BHB Ultimate XL

[BarHarborBasher]

Ultimate XL ... well that's to be seen... I just thought it sounded interesting and fairly honest lol.. I've been pondering the idea of a hybrid central differential matted to two 1700 Kv T8 sensored motors for my new found love...pitbashing.. My mission objective is to have the ability to run HIGH SPEED gear ratios under SEVER work load conditions without overheating... This will also help me run ridiculous gears for 2200 Kv SPEED RUNS ..
I wanted to install the TWINS in a stock XL tub so I could maintain the XL originality but I've got a modified tub coming that will be really cool ..so stay tuned ..BTW is this thing still considered " A TOY" lol
Subscribe to my youtube page for future builds... BHB 1/8 Bomber XL 2028 coming soon





My new tub will house 4 6s batteries that I'll be running in parallel to the two MMX .. I have 4s 70c batteries to at least use in the prototype for tune and testing..

[Deckard]

You crazy man....you crazy.

This kind of stuff makes my head explode. I'm not creative and I'm pretty jaded on thinking outside the box. I tend to sick to what I know works mechanically and sometimes I may get slightly creative on the visuals. I still have fun RCing so I'm good with being a bit boring.

I have questions because this is honestly something I haven't seen before (like Brock Samson finding out Sasquatch was a dude). Why the two motors? Are they 1/5th motors? Wouldn't a single 1/5 scale motor be plenty of power? Can they possibly get out of "sync"? Is that even a thing with motors? I've only be back into this hobby for a little over a year. My experience with brushless motors is that each one is different even if they have the same model, manu, etc.

It looks awesome though. I can't wait to see it run.

[BarHarborBasher]

Originally Posted by Deckard

You crazy man....you crazy.

This kind of stuff makes my head explode. I'm not creative and I'm pretty jaded on thinking outside the box. I tend to sick to what I know works mechanically and sometimes I may get slightly creative on the visuals. I still have fun RCing so I'm good with being a bit boring.

I have questions because this is honestly something I haven't seen before (like Brock Samson finding out Sasquatch was a dude). Why the two motors? Are they 1/5th motors? Wouldn't a single 1/5 scale motor be plenty of power? Can they possibly get out of "sync"? Is that even a thing with motors? I've only be back into this hobby for a little over a year. My experience with brushless motors is that each one is different even if they have the same model, manu, etc.

It looks awesome though. I can't wait to see it run.

Thanks , this build is completely experimental... I'm using 1/8 scale motors because of the high kv and lower center of gravity. I like running 20-23 tooth pinion wile pitbashing but it obviously causes heat issues... so I did the math and it looks like 12tooth pin / 68 spur (center diff)will give me the speed I'm looking for and hopefully the 2 motors will divide the work load and keep things cool...I'm thinking that the synchronicity will work as long as the batteries,cables,motor and ESC are mirrored..?? Figured I'd be the fool to try it ....the XLX and the XL-T will be finished up about the same time

[84yoda]

It looks like you have 2 MORE motor mounts on the other side. Lol. Dooooo it. Go big or go home. I wanna see a video of this in action.

12s?!?!?!?!?!?!?

[BarHarborBasher]

Originally Posted by 84yoda

It looks like you have 2 MORE motor mounts on the other side. Lol. Dooooo it. Go big or go home. I wanna see a video of this in action.

12s?!?!?!?!?!?!?

I think I might be a 4s guy for a while with this beast... I'm sure I'm gonna get shit for this build but..... in the end the it's fun for me and good or bad it's one of a kind.... what if it works????

[cmbscx10]

BHB you sir are a madman, nutso and completely lost your mind. Wicked engineering you have done and so looking forward to it running. Should be like an elephant running at cheetah speed. Bomp e domp ah bomp e domp. WTF was that just flying by? Pure Awesome that's what that was.

[84yoda]

If people hate, your doing your job.

[pro mod steve]

Originally Posted by 84yoda

If people hate, your doing your job.

Yeah, hate because they are jealous they don't have it. Way to go man.

[BarHarborBasher]

Originally Posted by pro mod steve

Yeah, hate because they are jealous they don't have it. Way to go man.

Thanks Steve ... I've never understood jealously within families ,friendships and neighbors.... I feel happy for anybody that takes a step up in life...Serious B.S...

[BarHarborBasher]

I'm using differential bearing supports and output support bearings on both ends to try to keep things together... This is V1 test..If it comes out good I'll make a custom rear support as well for the fit & finish... I just was using the parts I had lying around.. For front mount I used a scrap piece of aluminum and crafted it with basic handtools..dremel/file and a drill press for the 16mm bearing..I was able to keep the tolerances close enough to have the bearing pressed fit..The front diff/motor plate attaches to the stock tranny holes and through the bottom of the battery compartment..



Also a HUGE THANKS to MaxxPain He offered to send me some spare parts to complete the XT-T !! Basically every thing I needed !! I thought I'd have to lose one of the XL's out of the Fleet for a wile !!! WHAT A GUY !!! Thanks to Everyone for the Support !!

[BarHarborBasher]

I figured some stand-offs would help keep thins under control..



I used the stock transmission mounts as well as fasteners up through the battery tray into the C/D ears.



I had some lexan laying around so I decided to make a rock/dirt proof enclosure for pitbashing



and far as speed runs... some one check my math please...

26 pinion 54 spur 2.07
differential 11/32 2.9
final ratio 4.96

6s= 55,440 rpm's

55,440 /4.96
11,177 wheel rpm's

18.25 inch tire diameter
X 60 minutes
12,239,274 inches per hour
/ 12 inches
1,019,939 feet per hour
/ 5,280 feet ( one mile)

(26/54 pin/spur 193 MPH ) with a 12 tooth pinion its around 111 MPH
4s 77 MPH....

[BarHarborBasher]

Hey Guys here's a video over the XL-T ad a unboxing from MaxxPain !! Thanks again Maxxhttps://youtu.be/rwCy_ZUsIK4

[BarHarborBasher]

Cool little quote from Aaron / Rc Sparks .... He doesn't know .. But if it works he's gonna receive it in the mail to test out lol


RCSparks Studio15 hours ago

WOW. What a DEADLY RiG YOU HAVE! What a BOSS!! That Dual Motor setup is super sexy.. and your work space looks nice and cozy! Really, I run Futaba for my Rock Crawler, and for my 5th Scales. I use spektrum every where else. I use Futaba with my Gas powered rigs because of the electrical field generated from the engine. Spektrum has been problematic for me in that area, multiple times. Futaba - all clear. But, in a rig such as yours - I can't say. I have never had a beast like that! haha

[MaxxPain]

Wow, I can't wait to see either one go. Looks great. Glad the parts arrived. Thanks for the video. Tons of coolness in your workshop.

[Pilot-Werx]

This is going to be cool.... And yeah, hitec sucks. Savox is awesome!