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Aug 07, 2015, 03:43 PM
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Top Model Grafas MAXi 3.5E discussion and build thread


I decided to order a Grafas MAXi this week from Esprit. I got an email the next day the last ARF was damaged I responded cancel the entire order and refund to the CC. A few hours later they call trying to talk me into the V-tail version which I did not want. I just don't like V-tails, I have two V-tail sailplanes and feel the rudder authority on them is just blaaahh. Then the bell went off that we could swap the wing from the V-tail version for mine! And that's what arrived today.

Here are a bunch of photos of the sailplane. To my surprise Top Model is still using that half baked elevator support from the Prelude design. It uses two wooden discs to support a carbon rod. I was kinda stunned. This has proven to be a total failure in the Prelude. So I'm going to have to repair this before I build the elevator. Shame on them.

What really surprised me on this ARF is the elevator servo goes in the rear. I'm like Yikes that's gonna be tail heavy. I will most likely change the design and put the servo up front to keep the weight down. They also use a pull pull on the rudder which is not typical for Top Model kits. I'll probably change that also to a standard pushrod since the elevator pushrod will be going down the boom.

A couple of blemishes on the canopy, they did not do a good job painting the edge. The wing has some weird material in it, it might be foam, I'm not sure but it looks a tad sloppy in a few places. The photos will show it.

I have great success with GliderDrives from HobbyKing and this ARF will get the 4.6 1120kv with a Graupner 11x6. That combo does 900 watts. I have two other sailplanes using that exact motor and they work great. I will also use a YEP 80 ESC which I use on almost everything these days, they also work great and are priced right.

Servos will be Hitec 85MG's for the wing surfaces. I was going to use Hitec 225MG's for the elevator and rudder but if I end up with the elevator in the rear it will need to be something lighter.

The radio will be the Graupner MZ-24 with a vario setup. Esprit was out of stock on the 8ch RX so I'm going to order one from OpenHobby or Tower if they don't come back in stock soon. Graupner recently released a fimware update that has me liking this radio a bit more now, but I still cannot read the LCD in sunlight. But overall the radio works well.
Last edited by gquiring; Nov 30, 2015 at 04:30 PM.
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Aug 08, 2015, 10:10 PM
Scale Aircraft = Scale Crators
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I love my Gracia Maxi (v-tail). I think it is well designed and built. I have no problems with the rudder authority. It's a shame that yours wasn't perfect out of the box. Mine was immaculate and went together very easily. Esprit is a great place and I love doing business with them.

I look forward to following your build. I'll see if I can dig up the link to my build threads and post them here. Perhaps you'll find them helpful.
Latest blog entry: Finished My Sbach 342!
Aug 09, 2015, 09:54 PM
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I'm hoping to get started tomorrow with the build. I added up the weight of all the components to get an approximate idea of what the total weight should be. Here's the breakdown:
Aug 10, 2015, 01:52 PM
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They include two glass epoxy motor mounts with this kit. One fits the GliderDrive perfectly. Remember to sand them on both sides and to sand the fuse area before gluing it in. I used 3x8mm socket head screws that are not included with the motor.
Last edited by gquiring; Aug 10, 2015 at 07:24 PM.
Aug 10, 2015, 01:59 PM
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The wing saddle area is not marked on the plans. You need to put the wing on to get an idea of where to glue the wing saddle. I don't like that they want you to hang half of the blind nut out of the wood, I prefer to see it go in the wood all the way. I made my own wing saddle out of 6mm ply. I also made it a bit larger, 26x45.

The pin that will hold the front of the wing to the fuse is stated as 6mm. I measured mine and it was 5.8, so make sure your drill bit it not 6mm, the hole would be too large. Also don't use the line on the fuse as center, it's not.
Last edited by gquiring; Nov 08, 2018 at 06:53 PM.
Aug 10, 2015, 05:07 PM
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I sent an email to the folks at Top Model last week about the elevator. This is their response: ( I am not sure what holiday he is referring to)

Hello,

We use the aircraft plywood. It isn´t much more another to replace this material. Laminate (fiberglass) is unsuitable, that would sanded the lever which moves in it. Perhaps we could use some plastic, but plastic (especially sliding) can be hardly glued.

Maybe we can use texgumoid (Textit), but it should be lubricate (after gluing), then it might have a good sliding characteristics.

We'll do some tests after the holiday and we will deal with the replacement of material

Yours faithfully.

Magda KUČEROVÁ
Aug 11, 2015, 10:49 PM
I74
I74
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Hi gquiring,
I was looking real hard at a Topmodel kit, from Esprit.
After checking out this thread, am not so shure now. ''Jeepers''
That's a lot of defects, for a fairly expensive kit.
Best of luck with it.
Ian
Aug 12, 2015, 07:43 AM
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Quote:
Originally Posted by I74
Hi gquiring,
I was looking real hard at a Topmodel kit, from Esprit.
After checking out this thread, am not so shure now. ''Jeepers''
That's a lot of defects, for a fairly expensive kit.
Best of luck with it.
Ian
I don't think any sailplane kit it perfect. I built a Valenta models Dragonfly last year and it had some issues also. What bugs me with this Grafas is the elevator, a known issue with their older models and they continue to ignore the problem. This particular kit is a tad more disappointing than I am used to for Top Model. There is no doubt in my mind the Valenta Dragonfly is about the same cost and is much better quality.
Aug 12, 2015, 04:53 PM
I74
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Thanks for the reply and info gquiring
Really hope if I order a kit from Esprit, that they would open it up and inspect it for me before it's shipped.
Am looking at a Super Sport.
You also have me looking at the Gliderdrive motors now
Ian
Aug 12, 2015, 05:01 PM
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Quote:
Originally Posted by I74
Thanks for the reply and info gquiring
Really hope if I order a kit from Esprit, that they would open it up and inspect it for me before it's shipped.
Am looking at a Super Sport.
You also have me looking at the Gliderdrive motors now
Ian
The GliderDrives are a no brainer. They are high quality motors designed for sailplanes that don't cost much. I have several, including one in a Top Model Prelude and Top Model Albatros. The YEP ESC's are also a great deal. No need to buy a Castle controller these days.
Aug 12, 2015, 05:27 PM
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As always the elevator gave me a headache. You can see in the photo the elevator is not even, it's leaning to the left and the bellcrank is touching the fuse. I tried taking some of the material off the bellcrank so it would not touch it but it was too far off. So I had to widen the opening arch on the fuse so the bell crank can clear the area. It's designed to stay inside, but in this case it's not gonna happen unless I were to pull the wooden discs and realign it. I had a very similar problem when I built the Albatros.
Aug 12, 2015, 05:32 PM
I74
I74
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I found the motor and YEP ESC that will work.
Pretty impressive specs and price, on both
Aug 12, 2015, 05:40 PM
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Next step, I bolted the wing on, taped the rudder to the rear of the fuse, put the spinner and prop on and did a rough CG check with a Hitec 85MG taped in the area where they want it on the tail. I didn't even have the balsa block or the hinges back there and NO WAY is this going to balance. I had to use a 1lb battery to get the balance right! I decided to at this point go traditional and move the elevator servo near the wing saddle and get rid of the pull pull rudder.

This fuse is small, I had not noticed that at first. Compared to the Albatros or my Dragonfly they don't give you much room in this one. I usually use Hitec 225MG's on 3.5meter ships, but they will not fit. I barely got a Hitec 85MG in there, the fuse is not very tall. I like to use ez-links, but they stick up too far, this ship will need standard clevis's.
Aug 14, 2015, 12:41 AM
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It's time to drill the holes in the wing saddle. I take some string and tape a ruler to one end and the other end of the string is taped on to the center of the rudder tip. Then it takes a few shots of moving the wing around while it's lightly taped to the fuse until you get an even reading on both sides of the wing. Then I tape it down with a lot of tape and recheck the distance before drilling the holes.
Aug 14, 2015, 06:13 PM
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Both servos are in the fuse for elevator and rudder. Everything fit fine with Hitec 85MG's. I think in the long run this was a better way to go than having that servo in the tail. As for the pull pull that had to go once I moved the elevator forward, there was no way to get the rudder servo centered and not interfere with the elevator. Overall I just prefer this setup.

When I attached the rudder it interfered with the bottom of the fuse. If I raised it, it looked kinda silly sticking up above the fuse. So I just mashed it a few times to put dents in the balsa where it was touching the fuse.
Last edited by gquiring; Aug 14, 2015 at 06:32 PM.


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