Mechanical Model ideas for Teenager

[NeedingCoffee]

DS, now 13, absolutely loved this last year (can’t recommend it highly enough for any 10-13 year old boys who like making things).
www.<a class="break-all" href="https://amazon.co.uk/Source-Wholesale-Hydraulic-Robot-Arm/dp/B01G5RI0KS?tag=mumsnet&ascsubtag=mnforum-christmas-3764794-Mechanical-Model-ideas-for-Teenager" rel="nofollow" target="_blank">amazon.co.uk/Source-Wholesale-Hydraulic-Robot-Arm/dp/B01G5RI0KS

Can anyone help me find something something along the same lines for this year; basically some form of mechanical model which will take a few hours to build and will “work” in some way at the end? Ideas hugely appreciated!

I got bought this last year and it was great to make and see working:

Haynes HM10R V8 Engine, Multi www.amazon.co.uk/dp/B00EQ4JOBC/ref=cm_sw_r_cp_api_i_gOS7DbT19WKCG?tag=mumsnetforu03-21

My DS enjoyed this www.mulberrybush.co.uk/geckobot

Thanks both; did those models take a little while to make? It seems difficult to get something with a degree of challenge but which is well designed and therefore goes together as intended! I had looked at some of the Spacerail marble runs but they all have pretty terrible reviews.

The engine took me maybe 2-3 hours and was reasonably challenging.

The elegoo smart car was quite fun, although probably most interesting if he's got some I terest incoding. It's been that side that has kept DS interested. They do have some smaller and cheeper kits, but double check what's included as I think some expect you already to have the computer board.

www.amazon.co.uk/ELEGOO-Tracking-Ultrasonic-Intelligent-Educational/dp/B01M6YHRJ4/ref=sr_1_3?crid=MZPXQX0ZKEM1&keywords=elegoo+car+kit&sprefix=Elegoo+car%2Caps%2C165&tag=mumsnetforu03-21&qid=1575969418&sr=8-3

Jumping on board, ds (11) only wants things that he can make/do but doesn't want mechano or Lego. He has an interest in dc motors but I can't find any kits that incorporate those.
So far I've bought the hydraulic arm, a 14 in 1 stem set, and a solar powered robot. I need a couple more so he has as many as dd (10) has craft type sets.

Pass, for an 11 year old I can thoroughly recommend gravitrax and also Hot Wires.

giggling, thank you; might be worth a try. He hasn’t done any coding at home but they do it at school so I don’t think it would be beyond him and it would be great if it sparked an interest.

Thanks needing, he has hot wires already, and unfortunately it's not really sparked his interest much further than doing a couple of experiments.
Gravitrax looks interesting, I'll show it to him. Surprises are pointless these days...