Custom Brushless Buggy!
[ratings]
OK, it is not Nitro. I would have said “Sorry…” BUT what the heck. Any good article, deserve to be in this blog.
Now this is what i call dedication and pure interest to the max. I salute this guy. Now, who am i talking about? I also do not know. He’s only known as Joeling in rctech. But he is friendly and i’m sure you’ll thank me and mesmerized by what he put his time to writing all these. Valuable post. you will agree me when you finished reading it. 
Introduction
I began to take rc seriously again after a 15 year layoff. Of course, ’serious’ is pretty relative in terms of the overall scheme of things. I was a basher & will probably always be one. I have never raced rc at any competitive level in my previous life either. I’m not about to change. Instead, I have always been a tinkerer, trying to make something different, though not necessarily better. In addition, I only knew electric stuff – no nitro for me. Hmm, thinking back now, I kind of remember that nitro was starting to take off just as my interest was fading. Could the two be linked ?
Anyway, enough of rambling – I guess once bitten by the rc bug, it will never go away. It only took a brief look at a Tamiya catalogue while shopping for toys for my kid to rekindle the fire again. 1 ½ year on, I’m looking to start something a little different. Just as I rediscovered this hobby, I came into contact with Brushless Technology. This is something that is pretty interesting. With brushless, one can conceivably compete with nitro. This is something that whets my appetite for something unusual.
So, I decided to convert a nitro vehicle to electric & I chose a 1/8 buggy, arguably the biggest, fastest, baddest & most popular of platforms in the rc world today. My little guinea pig is a 1/8 scale sacker buggy bought from my rc buddy Mr.Foo in Miri. I did the conversion & managed to get it running more consistently. Not all the bugs have been worked out but I’m getting there. Then, one fine day out of the blue, a thought came to me – custom ! Why should I have to put up with a layout that is optimized for nitro power plant ? I had a hard time squeezing in the electric power plant to my sacker & thus compromised on the handling of the vehicle. I want a custom job with optimized layout exclusive for electric power plant ! I had to fasten a crude adaptor plate to fit my electric motor to the position where a nitro engine would have been. I had to squeeze the batteries into the rock guard of the buggy far away from the center line of the buggy. Fitting the largish esc into the space on the chassis was also a pain. I want something better !
So, what is the objective & parameter of this custom conversion ? Obviously I do not have the knowledge or resources to build a completely new buggy from the ground up. So, I had to make a decision on a donor platform. I chose the Hong Nor X1-CRpro simply because I had one lying around. With this decided, I need to have some spec. to this thing :
1) XL sized motor
2) Low KV high voltage (probably a Feigao)
3) Esc that can handle 8S (probably a BK)
4) Retain center diff
5) Custom chassis, diff holder, motor holder, etc.
6) 8S lipo (3000mah or 4000mah) modeled after Maxamps pack size
With every venture, there will be challenges. Some of the things I will face are :
1) Where on earth can I get some custom fabrication done ?
2) Who can supply some custom dog bones ?
3) Money
4) Is having all the weight closer to the centerline better or lower done on the chassis for lower CG better ?
5) How to keep the chassis stiff now that I have removed the lip i.e. the knurled bit where the rock guard connects to)?
6) Where to put the steering servo ?
After a little huffing & puffing, I came up with a preliminary design drawing (refer to picture 1).
Picture 1
The chassis is pretty much flat & emulating the silhouette of the original nitro version of the buggy with the exception that the rock guards have been dispensed with. In this preliminary design, I went for the target to have the components as close to the centerline of the chassis as possible & trying to distribute the front / rear weight more evenly.
After consulting with experts & knowledgeable individuals from www.rc-monster.com forums, I made some changes (refer to picture 2 & 3).
Picture 2
Picture 2 shows a continuation of philosophy set forth in the preliminary drawing where the components are packed close to the centerline (CL) of the buggy at the expense of a higher center of gravity (CG). The motor is placed on top of the spur gear above the batteries. The front / rear weight distribution is also taken into account here.
Picture 3
Picture 3 shows a departure away from the preliminary drawing in that the motor has been place on the left front of the chassis for a lower CG but away from the CL of the buggy. To accommodate the motor, the batteries have been moved further affecting the front / rear weight distribution.
After some thoughts & help from my ‘consultants’ from the web, I decided to further work on picture 2 & leave picture 3 for now.
To be continued…
