aglaser

What are the pro and cons for mechanical and pneumatic retracts? Im thinking of putting them in a TF p-51.

BarracudaHockey

My Feedback: (11)

Air is more complex running airlines, require more onboard equipment (valve, tank, lines, actuators) and are subject to leaks. You also need field equipment such as a pump or small compressor, and cost more.


Mechanical is cheaper but involves a bunch of linkage tinkering to get them down and locked and up and locked, though down and locked is arguably more important
Also if they jam and the servo stalls it could drain your reciever battery flat in no time. They don't leak though.

Air up, spring down are probably your best bet if you don't mind the investment.

Which Mustang?

MinnFlyer

My Feedback: (4)

I have used both many times - and I'll take Mechanicals any day of the week.

To me, the only drawback to mechanicals is that they are a pain if you have a nose gear. So I avoid planes with nose gears

BarracudaHockey

My Feedback: (11)

The guys that bag on helicopters because they are too complicated and require too much fiddling, are the same ones that will stand at a table on the other side of the pits and spend two hours trying to get two landing gear to go up and down without binding or breaking

blvdbuzzard

"The guys that bag on helicopters because they are too complicated and require too much fiddling, are the same ones that will stand at a table on the other side of the pits and spend two hours trying to get two landing gear to go up and down without binding or breaking"

I fly helicopters and I have spent more time getting a SINGLE nose gear to work then I ever did building a helicopter kit. That includes the trim flights and re adjustments to the helicopter.

I have 3 sets of mechanical retracts and 2 air sets. To me, the setup for air is way easy compared to the mechanical. Find a spot to mount the fill valve, tank, run lines and you are done. The mechanical you will spend time getting just the right amount of travel to get it locked but not bind, then you have to do it on the other side[sm=bananahead.gif][sm=cry_smile.gif]

Over all, I have been pleased with both sets. I did have issues with a set in a pattern plane. I had to re adjust them after about every 10 landings. I went to a better set and the problems went away.


Dru.

dhal22

the spring air system is a very good one. expensive but reliable, strong and durable.

david

FILE IFR

I like that one!

+1

RVman

I have and use both systems. The pneumatic works well for me, however I have trouble getting them to slow down. They are a spring air system. If I restrict the air, the movement is very choppy and not smooth. You do need more equipment to run this system and don't forget the pump at home.

The mechanicals are simpler. I would go for mechanical on a P51, the gear retract inwards and there would be a straight run of pushrod to the servo in the centre. They are easy to set up. Measure the amount of travel that the retract needs, then use a blank servo wheel and drill two holes that distance apart, hook up the pushrods and your done. The JR 791 is the best retract servo I have used, it will break or bend something before it ever stalls. I use ball links on the servo wheel, they pop off if the gear hangs up or gets jammed.

da Rock

The third choice beats the other two hands down.

The LADO retracts aren't pheumatic. No hoses, little tanks, nothing of the sort. And no mechanical retract adjusting or rigging pushrods or servos.

Screw them in wherever the retracts go, plug them into a Y and the Y into the RX, and fly them.

Both planes in the attached have them retrofitted. Simply pulled the OEM retracts and servo and rigging, and screwed in the LADOs. (and plugged 'em in, of course) I did put struts on 'em too. That took more time than the retrofit.

RVman

I would love to try those LADO's someday. I would retrofit my air retracts if I could buy a electric actuator that fits where the air cylinder went.