Seagull Grob Tutor G115

[MikeS]

After reading the great review on the Tutor by David Ashby in the RCME special I decided I fancied one. Well a few months later I saw one on sale at the recent Wings N Wheels show for a good price of £165.00. Hold on though not enough cash in the pockets hmmmm.

Thought I would see what was on offer at the up coming Southern model airshow, however looking though a certain auction site led to me a well know model shop and they had it up for 135.00+8.00 P&P. Bargain I thought so I got it ordered.

And today it arrived.

Well as normal I could not check everything out before the delivery van was wheel spinning down the road. But on first inspection all looked good and seems to be complete. In the review it mentioned that mini servos would be required for the ailerons and also it looks like for the flaps as well.

After a bit of searching through this very forum I came across the suggestion of using the Hitec HS-225 servo. Now from my own personnel experience of plastic gears on a plane of the size and weight would concern me so I went with the metal gear version just in case.

As I have a Four stroke sitting idle (sorry couldn't help it) it is time to decide should I go with the ASP 70 or use the ASP 91. Hmmm. The 70 is in the Pawnee 40 so I might swap things around

So, as soon as possible I will start and get it built.

Mike

[Craig Kane]

It looks great. Does it specify an EP setup?

[David Ashby - Moderator]

Look forward to seeing what you think Mike. Mine's been flying for a year now, still going strong.

[MikeS]

Posted by Craig Kane on 11/07/2013 13:23:08:

It looks great. Does it specify an EP setup?

Craig hope this helps but yes it say in the manual:

Model size: 45-52

Motor: 35mm 830 rev per volt

Prop: 11x7-12x7

ESC: 50a

Lipo: 4S 3200

 

David, I will keep all my build findings etc in this thread and of course later on when flying the maiden, I hope it flys as well as your does

Mike

Edited By MikeS on 11/07/2013 13:46:37

[David Ashby - Moderator]

Mike, good, look forward to that, you'll have some 'moments' during construction, I gave the kit a bit of a kicking in places but I enjoy flying it, it's a bit different which I like.

Craig, treat the suggested electric setup in the manual with a pinch of salt. It's built strong but that means weight, my model coming out at 8.5lbs all up. I use a Power 46 and 5S spinning a 13x8 which develops 900 watts approx.

[Craig Kane]

Mike & David,

thanks for the info. We only fly EP at our club so whilst I love the aircraft, I need to weigh up the pros and cons of a conversion. We are somewhat restricted to model size as our site isn't the greatest for big models.

[MikeS]

Well started putting things together today and have a question. I am used to fitting horns to my control surfaces and where I do understand how the ones Seagull use with the Tutor work I am unsure of one thing.

The aileron, elevator, rudder and flap control horns have aluminium washers top and bottom of the control surface. I can see under the covering where the 3mm pre-drilled hole is located is a larger hole. Do the washers fit in the the holes each side of the control surface or do I just put the 3mm bolt through the pre drilled hole and tighten up it up so the washers are on the surface of the covering?

Mike

[Pete B]

From what I can see, page 7 and 8 of the manual show the washers on the surface of the covering, Mike.

As you tighten them down, they'll sink into the recess, on the flaps at least according to the diagram, but if there is no recess on the other surfaces, they'll remain slightly proud of the surface.

Pete

[MikeS]

Pete. That is also how I read the manual but was unsure as each control surface has the recess under the covering on both sides. The flaps it does show the washers recessed.. However each 3mm hole is not in the center of the recess holes. Not hard to sort out but thought I would wait for confirmation on here.

I have fitted them all but not recessed yet.

Mike

[MikeS]

I got a bit done today and have decided that unlike some of the artf' kits I have built this one is a little more tricky to do. This I think is down to the the manual not being very clear on what you need to do such as the control horns.

Anyhow moving on here is the progress so far.

I started off with the front nose gear. Remembering something from the review about have to half the nose gear leg this was straight forward.

 

Next I worked on the rear undercarrige. I had to cut down the rear axels to fit and also found I did not need both locking collects as one was enough on each axel.

With this done I fitted them to the wings and then trail fitted the wings to the fuse.

Mike

 

Edited By MikeS on 17/07/2013 19:41:14

[Pete B]

Posted by MikeS on 17/07/2013 18:50:05:

However each 3mm hole is not in the center of the recess holes

Ah, the road to ARTF manufacture is paved with good intentions........

Rather than have the washers askew when they are tightened down, one option might be to fill the existing off-centre holes with 3mm balsa dowel - you could whittle a bit of scrap to make some - and when they're dry re-drill in the centre.

Really nice model though....

Pete

[MikeS]

Very true Pete, they do try.

I did think of fitting the washers in the to the recesses and then re-drilling the holes as it feels this how the model was designed but did not want to cut the covering away until I had confirmation this was the correct way to do it.

Mike

[Paul Marsh]

I flew mine at the last Greenacres flyin. Strangely, Black Horse Models have brought out a slightly larger version, as they did with the Silence Twister

 

.

Edited By Paul Marsh on 17/07/2013 22:39:58

[MikeS]

Paul. I saw the Black Horse version at the recent Wings & Wheels show and in hindsight the larger version might have been the better size for me but as they say you make your choice's . The BH version has a 3.4" longer wing span than the Seagull version.

Well back to the Tutor. Now the fuel tank from the manual sits at an angle in the fuselage and bottom end sits in a slot. A small balsa block stops the tank from sliding backwards. I have my doubts about this as the tank does not feel very secure. I think some light packing foam around the tank will help.

 

I next fitted the servos in the fuselage. A little adjustment was needed to fit them. The width was fine but the length need opening up a little on each hole. This didn't take long. I just need to change the servo horn postion to the oppersite side.

 

With the servo's in place I trial fitted the rear and vertical stabs to get an idea on how they fitted. At first glance all looks good and cannot see anything that needs adjusting other than removing the covering where needed before glueing.

 

Edited By MikeS on 18/07/2013 07:40:05

[Tim Cheal]

Mike I found this really useful, so thank you. I have just ordered one, and wondered how you are progressing and any other tips you have found.

Did you go with the .91 or the 70. I am not yet sure whether to use the ASP 80 or 91 I have?

Tim

[MikeS]

Tim. My build is on hold at the moment.

The Mrs wanted the main bedroom decorated so I have been busy with that but I hope to get back to the Tutor in the next few days.

I would go with the 80. The 91 might over power it and also need weight at the tail. Its a heavy plane for its size but from the review it flys well. I haven't decided on the engine. The 70 is on the Pawnee at the moment and the 91 does not fit with the supplied engine mount. Mike

Edited By MikeS on 31/07/2013 22:31:22

[Jeff Hylton]

I've been trying to find time to finish one of these for at least a year now. Did anyone notice there is interference between the rudder control rod and elevator?

[Paul Marsh]

Yes, there is. Put a bend so that the rods miss each other.

Regarding engine sizes, I was going to put an 80 four stroke in it, but didn't have one at the time (now I have 2 spare!), and the full-size is more of a whine, than a four stroke sound.

So put a Kangke 50 two stroke, the same as on my Turbo Porter, and being quiet, powerful and light.

[MikeS]

Right well managed to spend a few hours getting the Tutor together.

One thing to note is the front wheel nose leg control rod does not line up as per the manual. Also the pictures show the control rods for the throttle and nose wheel threaded though holes each side of the fuselage. Well as I am fitting a Four stoke the throttle is not a problem for me as I have moved the position but the nose wheel is a problem.

The rod supplied is a thick rod not thin like the throttle so bending it to fit is not going to work and will put too much strain on the servo. I ran mine straight from the servo to the nose leg and it works a treat.

I found removing the covering very time consuming due to how well the cover is attached the the surface of the model. Not that I am complaining but found I had to be very careful not to damage the balsa skin. Anyhow after sometime I had the covering removed and ready to be glued in to place.

Covering removed.

Mike_

Edited By MikeS on 09/08/2013 22:29:12

[MikeS]

The tail and rudder have been glued in to position. I fitted my ASP 70 Four stroke with a 13x8 prop. I am a little concerned that this will under power the model a little but as it has been flying my Piper Pawnee 40 with an AUW of 8lbs I feel that it might be a good match.

Once it is all built and I have checked the CofG I may change the 70 to the 91 but we will see once I have done some taxi runs with it.

Both the 70 and 91 have the exhaust in the same position but I as of yet under decided on where I am going to place it. I am leaning towards getting some flexi exhaust and routing that out the bottom.

I have fitted the fuel pipe using the last of my stock which just happens to be bright pink. ( Dont ask ). As for the fuel tank this it seems is held in place by the canopy when fitted. You do glue in a small balsa block to stock the tank moving backwards.

 

I am currently following the manual but I have been a fan of self tapping screws. I most likely will change over to nuts and bolts.

Mike

Edited By MikeS on 09/08/2013 23:13:17

[MikeS]

Well progress so far with the pink fuel pipe, well that will be hidden about from the filler pipe.

I still need to cyno the hinges and locktite all the nuts, grob screws etc but it is not far from finished. I have now started to think about the elctronics layout in the Tutor. I am using the same setup as in my H9 Piper Pawnee and H9 P40.

AR7000 using a rce-b6x with a 2s lipo which works very well. This gives 5.9v to the Rx and keeps the servos happy which are all 6v rated.

Mike 

Edited By MikeS on 09/08/2013 23:27:17

[Nev Haycox]

Hi Mike,

I'm following this with interest as I have a Grob Tutor sat in its box waiting for me to throw it together, this will probably be in the autumn. One thing I did notice on inspection was that the pilot figures are a little on the heavy side, other than that, all looks good.

Nev.

[MikeS]

RS. Yes the pilot figures are very heavy but even with them in the model it is still tail heavy. The pilots sit just about in line with the CofG. I have yet to install the cowl, spinner and flight battery though. Also the 70 four stoke is at the lower end of the power and also the weight ratio. I do not want to add any weight as this already a heavy model for its size.

Right moving on I have cyno'd the aileron and flap hinges so all good there and put locktite on the small nuts holding the control links. However the pre cut holes in the flaps are slightly out if line with the servo so the linkage is not 90 degrees. I have adjusted it as much as possible as I was suffering from a little servo buzzing. If my the adjustments have not made any difference I may have to reposition the flap control link.

Mike

Edited By MikeS on 13/08/2013 06:18:47

[MikeS]

Spent last night fitting all the servo extensions for the flaps and ailerons in the fuselage. I have finally decided on the location for the rx, ubec and lipo and temporally fitting them. I did a rough first attempt on the CofG 80mm from the leading edge at the root and was happy that while still a little tail heavy it should balance in the CofG range once the cowl and spinner are fitted.

Ok something I feel should be pointed out. I decided to look at the cowl and checked the manual to see how they are suggesting you install it. So step one reads:

1) Slide fibreglass cowl over the engine and line up the back edge of the cowl with the marks you made on the fuselage then trim and cut as shown.

Nothing new here but hang on, what marks and when did I mark the fuselage and at which point in the manual was I instructed to do this. Also the cowl is small and will not fit over any engine installed. A quick re-read and I still can find nothing in the manual. Not a major issue to me or anyone who has built a ARTF before as they should have some experience of fitting a cowl but anyone buying this who has little or no experience will find them selves scratching their heads.

As no holes have been pre-drilled in the fuselage for the cowl it does give me some flexibility to install how I want to which I prefer

Mike

Edited By MikeS on 15/08/2013 05:25:15

[MikeS]

Here is my layout for the electronics in the fuselage. Just need to put in some foam for the rx, sat and also add the hook and loop for the lipo. Once all this is done I can tidy up the wiring.

Remember I said about the nose wheel control rod not lining up with the hole in the fuse. As you can see ,the rod with out bending in shapes will not go through the hole. It works fine as it is but is touching the former so a little fettling is needed here

When you glue in the pilot seats the manual gives a measurement of 25mm from the back of the canopy floor to the back of the seat. Well 25mm is 2.5cm and I think they got this wrong and it should 25mm from the front of the pilots to the front former of the canopy floor. This puts the pilots where they should be. If you follow the manual you will end with seats and pilots at the back of the cockpit and a very tail heavy model.

Mike