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Nikko85

Radioshack 4x4 Off Roader Conversion

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I got this truck alongside the fake QD Clodbuster and have been wanting to do something with it for a while.

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This version is called the Off-Road Tiger, but the truck is based on the classic Tandy/RadioShack 4 x 4 Off-Roader released in 1985. It's not as pretty as the earlier blue and yellow trucks, but it is cheaper at least.

Even stock the car is pretty awesome for what it is. It's got a lovely double differential system so the left and right side of the car are linked to the same differential. The gearing is nice, with a great slow gear setting for really steep hills and a faster mode for the flats and it's pretty robust, with many examples holding up well after so many years. It does tip over and has no suspension, yet it climbs quite well.

It's not without issues however. The car takes 4 x C batteries (plus a 9V for the radio gear), it isn't that fast, and the steering and acceleration are not proportional.

With all that in mind I decided to give it a new lease of life.

The first job was cleaning out all the 35 years of accumulated leaves, grass and crap that had got stuck in the gears and drive.

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The shafts had a little oxidization on them, but the gears were in really good condition. I removed all the rubbish and greased up with my trusty marine grease. 

Next up with was the steering. This is one of the easiest conversions out there, I simply dropped a regular servo into steering mechanism. I've seen a few different ways to keep the servo locked in place, from large washers to 3D printed housing. I used a small section of a black plastic clothes hanger which was then bolted across the servo locking it down. It looks neat and seems to work very well. The bolts when straight into the pre-existing screw holes. 

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The battery was a little more tricky. I've seen lots of people cut away a small section so they can use a shorty lipo, but I'm happy to stick to NiMH. There wasn't space in the battery bays for many options, and space is also limited by the two drive shafts. In the end I decided to lay the battery on top of the chassis. This means you do need to remove the body to change the battery, but I think that was my best option. I stuck the battery lead out the car, so it can be charged easily, but I might move that connection to the battery bay again.

To keep the battery in place I used another section from the clothes hanger. This time the bar is attached by a pair of bolts which are attached to springs on the other side of the chassis in the battery bay. To insert the battery you lift up the bar, place the battery in and then the bar is pulled down by the springs, keeping the battery locked tight.

Next up was the body. The window had a massive crack in it, so I made new windows using double sided tape and green acetate. 

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I then added a blue opaque sheet so when you looked through the window it didn't look too messy. The blue through the green makes a colour that really works with the truck's colour scheme. I also remove the rear wing and some of the extra engine bits.

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And then I was done. The transmitter is almost an exact match for the wheels, which is a nice plus! 

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It runs pretty well. The 280 engine isn't a monster, but it's pretty respectable speed for a 35 year old truck! I could get a more powerful 280 motor, but if I do need more speed I'll probably looks to a brushless system to keep down the temperature. On low gear goes over a super thick pile rug with ease (and will pull wheelies on it) and on high gear it's more than fast enough indoors. 

It's not as lively as much other mini monster trucks, but it's quite fun still.

Any questions please shoot, I know these builds aren't for everyone but hopefully someone will find useful or be inspired.

 

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nice conversion :D

its about the right size for tamiya TLT (Tamiya Little Truck)

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thanks,

It's a little smaller than the QD trucks I've got, I think it's around 1/15 to 1/16 scale, although I think it was described as 1/12 scale to make it seem bigger to kids!

Those TLT do look nice, but I've not got three small scale (1/14 - 1/16) trucks, so I probably don't need any more.

Left to right is 1/18, 1/18, 1/16, 1/15? 1/14, 1/14 
 

nk7zGmO.jpg

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Nice conversion.  I'm liking what you do with these little trucks.

I never really looked at them before.  It seems not that long ago if I did a search for Clod Buster on ebay I would get a dozen hits for QD clods that I didn't want.  Now I actually want one (I want to make a neat-looking 1:14 scale monster to sit on a trailer behind my 1:14 scale big rig) they have become like gold dust :o 

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Many thanks,

These trucks were built really tough. They'd be played with by kids with no way to get new parts, so shops didn't want to be refunding angry parents I guess. One of the ways they were built to last was to be underpowered, so even a cheap ESC really wakes them up too, so you get a tough truck that's easy to improve. They are going much faster now, so they may break, but lots of cheap parts out there.

Good luck with the search. I saw a QD Clod go for £88 last week, so they are gaining some popularity, I guess people are realising how great they are (and people who played with them as kids are getting old enough to be nostalgic, like me). I'd say that these Tandy/RadioShack trucks are very similar in scale to the QD so you might find one of these to go on the back?

I also want to try one of the RadioShack Hot Machines. I'd love to see what the gearbox looks like, and if they fit a QD body - as they are 4 x 4.

 

 

 

 

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So having the truck for a week or two the stickers started to bug me a little, so I got out some white spirit and removed them all. 

I also decided the neon green wheels were too much, so I painted them chrome. I also redid the grill and engine hood, using shoe polish to give them a brushed, aged look. I cut down the oversized wing/rollcage and painted this chrome.

I made a new windshield set and finally added some white trim.

I think it looks much nicer now. Some of these 80/90s cars look amazing (Tyco Bandit or the original Yellow Radioshack 4x4) but the Off Road Tiger was not a design classic.

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In terms of how the car runs, I realised I really didn't like the lead coming out the car and coming back in, so I put the power lead connections and the on/off switch into the battery bay. You still need to take off the body shell to swap out the battery, but that's fine really.

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All done now I think. With a proper ESC, 2.4GHz radio and proportional servo it's certainly an improvement. It's also pretty good at moving through grass and rough terrain. It's not a proper crawler, but I think people would  be surprised at what it can do. And it looks pretty badass.

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Now I just want to add real headlights for the third channel of the Rx.

 

 

 

 

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Nice work! I have the yellow 4x4 off-roader from when I was a kid. I recently converted it too and now it's better than ever!

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Lovely, what's the ESC and battery? And are those LEDs in the front?

I'm really liking mine at the moment - it's just fun, great at climbing on low and squeals on high gear. Am debating a brushless at some point so I can really rip.

Andrew

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On 4/6/2021 at 10:46 AM, Nikko85 said:

Lovely, what's the ESC and battery? And are those LEDs in the front?

I'm really liking mine at the moment - it's just fun, great at climbing on low and squeals on high gear. Am debating a brushless at some point so I can really rip.

Andrew

That's a cheap 30A ESC from banggood. I use a small 1300mAh LiPo that I just slot into the battery compartment. The LEDs were a pain to install because there is little space between the back of the lights and the inner fenders. I recommend using shoe goo if you want to give it a go.

I'm not tempted to go brushless...yet.

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Photo Resizer 2021_04_07_08_35_06.jpg

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Well it seems like I blew out my motor today! I was running it pretty hard for 20 minutes and it just stopped. Steering still works but when I pulled the motor and connected it to a 9V battery...nothing. I guess the old motor didn't like the extra voltage from the lipo. Any advice for a good replacement?

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3 hours ago, Grumpy pants said:

@nowinaminute has a good font of knowledge and well worth asking 👍

yes, I think in the end he went brushless.

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Yeah I burnt my stock motor out pretty quick. All was well at first just pottering around in the slow gear off road and going up and down the street in the fast gear etc but before long, I got a taste for the high gear on grass and going up and down bumps and lumps and hills etc and the motor died very quickly. It got so hot the solder securing the windings to the comm melted and splattered everywhere. I re-soldered it but the same thing happened and this time the ceramic coating on the windings went black too so that was game over for that motor. This was only using a 7.2v pack made from 6 eneloop AA batteries too, not even lipo!

This was back in 2016 when I had just got back into RC since owning toy grades as a kid so I was still a bit naive and let someone convince me a more power motor would run cooler so I got a Dynamite Tazer 280 motor to put it. Top speed with this was great but within the first 5 minutes, I noticed the motor got noisy and top speed seemed to be intermittent. Turned out the plastic end bell on the motor had already melted and the brass bushing was just moving around of it's in free will among the melted plastic! Lesson learned: Faster motors of the same class run hotter not cooler!

I think the issue here is that the truck is quite heavy for it's scale and the 4x4 drivetrain adds additional drag so there's simply a limit to fast you can go with such a small brushed motor before you hit a thermal ceiling. The standard motor is simply too fast/powerful (for it's size) to run on 2s lipo or 7.2v nimh in this particular scenario. If you show it a hobby ESC and a lipo, it gives it enough rope to hang itself vs the 6v maximum it saw stock and with wimpy electronics limited to only a couple of amps.

The only easy solution if you want to stay brushed is to try a slightly slower motor which will draw less amps and get less hot but also not spin as fast either but it's a matter of compromise.

It can be quite tricky to nail down useful motor specs because they vary by manufacturer and some sellers give different specs for the same item etc. 

All I can really do is point you in the direction of something I tried and didn't have a problem with but I only tested it short term:

https://www.ebay.co.uk/itm/DC-3V-12V-6V-11200RPM-RF-280-2865-Micro-Carbon-Brush-DC-Motor-For-RC-Toy-Car-DIY/121983455790

Now that motor is a 2865 which means it should be 65 turn which in theory is the same as the stock motor but in practice mine was noticeably slower and seemed to run cooler too.

If that doesn't do it, you can get 85 turn motors like this one:

https://www.ebay.co.uk/itm/254854265896?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338624526&toolid=10001&customid=1a91a9560a05a746b78a0aaec44ac039

And maybe try a 120 turn one too? https://www.ebay.co.uk/itm/DC3V-6V-12V-16000RPM-Mini-Carbon-Brush-RF280-20120-Motor-Strong-Magnetic-for-Toy/264912169194?hash=item3dadfee8ea:g:6n4AAOSwMhVgWCqZ

Those motors are all cheap so might I suggest trying one of each and see which one gives the best compromise between performance and not melting? Speed is overrated in these things anyway. Although it's cool going around quite quickly in the fast gear, there are zero bearings in this thing so parts tend to wear out exponentially faster with every small increase in speed.

Another possible avenue is a 370 motor. Those are essentially the same size as a 280 with the same size shaft but they tend to be slightly more robust and heat tolerant (end can is usually metal) only problem is the holes on the front are spaced differently so you'd have to address that somehow.

Anyway, that's about all the advice I can give as I moved over to a brushless on mine.

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Thanks,  that's great advice.

I've got 9.6 volts in mine. I've not noticed high temps, but I'm playing on the flat inside at the moment. It's literally the perfect truck for driving inside on a rainy day.

I think if I go brushless I'll jump down to  7.2 or 6 volts. The Ezrun 2030 @9.6 v I've got in my similarly sized QD Pumpkin gives it more power than I'd ever need. However the Ezrun Combo is x 2 the price of the truck!

 

 

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A little video of the truck on a gravel track in my local park. It bumps around, even on the flat, but that just makes it more fun! 

It's surprisingly speedy, although I think it works better on a trail or path. Once again, surprised at how well these toy grade trucks run.

 

 

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On 4/14/2021 at 4:12 PM, Nikko85 said:

A little video of the truck on a gravel track in my local park. It bumps around, even on the flat, but that just makes it more fun! 

It's surprisingly speedy, although I think it works better on a trail or path. Once again, surprised at how well these toy grade trucks run.

 

 

Your original motor is holding up well. I'm about to order some replacements for mine. 

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Thanks, do let me know how it goes.

I was surprised at the speed on this to be honest. It's slow enough to drive carefully indoors but on an open flat it really came alive.

The 4 wheel drive also really helps on very low traction surfaces like the one above. I tried two QD trucks, which admittedly more powerful, were really sliding around on this surface and I had to manage the power to get them anything like straight, despite things like actual suspension.

I think I  will start looking for other cheap copies of the truck to build up some spares, as I think it's my favourite.

What's funny is the Taiyo versions of this truck go really cheaply - despite the truck being made by Taiyo, where as the Tandy/Radioshack versions of Nikkos are often super cheap and less than half the price compared to the real Nikko ones. It's why (despite my name) I've stopped collecting Nikko cars - also I feel they are too collectable to chop up! 

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On 4/13/2021 at 3:05 AM, phantomRC said:

@nowinaminuteThanks for the great advice! Hopefully I can find something reliable. 

I also wonder if a fan might help, either inside the gearbox (if space) or over the motor. However there's really little space under the body, so I'm not sure how much that might help. I've got a 3 channel RX, so I could try and see what fits.

I'm not sure if RC fans to much for a motor that's going to kill itself, or are they more for lowering moderate temperatures a little?

 

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On 4/11/2021 at 7:03 PM, nowinaminute said:

Yeah I burnt my stock motor out pretty quick. All was well at first just pottering around in the slow gear off road and going up and down the street in the fast gear etc but before long, I got a taste for the high gear on grass and going up and down bumps and lumps and hills etc and the motor died very quickly. It got so hot the solder securing the windings to the comm melted and splattered everywhere. I re-soldered it but the same thing happened and this time the ceramic coating on the windings went black too so that was game over for that motor. This was only using a 7.2v pack made from 6 eneloop AA batteries too, not even lipo!

This was back in 2016 when I had just got back into RC since owning toy grades as a kid so I was still a bit naive and let someone convince me a more power motor would run cooler so I got a Dynamite Tazer 280 motor to put it. Top speed with this was great but within the first 5 minutes, I noticed the motor got noisy and top speed seemed to be intermittent. Turned out the plastic end bell on the motor had already melted and the brass bushing was just moving around of it's in free will among the melted plastic! Lesson learned: Faster motors of the same class run hotter not cooler!

I think the issue here is that the truck is quite heavy for it's scale and the 4x4 drivetrain adds additional drag so there's simply a limit to fast you can go with such a small brushed motor before you hit a thermal ceiling. The standard motor is simply too fast/powerful (for it's size) to run on 2s lipo or 7.2v nimh in this particular scenario. If you show it a hobby ESC and a lipo, it gives it enough rope to hang itself vs the 6v maximum it saw stock and with wimpy electronics limited to only a couple of amps.

The only easy solution if you want to stay brushed is to try a slightly slower motor which will draw less amps and get less hot but also not spin as fast either but it's a matter of compromise.

It can be quite tricky to nail down useful motor specs because they vary by manufacturer and some sellers give different specs for the same item etc. 

All I can really do is point you in the direction of something I tried and didn't have a problem with but I only tested it short term:

https://www.ebay.co.uk/itm/DC-3V-12V-6V-11200RPM-RF-280-2865-Micro-Carbon-Brush-DC-Motor-For-RC-Toy-Car-DIY/121983455790

Now that motor is a 2865 which means it should be 65 turn which in theory is the same as the stock motor but in practice mine was noticeably slower and seemed to run cooler too.

If that doesn't do it, you can get 85 turn motors like this one:

https://www.ebay.co.uk/itm/254854265896?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338624526&toolid=10001&customid=1a91a9560a05a746b78a0aaec44ac039

And maybe try a 120 turn one too? https://www.ebay.co.uk/itm/DC3V-6V-12V-16000RPM-Mini-Carbon-Brush-RF280-20120-Motor-Strong-Magnetic-for-Toy/264912169194?hash=item3dadfee8ea:g:6n4AAOSwMhVgWCqZ

Those motors are all cheap so might I suggest trying one of each and see which one gives the best compromise between performance and not melting? Speed is overrated in these things anyway. Although it's cool going around quite quickly in the fast gear, there are zero bearings in this thing so parts tend to wear out exponentially faster with every small increase in speed.

Another possible avenue is a 370 motor. Those are essentially the same size as a 280 with the same size shaft but they tend to be slightly more robust and heat tolerant (end can is usually metal) only problem is the holes on the front are spaced differently so you'd have to address that somehow.

Anyway, that's about all the advice I can give as I moved over to a brushless on mine.

I've ordered one of each. Which pinion remover do you use? 

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I've used this before, and it works a treat. Do let us know how you get on, my motor is still working. I wonder if certain lower powered ESC might be an option too. More oomph than the original but not so much to fry it...

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