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Asked — Edited

Bigtrak As A Rover Platform

What I think would make a great rover platform for the EZ-B is the retro Bigtrak that came back in 2010. This was based on the 1980 hugely successful toy that sold in millions. You can pick them up on Ebay for as little as 10.


What is cool about Bigtrak is that it has a magnetic clutch that lets the rover move in straight lines, this is a very clever design and was in the original toy in the Eighties. Also it is possible to "tap into" the existing H bridge on the main PCB, which you can see from the picture below. The motors also have encoders this is how Bigtrak knows where and how far it has moved when sent on a mission.

User-inserted image

So for around 10 quid you get a great rover platform that has encoders on the drive motors with a magnetic clutch together with 2 H bridges that are accessible if you remove the original microcontroller hybrid board.

My toy invention company (Conceptioneering) has designed and licensed the next generation of Bigtrak which we have called Bigtrak XTR (Xtra Technology Robotic) here is the original sizzle that we did for it

At the end it is chasing the ball by itself using colour tracking, Bigtrak XTR is set to be on sale this Christmas.


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Toymaker that's a very cool platform, missed her here. I guess the magnetic clutch corrects the small difference in speed of the motors to go in a straight line as mentioned, if so they had had a great idea 30 years ago. I'm sure the XTR Bigtrak new platform will be a very salable product, greetings.

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Hi R2

Yes the magnetic clutch works by having magnets on both sides to the dual motor gearbox, when moving forward there is just enough attraction to let the magnetic clutch lock and the Bigtrak usually goes in exactly a straight line. When turning left or right in a skid/steer system like this, the magnets are forced to disengage by the turning and unlock temporarily.

I have some units here, and if you start them from a known point they usually get to where they have been programmed to go previously. Thick carpets can cause traction errors, but on a solid floor its quite amazing how accurate their movement can be.

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I've been on the look out for one since you told me about it. It's just what I need for a test bot upgrade.

Also, the rocket launcher and drinks can carrier can still be found all over the place, do you know if the rocket launcher is easy to add to the EZ-B? Camera + rockets = loads of fun!..

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I agree with Rich it could be great test platform. But I really dont another noisy clattering Robot so is it quieter than say an 80's Omnibot? does anyone know?


I use to have one as a kid!


This brings back memories! I'm kicking myself because I had one of the originals up until about 2 years ago. I gave to a friend of mine, because he found one of the trailers. If I remember correctly, they were not extremely noisy, but definitely not silent.

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Rich, the rocket launcher is on the accessory port and pretty easy to control from an EZ-B

On noise have a look at one of the distributors video of our XTR, the retro Bigtrak is about the same noise, also on this video you will see the rocket launcher working.

I also had one years ago, but they were expensive then, I think they retailed at $40 which in 1980 was a lot of money.


Great platform , but those guys are worth lots of money , lol I can't afford one here in the USA


That looks good,i have 2 of them ,one to restore and other for EZB I BOUGHT THEM AWHILE .

JOSH i got mine for $10 and $14 on ebay,maybe price went up some.

Do a ebay search,also found much hacking info on pcb and other stuff on the BIGTRAK right now its just sitting in a box with hacked and ready for EZB.

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This thread seems to have disappeared, so posting again to see if it returns.


What do you mean Tony?

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DJ do you ever go to sleep, it must be 3.47am there in Calgary!

I saw the thread was still invisible, but was still in my account, so knew it was not lost so guessed that posting on it would start it again. I think Bigtrak is such a good platform for an EZ-B rover that it would have been a pity to lose it!

I like the new website look, great job.


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Here is a 2010 retro Bigtrak with a toy arm, this shows the versatility of the platform

The Bigtrak in this video is noisy here as the user is hitting the motors with way too much voltage. When using PWM to slow down the motor drives the retro bigtrak is a lot quieter.

Rich, would this arm suit your Hearoid build? I have one here and its a nice arm, and fairly easy to hack.

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Josh, the Retro Bigtrak are selling on ebay at around £10, thats a lot of rover platform for small money see


I not sure what delivery to the US would add, but you may still find that even with delivery costs it is still viable.

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I've looked at that arm (or a similar one) I'm not sure on the arms still...

As for that video, it's a quick little sucker! Now to win one of them on ebay...


Toymaker i think DJ sleeps next to his computer lol

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Hey this thread has disappeared for the second time, is this a new bug?


Here in the USA they are 50 to 75 dollars starting http://item.mobileweb.ebay.com/viewitem?itemId=181114153720&index=12&nav=SEARCH&nid=97563293476

If looks like I could grab one for not too much. How well to they do on gravel , grass , ext just in the yard?


JOSH your video you put up doesnt work

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@Josh your link was broken... Ebay Link

Seems the youtube forum link code picked up something it thought was a video...

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Josh, Bigtrak should work ok in your yard, but I am not sure about working on long grass.

In 2010 a Bigtrak JR went up in a rocket and did a simulated moon-landing mission

You can see that it handled those surfaces pretty well!


Here is an original '80s bigtrak on ebay ending in 5 hours. it is at 15 dollars and 15 for shipping, no bids http://www.ebay.com/itm/230956284950?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Ebay BigTrak


I see the front axle is broken on the one from ebay

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Do Big Traks have any suspension?


Nope standard solid mount , normal for toys.