vmsguy

A quick update..

I have the fuselage covered.

I started work on the bottom of the wing.

Just like MinnFlyer's videos, I started with the bellypan and worked outward. My thought was I would proceed like I did on the bottom of the stabilizer. Start in the middle, add stripe, by stripe and work towards the outside. That theory worked until I got to the open ribs. Once there, I couldn't get the new piece to adhere to the old. Admittedly, I didn't have enough of an overlap. See the first couple pictures.

So I gave up, ripped off the first couple stripes on each side, and decided to put down the base of white, and overlay blue. That worked out wonderfully well. In about 3 hours, I had all the blue stripes in place. See last couple pictures.

Next, I trim off the extra, add a white trim/separator stripe, and add red, hopefully tomorrow night.

Oh! I found painters tape is really handy for positioning covering. I can measure, fuss and fiddle, and position the tape so an edge of the tape is where I want the edge of the covering to go. Then positioning the covering is quick. You can see the tape in the pictures. To assure the stripes are as parallel as possible, I always measured from the starting point. Not from the edge of the last stripe. That way, any error in stripe placement wouldn't be carried to the next stripe.

vmsguy

Finished the bottom of the wing.

FallDownGoBoom

My Feedback: (1)

Your US is looking great.

And you also figured a couple of the great covering mysteries... putting down an entire base coat, then adding stripes. And using masking tape to line stuff up, then hold it in place.

vmsguy

Let's see.. What's the word... Oh yea,


TA - DA !!!!

vmsguy

A few details.

Final weight: 8 lb 11 oz.
Balance Point: 4-3/8" from leading edge. (1.75oz needed in tail)
Motor: Rimfire 50-55-500.
Battery: 2 ThunderPower Pro-Lite 4200mAh 3S2P batteries wired in series (6s2p)
ESC: Castle Creations 80Amp.
Prop: APC 12x8 E-Prop.

FallDownGoBoom

My Feedback: (1)

It looks great... but then I've said that before .

Yours came in within 1 oz of mine, although I'm still suspicious of the scale we used to weigh it. It will be interesting to see how yours flies in comparison with some of the wet-powered US. When's the maiden?

vmsguy

When's the maiden??? I don't know. I'm still hoping Mike (MinnFlyer) will be able to fly it. Hopefully in the next couple weeks.

I am not qualified to fly it.

I was a bit disappointed at the final weight. I was hoping for a bit less. I was hoping for about 8 lbs to about 8 lb, 6 oz.

I've said this plane is an experiment. If I were to build another from scratch, I would build in some things that could help. And maybe save another 4 or 5 ounces. I've got to believe my efforts in rebuilding added weight that wouldn't have been there on a new built.

FallDownGoBoom

My Feedback: (1)

The US experts feel that the weight isn't a big concern. Short of major liposuction (lightening holes in the fuse/stabs/control surfaces, using 3/32 balsa instead of 1/8. etc) I can't figure out a significant weight reduction program, other than the obvious deviations from the plan: a 75 instead of a 60 engine, and adding the retract system. Even with those left out, I think it's a 7.5 to 8lb airplane.

Hopefully you and Mike can get together fly yours. If he can get it off the ground and land it, you should be able to fly it as long as you stick to basic loops, rolls, etc., and keep it a couple of mistakes high. It's a very smooth flying airplane and seems very well mannered. It certainly isn't as terrifying as some of the 3D ships out there.

vx99

that looks great vmsguy. i'm not much of a forum poster; more just a reader, but i had to chime in after following the thread since you started, and say the finished product looks tops! great covering job too, from what i can see in the photos. i've always liked the ultrasport (have a .60 kit i need to build soon too), but wasn't super keen on the exposed engine (hope minnflyer doesn't read this). the electric with the full cowl looks real sharp.

looking forward to a maiden report, maybe a video?

cheers, dave

hrrcflyer

Hey VMSGUY,

Nice Looking Ultrasport.....

David

vmsguy

Good news and bad news...

The good news, is the Ultra Sport flew today.

The bad news, about 1:30 into it's maiden flight, all control was lost, and it spiraled in, nose first.

Technically fixable, I'm chucking it. As I was rebuilding it, it didn't seem "right". Inever could identify exactly what was wrong, but the wing didn't seem balanced or symmetrical left-to-right. Don't know. Others offered to take it home and rebuild it, but Ididn't give it away. Ididn't want to curse somebody else with a goofy plane.

I always considered it an "alpha test". I've learned about the structure of the plane, what I would do differently ifIwere to build it from scratch, etc. So it has served it's purpose.

I'm working on editing the video. Once Iget it figure out, I'll post it.. if I can...

FallDownGoBoom

My Feedback: (1)

VMS:

That's a shame. Ihate putting all the work into a plane and then losing it, especially when you can't readily identify what caused the problem. At least if you decide to do another one you've still go the power system.

Fred

vmsguy

The only thing that was amiss was the battery connection to the receiver's power switch. Either the battery shifted mid-flight, and broke the connection, or it shifted at impact.

Yes, I plan on doing another US-60. I have a couple kits still in their boxes waiting. As I stripped all the goodies, I put them in a zip-lock bag, and put them in one of the waiting kits. I already have ideas to make things better. And hopefully a little lighter. I hope, with simple things, I can trim a few ounces. I'm not looking for extreme weight loss, but I have to believe all the rebuilding I did added weight that wouldn't be there in a new build. For example, the doublers on the wing ribs for the landing gear, there was extra there, as well as the old material remaing when it was a trike setup. If I could trim 6 to 10 ounces, I'd be content.

I'll probably go with a different power system. Comparing it to Mike's my was pretty slow. Or his was pretty fast.. But it was an obvious disparity. In the words of Tim Taylor.. More Power.


Here's a link to the video.. incase anybody's interested.

http://www.youtube.com/watch?v=hlQ8oCloeOw

FallDownGoBoom

My Feedback: (1)

I'm not sure you've got a real apples to apples power comparison going with your Rimfire vs. an OS75AX. This is all"qualitative",but when I fly myelectricMinishowtime with a Power 10, the power flow feels smoother (maybe more linear?) than with my nitro engines. But when my nitro enginesfind their power band, their thrust comes on like gangbusters. Butcomparing the flightcharacteristics ofa 30oz electricvs. an 8+lb UltraSport isn't reallyvalid.

I think you're right about being able to save some weight if youbuild a kit from the ground up, especially ifyou're thinking electric power. There are definately a few places in the USbuild process where you could shave some ounces.

Meanwhile, you can play with the P38!Electric power for that as well?

vmsguy

Yup... I've got the motors. Bought all new Robarts air retracts. Slowly getting everything together.

Next on the building board is a 4*40.

FallDownGoBoom

My Feedback: (1)

You should like the 4*... I had its cousin, the Bruce Tharp Venture 60, and enjoyed it very much.

RR24

vmsguy,
What would be a good watt setup, and what would the max prop diamter for ground clearance. I will not be using retracts so as to keep the weight down. What else do you think needs to be done for E-power.

Thanks

vmsguy

Hmmm...

I think the prop diameter I had was about the best you could do if using stock landing gear configuration.

If I remember right, I was getting just over 1000 watts with that setup... The bird flew "fine" compared to a glow US60. Both US60s crashed that fateful day. But the glow bird (75AX) was definitely a faster plane.

I think I might try a prop with a higher pitch. Get a motor that can handle the torque, and take big bites out of the air.

Oh.. before I settled on a prop/motor/esc/battery combination.. I'd build a motor test stand. Then I could test the combinations free of any constrictions, see what combinations yielded the power you wanted. (picture 1)

If you read the thread, electrification of this plane was a challenge. When I build a new one, I plan on the following alterations.

1. Open up the entire bottom of the cowl for motor installation/removal/cooling. Imagine an inverted motor with a pitt's style muffler. I'd retain just enough of the cowl to retain the "profile". This would eliminate the need for the first hatch on top. And profide more/better cooling. (without the cowl) (Picture 2)

2. I'd mount the ESC in a "dug-out" behind the F1 and the wing. Imagine the fuselage upside down, the area just aft of the F1 would be like a sunken living room, the ESC on the floor. This would retain the profile look of the plane, profide plenty of cooling.

3. I'd mount the master power switch in that same dug-out, so it was more easily accessible.

4. I'd retain individual aileron servos. Even if I didn't have flaps. This would free up the entire area from F1 to F3 (aft of wing) for battery (and hence balance) adjustment.

5. If I want flaps, I'd use individual servos for flaps. (for reason stated above) Probably mini servos would be sufficient.

6. I'd come up with better hatch holding/alignment system. The hatch I had could shift a little side-to side. I'd want something better to hold it in place; Magnets, alignment pins, something.

RR24

I know it is kind of a bad word to most, but what about using a fiberglass cowl. I think it would make it easier with the elec. motor and also less weight up front. By the way i order a kit from Tower last night, and i will have to make it e-powered or not at all. All of my planes are elec. or gas, no more glow for me, i like it much better this way. Any other great ideas on this plane please share.

Thanks again

vmsguy

First:

I mistyped something in my previous post.. I typed "without the cowl" in line item 1. I should have typed "without the air scoop".. I hope that didn't confuse some readers.



Onto to the topic at hand:

Fiberglass cowl...

Hmmm.....

One of the key characteristics of an Ultra Sport, is it's "clean" lines. It is elegant in it's simplicity. Those who poo-poo fiberglass cowls, I think, are lamenting the potential of a cowl dirtying up those clean lines.

In point of fact, electrifying a US 60 could actually enhance those clean lines. If done as I propose - having bottom of cowl open for motor access - the nose would have a cleaner cowl area than a glow bird. Imagine a solid cowl, top, and each side, sitting on the ground. Heck, you might be able to get away with omitting the side vents like I had.


My difficulties with electrifying the US was two fold. First, I was electrifying an existing airframe. The build sequence of the Ultra Sport is to first mount the motor, and then use the mounted motor to build the cowl around it. My challenge was to properly mount, and center, an electric motor in an existing engine bay. Once an electric motor is determined, the build of the wooden cowl around it should be the same as if a glow motor were used. In fact, because it's not glow, no need to worry about cutting the side around that pesky cylinder head and muffler. Second, I had no previous experience with a Great Planes airframe. I didn't know how they were constructed, their "style" if you will. So I needed to adjust my techniques to the engineering style.


Another thought or two... (ok, three)

1. I highly, highly recommend the staged mount system I used for the motor. It worked like a charm, and if you decide on the solid cowl, it'll be a benefit.

2. I also highly recommend the added radial mount to elongate the the "snout" of the motor. It is also necessary in the long narrow confines of the built up cowl. Could be very handy under a fiberglass cowl too.

3. I'd try building the wooden cowl first.. see how it goes. Heck, if it doesn't work, cut it off, and get a fiberglass cowl.

hrrcflyer

Hey Vmsguy,

I have an old US60 that was built around a K&B 61 2-stroke. The plane needs quite a bit of TLC and I need to modify the front end. The reason being is that I'm short on funds at this time and the only engine I have available is a YS 91 4-stroke. So, with that being said, I have a question for you. Did you ever find a decent fiberglass cowl for an Ultrasport 60? I'm thinking about cutting everything forward of the firewall off the plane and going from there. Do you think I should try it or do you think I need to find a shorter motor?

Any advise would be welcome. TIA

Take care,
David