brushless 1/5 4wd conversion about to begin! couple questions.

[Ryu James]

Originally Posted by redshift

Ok James, it does look thicker than it is apparently. I have to cauton you about "splitting" the flow with these little fans. They load up and will themselves run hotter, if there is obstructed flow.
You can try it, just hold one while it's running and cover up a small part and you'll hear it bog.

So my suggestion would be a venturi setup for smooth flow between the fan dia. and the square hole. A piece of modified tupperware, something like that.

Certainly not as clean as what you had, but if it keeps that big dollar motor happy for now.... :)

thanks for the input. i am gonna try the larger fan and maybe that will do it. i dont think it will be often that i see temps that high but i dont want to even risk it. i want to be able to confidently run as hard as possible and not worry about heat issues.

[KaztheMinotaur]

Looks very nice. You've been running the 15T then? You like it? I'm going to stick with the 12T for now. I'm not going to have much of an RC budget for a while.

I'd like to get my chassis motor mount holes slotted this today.

[Ryu James]

Originally Posted by KaztheMinotaur

Looks very nice. You've been running the 15T then? You like it? I'm going to stick with the 12T for now. I'm not going to have much of an RC budget for a while.

I'd like to get my chassis motor mount holes slotted this today.

hey kaz,
good to hear from ya. you should go back and read through the posts. there are a few things i have posted you may want to know. like running the 12t pinion really put stress on the motor shaft because of how long it is. and the 15t pinion just performed so much better in every way. i would recommend cutting the 12t pinion in half if you are going to run it. maybe run it first and see how it goes but when i used it there was evidence of stress on the motor shaft. also, here is a vid of mine if you didnt already see it: http://www.youtube.com/watch?v=Zgx-ySspOhk

also, not sure if you saw my post on this but saturday i ran my rig very hard and although the motor temps had always been below 115* they got up to 170* that day. it isnt often that i run my trucks as hard as i did that day but i am trying to figure out what i can do to get my temps down. every other time i ran temps were very low. but maybe you could provide some input as to what you think i could do. i dont want to just strap on a bigger fan, although i will, but i would rather find the cause. eg gearing, weight, motor kv, amps, etc?? do you think i am geared too high? too low? any input would help.

[lutach]

Do you have a video without music? The song is great, but I like to listen to engine and motor music instead .

[Ryu James]

Originally Posted by lutach

Do you have a video without music? The song is great, but I like to listen to engine and motor music instead .

sorry dude,
kulangflow posted the vid and said that youtube wouldnt allow the sound to be posted for whatever the reason. i will tell you this: it is surprisingly quiet and smooth. it really doesnt sound any louder than my 1/8 brushless rigs. in fact, i would venture that it is quieter than my 1/8's. i am gonna try to get another vid up with sound in the next few days.

whats your thoughts on the temps from saturday, lutach? you must have some thoughts about a possible solution.

[KaztheMinotaur]

Yeah, I did read all the posts. I 'm going to use the 12T for now. I will slid it all the way back to the can and then the whole thing as close to the spur as I can get. That should minimise as much stress on the shaft as possible.

When you were running it hard was that with the 15T pinion? If so I would re-gear with the 12T and run it hard again. That will give you a better idea if it is caused by gearing.

I broke one of my straps that hold the motor to the plate...so I am currently making another one.

[Ryu James]

Originally Posted by KaztheMinotaur

Yeah, I did read all the posts. I 'm going to use the 12T for now. I will slid it all the way back to the can and then the whole thing as close to the spur as I can get. That should minimise as much stress on the shaft as possible.

When you were running it hard was that with the 15T pinion? If so I would re-gear with the 12T and run it hard again. That will give you a better idea if it is caused by gearing.

I broke one of my straps that hold the motor to the plate...so I am currently making another one.

when i rant he 12t i had it slid all the way on too. so that the end of pinion was right close to the can. i am sure it will be fine but i thought that because i had it slid on so far that is where the stress came from and that it might stress it less if it wasnt slid down on the shaft so far. idk, just my thoughts but i know the 12t can work. be sure to post what kind of temps you see when you get yours running.

when i hit the hot temps i was using the 15t. i am gonna try some other pinions and see what happens. i did do some tests with both the 12t and 15t pinion and i initially thought the 15t would be geared too high but i really didnt see much difference in the temps when testing them both. i wonder if simply it was too high rpm. i will experiment and see what happens.

[lutach]

Originally Posted by Ryu James

sorry dude,
kulangflow posted the vid and said that youtube wouldnt allow the sound to be posted for whatever the reason. i will tell you this: it is surprisingly quiet and smooth. it really doesnt sound any louder than my 1/8 brushless rigs. in fact, i would venture that it is quieter than my 1/8's. i am gonna try to get another vid up with sound in the next few days.

whats your thoughts on the temps from saturday, lutach? you must have some thoughts about a possible solution.

Strange that youtube took out the sound of the car, but youtube does sometimes take out the sound if a song has some sort of copyright to it. I just wanted to hear just the vehicle though with no music at all that's it .

Your temps are good as with the other efficient set ups we have on the forum. Now I saw that you mentioned 170, but how was your driving style when and if it got that hot? Have you thought about going higher on the spur tooth count? I see that you have the space for one.

[Ryu James]

Originally Posted by lutach

Strange that youtube took out the sound of the car, but youtube does sometimes take out the sound if a song has some sort of copyright to it. I just wanted to hear just the vehicle though with no music at all that's it .

Your temps are good as with the other efficient set ups we have on the forum. Now I saw that you mentioned 170, but how was your driving style when and if it got that hot? Have you thought about going higher on the spur tooth count? I see that you have the space for one.

i was driving like a bat out of he11 when i hit those high temps. i do have a 17t and 18t pinion that i plan to try tomorrow and see what happens.

[brushlessboy16]

Freaking amazing!

[redshift]

Originally Posted by lutach

Strange that youtube took out the sound of the car, but youtube does sometimes take out the sound if a song has some sort of copyright to it. I just wanted to hear just the vehicle though with no music at all that's it

Gotta keep in mind Lutach , anythime you do slo-mo or fast, there will be gaps in the audio, continuity is important in making a 'watchable' video IMO.

Kulang and Ryu, I really like Vimeo. Converting takes less than an hour, your video won't go thru 15 different filtering programs and such. I suggest you upload the same vid, the way you guys wanted it originally, to Vimeo. Many of the guys on the RCG Aerial Photography forum swear the quality stays more intact with Vimeo than YT, and I quite agree.

[lutach]

Originally Posted by Ryu James

i was driving like a bat out of he11 when i hit those high temps. i do have a 17t and 18t pinion that i plan to try tomorrow and see what happens.

How fast is your vehicle now? At that size, making it faster would be just too risky I think.

[Ryu James]

Originally Posted by lutach

How fast is your vehicle now? At that size, making it faster would be just too risky I think.

its 55mph currently. that is my estimate. i havent gps'd it yet but i know its in the 50mph range. i could definitely take off someones leg with it. who knows the formula for determining impact force. weight x speed ?? it weighs 27lb.

[lutach]

Originally Posted by Ryu James

its 55mph currently. that is my estimate. i havent gps'd it yet but i know its in the 50mph range. i could definitely take off someones leg with it. who knows the formula for determining impact force. weight x speed ?? it weighs 27lb.

The plans that I have laid out for when I start my 5th scale vehicle shows a speed of only 40mph max for the onroad version. The problem with the 5th scale that I see are the plastic parts breaking at such speed. You could go with a bigger spur and 12T pinion to get a more efficient set up which will provide tons of torque and will be fun getting a few extra minutes of run time.

[Ryu James]

Originally Posted by lutach

The plans that I have laid out for when I start my 5th scale vehicle shows a speed of only 40mph max for the onroad version. The problem with the 5th scale that I see are the plastic parts breaking at such speed. You could go with a bigger spur and 12T pinion to get a more efficient set up which will provide tons of torque and will be fun getting a few extra minutes of run time.

i actually wanted a larger spur gear but the next available size was 48t and just too big to mount. it could be done with a very large alum. shim under the center diff mount but i want to stick with the 40t spur cuz its simple and clean.

as far as durability the rampage has proven to be very durable. i have taken a couple of heinous spills and it didnt skip a beat. i have the Vertigo titanium turnbuckle kit since i heard the stock ones can bend .

i am just gonna play around with things and i am starting to feel not really concerned that i will see hot temps again. that day it got hot was when i was letting my 12yr old nephews drive it and they were making me nervous cuz their driving was not good. it was after they drove when temps were high. i had checked temps a few minutes previous to them when i was driving and temp on the motor was only 100*. so i am thinking that what happend is what aqwut said, that stopping and starting over and over and revving to top speed instantly builds up the most heat and i think thats what they were doing.

i am bidding on a baja currently for my next project. cant wait to convert the 5b. they look like a blast too. i want to build a nice 1/5 collection for myself.