Lunchbox with Ampro parts. Now with more Pumpkin!

[Kingfisher]

I just installed the Ampro double wishbone suspension arms (8mm offset) and transmission brace on our Lunchbox. The difference is quite noticeable. It looks like it's ready to go rock crawling. 

 

 

[Country Mike]

awesome

[Wooders28]

It's on my wish list!

Another, why didn't tamiya do this....

[Kingfisher]

Over the last few months, I have come to the realization that "OUR" Lunchbox has actually become "My girlfriends" Lunchbox. She's named it, refers to it as her Little Buddy, and treats it like a little robotic pet. She'll go on walks with it following just a few feet in front of her as if it were a dog on a leash. It's become clear to me that it's her favorite RC that we have. Right after we first built the Lunchbox, I got her the Amarok Custom Lift to build. It's been sitting on a shelf unbuilt and untouched for almost a year now. Anytime we take RC cars out, she always chooses the Lunchbox. I'll offer to let her drive any of the others that I have, and she declines. Sometimes, she'll accept my offer and drive another car for a very brief run around the lot, then give me back the controller in favor of the Lunchbox. If I want to drive the Lunchbox, my time is limited because she will be quietly waiting for me to finish. I fix it when it breaks, upgrade as I please, and she has a lot of fun with it. I'm fine with that, and glad that it brings her joy.

But, I also see other things when she really gets into the fun of it. She launches it over jumps that I'd be weary of attempting. Drives it head on into obstacles, sends it tumbling over rocks at full speed, crashes it into things, does backflips off of trees, and just generally beats the crap out of it sometimes. And it keeps going without a single problem. She's only ever broken body mounts. I think she's so confident and careless with it because we put the nicely painted body on a shelf and use a plain black body that we got as a bash body where she doesn't have to be concerned with scrapes or scratches. Because of all of this, I have given up the thought of any ownership of the Lunchbox. 

I've built myself a Midnight Pumpkin following the same format as her Lunchbox.

It's the Metallic Special. I couldn't bring myself to allowing the nice metallic body to get beat up when my entire purpose for this build was to beat on it. Just like her Lunchbox, I got a black body for it. I went for the cheapest body parts I could find on eBay, which happened to also be for a Metallic Special. I have a black body, with the metallic grill and tailgate. At first, I thought I was a bit silly putting the metallic body on the shelf, but truthfully, this would be me with it:

 

Matching the Lunchbox build, I included full bearings, Sport Tuned motor, Ampro double wishbone suspension arms (8mm offset) and Ampro transmission brace. Both also have a metal rear shock mount, which relocates the shocks just a little further away from the motor. I also added the Ampro diff locker, which is something the Lunchbox doesn't have yet. 

When we first built the Lunchbox, we added CVA shocks. I don't remember which ones, but I do remember we chose shorter shocks to compensate for the funny wheel droop that the Lunchbox originally had before the Ampro parts. I used Blackfoot CVA shocks on the Pumpkin, and the difference is quite dramatic and really shows the benefit of the Amrpo suspension arms.

 

 

 

I'll do some testing with the taller ride height to see if I like it, or if it's too tall and rolls easily. 

More pics:

 

 

 

 

[nowinaminute]

I definitely need to get a Lunchbox sooner or later and double wishbones at the front will be a major priority. I wonder how well a new version with a modern chassis would sell? I know it would outrage purists but it would be nice to have the option. Lord knows the rerelease holiday ****** handles better than the original!

[Mad Ax]

To be honest, a "new version with a modern body" would just be a WR02 with a slightly longer chassis to correct the wheelbase.  Or even a GF01 for 4wd.

For years I intended to build a "Box Deluxe" based on a shortened TL01 with Wild Willy 2 wheels, but I never got around to it.  The GF01 pretty much ticks that box anyway now.

I do love the look of those Ampro arms tho - I'm supposed to be restoring a friend's original Pumpkin, but I've had it a few years and he still hasn't committed to spending any money on the parts it needs.  I think I just need to make him an offer to make it mine and start throwing some of these awesome 3D parts at it  

[Phil_H]

Always loved the LB...

My 4x4...using Maverick Scout Chassis parts, TLT Axles and a bit of blood, sweat & tears to get it right. (I bought it as a 4x4 converted LB..but it was pretty poorly done)

 

[Munchbox]

King, I run Blackfoot cvas on my non double wish bone front Lunchbox. I built the fronts to a length for neutral camber and the rear to match standard ride height. I use the brass colored (rear BF) springs on the front of my Lunchbox and silver springs on the rear. The ride is great. With this setup, third shock mod and a front strut brace it was ready for brushless.

So I went with a 2400kv sensored brushless motor and that was pretty close to your Sport Tuned but with tons more torque. Runtimes were insane. 60+ mins on a 3000mah NIMH.

Of course that wasn't enough so I switched to the Hornet pinion and lost the Lunchbox motor mount. This made tons of clearance for my motor from the rear shocks and close to doubled my top speed. All the torque in that brushless motor means I'm still doing great wheelies too, just that I can make 28mph in a straight line.

Funny thing is I still don't think I want to try the front double wish bone setup. The front seems fine at full speed even on bumps but my main problem is traction. I was thinking maybe spiked Chevron tires next time around..

[nowinaminute]

I definitely want to make one on a 4x4 chassis, maybe shortened tl-01.  I want to make 2 actually, 1 lunchbox and the other one a replica of my favourite toy grade ever and my only decent RC as a kid, radio shack jumbo van! Body style is exactly the same as the Lunchbox but it needs to be 4x4 like the original and maybe with the shorter arms to keep the track width narrower like the original too.

[Kingfisher]

20 hours ago, nowinaminute said:

I definitely need to get a Lunchbox sooner or later and double wishbones at the front will be a major priority.

The combination of the suspension arms and rear trans brace makes a big difference in handling. It rolls over a lot less when turning at speed and feels more stable.

 

14 hours ago, Mad Ax said:

I've had it a few years and he still hasn't committed to spending any money on the parts it needs.  I think I just need to make him an offer to make it mine and start throwing some of these awesome 3D parts at it  

A few years? He's probably already forgotten about it. I'd make an offer and make it fun again.

13 hours ago, Phil_H said:

Always loved the LB...

My 4x4...using Maverick Scout Chassis parts, TLT Axles and a bit of blood, sweat & tears to get it right. (I bought it as a 4x4 converted LB..but it was pretty poorly done)

 

Awesome. Never thought to use a shovel. I enjoyed watching yours in action. Nice work.

 

9 hours ago, Munchbox said:

King, I run Blackfoot cvas on my non double wish bone front Lunchbox. I built the fronts to a length for neutral camber and the rear to match standard ride height. I use the brass colored (rear BF) springs on the front of my Lunchbox and silver springs on the rear. The ride is great. With this setup, third shock mod and a front strut brace it was ready for brushless.

So I went with a 2400kv sensored brushless motor and that was pretty close to your Sport Tuned but with tons more torque. Runtimes were insane. 60+ mins on a 3000mah NIMH.

Of course that wasn't enough so I switched to the Hornet pinion and lost the Lunchbox motor mount. This made tons of clearance for my motor from the rear shocks and close to doubled my top speed. All the torque in that brushless motor means I'm still doing great wheelies too, just that I can make 28mph in a straight line.

Funny thing is I still don't think I want to try the front double wish bone setup. The front seems fine at full speed even on bumps but my main problem is traction. I was thinking maybe spiked Chevron tires next time around..

60+mins on a 3000man NIMH is crazy. Nice work. Can you elaborate more on the Hornet pinion? Does using the Hornet pinion allow the motor to mesh up to the trans without the motor mount? 

 

2 hours ago, nowinaminute said:

I definitely want to make one on a 4x4 chassis, maybe shortened tl-01.  I want to make 2 actually, 1 lunchbox and the other one a replica of my favourite toy grade ever and my only decent RC as a kid, radio shack jumbo van! Body style is exactly the same as the Lunchbox but it needs to be 4x4 like the original and maybe with the shorter arms to keep the track width narrower like the original too.

I googled for pics of the Jumbo Van just to see it, there's even one on eBay right now. The body style is the same, but is the Jumbo Van the same physical size as the Lunchbox? It would be neat to paint and sticker a Lunchbox the same as the Jumbo Van.

[nowinaminute]

1 hour ago, Kingfisher said:

4 hours ago, nowinaminute said:

I definitely want to make one on a 4x4 chassis, maybe shortened tl-01.  I want to make 2 actually, 1 lunchbox and the other one a replica of my favourite toy grade ever and my only decent RC as a kid, radio shack jumbo van! Body style is exactly the same as the Lunchbox but it needs to be 4x4 like the original and maybe with the shorter arms to keep the track width narrower like the original too.

I googled for pics of the Jumbo Van just to see it, there's even one on eBay right now. The body style is the same, but is the Jumbo Van the same physical size as the Lunchbox? It would be neat to paint and sticker a Lunchbox the same as the Jumbo Van.

Well this is the part I agonise over. It would be easiest to do a minor wheelbase reduction and use a lookalike Lunchbox shell to make a big bad version of the original but on the other hand, if I aggressively shortened a TL-01, losing the battery holder and all, then I think I can make the wheelbase match the original shell. And if I use on-road size arms like on a WT-01N then the wheels wouldn't stick out too far, just typical monster truck proportions.

So the pros for lunchbox shell are this:

Smaller reduction of chassis needed and no battery relocation
Small suspension arms should give a track width similar to the original or I have the freedom to use TL-01b arms too and it will still look good.

And the biggest con is that it will be substantially larger than the original.

With the original shell the biggest pro would be the overall scale would be much closer to the original but the cons are that even with the short arms it will have a much wider track than the original and also having to relocate the battery is a pita.

Really tough call. There's one other toy grade I'd like to do the same thing with though so maybe I can try different techniques on each and decide which works the best.
 

[Munchbox]

King the Lunchbox and Hornet share the same gearbox the difference is that the Hornet uses a shorter 18 tooth pinion and no motor spacer mount. The motor goes straight to the gearbox making lots of room for the shocks. 

The stock LB pinion is a 10 tooth so you'll need a medium kg brushless or high kv/lipo setup to keep enough torque to do wheelies. The 2400kv I use is perfect for this and was neck and neck when I drag raced a Pumpkin with a sport tuned motor (on the 10 tooth pinion) I think it topped out at 17 mph was what the gps said. On the 18 tooth pinion I have clocked 28mph.

A word of warning: you will not want to use the Hornet pinion unless you are using a brushless motor. Your ESC will be bouncing off the thermal limiter in just a few minutes with a Sport tuned brushed motor.

[Kingfisher]

20 hours ago, nowinaminute said:

Well this is the part I agonise over. It would be easiest to do a minor wheelbase.........
 

Have you seen the Youtube channel called TheLEDwheel? He took a Radio Shack Monster truck, ripped out all of the old electronics, and fitted it with modern servo, ESC, and receiver.

https://www.youtube.com/user/TheLEDwheel/search?query=rst3

10 hours ago, Munchbox said:

King the Lunchbox and Hornet share the same gearbox the difference is that the Hornet uses a shorter 18 tooth pinion and no motor spacer mount. The motor goes straight to the gearbox making lots of room for the shocks. 

The stock LB pinion is a 10 tooth so you'll need a medium kg brushless or high kv/lipo setup to keep enough torque to do wheelies. The 2400kv I use is perfect for this and was neck and neck when I drag raced a Pumpkin with a sport tuned motor (on the 10 tooth pinion) I think it topped out at 17 mph was what the gps said. On the 18 tooth pinion I have clocked 28mph.

A word of warning: you will not want to use the Hornet pinion unless you are using a brushless motor. Your ESC will be bouncing off the thermal limiter in just a few minutes with a Sport tuned brushed motor.

Thanks for the information. I very well may do this swap in the future.

[nowinaminute]

10 hours ago, Kingfisher said:

 

Yes! I know the guy through a few facebook groups etc, very inventive guy. I have the same truck, also modified!
 

It handles surprisingly ok off road up to a certain speed thanks to it's big soft tyres but there's no escaping the serious limitations of having no suspension, even the basic friction setups on toy grades and lower end Tamiyas are a lot better than nothing once you're going fast. Same story with the Van really, that's why I'd like to try and make a replica of it that's more capable of going fast off road. The originals are great for slower stuff though like taking on forest trails and paths etc, amazing how steep they can climb, it's only the fact that they tip backwards that stops them lol. That's why the Van I had as a kid left such an impression. Even using it now and totally stock it's still amazing how well it can off road compared to modern toy stuff which is 99% useless. It's not a pro crawler by any means but it definitely tries hard for a toy.

[nowinaminute]

 

21 hours ago, Munchbox said:

 

A word of warning: you will not want to use the Hornet pinion unless you are using a brushless motor. Your ESC will be bouncing off the thermal limiter in just a few minutes with a Sport tuned brushed motor.

I have been continually amazed by how tough and cool running brushless systems are, I have a hobby converted Nikko truck that started off with a brushed 380 motor and trying to put faster brushed motors in resulted in burnt out motors. I decided to try brushless but because brushed 380 has 2.3mm shaft and brushless 380 has a 3.17mm I had to go down to a 2445 brushless which is essentially a brushed 280 diameter can but longer. I was sceptical that this tiny motor would work in such a large truck but it not only worked but it ran cool too! I gave it an extreme torture test by blasting it up a grass hill over and over and it was only lukewarm afterwards, like some kind of voodoo! The only time this little motor has ever gotten hot was when I was blasting the truck around on sand with the throttle wide open for 20-30 minutes and even then it wasn't REALLY hot and loose sand is a strain for any motor. The only downside is that it can cog slightly if you try to pull away very gently but to be honest I've seen setups with bigger motors that are worse for that. I've also had the same motor in my Grasshopper and it was great in that too and the lighter motor can't hurt when it comes to reducing that massive unsprung weight.
 

After that I tried a brushless in my Radio Shack Dash (I posted the video in another post just above) this truck uses 280 brushed motors but again, trying to put faster motors in there was a disaster as they just burnt out. I put in a 2430 size brushless and it hasn't missed a beat, I've even taken it on hours long hikes and the motor hasn't overheated.

Brushless motors run much cooler all other things being equal. In fact, several of my "540" brushless motors are not 540 at all and just 380 motors with huge heat fins that fill them out to 540 size and they still run much cooler than brushed 540s.

[Kingfisher]

2 hours ago, nowinaminute said:

Yes! I know the guy through a few facebook groups etc, very inventive guy. I have the same truck, also modified!
 

.

I've had no interest in upgrading a toy rc vehicle with the abundance of Tamiya kits that I want and don't have, but between theLEDwheel and your video above, I am reconsidering my choice. I may start watching eBay and see if one comes up at a price that tempts me. Nice work.

 

2 hours ago, nowinaminute said:

 

Brushless motors run much cooler all other things being equal. In fact, several of my "540" brushless motors are not 540 at all and just 380 motors with huge heat fins that fill them out to 540 size and they still run much cooler than brushed 540s.

I read somewhere that half-turn 540 motors (example: 10.5T 540) are actually 380 motors in a 540 can. Do you know if that statement is true? 

[nowinaminute]

35 minutes ago, Kingfisher said:

2 hours ago, nowinaminute said:

 

Brushless motors run much cooler all other things being equal. In fact, several of my "540" brushless motors are not 540 at all and just 380 motors with huge heat fins that fill them out to 540 size and they still run much cooler than brushed 540s.

I read somewhere that half-turn 540 motors (example: 10.5T 540) are actually 380 motors in a 540 can. Do you know if that statement is true? 

That seems to be the case a lot of the time yes but also a lot of the Chinese suppliers don't even give a T rating and just KV but you'll notice a similar thing where all the motors with a KV rating ending in 00 ie 3300KV 5200KV seem to be full 540 motors and most of the ones ending with 1 zero such as 3930kv 4370kv are the ones that are 380 motors with find on them.

The easiest way to tell is to just look at them, the ones with the fins are obvious, reminiscent of an air cooled motorcycle engine with the cooling fins all around it. 

I might just be lucky but every cheap Chinese brushless motor I have bought has been fantastic and some of them were ridiculously cheap like £4 for a 2430 size, that's cheaper than any hot 280/370 brushed motor and even the 540 ones can be as low as £10 or less than £30 with an ESC. The best bargain I got was a while back for 2 3930KV 380 size motors and matching escs which came to about £25, I fitted them in my old Nikko Dictator, now that is a good one to modify, the car was more or less hobby level and just happened to come off an assembly line, they even sold bearing kits and faster motors back in the day! 
 

I don't always put brushless motors in everything but it's nice to have something that you know isn't going to ever overheat and will usually have as much power as you could ever want. If a brushed motor is doing the job I won't change it but any time I find a vehicle that tends to eat motors now I just switch to brushless and it cures the problem instantly and that's without even putting a heatsink or fan on.

[GregM]

11 hours ago, Kingfisher said:

I read somewhere that half-turn 540 motors (example: 10.5T 540) are actually 380 motors in a 540 can. Do you know if that statement is true? 

This is wrong.

Usually, something like 10.5 turns or something else with .5 means there's a full 540 motor .
Just don't expect every manufacturer or seller following this code. Look for the telltale cooling fins to uncover a 380 motor in a 540 disguise.

[GregM]

10 hours ago, nowinaminute said:

(...) thing where all the motors with a KV rating ending in 00 ie 3300KV 5200KV seem to be full 540 motors and most of the ones ending with 1 zero such as 3930kv 4370kv are the ones that are 380 motors with find on them.

It is not uncommon to see a full 540 brushless motor advertised with an odd kV rating. E.g. Carson Modelsport sold full 540 brushless motors with an odd kV rating and without noting .5 in the turns specification.

To my knowledge, the only true indications of a 380 in disguise are the cooling fins integrated into the can.

[nowinaminute]

One other thing people often miss is that brushless motors come in various can lengths for the same diameter, much more than with brushed motors. 380 diameter motors come in lengths right up to 65mm, that's longer than a brushed 540 and much longer than a brushed 380 which is about 38mm.

These finned 380 motors probably have the same rotor size as 2850 motors so while they are only 380 size in terms of diameter the rotors are probably as long as a 540 motor which would help explain how they seem to work so well. In terms of "displacement" they are probably in between a 380 and 540.

[Munchbox]

Both of my brushless motors (15.5t, 2400kv in Lunchbox and 10.5, 3600kv in my Dt03) get hot. They're both sensored brushless and don't cog unless you're physically pushing the car around with your hand.

Both cars run the largest pinions available and both have loads of torque. The runtimes are similar to the original brushed motors I was running with smaller pinions but they're both much faster than stock.

I recommend this kv rating and setup for both cars, it keeps them both pushed right to the limit of their handling.

[nowinaminute]

5 hours ago, Munchbox said:

Both of my brushless motors (15.5t, 2400kv in Lunchbox and 10.5, 3600kv in my Dt03) get hot. They're both sensored brushless and don't cog unless you're physically pushing the car around with your hand.

Both cars run the largest pinions available and both have loads of torque. The runtimes are similar to the original brushed motors I was running with smaller pinions but they're both much faster than stock.

I recommend this kv rating and setup for both cars, it keeps them both pushed right to the limit of their handling.

That's why I like brushless so much, you can set them up exactly the same as the brushed motor you're replacing and they will be cooler and run longer and you then have a load of headroom to gear it faster and still only consume the same power as the slower brushed setup. Even when you gear them quite tall they still have excellent torque.

Sensored motors are definitely much smoother, I find with sensorless there's a lot of variation, I've had some that barely cog at all and others that are quite bad. That yellow radio shack truck I converted has a tiny 5800kv 280 motor and is locked in the "fast" gear yet it barely cogs at all no matter how slow and steep if goes. I've seen bigger and slower motors that have cogged more.

 

 

 

[Kingfisher]

Well, this happened. 

 

 

My girlfriend and I were running the Pumpkin in the back yard. We (she) was going on a full speed run across the back yard, got too close to a lamp post, and caught it with front tire. We heard a loud snap, thought "that didn't sound good", and had a look. On first glance, we didn't notice anything wrong, and continued running the Pumpkin. It ran fine without any noticeable handling issues through the grass. When I was going to put the Pumpkin away, I noticed what looked like a fracture in the control arm. I spaced it apart for the first photo. Any chance I could glue this back together and it would be fine, or should I just replace it all together? What glue would you use? 

I do not blame Shapeways or Ampro for the break. I blame the lamp post for being in the way. 

Build, Bash, Break, Repeat, Right? 

[TheMidnight Pumpkin]

Me, I would just use CA glue and give it a try. Worst case you have to repair it again, or just buy a new arm. A dot of glue is cheap in my world.

[TheMidnight Pumpkin]

5 hours ago, TheMidnight Pumpkin said:

Me, I would just use CA glue and give it a try. Worst case you have to repair it again, or just buy a new arm. A dot of glue is cheap in my world.

Sometimes I will add a bit of metal when gluing parts for extra strength.....forgot to add that to my previous post. In this case you can't really drill for an internal metal support. So maybe a little piece of paper clip glued on the side will keep it together.