Hey guys

i use always restrictor in my retracts airlines...closest to the cylinders so they wont hit at the end when i lower them

plus they look nice when they move slow


..but when i retract them up
only there waith of the leg with out restrictors some times its good to slow them in a scale move

plus some times when restrictors used on the way up and you have secuense main doors they will be too late and the doors will close?


i want to share with you an idea i had so to overcome this

the use of a one way valve:
so when leg is going down the one way valve is closed and air is restricted so slow move and not a slap at the end

and on the way up the one way valve opens and bypass the restrictor so full power right away


..what you think?[&o]


forgive my poor english and my drawing skils

...im away from my workshop so no picks to upload..

thanx for your time reading this

regards
George

Festo makes adjustable restictors (one-way adjustable flow-valves) that do just that.

They work great!

Hans

http://www.hawe-modellbau.de/englisc...sch%5B1%5D.pdf

Page 15 !

These very simple restrictors work just fine!

Regards, Henk

I think maybe u guys both missed his point? It's not that the restrictors he's using don't work, it's that he want's more flow/speed in one direction than the other. Even the adjustable restrictor won't accomplish this.

George: It's an both the drawing and English are excellent, and I think it's a great idea. I don't know what valve you are using and whether it "vents" via a vent fitting on the up stroke, down stroke, both, or neither, but sometimes adding the restrictor to the VENT side does the job....?

Don.

Hans yes this is the valve: http://www.festo-didactic.com/int-en...i4xMjQ4LjY2MDk




Hey Don! you are right! what i do is i bypass all restrictors when i retract up (to alow more flow as you discribed) !

but i dont think if you fit a restrictor on the vent of the valve will alow you to have no restrict when you retract up the gear
couse up or down move

air comes always out from the vent in one direction ...so you still cant avoid restriction while retract up?

Excellent idea George. and THE solution if you have a blue Robart type valve where there is no exhaust control. On the Jet-tronic type valve with a single exhaust for both up and down air, I prefer to use the adjustable restrictor on the exhaust because it is simpler and give you control over the up speed as well. And the principle should be to always adjust the exhaust air from the cylinder(s) if you want a slower movement.

Per

I find it easier just to get the Robart variable rate and control exhaust (Part # 167VR) or they also have a air up spring down version(Part # 186VR). Figure it would be cheaper and less complex. Fewer parts to fail.

Hey guys,

Does this mean that if i want my gear DOWN movement to be slower (without changing the gear up movement speed), i need to put the restrictor on the gear UP air line (if i dont have an exhaust option) ?

Or basically - whats the best way to have the gear go up in full spower \ speed but have a more gentl gear down movement ?

Yes, try it. The up side IS the exhaust for the down side...

i will give it a shot.
Will also try on the exhaust line fromt he valve itself. should make an interesting expiriment to compare them.

Sometimes experimenting is the key. Try different combinations of restrictor locations until you get the desired results.

On the other hand, if the cylinder size and/or mechanics of the gear are not matched correctly for the application you may never get them to extend or retract just how you like. In that case you may be forced to accept a gear that slams down in exchange for a clean retraction cycle. I have that problem on my big A-10 with it's heavy wheels and main gear.

It would be interesting to experiment with DelGato's plumbing suggestion the first post but I have not tried it as yet.

Craig

i did play with it a little bit and the restriction indeed works better on the exhaust side rather than on the pressure side - thats an important and interesting conclusion !

for future searching ill add the video and a photo here

one restrictor used closest posible to the sylinder on the "exhaust" line

this stop retract hit at the end when going down.

using a one way valve to bypass this restrictor on the photo per drawing

the gear on the video will go faster up with more power.

good luck guys

[youtube]http://www.youtube.com/watch?v=uARMUHOSryE[/youtube]

I’m convince it’s not a lamp

George,

I have tried your idea on my A10. Works very nicely.
I have a parallel valve arangement with a restrictor and cehck valve. Allows full flow for "up" and restricted exhaust air from the "down" exhaust and keeps the big gear from slamming down.

thanks for the tip!

Dave

im glad it work for you Dave!
[8D]

The only downside to this plumbing is a bunch more Ts and I needed to have some adapters from 3 to 4 mm for the festo 4mm check valve. So far no leaks...

you can use a Festo 3mm check valve.

I shopped for a 3mm check valve and could not locate one where I "usually shop" Dreamworks/BV...

Hmm., if I could get a few it would make this a little simpler.

Thanks
D

Hello Craig
I have the same problem as you on the A10. The wheels are heavy and with full pressure the L/G just fight the relative wind and close normally but when I extend the L/G everything are very brutal.
So I bought this :
http://dreamworksrc.com/catalog/prod...roducts_id=733
It is not written in the descriptive but this restrictor is "assymetric". I mean "no restriction" in one way and "restriction" in the other way. There is a little drawing on it to explain the restricted direction.
So I installed 3 of them ( one close to each cylinder ) and now the gear extend very smoothly.
Best regards
Stan

Excellent. I had missed that fine point about the restriction being one way. THANKS !!

+1.

Thanks Stan

pic