JRX Pro SE runner build

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sixdub
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JRX Pro SE runner build

Post by sixdub »

The original idea for this build was a low budget runner using the best used parts from my pile. As with any project, there has already been significant "scope creep" as visions of big bore shocks, modern tires, and mild brushless power sent me to Ebay. :mrgreen:

So now I'd like to end up with a mildly capable, trackable buggy thats equipped with modern parts in the right places.

I forgot to take pics earlier in the process, but up to this point it is basically a stock SE in long wheelbase configuration.

Test fitting B4 wheels



XX retrofit trans in 2.6:1 "truck" ratio. This ratio is the same as modern buggies and will allow me to use the brushless gearing knowledgebase on the intarwebz. Also using dogbone outdrives and tecnacraft turnbuckles.

Image

Installed a double slipper and 78t losi spur using guidance from mytimac's awesome website. http://vintagelosi.com/SingleToDual.html

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Kyosho, JRX-2, Gold Tub Fan

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LosiXXkid
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Re: JRX Pro SE runner build

Post by LosiXXkid »

Yay! A new(ish) Losi build........ :D
~I'm a lot older now than I was then and wish that I knew then what I know now~

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matt1ptkn
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Re: JRX Pro SE runner build

Post by matt1ptkn »

I recently acquired my 1st buggy XX retro transmission. The internals are like new. Outside is just a little dirty. Its taking a lot of internal resistance to not create a new project like what you are doing. Hopefully I can just follow your project and not be tempted to do my own. However, a Pro SE is all that's missing from my stable. :roll:

Anyway, great start! Please update it often so that I can get my "fix". :lol:
Matt

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Re: JRX Pro SE runner build

Post by popboy905 »

lookin good i am also doing a pro-se runner. i haven't put much thought into wheels yet, most likely will go the b4 route

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Re: JRX Pro SE runner build

Post by Lavigna »

Sweet build. Looks almost too nice for a runner, but should be a blast to drive.

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Re: JRX Pro SE runner build

Post by sixdub »

Thanks all! 8)
I'm still working on axle lengths and shims to get the track width right. I'll post details when I get it sorted. I'm sure a thread exists here that spells it out, but I haven't spent much time searching.

A little progress. Upclose with the Sabulatech battery holder and servo mounts. To avoid servo tape, I'm using Kyosho RB5 mounts I had at hand. I'm also using Sabulatech bearing bellcranks.
Image

The shocks arrived, bigbores for a Losi 22-4. They should be pretty close to the right length, but may need an internal limiter to be perfect. Spring rates may be a challenge to get right, but I'll build them with the supplied springs and deal with it later.
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Kyosho, JRX-2, Gold Tub Fan

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Re: JRX Pro SE runner build

Post by Delorean »

re the gearing

Generally brushless need a taller ratio than its comparable brushed motor so if i were choosing, i'd be going with the 2wd box rather than the truck one but great build either way!!

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Re: JRX Pro SE runner build

Post by sixdub »

Delorean wrote: Thu Feb 23, 2017 7:40 pm re the gearing

Generally brushless need a taller ratio than its comparable brushed motor so if i were choosing, i'd be going with the 2wd box rather than the truck one but great build either way!!
For sure I considered a buggy ratio, but 2 things led me to the truck ratio:
1. I already had most of the truck ratio stuff
2. I can use the gearing knowledge and pinion stash from my RB6, which has a 2.6 internal ratio.

If I get in a gearing "bind" :mrgreen: I may just have to build a buggy trans.

A little more progress. Built the 22-4 shocks without oil to test fit.
Image

Rears fit nicely. Length looks spot on.

Image

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Droop looks ok

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Fronts fit well. Overall length is a couple mm too long. I'll have to install some internal limiters .

Image

I'm using upper shock mounts from a Losi SCTE and had to drill both the towers and the 22-4 shock bushings to fit, as the mounts are larger diameter with 5-40 hardware.

Image
Kyosho, JRX-2, Gold Tub Fan

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Re: JRX Pro SE runner build

Post by Splat! »

Thats looking great, Nice work!

Did you see the guy selling woven carbon towers on the bay for this and other older Losis? They would set this build off perfectly!
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Re: JRX Pro SE runner build

Post by Splat! »

What are you doing for wheel hex drive system?
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Re: JRX Pro SE runner build

Post by sixdub »

Splat! wrote: Thu Mar 02, 2017 12:37 pm Thats looking great, Nice work!

Did you see the guy selling woven carbon towers on the bay for this and other older Losis? They would set this build off perfectly!
I have not, I'll check them out. Thanks!

I'm using B4 bearing front wheels and pin drive rears. I don't want to deal with the headaches of the hex conversion.
Kyosho, JRX-2, Gold Tub Fan

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Re: JRX Pro SE runner build

Post by LosiXXkid »

Splat! wrote: Thu Mar 02, 2017 12:37 pm Thats looking great, Nice work!

Did you see the guy selling woven carbon towers on the bay for this and other older Losis? They would set this build off perfectly!
I did.....
s-l500.jpg
s-l500.jpg (26.38 KiB) Viewed 3189 times
s-l500.jpg
s-l500.jpg (26.38 KiB) Viewed 3189 times
I'm now just waiting for them to arrive. :D
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matt1ptkn
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Re: JRX Pro SE runner build

Post by matt1ptkn »

LosiXXkid wrote: Thu Mar 02, 2017 6:21 pm
Splat! wrote: Thu Mar 02, 2017 12:37 pm Thats looking great, Nice work!

Did you see the guy selling woven carbon towers on the bay for this and other older Losis? They would set this build off perfectly!
I did.....

s-l500.jpg

I'm now just waiting for them to arrive. :D
Those towers look nice. I even like the packaging. I see they are both labeled as rear towers though. The seller must've needed to save some $ on the fancy packaging. :D
Matt

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Re: JRX Pro SE runner build

Post by mytimac »

Looking sweet, glad to see one intended to be a dirt collector and not a dust collector.
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Re: JRX Pro SE runner build

Post by LosiXXkid »

matt1ptkn wrote: Fri Mar 03, 2017 8:17 am
LosiXXkid wrote: Thu Mar 02, 2017 6:21 pm
Splat! wrote: Thu Mar 02, 2017 12:37 pm Thats looking great, Nice work!

Did you see the guy selling woven carbon towers on the bay for this and other older Losis? They would set this build off perfectly!
I did.....

s-l500.jpg

I'm now just waiting for them to arrive. :D
Those towers look nice. I even like the packaging. I see they are both labeled as rear towers though. The seller must've needed to save some $ on the fancy packaging. :D
I emailed the seller (Todd) because he didn't have the original front shock tower listed to which he replied that it was being cut and would be listed shortly so I think the header card was probably done in a rush!
~I'm a lot older now than I was then and wish that I knew then what I know now~

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