daveopam

My Feedback: (9)

Thank you for taking my comments in the spirit which they were intended.

One of the things that makes an Ult bipe different from many other models. Is the fact that the wings, cabanes and fuse make up a structure. Most planes the wing has nothing to lean on to gain strength. When you grab an Ultimate wing by its self it can be twisted and feels kind of flimsey. But bolt the whole thing to gether and it's like a bridge. This is why I was talking about keeping weight down. I had a friend that had 10 different GB Ult's back in the day. They flew great but he would loose one every time he dead sticked. He was reinforcing here and doubleing there until his were 5 lbs heavier than mine. I may be exagerating but he was using Enya 1.20 four strokes and smoke systems so I know they were 3-5 lbs heavier. Anyway my point being they just dont need all of that. I think you have yours well under control but you are not the only one reading this.

David

abbott915

My Feedback: (1)

I really do appreciate all the comments, it is always a learning experience since this is only the second one I've built, so I know I'm way behind the 8-ball compared to some of you out there.

I'll continue to update the progress and hopefully more will provide their comments and expertise to help me along the way.

Jeff

abbott915

My Feedback: (1)

Made some progress last night and today.

I trimmed a piece of 3 inch 1/16th balsa sheet down to 2 1/2 inches and made marks on the ribs up 3/4 inch from the back edge of the TE cap. This is the same location as the original plans call for. I used 2 1/2 inches because I'll be cutting out the ailerons from it.

I moved on from the trailing edge sheeting and put down the leading edge sheeting using the template from the original plan to cut the slot for the wing strut mount. Prior to putting down the leading edge sheeting I sanded down the sub LE to match the front edge of the ribs.

So far, everything is shaping up pretty well, and the ribs and the sheeting all matched up well.

I've unpinned the wing from the board and will cut off the tabs on the bottom of the ribs and cut out the ailerons and get started on building them.

Since this is the bottom wing, I'll need to get the basswood blocks mounted in before putting on the rest of the sheeting.

4570jackjack

My Feedback: (74)

Subscribed.

daveopam

My Feedback: (9)

Looking good!

David

rem0.061

My Feedback: (30)

Made any progress over the holidays? I've about finished the electric setup on my 10-300.

abbott915

My Feedback: (1)

No real progress since the last post. I did get the wing mounting blocks in the lower wing both front and rear and also got it sanded down and ready for the top sheeting.

I'm struggling a bit trying to figure out my motor, esc, battery combo, and a couple guys in the club who are super knowledgeable are helping, but I've been a bit tied up so we haven't completed that process yet. What setup did you find will work for your motor, esc, battery combo.

I also constructed the fin and rudder per plan, nothing earth shattering there.

I have all the ribs cut for the upper wing and ready to go, but I'm waiting to start construction of the upper wing until I have the lower wing completed and I know it all went together.

Before sheeting the final part of the lower wing I want to check the incidence and again double check that all my drawings and cuts are correct. Hoping to get over to a friends shop to do that this weekend.

daveopam

My Feedback: (9)

I was curious. Are you going to put a battery tunnel in the location of the tuned pipe tunnel? This seems like the logical place and would be easy to get too with the exception of the cowl. It should also be close to the CG. Wish i could help you more on the motor and ESC but that is not my forte'.

David

rem0.061

My Feedback: (30)

I don't know what kind of performance you are looking for, but my setup is light weight and probably would have no more than a 1.1:1 thrust to weight ratio. I still have not tested it yet, but it looks like a bigger motor and battery can be used to balance mine out (I'm not sure how different the balance of your airframe will turn out). I'm using an NTM 4258 500kv motor, Hobbyking 100A red brick ESC, and it looks like I will need at least a 5800mah 6s lipo to have a chance at getting the CG in the right spot.

rem0.061

My Feedback: (30)

If you want lots of power you should use a 100A esc and 5800mah 6s lipo with a Rimfire 1.20 motor and an APC 16x8e prop. that should push it to 70mph and have about a 1.3:1 thrust to weight ratio.

abbott915

My Feedback: (1)

I haven't really thought about it yet or looked into where some of those will go. I spent some time yesterday back on the computer designing the ailerons and printing pieces to cut out. Hope to get that started to day. Batter / ESC location is on my list to figure out.

Thanks for the thoughts, I'll certainly check out that location and see if I can make it work.

abbott915

My Feedback: (1)

Right now I'm pretty much just a recreational flier. Not much more than a roll and a loop now and then. Starting to learn some of the other things, so I don't really need to hover it but I do want it to be powerful enough to learn some of these other basic maneuvers.

I'm still pretty new to flying and feel fortunate when my plane comes home in the same number of pieces as when I arrived at the field, and it doesn't take me two weeks of repairs to get it airborne again!!

I did see your post over on my other thread, and I was looking at the ESC reviews. Some people were having troubles with it. Any issues with yours?

A 16x8 seems like a big prop for that plane. My GP with a Super Tigre 90 had a 13x6.

Thanks for the response, I do need to get this figured out so I can finish up the firewall and fuse construction.

daveopam

My Feedback: (9)

My last one ran a 17x6 prop with the OS 1.20 so clearance is not an issue.

rem0.061

My Feedback: (30)

The wire gear on mine makes it look like it's on stilts; it should handle an 18" prop without scraping the grass. Electric motors tend to turn large diameter props at lower rpm while nitro engines work best with small props at high rpm. With your flying style I think a NTM 4258 500kv or a Rimfire .80 with a 6s lipo and 14" prop would work for you. Just know with the NTM motor you should carefully disassemble it and run a stream of CA glue between the magnets to keep them secured. The HK Red brick 100A ESC is just a cheap one if you want to save some money. I never program them or run more than 6s voltage through them, so I never have any trouble with them. The only programming options which you might need which should be available on which ever version you might get are the low voltage cutoff and the brake. You could use a minimum of an 80A ESC if you want, don't forget to get motor bullet connectors and battery plugs.

Lucky for you, you can make the firewall to fit the motor whereas I had to make a motor mount to adapt to the nitro setup. You will need some standoffs though to space the motor out far enough from the firewall, or you can make a mounting block like what most wood electric ARFs have.

abbott915

My Feedback: (1)

Thanks for the comments on motor, ESC, prop combos this weekend. I'll do my research this weekend and make a decision and get moving.

I spent some time this weekend catching up on drawings and some minor revisions needed as well as noting that the pdf files that were sent out before of the tracings did not include the slots in rib #2 for the ply joiners. I'll make those available to anyone that wants to send me an email to the address below.

The images are the start of the aileron construction. I cut out the first sheeting from the wing construction and laid out the ribs on them. The leading edge is a 3/8th x 3/8th balsa stick. I took the design from the Great Planes Extra 300S instructions.

So far, it's gone together well.

I still need to get the incidence checked before finishing up the wing and fuse connections. I want to make sure all the cuts and drawings are correct.

[email protected]

rem0.061

My Feedback: (30)

Looks like I will be test flying mine soon, I'll let you know how my setup works. This is a pic of when it was nitro, and with my setup now. I figured out that the CG will probably be ok after I managed to stuff a 5000mah lipo up front, it might even be a little too much weight that far up, but I have not put the wings on yet to see. It would be best to use an electric prop with the NTM motor, but I only have some light wood props right now.

rem0.061

My Feedback: (30)

I just got back from flying it. It was a tad nose heavy, so the lipo could be turned sideways and moved back some. AUW was about 8.5lbs, it had about a .9:1 thrust to weight ratio, needed about 50% or more throttle to fly, and it got an 8min fly time with a couple to spare for landing. It was kind of slow and lazy, 35-55mph flying speed range, but could roll, knife edge, and loop well. It would try to roll out of a loop if it is too tight. It lands with about 1/3 throttle to help keep it from dropping on the runway.

Final setup will have a 4000mah 6s right behind and parallel to the firewall with a 5 cell nimh back with the rx to balance it.

abbott915

My Feedback: (1)

That's great, thanks for the update.

I'll keep going here and keep updating.

mustangherb

My Feedback: (6)

I want to thank you for the reply and telling me about this build. I will definitely follow this to the end.

abbott915

My Feedback: (1)

Here's the latest on the project.

The cowl and canopy arrived from Fiberglass Specialties and it was packaged and shipped promptly. There is what appears to be a spot where there was a dust speck on the canopy, but I'm not 100% sure since I don't know how they are made, just my thought that it was a speck of something that didn't allow the plastic to lay down tight.

Anyway, on to my progress.

Lower wing is done now except for the end caps and the mountings for the servos. I'll do that when both wings are done.

Ailerons came out as I expected, and no problems there once I sanded them down.

Leading edge also came out as expected after I glued the leading edge stock to the sub leading edge (and two fingers, then removed the fingers, gotta be more careful), and sanded it to the correct shape, using the included leading edge sanding tool from the kit. I started with 40 grit, moved to 80 grit and finished with 150 grit for now.

I do still need to mount the hinges I just realized, but will probably do that when I'm building the other wing and glue is drying.

So, on to the upper wing.

abbott915

My Feedback: (1)

Nothing much to report except I'm building the upper wing. Next bit of head scratching will be the upper mount. I'd like to use wing bolts instead of that wire, so I've been looking at the build info from peternj and will work something like his mounting into my build.

Pretty frustrated also when I checked the incidence. Everything was right on except one wing tip. Somehow I got a bit of a twist. It had to have been when I put the last piece of leading edge sheeting on. I must have pressed down just a bit to hard and didn't catch it until it was to late. So, some research shows I should be able to mist it and weight it down and get it out.

I'll be picking up the motor and ESC Friday, so I can get that mounted and the rest of the fuse done.

More to come.

rem0.061

My Feedback: (30)

Yea, that wire can be pretty annoying to get in correctly sometimes.

daveopam

My Feedback: (9)

The covering will take the twist out most of the time. Since it's not covered yet though, I would put a few degrees of opposite twist in it and mist it with some water mixed with ammonia. Just weight the center down, block the desired twist and go.

david

abbott915

My Feedback: (1)

Thanks Dave,

I tried already to get the twist out and misted it with just water, and let it sit over night. Came out next morning, un-weighted it and it was perfect. A few days later, and the twist is back for some reason. I'll try again with the ammonia and see if that was the issue. Strange it came back. Maybe not as bad, but it still came back.

daveopam

My Feedback: (9)

Not uncommon at all for it to come back to a lesser degree. I also massage the water in a little. In other words after I mist it I rub my fingers over it a few times. It speads it out and penetrates better. Keep in mind also your twist is not just in the sheeting. it is also in the spars and LE & TE. So when you are done the sheeting is having to hold the spars straight. I would not be suprised after you flew it a few times that some of the twist mwill show up again. This is where using the covering will come in handy.

David