah pack only required one pit. they still had the advantage but it was pretty close to equal amounts of time in the pit.

i think like arctik said electric classes will become the norm and run 12min mains or if you still race with the nitros and run the longer mains just know that you will not have to pit as much and when you do just go fast as hell and you will probably be ok.

before long we will start seeing production of quick-change trays but i dont think they will ever be as fast as a 3 second fuel up. the nitros will most likely always have us beat on that one thing......and one thing only...ha!

Alrighty. did some more thinking on this concept and came up with a different design.

-This still utilizes the hot swappable batteries with the bullet connectors.. here is it in a nutshell, cad drawings are to come when I get home from school


-Turn trays on there sides
-modify the inside of the tray to use the bullet connectors and short high tension springs for battery ejection..

(now for the fun part) The latching/quick release.
I plan to make up something like a garage door latch.. with a twist latch and a small cog that would latch under the head of a buttonhead screw. connected to a twist handle with a bar or turnbuckle.. on the other end of the hold down is just a notch or slot to slide under another screw but without the latch....

Kind of hard to explain without pictures..

Personally I think you need a cartidge system - Mount the battery in a cartridge that has a deans connector than the had required female powerpoles on the outside.

Cartridge slides into the holder and engages with male connections.

Also think you need a mult-dimensional locking mechanism so that force in multiple directions simulateously is reqiured to eject tray - I don't want it ejecting when lawn darting.

I also like the cartridge "plug and play" system and the bullets integrated into the tray accomplishes the same goal


If my system works out it will be able to be mounted to existing tray

So I spend a few hours toying with way to release my batteries a bit faster.. Came up with this..

http://i152.photobucket.com/albums/s...0512091744.jpg
http://i152.photobucket.com/albums/s...0512091944.jpg
http://i152.photobucket.com/albums/s...512091749a.jpg
http://i152.photobucket.com/albums/s...512091749b.jpg
http://i152.photobucket.com/albums/s...0512091943.jpg

I used some 3/16 kydex plastic. some angle aluminum stock and 2 quick disconnect throttle cable connectors that I found in our race trailer... It was entirely by accident but was a "Eureka!" moment.

(Connectors)

To take the Battery straps off- you simply slide the locking collar back 1/4in and the entire thing comes off- the opposite side attaches with just a slot that fits under a cap head m4 screw.



The studs for the quick disconnect were 10-32 So i had to drill and tap one hole on each of my novak battery trays- no Big deal.

Then Mounted the Female quick disconnect to a strip of angle aluminum using a m6 button head screw(I was surprised that they are metric from the factory) and mounted the other side of the aluminum to the kydex strip with 2 countersunk M3 screws for a flush underside.


My next task is to somhow spring load the bottom of th packs so they pop up when you take the straps off for easier removal.

Let me know what you think

Neat idea- let us know how it works out! :mdr:

This doesn't totally have to pertain to this thread or this individual post by you Ian, but do you ever post anything but "nice" things? I rarely see you posting something of usefulness..... :no:




Anyway, sorry if I missed it, but the quick release mechanism slides back so is it spring loaded to come back forward into the locking position? Or do you still have to do that?

And for making the bottom of the tray spring loaded, you should get a some of those little springs they use in devices that take AA batteries, and put like 8 of them along the bottom of each tray.

Yes the quick releases are spring loaded so they automatically clip.

Might be something worse than those quick releases, but those look so tacky..

You can just hook up something like a regular ball stud:
http://www3.towerhobbies.com/cgi-bin...?&I=LXCZJ5&P=7

and a regular ball link:
http://www3.towerhobbies.com/cgi-bin...?&I=LXAMT1&P=7

Looks more.. efficient to me.

Those quick releases, if they're pull back (towards the end of the pack) and pull up, that's a good idea, but the mounts look tacky as hell, does it not?

Maybe it's just my OCD kickin in.

I've been playing with this idea for a couple years, haven't built anything yet, though. I think bottom access is best. The body would get in the way no matter how you slice it and dice it otherwise. That is a non-critical area of the chassis, and both the cups and the chassis braces would provide all the rigidity needed. If worse came to worse, you might have to run the alum braces instead of the plastic the team drivers run.

My idea was similar to yours. I was going to have a beveled lip on the end of the tray opposite the bullet connectors, and engage that lip, and push the front of the tray in place. I was going to have a post on the front of the tray that would engage with a mount in the cup and then lock it all together with a 6mm by 50mm ball release pin. Pit stops would be reaching under the body, pulling out one pin and dropping the battery tray, replacing with another battery tray with the fresh packs, replace the pin, and go.

Oh stop your whining. and why would I use normal ball cups
that defeats the purpose of a quick release... thes are the prototypes anyways.


they pull towards the center of the pack.. will test them out at the track this weekend..


@ Pb4ugo

I have encoutered the same thing- trying to make a botorm release pack.. unless you weld in an aluminum tray your not going to have the support you need..

Im thinkign of putting my trays on there sides and moving them outboard so you dont have to take the body off but just bend the sides up.

Is that much quicker than a clip on a zip tie? You'd make more of a difference changing your setup to a single pack i would think..

It is faster. alot easier to work with- especially when it comes to reinstalling it- you dont have to fight getting a tiny body clip into the hole.

In conjunction with the battery ejector that Im working on it will be much faster then the standard setup.

Ah, if it wasn't a quick release, it looks bulky, but being that it is, I get it.

:P

Yep, it was my OCD.

I plan on Trimming down the pull tabs (giant squares) Now I just need some short high tension springs to put under the pack for battery ejection

You are still missing built-in connectors, it would save time.

Bad idea on having anything come out the bottom of your chassis, it takes way way too much of a beating to ever mess with... iMO you have two choices

1) side access similar to the e-revo but with a simpler connection to make a swap faster as plugging in any connectors (deans etc) takes too long messing w/ the wires and stuff.. it needs to slide into place and "contact" w/o any extra wires. I've run several long 30+ A-mains and even w/ just one battery swap it takes longer than all the nitro pits.

PS may want to have a body w/ the side cut right out in this small area to speed things up further. The e-revo stock body is weak on the side by design so you can bend it back and swap out packs, most are not like this.


2) create a top load system w/a custom body with a removable panel for access, the body in a small section would essentially be part of the battery tray in a sense allowing you to release and pull it up. The problem here is the body holding up over time as it too would be greatly weakened, but far better than your chassis being hacked up and weakened. If you are a good driver though and don't flip much, this would prove very nice as well.

I came up with idea like this:
http://i92.photobucket.com/albums/l1...ck-release.jpg
Just pull back that release and battery "pops out", then slide new battery in...
This requires special battery casing.

I think thjat top loading trays could be a problem. because that basically neccesitates the need to remove the body.. side loading should be the winner in that department.. I need some uniform packs with all Bullet connectors. Or somehow convert all my packs to a standard connector.

Maybe have a eflight connector on a swivel on one end of the battery tray (allows some movement) and then figure out a way to have the female be part of the battery pack (solid). This would let you insert it drop it into position quickly, then just a xross bar to hold in place, also just as fast removing. Obviously in all of these scenarios you need to have identical packs all setup the same way (size voltage etc)