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-   -   Patriot Retracts - Mechanical or Pneumatic? (https://www.rcuniverse.com/forum/extreme-speed-prop-planes-104/495862-patriot-retracts-mechanical-pneumatic.html)

controlmech 01-20-2003 04:43 PM

Patriot Retracts - Mechanical or Pneumatic?
 
I've got a Patriot kit and am planning out how to build. The plans call out the Hobbico 3 gear mechanicals. What I was wondering is whether the robart pneumatics would give a lower weight. The mechanical setup requires two servos, a standard for the nose and a low profile for the mains. If the pneumatic valve can be driven by a mini or micro, the total weight might be less.
Hobbico doesn't publish weights so does anyone out there have a set, mains and nose, they could weigh? Robart does list their weights and the servo weights are easy to get to.

Cyclic Hardover 01-20-2003 07:50 PM

Patriot Retracts - Mechanical or Pneumatic?
 
Mechanical work fine. Not much room in theplane for tanks and such

Razor-RCU 01-21-2003 09:24 AM

Concur-
 
The weight would probably be pretty even, when considering tanks and the beefier Pneumatic gear...

B&D makes some pretty small gear, I know Galen put those in his Lanier F-4 (Similar size plane..) and has had good luck.

What motor you gonna use?

james

controlmech 01-24-2003 04:36 PM

Patriot Retracts - Mechanical or Pneumatic?
 
Tossed up on motor right now, but leaning towards an OS 50FSR I already have. My goal is 120mph. I had a scat cat several years ago that I got to 97mph (radar) with a K&B 40 on a pipe and perry carb.
I'm going to put the 50 on the test stand and test with some smaller higher pitch props to see what it will turn. I'll add a pipe if it looks close, but otherwise I'll be looking for a new engine to pull it around.
Do you have a Patriot to?

Razor-RCU 01-24-2003 05:31 PM

Who me?
 
I have a "well used"Patriot ARF, and one that was recently built from a kit (Not by me.. :D ) so it is built straight and nice-

YS-45 on the nicer one (Not yet finished..)
TT pro 46 on the beater Patriot-

Keep us posted,
james

viper21 01-24-2003 07:51 PM

Patriot Retracts
 
I just bought my Patriot kit from the LHS I got lucky and they had two left so I bought one. I also bought the Hobbico mechanical retracts. I plan to use a retract servo for the main gear, low profile. And an HS 85 MG for the nosegear Its got more than enough power to pull and push the retract and I can dial in my EPA so the servo is not stalled when it retracts the nose gear or extends it. This way the servo will not suck excess current. And I am using a 5 cell 1100 mahr pack for the plane its the same size as a 5 cell 600 mahr pack.

But I am still trying to decide on an engine myself. I first thought of the OS 50 SX because I have a Macs header and pipe for it but then I was thinking about a YS if I can find one. I have also considered a Jett 50. Controlmech please keep us updated on your testing of the 50 SX.
Thanks Joe

controlmech 01-24-2003 08:42 PM

Patriot Retracts - Mechanical or Pneumatic?
 
My 50 is an older vintage 50FSR, not the newer SX. I just bought a new OS 32SX for my Modeltech Extra 300. I'm going to break it in this weekend, but if the props listed in the manual are for real, the SX is a much stronger engine than the OS 32F it is replacing. Are the OS manuals optimistic?

controlmech 01-24-2003 08:46 PM

Patriot Retracts - Mechanical or Pneumatic?
 
Viper 21 - I forgot to ask, do you have a way to weigh the Hobbico retracts you bought? I'm trying to decide on retracts now and Hobbico doesn't list weights on the web site.

viper21 01-24-2003 08:52 PM

OS Engines
 
In my expiernce with OS engines their manuals have been pretty close to the real time flying data. I run a 12x8 in my 61SF on the pipe it will run at 14+ grand rpm so that's pretty respectable. I may go with the 50 SX on a Macs pipe for my Patriot.
Not sure yet.
Joe

viper21 01-24-2003 08:54 PM

Hobbico Retracts
 
I sure can weigh the retracts for you if you give me about 10 minutes to go out to my shop and do it?
Joe

controlmech 01-24-2003 08:56 PM

Patriot Retracts - Mechanical or Pneumatic?
 
That would be awesome!!!!

controlmech 01-24-2003 09:11 PM

Patriot Retracts - Mechanical or Pneumatic?
 
From the Robart site for the Patriot:
6.7 oz 605hd mains
3.3 oz 607 nose gear
3.0 oz air kit (tank, valve, etc...)

13.0 oz for gear

For pneumatic only 1 micro servo is needed, for the mechanicals it requires 2 and 1 as to be a low profile.

With al the weights I can figure out which one comes out lighter.

viper21 01-24-2003 09:18 PM

Hobbico Retracts
 
Controlmech, as weighed by my very accurate 4 pound digital scale. All three Hobbico Mechanical retracts weigh 7.0 ounces. But I did not have a retract servo on hand so you would need to take that into account. And I plan to operate my nosegear buy a Hitec HS 85 bb Metal gear servo that weighs less than an ounce. I hope that his helps. Now how about some ideas for which engine I should buy? I have a Macs header and pipe that will fit the OS 50 SX or I can buy a header for a YS 45 and use the same pipe on it?
Joe

controlmech 01-24-2003 09:24 PM

Patriot Retracts - Mechanical or Pneumatic?
 
Thanks - looks like the I'd have to save 6 oz on servos to break even. Mechanicals it is.

I'll post what I get out of my 50FSR, but that ones been out of production for a while. I've read good things about Jett, but no experience myself.

vasek 02-03-2003 12:34 AM

why not air for the wings & servo for the nose!
 
I have a Patriot kit waiting on my building board :) .
I will be using an MVVS .48 fitted with a "mousse" muffler and a combination of- pneumatic retracts in the wing and a mechanically operated nose gear.

The servo in the tail will operate the front retract AND at the same time will control the valve for the pneumatic mains. I am not sure about the total weight of this arrangement, but I am sure about eliminating the low profile servo (and some rods) in the wing!

If anyone has a similar setup, let me see some PICS!!!!! :D

viper21 02-03-2003 12:52 AM

Retracts
 
Vasek, I am just going to run two low profile retract servos one for the nose wheel and one in the wing for the main gear. Had I thought about this before I bought the Mechanicals I probably would have sprung the extra money for a set of slimline Spring Airs. All the Slim Rhom Airs that I have are going into glow Ducted fan jets so they are out. So it looks like to be on the safe side I pop for two retract servos or figure out how to make a mini servo shut itself off.
I will tell you one thing however and thats that I have decided to just buy a new OS 50 SX and use my new Macs Header and Pipe and just fly the plane it will be plenty fast. And if I need to go really fast I will just fly one of my ducted fans. I am not paying 300 bux for an engine on a sport plane? I wish I had thought about the retracts though before I bought them. Mechanicals are great once they are all set up I am installing a new set of Supra Mechanicals in my new old Style EZ Dago Red. They are just a pain to hook up right is all.
Viper

Razor-RCU 02-03-2003 02:01 AM

Hmm..
 
OS 50 it is!!

I was gonna run a mini on the nose gear, but did not realize the possibility of servo drain during flight... Hmmm-

I don't wanna pop for another retract servo-

Keep us posted- What D/F's are you flying?

james

viper21 02-03-2003 02:09 AM

Ducted Fan
 
Razor, yep that's a major concern of mine is to have a stalled out mini servo sucking juice from my battery for the entire flight not good :( So I will most likely run two low profile retract servos.

Right now I am halfway through building a Jet Hangar Hobbies FJ-3 Fury Navy version of the F86 Sabre. I have all the scale landing gear for it and am installing a new OS 46VX with a Turbax I 5 inch fan and it will have retracts, flaps and speed brakes. I just bought a brand new OS 91VR and Dynamax Fan for my next ducted fan and that will be a Jet Hangar F4 Phantom with scale landing gear and all the goodies on it.

You gonna run the OS 50 SX too huh. I hear its pretty hot for the price and since I already have the Macs Header and Quite pipe I will buy one and try it out.
Joe

Razor-RCU 05-09-2003 05:18 AM

Hey Viper-
 
1 Attachment(s)
I got a Patriot (right here on RCU- :eek: ) and it has Spring Air gear- and split flaps!

They work flawlessly, and the small air tank fits easily in front of the servos...

On 60PSI I can cycle them about 8 times-

What happened with yours?

Also, I got ahold of a JHH A-4 Dynamax combo- should be a hoot


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