Arduino controlled automatically actuated grill block

[Daox]

That is quite possible, and quite doable. But, its also way over my head lol.

I had originally thought of providing adjustment pots to adjust open and closing temperature. However, if you have to program the duino anyways, its very easy to just adjust a number in the program to achieve what you want. Plus, once its set, you'll never need to change it.

[dremd]

Subscribed:
Definitely interested.

[Daox]

Well, the block is almost done. I've been slowly making progress here and there when I have some time. I'm still thinking it'll probably need some reinforcement. The coroplast is strong enough vertically, but horizontally it bends and that tends to bind up the hinges and L arm. I'll probably use some sheet aluminum to strengthen it. However, with it being fairly rigidly bolted to the grill, I'm unsure if this will be necessary.

[i_am_socket]

Nice!

[lunarhighway]

looks very nice and professionally made! i which i had something like that already...
but i'd be a little bit worried about strength...

i imagine the actuation is quite snappy so i'd give some extra attention to the lolt locations so they don't start to rip trough... the flex might be cured by gluing a strip of coroplast to the one you have now with the lines running horizontal ... coroplast flexes more easy along thes lines than accross these.
but basically anything light and stury could work.

you could even insert something between the two layers of the plastic. a piece of very think metal wire or a thin strip of metal could pierce the "braces" between the two "sheets" of plastic and create an internal suppory brace... running the screws of the actuator or the hinges trough it as well will reinforce this location as well as secure the brace... might be a bit overkill or impractical but i've used similar methods to attach things like brackets to coroplast with good effect

[dcb]

Nice

I would suggest having it pivot open (on a steel rod) instead of swing open, so the aerodynamic forces on the flap are neutral.

Unless there is a pretty hefty detent in the actuator when it is closed (or if you continually run current through it), it looks like it will want to open up when driving at speed.

[Daox]

I really like the pivot idea too, but I'm planning on mounting the whole assembly directly on the back of my lower grill. So, everything has to swing backwards.

As for it staying closed, if it needs it, I'll probably just use some thin magnetic strips along the door to keep it closed. The actuator has gearing it it though, so it does have some holding force while its not powered up. We'll just have to wait and see if its needed though.

[davidgrey50]

I'm new around here, so excuse me if this idea has already come up. It strikes me the only time you'd want the grille door open is at a high coolant temp, which is exclusively a problem at low speed, and that you'd want it closed at lower coolant temp, which would generally occur at higher speeds. So hows about a nice simple spring-loaded flap which would stand open at low speeds and push closed at higher speeds?

A little experimentation with spring rates would allow opening and closing at a desired temperature.

[lunarhighway]

it's a good idea... i think it's been mentioned before... however it's got several practical problems... tweaking the spring rate is not all that easy.... especially when you have to monitor when it opens and closes... unless you find a volunteer to lay flat on the hood at highway speeds that won't be to easy... well today you have webcams etc but still. the main disatvantage is also that you don't have any controle over it once it's installed... an electronic controlled setup could in theory react to many inputs... speed, temperature, the fan, a button...etc.

than again if you think you can pull off a spring operated example go for it!!!

[davidgrey50]

Perhaps we can refine the question: Above what speed can you get away with a grille block? Offhand, I would have thought that an open grille would only be required when crawling through traffic i.e.below 20 km/h. With more-or-less continuous forward motion above that speed a grille block would be OK. Thus, a pretty durned gutless ("No, I'm sorry, we only have pretty gutless and durned gutless, but no pretty durned gutless springs in stock") spring would suffice.

I accept that some folks just like doing things with all them motors and relays and electrowhoozit doodads, too. Me, I like to drill holes in things.