Yesterday I test flew a Cutlass that I bought at an estate sale a couple of years ago. The model was complete less an RX and battery. It has an Magnum 61, Futaba S148 servos and Rhom Air retracts. I figure the model is scratch built and is at least 25 years old. The builder made it as a tail dragger and streamlined the nose to the spinner instead of the jet-like intake nose of the original design. The fuse is glassed and painted, while the wing is built up and covered with MonoKote as is the tail feathers. The ailerons use a single servo in the center of the wing and links up to bellcranks! I replaced the aileron servo with a Futaba servo that has more torque for peace of mind. Overall the Cutlass is in excellent shape and I'm happy to report it flew very well! I don't know when the engine was last run, but after choking it, 3 flips later it was running and never faltered! I could tell this was going to be a good day!

I flew the model 3 times and the 1st two flight went very well. The CG is a little on the nose heavy side (on purpose) and the control throws needed to be bumped up. I think the old servos have something to do with this. They're going to be replaced over the winter with proper servos. I had a small problem on the 3rd flight though. About 1/3 through the flight, the retracts dropped down. Being Rhom Airs I knew an air line must have parted ways. The belly landing went well even with the gear hanging down and not locked. The only damage was a broken prop. Funny thing about the retracts was that when I was checking out the model last month, I pumped them up to 100psi and let them sit for two days. They only lost 15psi so I figured they were good to go. Anyway, the air lines have been replaced and the gear is again working.

While the model is in good shape, I plan on stripping it and refinsihing it. The current finish is a little on the rough side. Besides, a sweet model deserves a proper finish! I'll post some detailed pics later.

FB

Nice job FB, now go practice some pattern for Octoberfest!

hey, convert it to a nose gear while you're at it.[sm=teeth_smile.gif]

Hmmm.....if only I didn't have to work for a living!

As much as I would like to do that, it would take far too much work, especially on the wing. I could build a new model much quicker!

FB

just making sure that we have considered it. now it's safe as a taildragger.

LOL!!!

FB

That is a nice looking Cutlass Supreme. I'm never good for providing better than a 12' finish anyway (looks good at 12' away).

Rom-Air gear are really robust and good, as you know. I just located and purchased a new set of tricycle Rom gear with the belly mount nose gear. I knew I wouldn't find them until I had spent money on a set of mechanical gear. I'm still going to use my Dave Brown tricycle gear. They're brand new, but I love Roms. Old habits are hard to break.

I can't get over how small the rudders were on some older patternships, yet I knew that those models won their share of contests/trophies.


Ed Cregger

This one is more like a 6' finish! This is my first experience with Rhoms, so far, so good. Only wished that they locked down if pressure is lost (ala Spring Air). This is my 2nd Cutlass (1st one expired about a month ago). This is a model that I really like, they're sweet flyers, easy to scratch build if desired and nobody else flies them! I now know why my father used to love his!

FB

The problem area with all pneumatic retracts is the finish on the tubing nipples. They must be perfect. That is, no knicks. One tiny knick will cause a leak or the air line to blow off. NEVER REMOVE THE PNEUMATIC AIR LINE BY CUTTING IT OFF WITH AN EXACTO KNIFE OR RAZOR BLADE. A tiny knick that you can't even see with the naked eye can cause you endless aggravation. Pull the lines off with your hands. Yes, it is tough, but you can get help from the XYL or from a friend. Don't cut them off.

Now that we have cleared up the point of no knicking the fittings, you have only one more thing to do to ensure that you will always have a set of gear that will retract and extend reliably.

Forget using Freon and airconditioner oil, as mentioned in the original instructions. Use good old air and get your hands on a silicone grease stick or two. The kind used to help wooden drawers move smoothly in furniture.

Disassemble the cylinders, inspect the o-rings. Replace the o-rings if necessary. When it is time to reassemble, smear the o-ring with the silicone grease stick and then put'er back together. That's it. Your system won't need any messy oil and it will be good for a year or two without regreasing.

My Rom-Air gear never failed to retract or extend in all of the flights they flew. I used to run 100 psi of air with the stock air tank. That was good for five or six solid retractions and extensions.

Don't mind me. You probably know more about these things than I do.


Ed Cregger

well said Ed.

I saw FB's Cutlass after the last gear flop landing. That's when I arrived for the maiden of the Jr. Skylark. Nice plane, well-built, no signs that it was a kit, so we're thinking it was a scratch project. Glass/paint body, monokote wings. When FB gets done with his recovering magic, it will be beautiful All you Octoberfest guys, wait until you see his Perigee!

Those are excellent points Ed that I'm sure a lot of modelers don't know or remember. Quite honestly, I was very surprised that the retracts even worked at all. They had been sitting inactive for many years. When I replaced the lines the other day, I looked at the nipples under a glass and didn't see any scoring. The failure this time was an air line that couldn't take the pressure anymore (pun intended!). Never use a petroleum based product on O-rings, only silicon as you already mention.

BTW - does anybody know of a replacement source of O-rings for Rhom Air retracts?

WEDJ - Thanks for the kudos. I'm only trying to keep up with you!

FB

I have attached pictures of the my original Cutlass Supreme from Mini-Flight that I first flew in 1985. I too this year pulled it out of the closet. It had a Kraft .61 in it that was just too weak, so I upped it to the Tower Hobbies .75. I had to raise the front of the plane for the larger prop. I can easily say it's the 3rd fastest plane I've seen all year at my field. The paint scheme on your plane looks like the original Midwest Mach 1. I had the Mach 1 with the Rhom-Air retracts in it but did not go with retracts in the Cutlass Supreme.

Nice looking Cutlass! When my Dad was around, it was one of his favorite planes. I've managed to find a NIB kit that I'm going to build in the near future.

Update on the Cutlass from the start of the thread. The last time I flew it, the back part of the muffler parted ways in flight (I hate these 2-piece mufflers!). This of course made the engine go very lean. Being the engine is very strong running and not wanting to ruin it with a lean run, I decided to land the plane. Well the engine wouldn't shut off, so I ending landing it "very hot". During the landing, the right gear parted from the wing, damage was minimal and there wasn't any damage to the rest of the model.

First, this model is definitely scratch built. There isn't any kit-type marking on the ribs or in the fuselage. Next the gear coming out was only a matter of time, there's no reinforcement to speak of holding the gear in place, mostly only 1/16 sheeting over the mount blocks. Next, I mentioned above that the ailerons felt mushy and slow. I had turned up the rates and that really didn't do much of anything. It turns out that the bellcranks are very flexable. The bellcranks are nylon and as I twisted the ailerons, you could see the bellcranks twist and that there was no feedback to the servo. I guess that would account for the mushy aileron response. I'll be going to dual servos during the rebuild to eliminate that problem.

So the game plan is to re-do the landing gear, change the servo configuration in the wing, strip the airframe and fix any other sins that may be revealed. Hopefully it'll be ready for paint in the spring. After flying it, I can uderstand why my Dad liked it so much!

FB