Retro Losi build

[300bhp/ton]

So after juggling some bits about I ended up with a spare ESC, motor and servo. So only needing an Rx and I could get my Losi up and running again. 

 

Not it sure it’s really all that old or retro. I bought it as a US import back in 1996’ish +-. But I guess that does make it 20 years old!

 

It has been raced a LOT. Even done a few National rounds with it back in the day. Mostly grass tracks and carpet. And it’s been bashed even more over the years. It really has been put through some abuse. 

 

This is isn’t the orignal shell but one from my brothers truck. It’s slightly younger but not much. 

 

 

That said only mods on it are titanium turn buckles. A ‘must’ mod for these. Front chassis bulkhead brace and a graphite front shock tower.  They were in their day pretty robust and durable. A few suspension arms and bits have been broken and replaced over the years. And I do still have a few spares including an extra chassis. 

 

 

 

 

 

It has a “bling” polished motor plate. Although stock ones were all aluminium anyway. Complete with functional hydra-drive behind the cover too. With a smooth and functional ball diff. 

 

 

These came well specced with lovely alloy shocks, super smooth and didn’t leak. Mines running custom 556 pistons and something like 30-35wt shock oil. 

 

 

I even have my last set of grass track race tyres fitted. Being Losi ‘silver’ Step Pins on the back and Stagger Ribs on the front. 

 

 

As it’s a retro build it’s tricked out with mostly retro electrics too. 

 

-LRP V6 ESC

-KO Propo PS-302 servo complete with separate booster box

-Street Fighter Modified motor (brushed). Think it’s an 11x3 but not sure without pulling it apart. Might be a 13 turn or a 10 turn. Either way it’ll be plenty for bashing. 

 

 

I did switch out the old Power Pole connectors I used to use for an XT60. The Power Pole was up to the task. Just a bugger to assemble compared to the XT60’s. And added a modern 2.4Ghz receiver. 

 

That’s it for now. Sadly by the time I got finished with it darkness had fallen. So will probably be next weekend before I get to run it. Will try and get some video of it in action. 

Edited February 18, 2018 by 300bhp/ton

[Planet xxt]

Awesome.

I've retired both of mine to the shelf due to lack of spares.

One is beat to death and on its last legs and the other one is minty fresh and too nice to use.

I love the way they drive and handle, so light and supple.

[Candyman]

That looks familiar............... I think I know you

[300bhp/ton]

1 hour ago, Candyman said:

That looks familiar............... I think I know you

I think you might be right.

 

In fact I suppose it would be appropriate to thank you for the quality of your paint job on my Losi above. Think it was around 1997/8 when you painted it. It’s held up incredibly well.

Edited February 19, 2018 by 300bhp/ton

[Candyman]

18 minutes ago, 300bhp/ton said:

I think you might be right.

 

In fact I suppose it would be appropriate to thank you for the quality of your paint job on my Losi above. Think it was around 1997/8 when you painted it. It’s held up incredibly well.

 

I couldnt tell if that was the one or not! oh boy, if you want a new one, my painting is a little bit better now.

 

If your after any bits let me know, I still have a few brushed motors I think, plus a bunch of other bits. Although im not sure I have any losi parts anymore.

 

 

[collective itch]

nice, am in the same boat with some rc10 gt's, do like the older stuff, wish stadium truck was still as popular today..

[J.K]

Whats the purpose of the booster box for the servo? I've never heard of one of those before, is it similar to a BEC?

[Si Coe]

Basically KO FET servos used to get a bit of extra power by running a 7.2V feed from the battery and using whats basically a mini esc to run the servo. It was too much to fit in a standard servo case so there was a separate booster box. 

Performance wise they still have impressive specs, but plastic gears and no spares means they are more for shelves now. 

[300bhp/ton]

No running video yet. But here is a steering test to give an idea of the performance of these ‘old’ FET servos. This one is a PS-302 FET. 

 

 

[300bhp/ton]

Got to give it a run today. Forgot just how well these drive. It felt light, nimble, stable and direct. 

 

Tyres weren’t the best but held up ok. 

 

Still have it geared for running 5 min races on 2600NiMh cells!

 

 

 

Sadly the run wasn’t faultless. The truck performed great. But the electrics didn’t!!!

 

I've had this before. My gut feeling is low turn brushed race motors (11 Triple in this case I think) with a high amp race ESC and LiPo batteries just don’t mix well. 

 

The ESC is an LRP V6. This was a £130 ESC nearly 20 years ago. Think it’s rated at 690amps Peak. 

 

The motor will suddenly stop. Did it a couple of times. The motor can nor ESC are hot. But the posts for the brushes are and I think the wires and terminals get hot too. 

 

The final time it stopped the result was the solder joint failed on the positive wire on the motor. I’ve seen this before too and always only the positive terminal. 

 

 

Very certain it’s not my soldering as I’ve been soldering wires like this since 1995. And all my LiPo connectors and those for my RC aircraft are soldered by me as are my brushless motors. It’s only this combo of old race motor/ESC plus LiPo that results in this. Think it might be time to ditch the old gear and fit a brushless system to the Losi. 

Edited February 25, 2018 by 300bhp/ton

[300bhp/ton]

So I thought I’d try and solve the issues I was having with motor wires de-soldering. 

 

Easy solution. Fit a brushless system!

 

Found this SkyRC Cheetah setup for a great price on eBay. Just over £40 delivered. And only took 2 weeks for delivery. 

 

 

3S compatible and 8.5T. But more importantly a sensored setup for smooth throttle precision. 

 

 

I upped the pinion gear a bit. Gone for a 19 tooth (48dp) and will see how it goes. 

 

Had to extend the motor wires a bit too. They were a shade too short. Apart from that just waiting on a servo. I’ve got a UBEC on its way from China to run my old KO Propo. But I’ve also bought a used Savox. The Savox is going in here and when the UBEC turns up I’ll fit the KO in my other Losi. A XX CR buggy.