LOSI LST XXL Conversion ideas

[jpoprock]

How thick is yer CF plate going to be? Aren't you concerned with it not being durable for "bashing"?

[mistercrash]

The stock plate is 2.5 mm aluminum with a thousand holes in it for the tranny, the gears, the multitude of servos and what not. The CF plate is also 2.5 mm thick and has much less holes in it and CF is stronger than aluminum. If the stock aluminum plate is strong enough then the CF plate will be more than adequate.

On another note, I got myself a HPI FLUX motor mount to use for the rear of my 1521.

[Chadworkz]

Originally Posted by mistercrash

Since I have the T6 6061 alu sheet, I thought I would make a template of the final top plate that will help cutting the 2.5 mm CF plate that finally came in this morning. The CF plate is almost finished. I will post pics when it's done and then I should be able to start assembling the truck.

WOW, just WOW! You did an excellent job on that upper template! Even though it is just a template for making the final CF part, the aluminum template is flawless, and worthy of being the main upper plate in any build! Anyone would be happy to run that top-plate and show it off...you did an amazing job on it!

[Chadworkz]

Originally Posted by jpoprock

How thick is yer CF plate going to be? Aren't you concerned with it not being durable for "bashing"?

Like MC said, carbon-fiber is MUCH stronger and stiffer than aluminum, so there will be zero problems with strength or durability. In fact, the strength & durability of the carbon-fiber will be 10 times that of the stock aluminum...maybe even more!

[JThiessen]

Hey MC - I just noticed your location for the steering servo. It appears to be about a half a servo behind the stock location. What drove you to locate it there (I'm cutting my templates today....).

[jpoprock]

If that is the case... then why do so many people say "If yer bashing go alum, if yer racing go CF"? What they are saying is... bashers shouldn't use CF cuz it's more prone to break. No? Now, I've heard there are different degress of CF too. Integy CF is not the same strength as say a Vantage I'd guess. I know for a fact that Integy aluminum may as well be "plastic" cuz it bends easily. So I have no doubt that Integy CF weak too.

[Chadworkz]

There are very few places where aluminum should be used, but there are a ton of places where carbon-fiber can and should be used. Quality carbon-fiber is not only stronger than aluminum, it is stronger than steel as well, and far lighter than both. Aluminum will bend and stay bent, where as in the same instance, carbon-fiber may flex, but it will return to its original shape/position without any breakage or problems.

A lot of "bashers" say to use aluminum because they just like the bling factor, but in most cases, aluminum is not a good choice for most applications. Of course, if you are talking about building a full-blown Unlimited Engineering Supermaxx, then aluminum is fine, because UE uses 7075-T6 aluminum which is MUCH stronger, harder, and more durable than the industry standard 6061-T6 aluminum. But again, if the part can be made out of carbon-fiber, it should be, because carbon-fiber is (as I have stated) so much stronger, stiffer, more durable, far lighter, and just plain looks cooler!

[mistercrash]

Picture posting time!

Sorry for the delay but I started putting everything together and it was going so well that I couldn't stop.

After a couple months of thinking, planning, drawing, thinking, redrawing, shopping, and yadeeyadeeyadah. This is what I came up with for a LST conversion.

PARTS MODIFIED

I modified the chassis rails to make room for the Muggy steering. The bellcranks of the Muggy steering were also modified.

PARTS FABRICATED

To make the conversion, I made a new chassis top plate, a new middle skid plate, a front skid doubler for the steering, battery boxes from project boxes found on ebay, a mounting plate for the receiver box, a system to support the rear of the motor, a new motor plate. While I was at it, I made the plates that go under the shock towers out of CF but that is optional. I could've made other stuff out of CF but for now I want to keep those stock aluminum parts on the truck.



PUTTING EVERYTHING BACK TOGETHER

This is just a series of pics of the build in sequence. Many pics so I'll to post a few times.

TOP PLATE

[mistercrash]

CHASSIS RAILS, MIDDLE SKID AND BATTERY BOXES


COMPLETED CHASSIS


FRONT END

[mistercrash]

REAR END


MMM, RECEIVER, CAP BANK AND MOTOR WIRES

[mistercrash]

WHEELS ON, BATTERIES IN. IT'S ALIVE!


LOOKING PRETTY


TOTAL COST OF THE BUILD
$1293.56 CDN. Almost $340.00 of that is for shipping and brokerage fees

[mistercrash]

I just took the truck out for a spin. Just taking it easy in front of my house to get a feel for the truck. Handling is very very MT like

It is very different from my race E-Revo which has a more Truggy feel to it. But it was fun. I was running on a set of 3S lipos that were pretty empty, the top speed is not impressive. I will have to play with the gearing on that. I say it really felt like a MT probably because I am still on the stock springs and am running the thin sway bars at their softest setting so the suspension was very plush and soft. But those batteries placed low and on either side of the chassis are making it so the truck does not flip on fast cornering. Instead the tires will just loose traction and the truck will slide. No flipping on the lid at all. I have tons of steering off power and still a lot on power. Having so much weight up front really helps. That 1521 has so much torque I will surely be able to gear down to get more top speed. I had to bring the brake power up because that cap bank smooths the braking so much, it was hardly noticeable. I'm up to 75% braking from 30%.

[nitrostarter]

MC! Great job there! Nice finish on the chassis and battery boxes!!

I didn't see where you stated your gear ratio.

I'm not sure what kind of top speed you are looking for but here is how I ran my 1521/1Y 6s powered LST XXL:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.090909090909091
Other Ratio: 1
Spur Tooth Count: 63
Pinion Tooth Count: 26
Total Voltage: 22.2
Motor KV: 1577
Tire Diameter (inches): 6.6
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 2.42 : 1
Total Ratio: 16.7582 : 1
Tire Circumference (inches): 20.73 inches (526.66 mm)
Rollout: 1.24:1
Total Motor Speed: 35009.4 RPM
Vehicle Speed: 41.02 mph (65.89 km/h)
Effective KV Value: 1577
KT constant: 0.86 oz-in/A
Motor Torque: Amperage not specified...
Final Torque: Amperage not specified...
Final Power: Amperage not specified...

This was pretty quick for the LST and it's "MT" handling. Maybe your gearing is off? Not sure...

[mistercrash]

I think the E-Revo tranny I am using throws the data a bit. I have a 58 spur and a 22 pinion on right now. But I was also running lipos that were almost empty and the LVC kicked in after only 7 or 8 minutes of running easy. I only did one top speed run, maybe the voltage was just too low. I'll recharge the batteries and try again before I start playing with gearing. I might have to get other pinions from Mike as the biggest one I have is a 22. Going to nitro Revo spurs with matching pinions might be another option. But I don't think I'll have to go that route.

What springs were you running?

This is what I get from what's in the truck right now so it should've been more than adequate. As you can see, the E-Revo tranny ratio is very different from yours. I also chose the XXL tire option which is larger than what you have on your info. There's also a big difference in roll out from yours.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.8333333333333333
Other Ratio: 1
Spur Tooth Count: 58
Pinion Tooth Count: 22
Total Voltage: 22.2
Motor KV: 1577
Tire Diameter (inches): 6.75
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 2.64 : 1
Total Ratio: 15.98718 : 1
Tire Circumference (inches): 21.21 inches (538.63 mm)
Rollout: 1.33:1
Total Motor Speed: 35009.4 RPM
Vehicle Speed: 43.97 mph (70.64 km/h)
Effective KV Value: 1577
KT constant: 0.86 oz-in/A

This is what I get if I choose the same size tires as yours. It still shows plenty of top speed.

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.8333333333333333
Other Ratio: 1
Spur Tooth Count: 58
Pinion Tooth Count: 22
Total Voltage: 22.2
Motor KV: 1577
Tire Diameter (inches): 6.6
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 2.64 : 1
Total Ratio: 15.98718 : 1
Tire Circumference (inches): 20.73 inches (526.66 mm)
Rollout: 1.30:1
Total Motor Speed: 35009.4 RPM
Vehicle Speed: 43 mph (69.07 km/h)
Effective KV Value: 1577
KT constant: 0.86 oz-in/A

[JThiessen]

Originally Posted by JThiessen

Hey MC - I just noticed your location for the steering servo. It appears to be about a half a servo behind the stock location. What drove you to locate it there (I'm cutting my templates today....).

Hey - curiosity is killing me here man....