sthill

Sorry for my delay in posting, the holiday weekend really threw me off. I’ve gotten through mounting all of the control surfaces and all of the servos. I’ve included a couple of pictures of the tail feathers and the pull/pull setup. This is my first attempt at installing a pull/pull system and it went well. As always, I’m trying to get all control surfaces neutral mechanically first to minimize any computer trim later. The rudder will do about 45 degrees each way on the current setup and the max throws for 3D are 40 degrees so there should be plenty of room to play.

I spent some time on mounting the engine as I decide to NOT follow the instructions and instead mounted the throttle for my Saito the same way they show the 2 stroke install. This requires you remove and rotate the carb 180 degrees. IMHO this is a better option as allows you to not have to glue in the tall servo mount (which looked a little flimsy) and it allows the high speed needle to stick out of the top of the cowl for ease of tuning. The way they show mounting I would have had a 5+ inch extension on my HSN and it would have been sticking out of the bottom of the cowl which I wasn’t crazy about. Yes, I am going forward with a Saito 82. I’m sure folks will disagree, but it is where I’ve decided to start because I already own one and the manufacture suggests it!

One last thing, I received an awesome super custom decal set from Bad Brad Graphics. I suggest you give him a call before you decide to purchase a graphics package. He is really easy to work with and will help you make your plane your own.

da Rock

With both my Yak and Extra, I got the CG I wanted by building a balsa box for the battery and placing it back in the aft fuselage. Both were almost at the limit of reach for the connector wire. The box is glued to a bulkhead and a number of the stringers. The idea is to spread the load. (btw, if you can't figure out how to reach down in the fuse back there, cut the covering out of a lightening hole off the bottom. Do the job through it, and cover back over the hole. Invisible, quick, easy. taa daa) Neither airplane needed added weight. Both are powered by the OS61 and both have Slimline Pitts mufflers.

With a straight, no-resistance pushrod setup, I've used a micro servo for throttle. However, on the birds I figure to wear out flying, I'm using one of the best kept secrets for servos. I use it for ailerons because it puts out more power than most standard servos. It's also just an ounce and most standards are ounce-and-a-half or more. So you'll save a good ounce just using them in the wings. And it's really good to save in the wings. I buy them from Tower with a "volume discount" for three. And one of those 3 goes in for the throttle. Hitec Mighty Mini HS-225 Put in 3 and your model will start out 1.5oz lighter from the gitgo.

friedclutch

OK... I weighed EVERYTHING.

Complete airframe, motor-Saito .82, servos, Rx, flight battery and regulator, ALL hardware, fuel tank....

With a full tank of fuel. (I actually weighed the fuel) Powermaster 20%Nitro / 20%Synthetic oil

Grand total take off weight with a full tank of fuel is 7 lbs 12 oz

On the servo topic, The manual states using 80in/oz servos. I have a full set of HS-635hb that are rated at 83in/oz @ 6 volts. These barely meet the spec in the manual.


EDIT....

Here's a few comparison pics with my Funtana.

da Rock

Interesting.

Your canopy looks clear. Mine is tinted.

Also, my red/white/black Extra weighed 6 lb 15 oz with an OS61FX and Slimline Q-zone pitts muffler. no fuel
Most people weigh them dry. That way, different tank sizes don't affect the outcome.

friedclutch

Take 15oz off the weight I posted for "dry" weight. (7lbs 14oz minus 15oz.) So 109oz total dry weight. 6lbs 13oz all up dry weight.

BTW. My canopy is tinted. I think my garage lighting is creating the illusion. A side note.. I am running 2cell lipo for flight controls. (Regulated to 6v.)

EDIT: So the moral of the story is.... wait until tank is empty for doing hard 3D.

Reason for editing? Bad joke insertion.

gsilver

so a saito 1.25 will pull this around nicely?

Downthrust

My Feedback: (6)

I would say definitely yes. My Saito swings an Evolution 16x6 prop 9200 RPM's with 15% nitro and delivers unlimited vertical in an 8 pound plane with 20%. The difference in weight between the 82 and 125 is about 7 oz but it looks like this plane has plenty of room to move a 5.4 oz, 5 cell, 2000 mAh, 6V Rx battery around to keep from adding tail weight. As another option, I know that they offer a pull-pull rudder system, but I'm not sure if a rudder servo could be mounted in the tail instead without tearing your hair out. Anyone with one of these models have any comments/observations on this option? Some guys don't like to bash a new plane, but out of the box is really the best time. Adding a two oz servo in the empennage should more than compensate for the added 7 oz in front of the engine mount. I hate adding lead 'cause lead don't fly well. You can also do a mock setup to test it and eliminate the guesswork. And I have to say that I love my Saito 1.25. I bounce the prop backwards off TDC and it fires every time. No starters needed for this engine.

gsilver

It is a nice engine....been sitting around for a few years doing nothing.

sthill

My build is basically complete; I’ve added my custom vinyl graphics (thanks Bad Brad) and finished cutting the cowl. I’m glad I flipped the carb around and I just cut a small Allen wrench down to about 1 inch and it works well and is easy (and safe) to adjust on the top of the cowl while the engine is running. One issue with mounting a Saito 82 on this bird is that there is no reasonable way to attach a glow plug igniter to the glow plug through the cowl. Given the angle of the glow plug you would need a really long (6+ inch) glow plug igniter to fit. I decide to build my own remote glow to handle this. I used glow plug clip off a dubro remote glow I had laying around and purchased a 1/8 inch mono headphone jack from Radio Shack to as the connector between the plane and the battery. It was a very cheap and lightweight solution to the problem.

Just something I noticed for folks considering adding bigger engines. The distance from the firewall to the end of the thrust washer needs to be 4.75 inches per the manual. My Saito 82 is setup this way and the spinner is a nice comfortable 1/8th inch outside the cowl. The back of the engine is very close to the engine mount and I believe the bigger Saito engines are longer and may require a different engine mount or some “adjustment” to the firewall to get them to fit. I would just suggest making sure your engine + mount length is less than or equal to 4.75 inches to make sure the engine fits prior to purchasing to make sure you won’t have to perform extensive firewall modifications. The firewall seems to be firmly attached with triangle stock in the back and square stock up front so relocating it will take some effort. Just my $0.02.

The Saito 82 muffler doesn’t stick out much below the cowl so I ordered up an exhaust deflector to direct the glow goo down and away. Also, I ordered a Tru-Turn ultimate wide spinner to accommodate a 13x6 or 14x4 prop. Once I get those parts installed I will rebalance. Right now I’m at about 2.75 inches (2.5 inches recommended) and will hopefully balance without adding weight with this extra “stuff” added to the front.

To try and answer an earlier question, the airframe is extensively lightened out of the box I’m not sure exactly how you would mount a rudder servo toward the back and maintain a pull-pull configuration. I guess you could mount it to the fuse on the opposite side of the elevator servo (probably enough room) with a direct linkage but I would be concerned that you couldn’t get the 40% throw required for 3d rates. With the pull-pull setup I can get about 45% throw with little effort. I’m sure someone will figure this out but it just seems like too much hacking around.

Anyway, I’ve attached the pictures of the almost finished product. Can’t wait to give it a go!

Downthrust

My Feedback: (6)

Nice build. Great job, but now I have to have one, which also means investing in a motor size I don't have already. About the tail mounted rudder servo, I was indeed asking about the possibilities of mounting the rudder servo on the other side of the single elevator servo, but your answer about the measurement between the firewall and your Saito 82's thrust washer means that this option is no longer a viable one. The Saito 125 needs 5 inches and I'm not sure there is any room for modification without major surgery. Just not in the cards.

Great graphics by Bad Brad too. And the Saito 82 loves the 14x4 Wide APC prop. Be sure to try it if you have one. Not as much speed, of course, but great torque. I'm not sure it will fit in that spinner, though. It looks like it now has all the prop width it can handle.

sthill

I’m sure a Saito 125 would be a beast on this plane and I don’t want to discourage you from trying, but I believe it would take knocking out the firewall and moving it back to get it to fit. The good/bad news is that Aeroworks did a nice job of using triangle stock all over the firewall (front and back) so moving it would take some effort / hacking. In the past I’ve used loose fitting cowls to “cheat” the cowl forward to cover a little extra engine length. This cowl is great but the cowl mounting is pre-drilled and the cowl is bolted into place with blind nuts. This leaves you no room to move the cowl forward to cover extra engine length like you can do with some ARFs. Just my $0.02 and I’m sure someone will prove me wrong!

One engine that no one has mentioned for this plane is the new YS 70. I realize the displacement is less than some competing engines but I’ve read that it has the power of a 91. Could be a nice strong little engine for this plane if you keep it light enough. I already had a Saito 82, but if I were to do it again I would seriously consider the YS 70 or likely the OS .75AX. I realize it is a two stroke but it seems like the strongest “drop in” engine available for those worried about weight and OS reliability has been awesome for me.

You are right about the spinner. For the picture I mounted the standard Tru-Turn 2 ¼ inch standard spinner with an APC 13x8. This spinner is designed for smaller props and a 13x8 is just about the only 13 inch prop I could get to fit. I’ve ordered the Tru-Turn 2 ¼ ultimate spinner with the cutout for wide props so I’m hoping a 14x4 or a 13x6 will fit in that one, I’ll be sure to let you know.

friedclutch

Hey guys,

I have a Saito .82 in mine as well. I dont know exactly what Tru turn I have, but it is 2 1/4 diameter and it fits a 14/4w and 15/4w nicely. I'm not sure why, but the Saito really likes the 15/4w prop for hover pull out better than the 14/4w. I run powermaster 20/20 fuel and it seems very happy with this mix. I am getting 9800 to 10000 RPM with a 15/4w and 20% nitro. (Sea level in Sacramento CA) I originally had the Saito in a Funtana X50. I'm off work tomorrow and Thursday so Thur will be the maiden flight. Mine is pretty much done at this point other than securing the tank and rx. It balanced just barely further back than the recommended C.G.

Going to hit the hobby shop tomorrow and grab a 13/7 APC and maybe another size to try that will have more speed than a 15/4w. This will be my IMAC practice plane when I cant get the 50cc out to the field. Not to mention this plane will be cheaper to crash than my 50cc if I get a little too low and ballsy with the 3D. Do you guys have a prop recommendation that I can try on the .82? I would be happy to guinea pig a size or two and report back.

On the glow plug reach topic. I have a remote glow plug setup that I used in the Funtana that works great. I recommend using a remote glow plug kit.

On the weight issue.... There are quite a few ways that you can lighten this airframe.
The first way is using 2 cell lipo for flight controls. You can get a great regulator from Castle that is CHEAP and is rated to 10amps.

Another notable thing that is heavy on this plane is the "Giant scale" like hardware. The "tiller" type tail wheel assy is an awesome feature but heavy. You can get a cheap light weight set up anywhere.

Also there are some overkill areas in the airframe structure that you could lighten up, especially if you are running electric. The heavy and ultra durable airframe structure is really sweet for us 4 stroke glow guys but the electric guys can really shave off wieght without compromising too much flight load strength.

Dont for get about the landing gear too. I could shave 5-6 oz off this plane in a few very minor tweaks. Axle shave, wheel pants, fuse mods, tail wheel swap, etc..... however, I'm not going to change anything at this point. I'm prepared to buy a Saito 100 if the the .82 cant pull uplines hard enough. Or.... mild to moderate.

sthill: Thanks for the cowl clearance warning. I totally forgot to add the 4.25" clearance into my engine upgrade research. oops!

Downthrust

My Feedback: (6)

Friedclutch... it all makes sense because the 14x4W was with 15% Wildcat 2-4. Since we have a combo of 2c and 4c engines, we find that this fuel is a good compromise. I completely forgot about the fuel upgrade that the engine can handle, and the extra performance it will provide the 82.

Speaking only from experience with the 60 inch Edge 540T from AW, when we actually calculated the CG, we did end up move it back a bit, and it flew much better. Covering the hinge line and cutting back on the elevator throws also eliminated the snappy characteristics. It is really a fine pattern/sportship now, but we do have an O.S. 91 4c in it. Your comment makes me feel now that increasing the nitro level, and moving up a prop size, and down a pitch notch, may be just what is needed to move the Extra 300 to a pattern/3D hybrid. Maybe with the 82, and more likely with the 91. Let me know if you ever try the 15x4W on the 300.

Downthrust

My Feedback: (6)

Also, it seems that you have some downthrust in that engine setup, and I don't mean me. But I guess you will know when you trim it out, and when you cut back on the throttle while inverted. If the nose dies right away, you may need to make the adjustment to the mount. You probably knew that already, but it's tough to overlook how much seems to be there from the pics. The cowl looks dead-on, and from I've heard there are blind nuts for the cowl screws, so that can't be the problem. If adjustments are needed to the bottom of the engine mount, you may need to adjust that nice cutout job you did on the value covers, which would bother me a lot. [:@] Maybe they did it on purpose.

Please let me know if the plane flies neutral with the downthrust so we can keep it in mind.

da Rock

Your finish weight was???

da Rock

What does it weigh complete???

sthill

Da Rock – Sorry I don’t have a final weight as I don’t have a scale that is accurate enough to weigh a plane of this size. I’ve always just mated my ARFs up with a manufacturer’s suggested servos and engine and went for it!

Downthrust and Friedclutch – My engine has approximately the same cowl exit as friedclutch’s. I’m not 100% convinced that it is actually down thrust on the engine, it could just be an optical illusion with how the cowl is fitted to the plane. We will see what happens when it flies!

Friedclutch – how did you route the Saito crank breather? Folks on the Saito forums say that you should limit the length of the tube you attach to it to 4 inches but that won’t get it out of the cowl without drilling a hole. Any good tips or advice?

friedclutch

Ok... It is now flight ready. Complete assembled weight is exactly 6lb 14oz. The only weight cheat I used so far is installing an 11oz tank instead of the stock 15oz. Also note I am using a 2200mah 2cell lipo for flight controls. Going to grab a 1300 or 1500mah pack next week. 2000+ mah is overkill when using lipo. After 6, 10 min flights I was only putting 200 to 300mah back into the battery on the Funtana.

About the downthrust. I dont think I have you in my cowl. I "think" it may be an illusion with the angle of the shot. I used the stock engine mount without any changes yet. Check out this image of a side on angle and see whatcha think.

friedclutch

Hey sthill,

Just saw your post about the crank breather. I did not know there was a length limit on the breather tube. I ran it out of the cowl and secured it to the landing gear. Here's a picture. In hind site I can see how a long tube may restrict air movement. I may need to drill a hole out the bottom of the cowl. ?

da Rock

Thanks
With your .82 being about 18 ounces and only an ounce or so less than what I'm planning, I'm guessing mine should wind up about the same overall.

Downthrust

My Feedback: (6)

That's really funny how everything looks fine in that picture considering how the first pic looks like there is at least a few degrees of downthrust. But this angle obviously looks like a straight datum. I also did not know about the breather length limit, but I have at least seven inches of tubing on the 82 in the U-Can-Do, and it has been that way for over 200 flights. Never had an issue with that engine and it is still one of my favorites. But if that is what Saito suggests, then there must be a reason.

friedclutch

Ok.... So here's the flight report on how the Saito .82 did with a 6lb, 14oz airplane.

First take off.....

The Saito fired right up at 1.5 turns out on the high speed needle. Here are some thoughts after 3 flights.

Ground handling in 10mph cross wind is good and predictable. The tail gear was effective. Not knowing how much power the Saito would have, I let it roll out half of the runway. I now know that a long roll is not necessary. I can take off immediately and pull strait up.

I flew the 15/4w prop all day. I dialed the mixture a little rich today. (100 deg F) Full throttle was 9400 RPM. I still had good vertical, but with this large, low pitch prop it would slow down a bit on really long uplines. It did not stop though. Just chugged and kept going until it started getting hard to see. My next prop choice will be a 13/7 apc.

Could I do aerobatics with the 15" prop? Hells yes. Huge loops, high stall turns, big immelmans.. Quite easily.

BY THE WAY.... I have to mention awesome knife edge on this Extra. VERY little pull to the gear. On some planes, knife edge flight feels forced. Not this one. Leave the ailerons alone. I dialed in 6% up elevator mixing but it was not really needed if you are not into precision. Adding such a small touch of down elevator during KE was almost unnoticeable. I also added a mix for 5% opposite aileron. When strait and level, hitting full rudder caused a slow roll in the direction of the rudder. Not surprising. The rudder is very effective as expected. Even in a stall. Stall turns are easier to do with this Extra than on my larger Yak. Weird. I will actually take some rudder throw out. Snaps are snappy of course. I have not tried harriers yet. Did not want to push it too far on the first day. I can tell you that I noticed good stability in high alpha as I did try a few hovers. High hovers. It did not snap out of hover at all. The 10-15mph cross wind did not allow me to really get locked in or get a good hover feel though. As expected hovers are at about 3/4 throttle stick.

A few notes about precision flight. This plane tracks well even in a gusty cross wind. Does it track as well as my 50cc gasser? No. But at least there were no surprises. I also noticed solid tracking even at pos/neg "G" transition situations. (top of a loop etc.) The ailerons have really good authority and are twitchy if you have no expo.

If you are in hover and bang the throttle to full there is a little torque roll and a little down pitch. Which brings us to the next section.

DOWNTHRUST!!!. I stand corrected. There is a little too much down thrust! haha. Putting along at half throttle strait and level... Sudden throttle increase to full throttle does what?... Downward pitch. Not horrendous. But noticeable. I will be adding small shims to the lower engine mount bolts. Also a smaller prop may help.

Landings..... Landings... and Landings. Landings are non-surprising. (read>good) It was everything I expected for an aerobatic plane. Minus any weird low speed snapping. I came in the first one a little high and fast so I cut the throttle to idle for a drop and brought the power back on a little before touch down to ease the decent. Following landings were a lower approach with slight power into the cross wind. Cut the power right before touch down.

Sweet. I'm happy that I dont need to buy an engine for now. I will fly this set up for awhile. Hard core 3D guys will want more power but I have good vertical. Not rocket vertical, but good vertical. Here's a couple images from the day. The first one is of me with my New Extra and my 50cc Yak. The second with my best buddy Don's Aeroworks Extra 300. (100inch/100cc) and the new Extra .60-.90.

Robert

friedclutch

Added a very small amount of up-thrust. Flying tomorrow

EDIT:

Ok.... The adjustment of up-thrust was perfect. No more dipping on throttle up. I would guess the shims I used were .015" to .020" thick.

On a side note, watch the low altitude snaps. It snaps pretty fast. If you don't get off the sticks in time.........
I had a little surprise. I was plenty high, but caught off guard when 1 snap turned into 1.5 snap(s). And what a true snap it was. Full power got the wing back out of the stall.

sthill

OK, So I need some sage advice. I took my AW Extra 300 60-90 out this weekend for a spin and never got her off the ground. We have a grass field that was cut 2 days earlier and the grass was thick but not terrible, it was dead calm with no wind to speak of. I taxied her out and advanced the throttle. Going full throttle the plane just never seemed to come up on its wheels. I backed down (running out of runway) and double checked everything and need some advice.

Some background:

The engine: I tached the Saito .82 running 20% with a MA 14x4 prop at 10k RPM (richened from 10.5k), it seemed to have very good thrust and pulled pretty hard. I also verified the tach readings with another member’s tach and they were spot on.

The wheels: I used the stock wheels and wheel pants. The wheels spin freely, but the wheel pants could be imparting some resistance.

The CG: checked it an hour before takeoff and the CG was right on.

I am going to make a few changes before this weekend. First, I am going to change out the 2.5 inch wheels with 3 inch foam wheels and will remove the wheel pants. I am also going to try a different prop. I am struggling between an APC 13x8 “sport”, APC 14x6 “pattern” or MA 14x6 “K-Series”. I figure a higher pitch may give me more speed for takeoff. I haven’t tached the engine with any of these props but I have a feeling that the change will likely drop my RPM’s down to the mid-9000’s which I am OK with.

Any other suggestions (other than to buy a bigger engine!) or input on the best prop?

Downthrust

My Feedback: (6)

It's not the Engine, not the RPM's, not the prop, so it may be the grass, and the pants or elevator. Here are the facts.... 10K RPM's with a 4-pitch is still 55 ft per second or 37.5 MPH. If you can say that the plane was crawling down the runway and not obtaining anything near 37 MPH, while still taching out at 10K, then the grass resistance is probably the issue. With a wing area of 690, a 7.5 pound airplane will have a wing loading of 25. If you are really getting 10K RPM's, and your 300 did not finish out at 12 pounds, then it should get off the runway quickly at 37 mph.

The only other thing I can think of is that your elevator has too much up programmed, or you are holding up elevator all the way. Holding up elevator will keep the tail pinned to the runway, creating a ton of resistance so check this first. What would you estimate the speed was before you ran out of runway?