Few months have gone since I built my last alternative model from set 42106 and I got desire to build another one. The first model was Pullback Racer that I built for TC18 contest - more about it is here.

 

Then I built Pullback Plane - more about it is here.

 

And finally now I've built Pullback Helicopter. I planned to build it even before plane but I rejected it because I didn't see the way how to connect both rotor blades with pullback motor and landing gear. Set 42106 contains only 5 bevel gears and I usually use 6 for helicopter (three pairs). Later I find solution for problem with missing gear - I saved one bevel gear by connecting axle for tail rotor blade to another pair of bevel gears that transmit motion from horizontal axle to vertical. The only con of this solution is low possition of axle for tail rotor - see picture of mechanism. The last issue, I had to solve, was possition of center of gravity - it was too close to tail so helicopter made wheelies. I prevent them by adding structure under tail rotor blade.

 

Do you think it was all for now? No, it wasn't. I've got one more idea, much crazier idea - I wanna build Pullback Steam Engine! I focused more to functionality than its look so proportions are not correct but it really works. Pullback motor is connected to rear axle and it drives also middle axle thanks to piston-rods. Front axle with small wheels works just like stabilizer (I had to move driven axles too far to rear behind center of gravity and whole vehicle would fall on its front without small wheels). Finally I added optional flame on chimney (smoke would be better but I didn't find any in donor set).  I plan to make video of steam engine in action but it will not be anytime soon.

Any comments and criticism are welcomed.

Edited December 18, 20204 yr by Tomik

The Steam Engine looks very nice, the wheels are a nice detail.

DUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUDE!

Very nice ideas, very cool.

That's some very nice and functional alternative from one of the ugliest set ever made. Good job Tomik !

Thank you all for your comments.

11 minutes ago, fosamax said:

That's some very nice and functional alternative from one of the ugliest set ever made. Good job Tomik !

I totally agree with you - set 42106 is really ugly but honestly it is also the best set with pullback motor so far (apart from models it contains good amount of useful parts).

Wow... these are so cool!

A video of how they work would be cool though. ;)

Wow, ingenious use of parts !! Very inspirational !

Hell yeah these are mad - I'd love to see a video of them working

Amazing collection.

Steam engine is very original 

...and pullback plane is my favorite in this collection...

Perfect! 

The steam engine is really cute. Please, make a video of its moving.

Thank you once more for your positive comments.

 

16 hours ago, JintaiZ said:

Wow... these are so cool!

A video of how they work would be cool though. ;)

 

14 hours ago, Bartybum said:

Hell yeah these are mad - I'd love to see a video of them working

 

1 hour ago, Jonas said:

The steam engine is really cute. Please, make a video of its moving.

I will make video as soon as posible but I am out of time now. 

Suddenly that set doesn't feel so bad anymore :-) Amazing alternatives. I like the car and the locomotive best. Congratulations!

On 11/21/2020 at 11:26 PM, MajklSpajkl said:

Suddenly that set doesn't feel so bad anymore :-) Amazing alternatives. I like the car and the locomotive best. Congratulations!

Thank you for your comment.

You sir have single-handedly made this set into a desirable one... nice wave of alternates, and extra kudos for making the models so different from each other.

Some solutions and parts use is really inspirational!

I guess now we only need a boat alternate to cover all major transportation vehicle categories...

Edited November 23, 20204 yr by Rudivdk

9 hours ago, Rudivdk said:

You sir have single-handedly made this set into a desirable one... nice wave of alternates, and extra kudos for making the models so different from each other.

Some solutions and parts use is really inspirational!

I guess now we only need a boat alternate to cover all major transportation vehicle categories...

Thank you for your comment. You are right, I was thinking about building pullback boat but I found it not interesting. Maybe I will change my mind... 

I've made video of steam engine in action. If you would like to build helicopter or steam engine, you can buy building instructions at rebrickable here: helicopter and steam engine.

 

On 11/23/2020 at 11:41 AM, Rudivdk said:

...I guess now we only need a boat alternate to cover all major transportation vehicle categories...

OK, it is not ordinary boat but it can work as one - so let me introduce you my fifth alternative model built out of set 42106 - Pullback Hovercraft. As its name reveals it features pullback motor and it is connected to rear wheels (yes, there are four wheels hidden in chassis), rear propeller and fake engine with moving pistons. Front fan can spin too but it is not connected to wheels due to lack of gears. It is heavily inspired by set 42120 because I was thinking about getting it but then I changed my mind and built it from set 42106 instead. Building instructions are available for sale at rebrickable.com

I am back with the sixth alternative model built out of set 42106 - Pullback Off-Road Buggy. It is the smallest model from this set - it uses just third of its parts. It features pullback motor and custom suspension built without shock absorbers. They were substituted for rubber connectors and hoses. I am curious what you think about this concept and whether you have any improvements for it. Building instructions are available for free at buildinst.cz

My latest addition to this series is American truck. Since it uses almost 90% of all parts in set it is pretty big. I built it mostly to look good so functions are pretty basic: pullback motor, inline fake engine with moving pistons and opening hood and doors. Building instructions are available at rebrickable.com

From this topic I still haven't built the heli, the hovercraft and the steam engine :D.

For the buggy - front suspension is ok but it is easily dismantled.
Some longer axles and spacers to limit the sideways motion could be beneficial./or maybe I've worn my 3L axles with stop out from moccing that set/
Otherwise - it runs so smooth! And with the lower part count it's quite fast.

It bugs me that Lego doesn't do this suspension on regular pullback sets. Feels great to see it in action.
I guess the rubber isn't that durable for this, but who knows.

I've built the truck today and I've liked the linkage between the second set of wheels and the I5 engine, the engine details too.

On 2/2/2021 at 2:17 PM, GTS said:

From this topic I still haven't built the heli, the hovercraft and the steam engine :D.

For the buggy - front suspension is ok but it is easily dismantled.
Some longer axles and spacers to limit the sideways motion could be beneficial./or maybe I've worn my 3L axles with stop out from moccing that set/
Otherwise - it runs so smooth! And with the lower part count it's quite fast.

It bugs me that Lego doesn't do this suspension on regular pullback sets. Feels great to see it in action.
I guess the rubber isn't that durable for this, but who knows.

I've built the truck today and I've liked the linkage between the second set of wheels and the I5 engine, the engine details too.

Thank you for your comment. I haven't found any problems with front suspension in my model. It is pretty soft so you can easily hit ground with chassis but it didn't fall apart.

So my eighth alternative model built out of set 42106 is another propeller plane. This time it was inspired by planes from WW2 period. It is the most complex model I built from this set so far. It features pullback motor that is connected to landing gear and propeller. It also contains V6 engine with moving pistons.

Building instructions are available at rebrickable.com