Gary Binnie

I'm plodding along with the build but things are slower than I would like at the moment.

Looked at using the ABS wheel pants but the inboard halves are 1/8" shorter than the outboard halves! Fibreglass items are available in the UK so I'll probably go for them.

Couple of questions for you guys if I may; is the cloth strip around the centre section of the wings important and has anyone covered one of these in anything other than iron-on film?

I'm thinking of tissue covering the fin and tailplane before fitting them and covering the other parts with Sig Koverall, it would need painting afterwards which is not my favourite job and would add some weight.

GB

J.Paul Saure

My goal is getting this kit light, to compensate the smoke system.
I wouldn't use anything other than monokote...
Also, I won't make much ply reinforcements, except maybe areas that could wear out with use. Maybe a little in the interplane mounts....

Gary Binnie

It's stopped raining for five minutes so I've taken some more photos outside!

On its wheels for the first time with everything thrown very loosely together.

The 90 FSR only just sticks through the cowl, shame!

I added a small triangle of ply above the tailwheel to reinforce it and make it thick enough to take a 'T' nut.

The carbon undercarriage legs were initially too wide for the mounting plate and a 'V' needed to be cut for the wing leading edge. The two holes in front of it are for a Kavan fuel filler.

Getting there!

scale only 4 me

My Feedback: (158)

Anyone seen any EP conversion threads?,, I have a kit and have been thinking of going that way

JNorton

My Feedback: (2)

It is fiberglass and hugely important - unless you like your wings to fold. <GRIN>
John

skyracer068

My Ultimate is powered with a Hacker 50-16L, Castle Ice 100 ESC and, 8s- 4000 mAh. I'll send pictures if you like.

Gary Binnie

Roger on the tape John.

I had plans to cover the fin and tailplane before fitting them but I've gone ahead and followed the instructions.

The ply turtledeck that came with the kit could not be made to fit nicely and it also had both rear tabs broken off.

Made a new one with revised tailplane slots and it fits much better but still a struggle to glue it up, I had just enough hands and clamps!

scale only 4 me

My Feedback: (158)

I wouldn't mind seeing your battery access,, and maybe any cooling vents you provided,, just post it up here for all to see

Thisstrangeengine

Hey Gary, sorry for the late reply but work has been crazy and the lawn was getting out of hand!
I still havent located my decals but I don't think I would part with them just yet. I have been thinking about scratch building one since I still have the plans and some of the rib and former cut-outs.
All I need is time and to finish up other projects. As far as the decals go and my memory also; they are stickers and not the water transfer type.

Gary Binnie

No worries!

Cheers

Gary

sirzepp

My Feedback: (1)

Just finishing up my ultimate and have run into a snag.

It needs about 15 ounces of weight on the nose to balance.

I've installed a Saito FA-125, it has dual elevator servos (installed in the tail, forward of the horizontal stab). Current empty weight is 7 lbs 7 ozs. I have not installed the cowl, wheel pants, spinner or prop.

BTW, this required weight is with the battery all the way forward against the rear side of the firewall.

Should I just add the weight and enjoy the plane? (UG! I HATE adding weight!). Should I move the elevator servos to the standard servo location (there is room, as I installed the throttle servo forward of the CG in it's own location...anticipating a need to shift things forward a bit for balance)?

This is, of course, going off the CG location depicted on the plans...I had one of these planes before and I don't remember having this much issue with CG...but I didn't mount servos in the tail either.

Gary Binnie

The Tiger Moth in post #764 has 2 lb of lead sitting on the engine bearers and that is with everything fitted as designed! Just had to do it.

I build gliders mostly and there is a rough rule of thumb that one extra unit of weight at the tail will need four times that in the nose to balance it (but they do have longer fuselage moment arms).

I've thought about servos in the tail for the Ultimate and also a dual-drive bellcrank system but I'm probably going to go for an up-rated version of the system shown on the plan using a single carbon rod and two 3 mm wire pushrods (common use over here would be 2 mm pushrods).

Could you use smaller elevator servos with the same torque?

Cheers

Gary

alfredbmor

There are many strong mini servos in the market today, meaning that there is a big possibility on doing so, besides by using the double servo choice, the load will be reduced, taking in mind too that, by design, each elevator half has a kind of counterbalance that helps the servo to do the job with a lot less force required.
I have built several 40 size planes with regular mini servos with the purpose to save some weight, and they all have been flown great. Technologies are a great advantage in our hobby, and one of the great advances relay on the servo area.

alfredbmor

I am using an OS 120AX, two JR digital servos at the rear for elevators, (same placement as yours), and had no problems with balance, battery is placed near the tank right after the former. I do not know the diference between both engines, I will try to check it up, still I wish to comment that before that engine, I used a Magnum 120 four stroke engine, because of its size, the front of the engine was too much ahead than the place shown in plans, that allowed me to balance the plane, I also had a smoke pump but it was placed at the CG, when I changed the engine I was afraid to miss the CG, but I located easily just by moving the battery, I am still using the ABS cowling, I will post some pictures of the battery placement and post them as soon as I can.

Gary Binnie

Some more progress this week:

In an attempt to empty the kit box I've cut out the canopy and taped it on, looks good!

Tail feathers are virtually done.

The cabane attachment and upper wing were causing a hold up so I've pushed on with that area. The upper aluminium part (and the side braces) were missing from the kit so I've made my own. Was going to try a bolt-on upper wing but in the end I've gone for a modified version of the standard design.

I have run a brass tube through the centre section (instead of the plastic pin guide tube mentioned in the instructions) and added a ply piece at the spar (covering the oversize hole in the brace). The tube now spreads the load across three pieces of ply (instead of two) and has a direct attachment to the spar centre section. Should be able to close up the upper wing now.

Not much building left to do now, need to choose some servos for the ailerons and make up mounts for them.

Would be nice to get it flying for this summer but I'm not rushing.

GB

sirzepp

My Feedback: (1)

That is interesting, I just looked up the weight on the 120AX and it's only 4.3 oz heavier than the saito...I changed to a dual battery configuration (twin 1700 mah Life) to afford a more "manuverable" setup and now have the batteries securely positioned right on the back of the firewall. As it sits now, it still needs about 11-12 ozs to get into the CG range. I am going to build a weight box off the firewall and get it to balance as it sits (just to be sure), then fly it and tweak it that way. I'm HOPING I am not utilizing the CG markings on the plans properly and THAT is the issue. I just can't see why my plane ended up so tail heavy...I didn't do anything crazy...just most of the recommended mods (elevator servos in the tail, reinforced cabance strut mounts, reinforced interplane strut mounts, etc.). It DID come out light (which is what I was going for) at 7 lbs 12 ozs...so it's a bummer if it ends up needing the weight...especially because I skipped the DLE 20 on this bird to save weight!

sirzepp

My Feedback: (1)

Thanks for the encouragement, and thanks for the mini servo recommendation.

Honestly I COULD go the mini servo route, but one of my primary goals with this plane was servo SPEED, unfortunately, it's hard (impossible) to find a mini with comparable torque AND speed to the servos I'm using in the price range I require (<80 bucks), from a reputable manufacturer. I've chosen some really sweet Savox servos and they are one of the things I'm most excited about. Savox DOES offer some impressive minis, but not at the same torque/speed I am looking for.

I think I found a solution...

It was a combination of the problem solving itself and I built a box off the firewall that fits in the cowl. The weight was placed at the far forward end of the box, and it only required 3 ounces to squeeze into the aft end of the CG range. I weighed the cowl in it's current state and it weighs 5.6 ounces, so that will help as well (once it's installed, and it will weigh more after paint). In the end, my total empty weight will be around 8 lbs 12 ounces. MORE than I wanted, but still not bad I guess. I wanted AUW to be well below 9 lbs, but that's not going to happen it seems. I guess I'll know for next time. Perhaps I'll do mini servos in that plane and go electric (no vibes) and go crazy with structure lightening.

Anyway...it's mostly done...here's a pic:




There are still some finish up items on the squawk list...but I have to leave town on a four day trip so it'll be next week before first start and maiden.

Gary Binnie

Looks great!!

Savox have a good name over here, as you say, plenty of choice with servos but price becomes a practicality.

Talking of money, mine needs more parts buying!! Starting to look good though.

Have you balanced it laterally? I only ask because I had to replace the last 'D' box sheet as it was in a poor state (just battered by other loose parts in the box over the years). The new wood I used was much denser and it crossed my mind (has a big effect with large span gliders).

Am I imagining it or does a company somewhere make spinners that are filled with lead?!!

GB

alfredbmor

Heavy brass at 4 oz could be a solution for the need of weight:
http://www3.towerhobbies.com/cgi-bin...?&I=LXL715&P=0

They are not the Ultimate fashion but they work, just have to be sure of threads size.

Sirzepp, your bipe is becoming a great one!!!

sirzepp

My Feedback: (1)

Yeah, she's balanced laterally (both wings individually, then the entire assembly).

Spinners with lead would be awesome for issues like this!


I looked at the brass spinners, but I'm going to wait until the cowl is installed and see where things end up. I usually like my airplanes jusy BARELY nose heavy...to neutral...so I'll fly this one if the CG is in range...then tweak to feel after that. Thanks for the compliment! I'm really enjoying it now...all the memories associated with my old one come back when I look at it. It's funny, I've got some really NICE (and fairly large) gas airplanes, but the 'love' for a plane you have built from a kit (or scratch!) is much stronger than what you can have for an ARF (IMHO).

alfredbmor

Same opinion here.

Gary Binnie

Well the good news is that the Ultimate fits in my car in one piece (just!!)

Taking it to the weekly club flying evening to see what the boys make of it.

GB

alfredbmor

You must have a big car!!!
Let us know what the friends tell about your bipe. Have a great day.

Gary Binnie

Yep, it's a 7-seater Ford Galaxy (but with only three seats fitted!).

The guys liked the Ultimate, a club mate had his Sebino Ultimate there, have pictures but the forum seems to have a problem accepting them, I'll try again later.

sirzepp

My Feedback: (1)

I'm looking forward to bringing it to the field fully assembled (My Land Cruiser will fit it no problem). That's a nice thing about bipes...the shorter wingspan makes them more compact overall for a given size/class.