AeroDave

Dick,
I built mine with the stock front moment. I had to put the servos in the tail and add 3 1/2 oz oof lead to the tail to get the CG where I wanted it. oh yeah, I also pt the rx batt so far back iit was up against the vertical fin. It was quite a bit heavier than what DP is suggesting. Plus it was lots more work. I believe his original set up was very much like mine, so now he's refining the setup we all used from the original thread. My next one will be set up the new way.
Good luck,
Dave

Dick T.

My Feedback: (243)

Thanks for the comments. Sounds like one could still leave the servos in the tail and shorten the firewall maybe 2-3 inches and have the CG very close (this based on the comment of having to move the servos inside after the firewall mod because of tail heaviness.)

Sounds like you can go either way depending on preferenc

Overall weight with ARF's is always dependent on the materials used. On these size ARF's I have seen a pound difference in airframes while still in the box.

AeroDave

that's a good point too. I never thought about weight variables with different USLs. I think you're right, though. IIt comes down to preference. I would want my servos in the tail for short linkages. those "walls" are hard on long rods!

Dick T.

My Feedback: (243)

I agree on the short linkages, my preference too.

Have been thinking about the USL for my sitting G23, but then also contemplating putting it in a FuntanaS 90 just for the heck of it.

famousdave

My Feedback: (61)

Guys .. do the math.. this conversion is a NO BRAINER!!

My original setup with 20oz stock tank 11 pounds 4 oz + weight of fuel (over 12 pounds if using a full tank)

My new setup with 12 oz tank = 9pounds 14 oz wet. 9 pounds 2 oz dry.

The only thing I did different was cut of the nose (-4 oz)
Not have to use lead in the tail (-3 oz)
Not have to put servo trays in the tail (-2oz)
I also HAD to put the 5-cell NiMh (heavy) battery (11oz) in the tail far aft to balance.

Total weight savings on the nose job = 9 oz NOT 2 oz


Also a HUGE benefit of doing the nose job is that it allows you to put the battery AT THE CG. This allowed me to replace the heavy NiMh and put in a Li-Ion 1800 mah + small regulator. Savings = 6 more oz. That setup is 1/2 the weight of the NiMh. I can now adjust the CG at will simply by moving the batttery a few inches for or aft.

As far as the linkages being short... I replaced that stock binding crap with Sullivan Golden Rods.. they work extremely smoothe with no binding at all. Using the servos in the tail REQUIRED the use of either 4-40 hardware (heavy) or carbon fiber pushrods (still adds more weight). The Gold'n Rods weigh less than either.

I also built the wing using ailerons only. The quad flaps are useless on this plane.. so is the extra weight of two more servos...

Total savings = 11.25 # - 9.15 #

That is a total savings of 2.1 pounds! That is 19% of the total original weight. HUGE.

I measured this with a high accuracy digital strain gauge I am confident the number is dead on.
Both kits in the box weighed the same before starting. Plywood is less subject to variation than balsa.

I flew one gallon through the plane today. If you have ever flown a U Can Do 3d 40 size with a Saito 72 or 100 engine in it... this is not far off at all. I moved the battery back just slightly to balance it just aft of the factory setting. PERFECT. Slightly tail heavy is just right.

Easiest plane to hover I have even had. Does inside loops on the deck within one fuselage length (plenty of gasps on that stunt!!) , harriers, lands in place in a 5 mph headwind.. in one word .. AWESOME. I was NEVER able to do that with the old plane and could barely do it with a UCD (I'm not the greatest 3Der..)

I don't know if this is a good thing or not .. but I found myself doing more and more stuff I never dreamed of with the first USL...and a LOT closer to the ground. Not a single incident or "almost lost it" though.. very cool how it floats and recovers.

I am very pleased with the outcome. I flew most of the day today.. everyone was asking about what it was and whether I designed it!! When they found out it was a USL they could not believe it!! I was doing some really wild stuff and overall just had a blast.

I am probably going to get a set of CF gear made for it. I am sure I can take another 4 oz out that way. You could put wood gear on this plane and never need it it lands so gently and slow.. even in a good wind, in fact, I harrier landed in my pit nearly every landing today in a very slight cross wind with some good throttle management (and no company!!)

Honestly - this plane is so stable it will make even a marginal 3D flyer look good. It won't do everyting ( I tried a flat spin and it was horrible!) but at this weight and putting it a little tail heavy.. it is pretty amazing. I can't say enough!!!!!

With all the "good" IMAC flyers down at the shootout this weekend I can be a big fish in a small pound... at least until next week!!

I'm smilin!
DP

Dick T.

My Feedback: (243)

Thanks, it is a no brainer now that you have itemized the weight savings which were not in the original post. Can't calculate what we didn't know, that's why 2-4 oz. didn't make sense either.

It certainly makes the USL attractive for my G23.

famousdave

My Feedback: (61)

DickT - sorry if I wasn't super clear on the first post... I guess I was so excited about how it turned out that I didn't make it as clear as I could have...

One quick note for you.. for approximately $70 you can convert your G-23 into a G-26... 15% more power. Zenoah has a kit that changes the cylinder and piston / ring. It takes about 5 minutes to do it.

Good luck on the new construction!!

DP

Dick T.

My Feedback: (243)

I have thought about doing the update you mention, however it took two flying seasons to burn 10 gallons of gas. The G23 came alive on gallon six, now turns a 17 x 8 APC over 8000 rpm. It just runs too good to start over and will still be plenty of power.

Thanks for the construction tips, and I don't blame you for the excitement. Have been looking for a plane the G23 can perform in.....even considering the FuntanaS 90 although it may be a little fragile for the extra weight.

Had the G23 on the original US and it flew nicely for being an overweight pig. You are correct about the Quad flaps, total waste of time.

famousdave

My Feedback: (61)

Speaking of waste of time... the funtana 90... I have seen three.. all with Saito 100s... all three fell apart in flight... Yes they are light, but poorly made too. The 100 was overpowered... a G-23 or G-26 would kill it!!!

I actually was going to buy one until I saw three buddies lose theirs - one to flutter, one the wing tube / spar broke (go figure) and one the tail just came off in a snap roll. All three guys are pro builders.. they just are poorly designed... of course they were beating on them (3D) pretty good too, but that is what the plane is supposedly made for...

DP

JoeAirPort

My Feedback: (41)

I posted something that was off topic and deleted it. Nevermind.

joel_jones

My Feedback: (111)

i have a ultra stick... put a g23 on it.. added 4 oz to the tail and i fly it every weekend.. works perfect.. when this one crashes .. i plan to buy a nother and modifi it ..


smoke on!

mloywhite

My Feedback: (4)

desertpig, I really like your setup with the shortened nose. I am about to buy this plane and a G26, which will be my first gas-powered plane. I had a couple of (probably dumb) questions:

1. Why not cut less off the nose, and skip the stainless spacers? Does the engine need to be set off the firewall a certain distance?
2. What should I use for spacers, i.e. something I could get a Lowes, Home Depot, etc?
3. How long are your flights with the 12 oz. tank?
4. What are the Sullivan rods you referred to? Where can I get them?

Thanks for your help. I am really looking forward to building this plane. Mike White

famousdave

My Feedback: (61)

Mike - the only dumb question is the one that doesn't get asked!

1> The spacers are needed to keep the flywheel nut on the rear of the crankshaft from hitting the firewall
2> Cheap steel spacers - I bought them at Ace hardware for 20 cents each and cut them to size
3> 10-15 minutes easy. I set my timer for 9 min and still land with 1/4 tank or more
4> Sullivan "Gold-N-Rods" any r/c hobbyshop will have them. If they don't look up sullivan r/c on the web - they will sell them direct

Do the mods!! you will love it. Make sure you glass and pin the new firewall!! I think my pictures showed that, but just wanted to make sure!!

DP

ChrisAttebery

My Feedback: (15)

Hey DP,

I've got another question for you. It looks like the motor is mounted on the firewall higher that it would have been normally. Am I right? Would it matter if I mounted the motor either higher or lower so it will clear the Pitts muffler on my 3W24?

My 3W and USL are at home sitting in boxes. I promised myself I wouldn't start on it until I finished repairing the Super Sportster I was given. That way by the time I get the USL done I'll have some tail dragger time on my freebie.

Thanks again,


Chris

famousdave

My Feedback: (61)

Chris - you can mount the engine any way or any where on the firewall.. that is beauty of this setup! You will want the thrust line dead center, but up or down makes no diff...

Don't add any thrust to the firewall either.. it flies just great the way H9 set it.!

DP

ChrisAttebery

My Feedback: (15)

OK,

I guess it's time to fire up the bandsaw.

Thanks again DP!


Chris

otisflies

So does the light version knife edge any better than the others? I had a blast with my 40 sized one but just could not get over the poor knife edge performance.

AeroDave

Otis,
I built one the same time DP built his first. We had a huge thread going on them at the time. Mine knife edged fine. I had to mix out a bit of coupling, but it wasn't bad. It would hold a KE as long as you wanted, but wouldn't climb in KE. the first mod I made to mine was putting in the 12 oz tank. easiest way to save a bunch of weight! I did the whole servos and rx batt in the tail thing, but shortening the nose is a much better way to go.

ChrisAttebery

My Feedback: (15)

Hey Guys,

I finally got to work on my USL with the 3W24. Here are a few pictures. I cut 3.5" off the nose and relieved the bottom of the fuse for the muffler.

ChrisAttebery

My Feedback: (15)

A couple with the motor mounted up...

ChrisAttebery

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Last two for now...

chuck l

My Feedback: (17)

desertpig

I lost my Ultra Stick Lite with a G26 a couple of weeks ago when the radio and plane stopped talking to each. I still haven't figured out why that happened, but am contemplating shortening the nose on a replacement USL. I cut off the front 4" from the dead plane's nose and it weighed 2.5oz. Did the other 1.5oz of the 4oz you mentioned come from eliminating the 1/4" wood spacer behind engine that you replaced with the steel standoffs? I never had the sense to weigh my USL, but built it per the instructions, and was able to balance it with a 1200ma battery and 1/2oz of weight, both in the tail. Looking at my original build, I would only save the 2.5oz plus the 1/2oz for a total of 3oz. If I eliminate the flaps, that would save 2.6oz in servos.

Chuck

famousdave

My Feedback: (61)

Chris - nice job on mounting that 3W... man that thing is going to be insane..!! I had a 3W-24 on the CAP I just sold and it tore that cap through the sky at 12+ pounds. The USL will weigh less and you will have 30% more power available than the G26....


Chuck - Each plane has some minor differenences in weight due to wood selection ,etc. Yes, I did include the extra firewall spacer in that weight tally - also, since I was able to build my own firewall on the second round, I built it a lot lighter, used pins and the fiberglass was a lot thinner.

MG servos weigh about 2 oz each, so that savings is close to 4 oz ditch the extensions associated with the servos, there is 1 more oz

DP

chuck l

My Feedback: (17)

DP,

Can you describe the construction of you new firewall including how thick you made it? I'd like to go lighter also, but don't trust my design skills in that area yet. Regarding servos, I was using Futuba's which are advertised at 1.3oz, although, I will probably go to a larger torque rating because of the full length ailerons. Regarding mufflers, I'm using the stock G26 muffler, is the Bennett muffler noticeably lighter, if so, I might change that out also.

Chuck

stomper

My Feedback: (20)

Good looking USL DP!

Here are a few pictures of one I did pre USL.