QD build and information thread

[Nikko85]

The purpose of this thread is create a build thread that serves as a nice reference point for the QD series.

I am going to showcase two upcoming builds, one from the buggy and one from the monster truck class. 

All the builds are going to be resto-mods, adding modern hobby grade electronics and making brushed and brushless versions. I'll also be exploring options for different wheel options, including ways to get modern tires on the wheels, and new wheels on the chassis. I'll also be looking at alternative bodies you can use. Although this will focus on two builds - at the end I'll also drop some pictures of some other QDs I've made if that inspires people.

QDs are an interesting part in Tamiya history. Clearly designed to compete with the emerging "toy grade" market of the late 80s (which itself was inspired by Tamiya) they represent a really stripped back approach to vehicle design, with a really small number of parts. Tamiya must have sold lots of these, as they come up on Ebay quite a lot. 

Although the monster trucks can be expensive when complete you can pick up used or tired examples of both the buggy and the monster trucks quite cheaply, especially if you are not fused about the body or working condition. You can also pick up NOS spares, as although these might have been RTR, Tamiya designed them as upgradable, with bearings, new motors and even CVA dampeners. 

The buggies are often much cheaper 

I've bought two QDs, the first to arrive was a rather nice looking Avante 2001. Given the furore over the naming of the Super Avante, I wonder how this went down in 2001. Probably no one had the internet to get wound up on, so no one cared..

I've no particular love for the Avante, so the body will probably be going up on eBay, as it's in rather good condition. I will fix up the stickers and restore as best I can.

I'm not really a buggy person, I'm a truck person, but luck would have it, I've got a body I think is going to work well on this...

The original looks pretty darn good. The Quick Drives were not comicals, they were meant to match the 1:10 versions pretty closely, with a few cost saving corners cut.

Taking the body off there's a pretty sleek chassis underneath. It's basic as anything, but it all works. I've seen these with the bumper scraped down to nothing and completely bald tires, but rarely seen a broken one.

Like all truly great toy grade cars they had a gear selector switch. I think this is a cool feature I wish more cars would have now. The gearboxes are small and tough. The best way to think about these buggies is that they are small grasshoppers with a PCB over a mechanical speed controlled, and much smaller, with 210 mm wheel bases. 

The monster truck is in the post, and should be with me in a day or so.

[Nikko85]

The monster truck arrived. If the buggy was a solid 8/10 condition this is more a 4 or 5.

The springs are very rusted, the body is broken and the tires are shot, but the chassis is still all there.

Not planning on using this. It's more filler than body.

Chassis still pretty good however. Some rust on the springs but otherwise ok.

In order to keep the thread easy to follow  I am going to focus on the monster truck first but thought I'd share this now.

[svenb]

Although I'm not into QD's I'll find this interesting.👍🏻

[Nikko85]

On 4/28/2025 at 6:39 PM, svenb said:

Although I'm not into QD's I'll find this interesting.👍🏻

Many thanks. They are a cool slice of Tamiya history and make nice projects.

I decided to start the monster truck, as it is a more straightforward build. I will do the whole monster truck first then work on the buggy, just so I don't confuse the seven whole people who might actually read this whole thread!

I removed the cover and saw the PCB was pretty rusted over. I also don't have the transmitters this all get taken out and replaced. 

I usually keep the switches but this time I am going to make an exception.

Here is the whole car.

It's very similar to a CW01 but the front uses a solid axle. It's also smaller with a 195mm wheelbase.

Springs have seen better days. Seem to have some stickers placed between the shocks and springs.

My first job is going to be the rear axle.

Opened up and the gears are in great condition. They are thick and chunky and mostly 0.8 Mod. The pinion shows some brass dirt on it, but otherwise they are all pristine. I've seen people drop crazy brushless power in these and they hold up well.

I removed the rather weedy 280 motor. 

The motor sits on a metal plate with two small nubs that hold the motor in place and stop it rotating. These are 14mm apart from each other.

If you want to replace the motor you can simply get a faster 280 motor, new ones will still have this hole spacing.

You can also drill out these holes (they are pressed, so on the other side there is a depression making drilling a breeze) if you want to add small brushless motor. The EZrun 2030 works really well on these trucks and has a 14mm hole spacing option. This is probably the optimum solution.

This time I went for a 30,000 rpm 370 motor. I drilled new holes perpendicular to the old ones but this time 17mm apart. I used a 3.2mm drill bit to give myself a tiny amount of wiggle room. I used 3mm bolts to fit secure, making sure the bolts were not too long so they don't damage the motor. M3 x 5mm bolts were perfect with a little anti rotation washer.

Unlike the QD buggies there is a fair bit of space under the motor plate so the screw head won't foul any gears.

I also used a pinion puller to remove the stock pinion and place on the new motor with locktite to stop it moving. For reference it is 0.6M with 10 teeth and 2mm bore. From my experience most toy grade cars are 8 teeth so this is somewhat tricky to replace. 

I replaced the four bushings with standard 11x5 bearings. It's nice these motors take proper bearings in the most common size.  As well as keeping everything moving they also do a much better job of keeping dirt and hair out.

I finished these off with 12mm stainless bolts. 

For the gearbox you can also drill through and then put a nut on the other side if you want to. That's a good solution if the thread starts to go, but for now these are fine! 

[svenb]

Good luck mate

That electrical board would make me quit straight away 

[Nikko85]

On 5/6/2025 at 12:04 AM, svenb said:

Good luck mate

That electrical board would make me quit straight away 

Oddly it makes me happier. I usually replace with modern electronics. If there is a chance that they can be saved I feel guilty but this one was toast!

Steering next. For many cars doing hobby grade conversions steering is the hard bit. Here it is easy at least!

This is axle. It's servo on (or really in) axle. The steering on these is pretty darn good. The short wheelbase helps but on-axle steering (with zero wishbones to worry about) is about as direct a steering mechanism as you can get. 

 

You remove the 5 wire servo.

Very close in size to a regular servo. I trimmed off the wings from a simple waterproof servo and added a piece 3M  double sided foam pad to the bottom. The foam pad stops the servo moving down too far when pushed into the axle housing.

 

A very small amount of surgery is needed. The original servo is a little flatter, so you need to remove a small piece of the servo cover to allow it to close. I try and avoid doing too changes to the originals on these, but without it servos will struggle to fit. New old stock axle covers are available on eBay.

Simply push in and done. You can use the original servo saver and everything. For this build I've leaving the original steering rods. I've no doubt I could get some M3 rod and make some better adjustable steering rods, but these feel good enough for this type of bouncy vehicle. 

I loosely screwed back together with 10mm stainless screws. I've not got the electronics yet, so no point getting it all too tight if I've going to open up again to centre the servo! 

 

 

 

[Nikko85]

Bearings added to the front! They just take 2 standard bearings like most regular 2WD tamiya. With the front and rear axles pretty much done I decided to add some electronics.

The battery terminals were in really good condition so I was able to use AA batteries. I simply soldered a battery plug to the postive and negative terminals.

This then connects to the HW 1060. I could decide to hardwire the HW straight in, but to be honest this just makes it easier if I want to change ESC.

Other options are a small lipo or li-ion battery. I have found decent NiMH AA batteries work ok and have the old school charm too. For my brushless 12T monster truck I use li-ions but 9.6 volts of AA covers a 370 motor fine.

The old springs and shocks were quite rusty so I replaced with some from a RadioShack clone. You can see how close they were. These match the wheel colour really well.

I added wheels and tires. These are GF01 tires but I will probably go back to regular CW01 tires. Interestingly what we call GF01 tires were first released as a hop up for the QD series.

Next up was a wheelie bar. With a 370 motor this is going to wheelie, so I added a wheelie bar I designed and printed.

Next up is electronics. I removed a small section of the inside of the chassis to place the HW1060 switch where the original would have been. This is stuck to the side with double sided tape.

There's not really much to say here. The servo at the front largely slots in, and after fixing the motor and soldering you wire it all up and it is done. Some hobby grade conversions require lots of thinking but this is so close everything comes together so easily. 

Mechanically it's pretty much complete, so from here on in it is about making it pretty.

Here is what I am thinking, but as I want this to be a guide I will also show some other options!

 

This is Taiyo 4x4 1980s Ford Ranger. The yellow is a darn good match, and will look better once it's all spray painted it's certainly got that 80s monster truck vibe.

These bodies were made by Taiyo, and are still readily available. The body is a little worn, all the stickers are going and the chrome is disappearing,  but some paint and new vinyl and stickers and I think we'll have a winner.

I am pretty happy with it, certainly an improvement on how I bought it.

I've still got to  

• Completely clean
• Remove glue from wheels
• Get new tires
• Remove old stickers
• Paint
• Add decals

But I've done most of it. These are much more straightforward builds compared to what I have been doing recently, so it's nice to have something that only uses half my toolbox and I can crack on with in a few hours! 

 

 

 

[Nikko85]

Cleaned and repainted. I would have loved to use the original stickers but they were falling apart.

It was a lot paler underneath the stickers so I painted the while thing yellow to bring to the same colour.

The chrome was starting to go on the side strips so I used bleach to remove entirely, then added a black pinstripe.

I added some decals. I am not 100% at this point, but they look ok.

Wheels need a clean but it is almost done!

These bodies are a good option as they are lot more common than the official tamiya QD bodies. They have a 175mm wheelbase which fits on the 195mm for the QD pretty well.

At the moment it is just kind resting there, but I will show how I fit them.

[Kol__]

8 hours ago, Nikko85 said:

 

Looks amazing @Nikko85!!

Reminds me of this that I had as a kid...

[Nikko85]

Many thanks! I did have a blue taiyo body I was tempted with to make it even more like that playskool, but with yellow wheels I thought an all yellow truck would work, and it sits nicely with my other 1/16 vehicles in terms of palate.

I really like the look of these 80s monster trucks and fits the era when they were released.

 

[ucacjbs]

Great thread - thank you!

[Nikko85]

Body options

The most obvious choice are the original Tamiya ones. From least to most rare they seem to go Monster Beetle, Pumpkin, Blackfoot, Clod and then Jeep.

Underneath they are pretty much all the same, although the jeep was the latest released and had a 9.6 pack rather than 8 x AAs matching the trend at the time. The clod and blackfoot also had cool red axles.

I have only ever had my hands on the first two.

Being on the large part well used children's toys for the 80s to late 90s many are rather beaten up. 

Pristine examples, particularly of the Clod and Blackfoot seem to go for lots of cash, so I prefer to buy ones with broken bodies and then do my own thing. This means trucks are under £30 or so.

One options is the Taiyo 4x4 as above. These were sold for ages under the Tandy and RadioShack brands, as well as the Go RC brand as the Off Road Tiger. I have seen them in yellow, blue black and red. These are similar scale and size to the original Tamiya blackfoot and clod bodies.

If you want the original designs RadioShack also made some QD Pumpkin clones with the same bodies in cool colours which are a drop in swap. 

Going more modern there is the WPL D12. This has a good matching wheelbase and looks pretty cool.  This is more 1/10 scale, but I put it with my 1/12 collection.

You do need to drill out the bed to fit the shocks when they compress.

As this is roughly 1/12 it gets a driver

When making this one the thread on the gear box started to go, so I drilled through and added an m3 nut.

There are aslo MN models. They make a few different 200mm wheelbase cars, which is close enough. The FJ45 works well!

Same wheelie bar with printed blue wheel.

Lastly and now my personal favourite is the Lunchbox. The wheelbase is close enough so with a little trimming of the inside arches it all looks pretty good. This has a 3D printed grill to keep it all black.

For all these cars I used 7 to 12 mm hex converter and added GF01 wheels. At the front I used a spacer and two 5x12x4 bearings to replace the hex. This increased the track with quite considerably, which makes them much more stable. Under a 1/16 body this wheel conversion looks too wide, but fits this somewhat larger scale bodies well.

You can see the difference here.

This is also a good option as original wheels are often cracked. This means you can buy a chassis without body or wheels and still get it up and running.

There are probably lots mode bodies you can use, these are just ones I have found work.

[Nikko85]

15 hours ago, ucacjbs said:

Great thread - thank you!

Thanks. They are simple little cars but I enjoy them!

[lupogtiboy]

I do like the QD range, small and tough and can be modded quite easily. I was given a QD Clod many years ago, the shell was battered and it didn't work, but I swapped out the electronics for modern stuff and bashed it around for ages. It now runs a modded Grasshopper rear axle and 540 motor, so it goes quite well! 

I also have a QD Blackfoot shell on a painted Clod chassis with all new bits, looks smart. I found a boxed Clod at a bootsale cheap thats in pretty good shape, and I think I have the Monster Beetle too.

QD buggies are fun as well. I think I have 3, a Super Sabre, Thundershot that now has a EZ-Run brushless motor, and another buggy I forget the name of! 

I think somewhere I have a QD Ford Focus WRC that I was given, and maybe a Scooby? I haven't seen some of my RC cars for a while, so I forget now!

These are looking great though, I do like the yellow shell. I have a few of the Playskool Big Foot trucks, they are very similar. 

[Dante_R]

This is pretty awesome. I had the RadioShack version of the yellow truck. I recently just bought it again on eBay to rebuild it whenever I have time.

 

This is a pretty cool article about it here.
Tandy/Radio Shack 4×4 Off-Roader (1985) – R/C Toy Memories

[Nikko85]

I took the MT to the park but it felt quite slow, especially compared the the lunchbox QD 

Playing at home I realized the 370 motor was triggering the low voltage cut off, which was why it felt slow as it was running at half power.

I had a brushless QD version on Li Ion batteries, so I swapped the motors and ESC around, so I have the 370 on Li Ion and the brushless on AAs. This might sound counter intuitive, but the tiny brushless motor is very efficient so doesn't draw too much power, and you can turn off the LVC completely on the brushless set up.

Both now work pretty well, and I will do a test to compare. The brushless I am sure will be faster, but the smooth brushed power will also have some benefits!

When I compare I shall add in details here.

 

[Nikko85]

It would appear my trucks have been commandeered by my junior mechanic.

So let's move onto the buggy!

Whilst the monster truck has somewhat unique front axle set up (I can't think of many solid axle 2WD trucks) this is much more conventional, working like a small grasshopper. This means you have the same issues with camber gain as the suspension compressed is compressed. I may try a 3D printed option, taking inspiration from builds here to see if I can get double wishbone style suspension.

Like the monster truck this takes 9.6 volts through 8 x AA batteries.

There were two versions of the QD buggies.

Tamiya relased the Super Sabre and Thundershot in 88. Then the QD like got expanded to the monster truck line and it all got upgraded in 89 to include bearings and upgradeable motors.

The 1st generation had fixed bushings on the rear and the wheel straight on the axle at the front. 

The 2nd generation had bushings that could we be swapped for bearings and  better electronics and upgradeable motors. The QD Thunder dragon, Manta Ray and Avante were the most common of the 2nd generation, with some more obscure models like the Dash 1-4 models that seemed mainly for the Japanese market. The front arms are also wider by around 5mm.

Certainly in the UK the Super Sabre seems the most popular followed by the Thundershot. It's harder finding a good 2nd generation one, but worth it IMHO. It's not so much the you need bearings for super speed, but with the bushings you often get hair and dirt getting in. I have also found the front wheels on the first generation be quite wobbly. 

[Nikko85]

I had grand plans to get lot done this evening but I only managed to drill two small holes..

Once again the electronics were broken so this is getting a modern hobby grade conversion. 

It will have a 370 motor and HW1060 and a faster servo. I do have one brushless QD buggy but I've not got much space to run something that fast and these are too small for long grass.

So first up is changing the motor.

As with the monster truck there are no holes for the motor screws, there are just two nubs that the motor slots onto 14mm apart.

If you want a 280 motor just use these.

My 370 has a 17mm hole spacing so new holes would be needed. Some care if needed here in placement. The spur gear sits very flush to the gear case, meaning that a bolt to screw in the motor can foul the gear if placed in the wrong area.

You need to place them carefully so they are not under the spur gear or you may need to counter sink the thin plastic to keep the profile low. Due to the shape of the gearbox you are left with not much choice.

The silver coloured bolt is the one that is tricky. It's right on the edge against the side if the gear case. Any more to the left (anti clockwise) and it would not fit and any more to the left and it would foul the spur gear.

There's probably around 0.25mm before it would strike the spur gear! There might be other ways, but this meant everything fitted nicely. I have a hazy memory of getting this wrong in a car and having to counter sink the bolt, or slightly raise the spur gear to not foul the bolt

Finally drilled exactly correct. 

I used 3x5mm hex bolts to secure nicely. 

My pinion puller couldn't remove the original pinion, but I thankfully had a 0.6M 8T pinion that was long enough. The spur gear moves up and down as it goes from high to low, so you do need a longer pinion than most. 

All closed up with bearings.  Despite the motor being very slightly larger in diameter than the 280 the heat sink fitted fine.

I will bolt up and then sort out the steering.

[Nikko85]

Stainless M3 used to secure the two gearbox halves.

Five wire servo removed

Simple new servo added. Tabs have the be removed.

And a small piece of red plastic was placed behind to lock in place

I also made my own washer to keep the servo arm on, as I didn't have any correct size washers.

I then attach an ESC by soldering  female Tamiya connector to the postive and negative. Its a little busy but that's ok.

Now we add the body. I 3D printed some mounts to add the body posts.

And this is the result..

 

Happy with this!

I am using racing truck tires as they fit right on the stock wheels. Slightly wider at the rear but that looks ok to me.

I took for a quick spin. Brakes seem terrible and but otherwise runs nicely. Usually I add adjustable steering arms which I might do here, we'll see.

I will compare to my other brushes QD buggies. I am somewhat losing track of which have which motor so a speed test will be interesting!

In the next post I will look over some other body options too.

 

[Nikko85]

I added a better servo with ball connectors.

The steering is much tighter now

I also decided to solder the ESC straight to the AA tabs, forgoing the connector.

It all fits in ok. I could shorten all leads but they tuck into the chassis just fine.

With this done I was able to test out. It seems to work well but the brakes are terrible. They hardly have any power at all, and I am not sure why. In high or low gear the car doesnt really want to stop.

I know 370 motors aren't the most powerfull but these seem really bad. I've tried two HW 1060s and settings on radio are fine. They are technically working, so they'll stop the wheels from spinning, but there's almost no resistance. There's also very little drag brake.

I am almost tempted to use the F/R jumper just so I've got something that can stop the car.

All my other 370 qds are like this, apart from my brushless version.

 

[JimBear]

Just a question, sort of related to the "Pumpkin" above ... the rims, are they 12 mm hex or is it something else?

I am pondering "other tyres" options, thinking of the possibility to fit something high and narrow onto M rims - using something like the Tamiya truck tyres (1:14, if they would fit, not sure).

[Nikko85]

I was going to update on the tyre options so that's a good question! 

The QD rims above are not 12mm, they are 6mm I think.

These racing truck tires fit on m wheels usually, but they also fit here well enough! They are little wider on the rear but they still work nicely. Tires for m wheels generally fit well to QD rims.

It is also possible to fit m wheels on the QD with a 3D printer adapter for the rear.

I will showcase that later!

 

[wolfdogstinkus]

Kyosho 14x tyres are a very close replacement for the tamiya quick drive buggy tyres.

Sw-01 tyres from the mini lunchbox fit the buggy wheels but traction is terrible.

I think I saw hex adapters for sale on eBay at one point.

Sw-01 /standard slick/ m chassis rally block.

Kyosho 14x 

 

[Nikko85]

46 minutes ago, wolfdogstinkus said:

Kyosho 14x tyres are a very close replacement for the tamiya quick drive buggy tyres.

Sw-01 tyres from the mini lunchbox fit the buggy wheels but traction is terrible.

I think I saw hex adapters for sale on eBay at one point.

Sw-01 /standard slick/ m chassis rally block.

Kyosho 14x 

 

Yep, this is an awesome vehicle! I was going to reference it.

You are right about the SW01/Racing truck tires, but they can work well for concrete if you want to slide!

[wolfdogstinkus]

2 hours ago, Nikko85 said:

Yep, this is an awesome vehicle! I was going to reference it.

You are right about the SW01/Racing truck tires, but they can work well for concrete if you want to slide!

Thanks, I still have it if you need any pictures or anything, just ask.