OFNA Ultra MBX Conversion - The Latest Project - RC-Monster Forums

Batfish · **OFNA Ultra MBX Conversion - The Latest Project -** 04.26.2006, 09:59 PM

CCristo and I have been working on a conversion for my OFNA MBX buggy over the past few weeks. Here's what we have so far:

As you can see, we still have a couple things left to do (mainly, mount the electronics), but we're both very proud of how it has come together.

Need sleep tonight, but I'll take some time Friday night to post what we've done in more detail.

This buggy will compete directly with nitro 1/8th scale buggies at our local track.

Sylvester · 04.26.2006, 10:08 PM

Man, you guys sure know what your doing! Thats one nice buggy! Cant wait to see it all finished up, get a vid!

04.26.2006, 10:15 PM

Quote:

Originally Posted by Sylvester

Man, you guys sure know what your doing! Thats one nice buggy! Cant wait to see it all finished up, get a vid!

Me too! Please make a vid!

Gustav · 04.26.2006, 10:51 PM

Nice work!
I was thinking of a similar layout myself.Moving the diff way forward to get the batteries closer to the centre line.I was thinking of the steering servo on top of the steering plate to get the diff even further forward but looks like that's about as far as you can go leaving space for the motor.It'd be nice if there was a shell for a really narrow look,the Losi 8ight will be the narrowest bodyshell.

04.27.2006, 12:41 AM

Where did you get the battery mounts from

Serum · 04.27.2006, 02:13 AM

They actually begin to look like something Batfish!!

LOL

I remember the Jato. I see miles of difference in both.

04.27.2006, 07:01 AM

it looks good batfish.

MetalMan · 04.27.2006, 08:54 AM

Quote:

Originally Posted by Big Daddy

Where did you get the battery mounts from

Looks like they are cut out from an E-Maxx chassis.

Batfish, it's looking pretty good!

coolhandcountry · 04.27.2006, 06:36 PM

YOu have made a nice looking conversion. Either you have got better at hiding the zipties or you not using them. ;) I like that conversion though.

Batfish · 04.28.2006, 11:24 AM

Thanks for the compliments so far :003:
CCristo has instructed me to say that if you like something, he did it. Anything you don't like, I did. :005:

So here's some information on what we've done so far.
The chassis is custom cut from 3mm aluminum and extended 1 inch (to make mounting the batteries easier). This makes the chassis approximately .5 inches longer than most of today's 1/8th nitro buggies.
A UE 105mm dogbone was used from the center diff to the rear diff. The original OFNA front dogbone was used from the center diff to the front diff.
A rear brace was cut to go from the center diff to the rear diff. This is where the battery trays (cut from a stock E-Maxx chassis) are mounted. This rear brace will also (probably) be the mounting location for the ESC.
A front brace was cut to go from the steering posts to the center diff.
The steering linkage was swapped from the right to the left side to accomodate the motor, which will be mounted towards the front of the buggy rather than the rear (also to increase room to mount the batteries and help off-set weight).
The steering servo is mounted laying-down on the chassis.
The brake servo (mechanical rear brakes) is standing up next to the center diff using Traxxas servo mounts.
I swapped the c-hub suspension that was on the vehicle for the PBS suspension (personal preference).

This buggy will be powered by 4s2p 6400mah FMA/Kokam lipo packs, BK 9920 ESC, and Lehner 1940/6 motor. Gearing will be in the 26-30 MPH range. This buggy will be for racing only, so higher speeds are not needed.

About 3 or so hours of work remain before it can actually be run, but I'll make sure I have my camcorder with me when it makes it to the track :003:

There's a guy at our local track/shop who is an R/C geek and a CAD designer. When he saw what we had done so far, he wanted to "CAD the heck out of this thing", as he put it. I may actually let him have the buggy for a few days so he can model it and see what more can be done with it. Maybe we can even get an actual conversion kit out of this :003:

More to come...

MetalMan · 04.28.2006, 04:44 PM

Only 26-30mph?!? With that motor and those batteries, you'd have no problem getting to 45mph+ (assuming the 9920 can handle it). If you don't want those speeds on the track, you could dial down the EPA or just use a light throttle finger. You may even run into overheating issues with the motor not having enough of a load!

Batfish · 04.28.2006, 06:07 PM

Quote:

Originally Posted by MetalMan

Only 26-30mph?!? With that motor and those batteries, you'd have no problem getting to 45mph+ (assuming the 9920 can handle it). If you don't want those speeds on the track, you could dial down the EPA or just use a light throttle finger. You may even run into overheating issues with the motor not having enough of a load!

Although a light throttle finger could accomplish it, reducing the EPA on a radio is only a last-ditch effort when it comes to throttle control. When you reduce the EPA, it reduces the amount of usable throttle steps, which in turn reduces the smoothness of the overall throttle.

I know it CAN go faster, but that doesn't mean it HAS to go faster. It doesn't, and I have no need to make it do so :003:

crazyjr · 04.28.2006, 07:06 PM

Nice buggy. From one racer to another I agree,"Slower is faster"

coolhandcountry · 04.28.2006, 07:37 PM

I won't say slower is faster. Cause it can be to slow. It is a fine line in there and each track is different.

Batfish · 05.26.2006, 10:33 PM

Well, Folks, Chris and I got it finished up and it had it's first run on the track today. The outdoor track was under construction, so what you see is the indoor track. The indoor track has narrow lanes since it is intended for 1/10th scale stadium trucks and buggies.

Here's a short video to let you see how it runs.

I plan on racing it Sunday against the nitros - let's hope for the best :003:
Maybe we'll get more video on Sunday.

http://www.chriscristo.com/downloads...%20MBX%203.wmv