jimcork1

My Feedback: (4)

Ibought this Sukhoi (ASM SU-26M) last week and started the assembly.

Servos will be the Futuba 3152 digitals exclusive of 150 oz on rudder and std on throttle.

I am tracking the manual issues closely. It is a nice plane and looks great.

It is designed for 1.2-1.6 2 stroke or 1.5-2.1 4 stroke. Iam planning to use a saito 1.8 for power.

My first item was to check the firewall and found that mounting the saito on the fire will place the backplate on the spinner 1" too far forward so decision to cut or not cut the firewall is still hanging around.

Assembly of the wing has gone well with no issues. Ihave used all enclosed hardware and eventhough it is metric it is fitting up well.

My biggest issue is the wing tube. It was excessively tight in the fuselage and would not fit. Paint apparently had gotten into the tube and reduced the diameter. Iused my wheel cylinder hone to hone out the tube until it fit. This would be a issue for someone without a cylinder hone.

The manual states the wing joiner tube is drilled for attachment of the wing to the tube for flight with 2 screws. I started looking and there were no screws in the box. So Icalled about the screws. One other thing about the joiner is the holes for the screws weren't drilled. So In my conversation about the screws Iwas told that apparently the decision was that in building Ishould drill the tube for the screws to fit.

So no screws included and no listing on what size hole should be drilled. ?? Iam waiting for the screws to arrive and I will check for what size hole should be drilled based on screw size. I would have much preferred nylon bolts from inside the fuse screwing into the main wing rib and ply block to hold the wing on vs 1 screw in the wing tube. Any one else building this plane?

It is on hold for now until screws arrive. I will probably drill the wing tube for installation as it is designed but really don't like this idea. Loss of 1 screw would mean loss of the wing panel in flight. If anyone else has built this bird what did you do. Otherwise more to come.

Crazy4Flight

My Feedback: (540)

any updates?
hobby people put them on sale...is it worth 150.00 or should I keep my money?

jimcork1

My Feedback: (4)

That's where I bought it on sale. Nice plane.

I have all servos, engine, radio installed. I made it a point to follow directions (rare for me, just ask the wife).

The engine I am using is a saito 1.8 I pulled from a Stinson Reliant I sold. Way much power.

I am installing 2.4 Ghz XPS radio.

99% of the instructions are correct. I have been making notes on the manual for publication.

The plane looks nice. I thought I was going to use my Dubro Iso mounts for then engine but the prop would be too far foward so for kicks I tried the included mount. Perfect fit for the big saito. The prop is in the exact position. I wanted the spinner hub 1/4" infront of the cowl and that is where it fell out. I swapped a larger tank 18oz for the saito 1.8 but the factory tank was ideal fit. The swapped tank will also fit well.

I moved the throttle servo forward. Looked like it would be a bit tail heavy. I plan to use dual batt's and put them in the tank compartment.

The exhaust for the side mount saito comes out exactly where I wanted it. I used a 1/2" copper tubing extension with cross cut on the end and a hose clamp to clamp the extension to the muffler for fit. Works well.

So far I would buy this plane again. NOTE: I haven't flown it yet. But I thought it was a good deal, and it is well build and relatively light. I expect mine to be around 10# which isn't too bad since the saito was pulling around a 17# stinson.

The cowl is fiberglas, which is great and fits well. I deviated from drilling the holes because I could not get a good alignment. So I marked the cowl inside then drilled holes.

The saito side mount only has the valve cover tops cut through the cowl and not noticeable. Otherwise the engine is fully cowled. I haven't drilled the cowl vent holes yet.

So if you asked me to recommend based on building so far I would recommend it.

Flying, next week for that answer possibly given 97F and timing.

One complaint was the mounting of the wing tube was tight due to paint overspray and I used a wheel cylinder hone to clean it out. Tight fit. The wing screws will work but I don't like them. I might add screws inside the fuse vs the wood type screws (that were forgotten from the kit) that hold the wing panels on.

So for $150 I think it is a good deal. But more to come. Hope this helps in your decision. BTW,, This is the first ARF I have purchased and could not pass the $150 sale. I have only been in RC for 40 yrs and normally build my own Extras' and C130's

jimcork1

My Feedback: (4)

Update for those interested. The plane is now flight ready but hasn't gone to the field.

The saito 1.8 with spinner and prop came out right at 9#'s total weight. I had to add about 14 oz to the nose to balance. The CG is just behing the 4" recommended but less than the "advanced" range so it is in the ok to fly range. Total weight now is 9#14oz just under the box target weight. No fuel of course which will add 16 oz for flying.

The engine is almost totall in the cowl exclusive of the valve cover tops. I used the stock muffler vs pitts and a 1/2" copper tube to extend the exhaust to the left lower side of the cowl. I cut air exits for the engine in the cowl and they don't show from the sides or top. Hopefully they are large enough.

Hardware,, I had 1 clevis that was bent and I could not use it and 2 screws that attach the wing were missing but promptly sent when I called.

The plane looks like a hot dogger just setting on the bench. I probably will later (after test flying) add wing attachment bolts from the inside the fuse vs. under the wing bottom.

I managed to chip a 1/8"x1/4" spot on the black paint which touched up easily

The rec. was mounted on the left side of the fuse (2.4) so there would be no wires to be close to the antenna.

The throttle servo was mounted on the right side of the fuse in front of the cg.

Both (dual 6V) were installed forward of the fuse on the sides of the fuse in front of the wing tube mounted in foam.

I mounted the on/off switch internally with wire pull on/off through the side of the fuse.

One of the cross ply (1/8") supports were broken in the fuse when I opened the box. The really don't do much so I cut it out clean.

I used a fuel filler in the cowl for fueling. Just didn't want the ugly duckling tubes hanging out like I normally do.

Wheels are light foam, don't know how they will hold up on our grass bumpy field but we will find out.

Control throws are set very close to the manual. I will fly low rates with no mix for the first flight.

98 today so too hot to play with engine. It should be ok as it was removed from my Stinson and it preformed well there.

Prop is 16x8 classic series. Ok,, better probs but no local hobby shop and it bites to pay the postage for 1 prop.

Next week I will hit a hobby shop but by then I will know how it flies. The current prop turns 9650 rpm when set properly so that isn't too bad for a 10# plane.

Fingers crossed,, flight testing possibly tomorrow. Guaranteed at least 1 take off and 1 landing.

More to come. Pics before flight of course

blvdbuzzard

I too picked one of these up on sale at Hobby People for $150.00. Hard to pass up. Need to get an engine for it. I was thinking of a 26 to 35 gas engine for mine.


Dru.

Crazy4Flight

My Feedback: (540)

I have a Saito 180 on a JOSS STIK I know it could be put to better use. and 2 gal of 30%

jimcork1

My Feedback: (4)

Haven't flown mine yet so I have only opinion. Look at the weight of the saito at right at 2# and I added 14 oz. So keep the engine weight w/muffler at about 3# and you should be ok if you go to gas. But note also my batteries are forward of the CG and so is my throttle servo.

This is a nice plane. The only [>:] I had was attaching the horizontal stab to the fuse. I followed the instructions and the tail didn't bond well. So I mixed epoxy and microbaloons filler put it in a hypodermic syrenge and injected each fillet above and below the stab. After the expoxy set the stab is ready to fly. There is a note in the manual to check the tail after installation. So I would have to say this is covered in the manual.

The manual states it will fly at 1/2 throttle so tomorrow weathere (heat) permitting we will know. So until tomorrow. I think it is a really nice plane for the price.

jimcork1

My Feedback: (4)

That's a great engine but given the power to weight you could get by with 15% vs 30% and save some $$.

I expect this plane to be a powerful flier. There are warnings all over the manual "no power dives" or high speed flight.

Don't know if you folks picked up . I added counter weight to the elevators forward of the hinge line. I added 3/8 oz lead to each elevator tip hopefully to prevent flutter of the elevator. If I fly tomorrow I will let you know how this works. The lead makes the elevator almost balance with no servo connected. You know sorta like the 1:1 birds.

jakyying

hi all,we make and sell DA100 standard mufflers,I have a link for some other canister mufflers and mufflers of the aircraft engines,welcome to visit:http://jakyying.diytrade.com
you can contact with me by msn:[email protected]
skype:jakyying1

jakyying

hi, all,we make and sell DA100 standard mufflers,I have a link for other some canister mufflers and mufflers of the aircraft engines,welcome to visit:http://jakyying.diytrade.com
you can contact with me by msn:[email protected]
skype:jakyying1

jimcork1

My Feedback: (4)

It has flown. The first flight was exciting. NOTE : the rates shown in the manual. I used the manual LOW rate as MY HIGH RATE. I used 1/2 of the Low rate setting for flight. The plane balances exactly on the 4" mark and inverted takes a small amount of pressure to maintain level flight. I may take out 3 oz of weight later.

The elevator and ailerons were way too sensitive at the manual settings. The manual low rate made flying a bit easier.
Flying on the first flight at the low rate settings from the manual I was able to get into (lost count) many tip stalls due to sensitive elevator.

The first landing was bumpy. We had 15Knot cross winds and the landing had a strong gust of wind with the plane balloning up. I was a bit nervous to try and hold it at the low speed with elevator afraid of tip stall but landing was a engine running taxi back landing.

The second flight on lower control settings were more controllable but the winds still did not slack off. The landing was a long low approach with rollout on the runway and about 6' into the grass.

I planned a 3rd flight but the winds continued to pick up and since I was working on control settings I didn't want to push my luck.

The saito 1.8 with 16x8 prop turns 9700 rpm richened to 9400.

Power is great with 1/2 throttle take off. I used 3/4 throttle for normal flying but given the sensitive controls I didn't do much in areobatics due to the elevator tip stall at the high rates.

I am sure this will settle out with more flying.

Summary nice bird flies close to my Extra 300 but high wing loading. Very controllable if you watch the control throws.

Critique. some of the covering has bubbled after flying and needs ironing. The canopy has a 1/8" crack at the front edge by the cowl. Don't have a clue how this formed there is no pressure.

The XPS 2.4 preformed exceptional as normal with a new receiver.

More to come with more flying time. Yes I still would buy it again at $150.

Crazy4Flight

My Feedback: (540)

thanks for the flight report. I is great to hear from and actual user aka average joe pilot.

Are you using any expo on your rates?

As for 30% fuel I bought the 2 gallons from @ $10.00 each from former club memeber leaving the hobby.
I know the Saito loves 30% but would not buy it at normal street price.

bob

jimcork1

My Feedback: (4)

Bob,, I used 40% expo but on my radio expo only is active in high rate. So I could not use expo until after I reset the throws. Then I flew the 2nd flight with HI rate (the low initial flight settings / also the low rate in the manual). The expo did make a difference and made it smoother in the neutral position. The winds were 20 mph and I was being bounced around while the other folks were packing it in for the day. My landing was long and smooth but "not my typical landing". The plane stayed down when I pulled up elev to keep the tail down in the high winds.

I am thinking I might be a bit nose heavy at the 4" cg reco in the manual. I normally fly my planes tail heavy so they will flat spin better. But the 4" is a good start point.

jerrya

My Feedback: (4)

Jimcork1........ Thanks for the reports on the Sukhoi, I have one on order. Do you think a Supertigre 3000 is a suitable engine for this plane? Also, do I understand correctly that the control throws you used were the manual recomended lo rates were used as your hi rates, and 1/2 of the low rate was used as your low rate, ie ~1/2" throw on the ailerons and ~5/8" used on the elevator for your lo rates? As you continue to fly the plane, please keep up posted with any info that we may find useful. I do a lot of my flying with the Micropro also.

Jerry

jimcork1

My Feedback: (4)

Jerry you are correct on the throws.

The ST3000?

Might be a little large as the ST3000 normally uses a 18" prop and I fly the saito with a 16".

You might check the weight to insure not over 3#'s.

I would not use the ST 3000 but then I just haven't had any luck with the st3000.
I had 2 and gave one away and sold the other for $50.

Crazy4Flight

My Feedback: (540)

I had a ST 3250 on a SIG CAP 231EX ARF it flew lithargic. Then Iput a Saito 180 in its place moved the battery fro just ahaed of the stab to over the wing and the plane flew a lot better. The ST has a hugh head for cooling and is a very heavy engine.IMHO

Bob

jimcork1

My Feedback: (4)

Very politely stated.

Update.. The rates shown in the manual are what I used for high rates. On my radio I had 20% less than that for low rate. After flying I used the 20% less for high rate and 20% less than that for normal flying. Sorry I mentioned low and high rates in the manual. They only cover Test Flying and Aerobatci. The Test Flight is what I used for the first flight. The CG at 4" is pretty correct though. I used about 20% down elevator to fly inverted. However this was with my 18oz tank full. The 4" CG was at 0 fuel so I am a bit nose heavy with full tank and 14 oz on the nose.

98 today and too hot / windy to fly.

jimcork1

My Feedback: (4)

Rain can't fly []

A few notes on the sukhoi

1) I did not use servo extensions. I use solder/shrink tube and extend all leads. This way there is nothing to unplug.

2) The push rods included for the elevators were almost too long. You can't cut them they are only threaded on the end. The servo mount should have been 1/4" forward so you will have to be sure to position the control horn back far enough on the elevator. If you are too close the push rod and clevis will have to be replaced.

3) (covered this in previous post) The screws for holding the wing on were not in the box and I had to call for them. They arrived promptly and the supplier provided great support.

4) One of the clevis had a bent pin and could not be used.

5) one of the wheel collars was not properly drilled. I drilled it out to use it.

7) I added lock washers to the landing gear screws, (they were not suppose to be used) But I felt the need to insure I wasn't installing drop off gear.

8) The hole for the rudder linkage was difficult to find.

9) I used velcro to hold the tank vs. the tie wraps.

Hope this helps.

jerrya

My Feedback: (4)

Thanks for the continued updates on the Sukhoi. Mine should be here this week. Please keep us posted on yours and your final setups as you continue to fly it.
The missing wing retention bolts you mentioned, are you satisfied with this method? The online manual shows these to be 4x25 wood? screws. What size hole did you drill in the tube for them? How did you add the weight to the elevator tips? What is the oz/in rating of the servos you are using for aileron and elevator?
Jerry

jimcork1

My Feedback: (4)

I used 4 Futuba 90 oz 3152 High Torque digital (new) servos from ebay.

The rudder was a 150 oz servo from RCU classified. Nice new servo works well. Digital also.

The batteries are Dual 1200 Nicads through a Y connector to the Futuba HD Digital switch. I know there are folks will cover the you can nots on dual batteries but I can make this work. Every 3 months I cycle all packs.

The radio is XPS 2.4 from Graupner using frequency hopping and working well also.

The control is rock solid with this configuration.

One small item. Our grass field has a few bumps and I am considering larger wheels. This doesn't mean the ones that came with it don't work. They do, but if you have a rough field you might consider the larger wheels.

Aerobatx

My Feedback: (1)

hi jerry, good luck with the Sukhoi.

viper1676

My Feedback: (14)

I got this plane during Hobby people's Father's day special. I'm hoping to start the build either tonight or tomorrow. I'm putting an O.S. 1.20AX in it. I was a little concerned about power for it, but I had this engine in an Ultimate that weighed 13+ and it pulled it around pretty quick. For the servo's, I was going to go with the DS-821's. I know they are below the specs but I don't plan on doing anything nuts with this plane, and these servo's have worked pretty well for me.

jimcork1

My Feedback: (4)

The OS engine is pretty strong and I think you are ok. Servos. Prop size will be important. I use a 16" dia prop and only about 2 1/2 to 3" of the tips extend pass the large radial cowl.

I think the digital is overkill but I followed the instructions. My guess is a good servo will fly it. But remember it does have large control surfaces. There is a warning in the manual about NOT flying at full throttle in a dive as it will probably lose some parts you want to fly with. Been there done that before.

I did switch to larger 3 1/2 wheels today for our grass field. If it were just grass I think the OE wheels would be ok but we have a few bumps.

If you check the items on this thread you should be able to build a nice plane. I did not install the dash where gauges would fit because I have the 2.4 G rec mounted in that area and I can see my LEd for binding with the canopy on.

jimcork1

My Feedback: (4)

Update. Flew 4 flights today. Light winds and temps.

Few things

1) When landing carry power like a bipe and don't pull all the power off until about 3' over the runway. If you do it will drop like a stone. I set full throttle trim for takeoff and leave it that way to land. I also add 2 clicks on the throttle stick for flying until power off for touchdown. The plane will taxi at full throttle trim but not fly.

2) Vertical flight the nose tucks down up elevator is needed to maintain vertical

3) In slow flight mine will drop the left wing tip very quickly. Not a soft stall

4) The wing screws came loose in flight. I almost lost a wing panel with a screw comming out. If you overtighten it will break the wing panel. I will modify for inside screws. THIS IS A WARNING TO YOU !

5) The 1/8" lite ply screws holding the rudder in place stripped out. The lite ply is too thin. Reinforce it with spruce below before inserting the rudder servo.

6) The 3 1/2 " wheels I added made for better rough field landings.

Otherwise the plane flies very smooth and precise. Flat spins are nice but WARNING it takes a lot of airspace to recover. I actually got into an accelerated stall while diving out of a spin.

More to come but it will be 2 weeks before flying again.

jerrya

My Feedback: (4)

Keep us informed on how your plane is coming. I have a 120 AX I will use if it works out in your Sukhoi. Seems like it should be plenty of power for sport flying..... I'm not a 3D flier and plan to use 821's also.