Custom 1/5 Brushless

[kladal]

Hello. I have a custom aluminum buggy that was originally designed from an E-Maxx.

Here are the specs:
-Motor = 2217 2y 640kv CC/Neu
-ESC = Megapower 120A
-Battery = 10s (two 5s)
-Tires = Thinking of IMEX Swamp Kong

My questions:
1. How should I gear this setup?
2. The current transmission is a two-speed. Can anyone recommend a single-speed transmission?
3. How do I determine what the differential ratios are currently?
4. Would IMEX's Swamp Kong tires be too big (I do NOT plan on much road/even terrain)?

Any help is greatly appreciated!

Thank you.

[simplechamp]

Have you thought about getting rid of the trans and using a center diff with integrated motor mount (like this: http://www.rc-monster.com/proddetail.php?prod=rcmcdmm)

That stock blue motor plate on the trans doesn't look like it would hold up for very long with a 2217 bolted up to it. Center diff design would make the setup a lot tougher.

Welcome to the forum, look forward to seeing this thing completed!

[kladal]

Hello and thank you for your response.

I will be changing the transmission in the following ways:

1. Plastic gearbox to fully aluminum ( http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT )

2. Then changing the two-speed tranny to a one-speed via GorrillaMax ( http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT )

3. A custom-machined, thicker, motor mount (perhaps twice as thick as stock on picture).

I will also find a way to use an all-metal gearing system.

Any thoughts?

Thank you!

[scarletboa]

a 2217 motor is way over kill for something this size. a castle 1520 or 1717 would be much more suited for a truck like this and you would have way more options for the esc. i'm thinking a MMM esc and a 1717 motor would be awesome in that thing on 6s.

[suicideneil]

Do you have any better pictures of the diffs?The look like alloy cases so probably will be UE Ultralites and 6 or 8 spider internals- 43/13 ratio.

Your plan for the tranny is fine, might want to find a steel idler gear though as the stock plastic one self destructs under brushed power, let alone BL power at this level.

I agree with Scarlettboa about the motor and esc though, thats massive overkill in a truck this size- nothing wrong with low kv & high voltage for efficiency, but that motor is large enough to move a 20lb+ 1/5 scale conversion, let alone a 12-14lb maxx based vehicle. MMM and 1520 on 6s lipo would be rather awesome too, or the 1717- only thing with the latter is its a bit fatter ( huh-ha, it ryhmes! ) so you may have trouble setting the mesh.

Useful tool for working out your speed and gearing, courtesy of BrianG:

http://www.scriptasylum.com/rc_speed/_top_speed.html

[Jahay]

i love overkill projects. Dont listen to these guys go ahead with the 10s!!! Haha onlyjoking...

Interested to see how this project materialises...

What sort of speeds do you want to achieve?

[kladal]

Hello All,

Thank you for the valuable advice.

I know the 2217 2y is a remarkably powerful motor. However, including the chassis, wheels (IMEX Kongs), batteries, and electrical components, this vehicle WILL EXCEED 20 pounds. In fact, I expect to be around 24 total; potentially more if I decided to strengthen the lower chassis plate. Also, I intend to exceed 50 MPH despite the fact I'll be using the 8" Kongs. Furthermore, as amperage is a direct correlation to the traction/tire setup, I should not be exceeding peak amperage draw of 150A.

Someone suggested using a Savage Flux-based transmission. I own a Flux and will custom-design an aluminum housing for the gears.

I will make sure to post more detailed pictures of the differentials this evening. Once I get a better idea of the differentials, I am hoping to find the right gearing setup especially since I'm using 8" Kongs.

Thank you all!

[kladal]

Hello,

I finally disassembled the differentials and saw that I have a 13/37 setup (illustrated in picture).

What type of gearing would you folks recommend for this truggy? Kindly recall that there are 8.5" Kong tires on and I'd like to exceed 50MPH. Also, I'll be using an all aluminum version of an HPI Savage Flux transmission (stock is 44T).

Thank you!

[Jahay]

Firstly those diff gears are not going to last long with those tyres and weight!!! HAHA they look weaker than the HD ones for the savage haha... You need to get some Bulletproof gears from the flux or much stronger... I cant help on anything apart from a savage, so sorry about that.
But i personally wouldnt use a savage tranny with that beast! It would just fall apart immidiately!!! Thats why i am so desperate to take mine out!

[suicideneil]

Flux gears wont work in a maxx.

Those appear to be the original 3906 diffs in an alloy casing, an old alloy casing at that ( note the 2 screw instead of 4 screw fixing pattern ). They wont last 2 seconds Im affraid.

Best bet for an overpowered heavyweight is the UE ultraLite diffs- check on ebay for 'supermaxx' or 'UE' / 'Unlimited Engineering'. You also have the option of FLM hybrid bulks + 1/8 ofna/ hotbodies diffs or the cheaper option of modding some Losi Muggy/ LST2 diffs to fit the maxx bulkheads.

The emaxx 3905 transmission is quite sturdy compared to the older 3906 version, though if you have all-steel gears ( UltraMaxxed ) then it would hold up brilliantly.

UltraLites: http://www.rc-monster.com/forum/showthread.php?t=8012
LST2/ Muggy diffs: http://www.rc-monster.com/forum/show...t=9153&page=15
FLM hybrids is the same principle & assembly method as the UE diffs basically, just that thr diff cases are built into the insides of the bulks.

[Jahay]

the ultralites look really good.

Just a thought... Would the ofna 8 spider diffs work? Obviously internally they are stronger and smoother than any 4 spider set up, but how good are the ring and pinion gears? are the teeth big and strong enough?

[suicideneil]

Oooh yeah, the ofna 6 & 8 spider diffs are what UE actually use- the stock traxxas diff is 4 spider, hotbodies is 6 spider. The ofnas are more than strong enough- only complete loonies have ever managed to break those, and its a rare occurance believe me...

[Jahay]

yea i am considering running them on the front and rear of my savage if it will work... They are smooth like butter with no play at all. I will test the crap out of my centre one and see how it performs

[steveo]

look those kongs just arent big enough your going to need these 10" ers

http://rc4wdstore.com/2/product_info...27c4e80c4a2ce2

[Jahay]

wow i have never seen anything like that hah how much would you say one weighs