controlmech

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

My Feedback: (3)

Mechanical work fine. Not much room in theplane for tanks and such

Razor-RCU

My Feedback: (50)

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

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

My Feedback: (50)

I have a "well used"Patriot ARF, and one that was recently built from a kit (Not by me.. ) 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

My Feedback: (9)

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

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

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

My Feedback: (9)

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

My Feedback: (9)

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

That would be awesome!!!!

controlmech

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

My Feedback: (9)

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

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

My Feedback: (4)

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!!!!!

viper21

My Feedback: (9)

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

My Feedback: (50)

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

My Feedback: (9)

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

My Feedback: (50)

I got a Patriot (right here on RCU- ) 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