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BJ Craft Etude

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Old 06-12-2016, 11:26 AM
  #26
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Quote:
Originally Posted by Rudy View Post
I cut out the back of the canopy on my Nuances and again on the Etude.
Why do you do this?

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Old 06-29-2016, 09:16 AM
  #27
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I added a couple of stripes to the bottom for visibility. Will maiden tomorrow. CG is about 275, per the pics on the BJ Craft website. Dave Snow is the builder of this one. Excellent Job!!
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Old 06-29-2016, 09:55 AM
  #28
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I didn't see BJ's Etude pictures until today. My CG ended up at 275mm as well. I started out 0.6 degrees on my incident and will try 0.5 at some time to see if that make any difference. It flies so well it really isn't an issue now. After 24 flights I'm still impressed how it flies each time out. I'm flying 7 minutes with 2 - Zippy Compact 25C 5000 mAh batteries and landing with 37 to 40% left in the packs.
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Old 06-29-2016, 10:43 AM
  #29
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Can I ask what motor and prop you are using?...sounds very efficient.
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Old 06-29-2016, 11:22 AM
  #30
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Sure, I use a Hacker Q80-13, Falcon 21.5 x 13 prop, Jeti Mezon Lite 90 12S Brushless ESC. On my Nuance I changes from a 21 x 14 Falcon prop to a 21.5 x 13 and it improved throttle became very smooth and is efficient.
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Old 06-30-2016, 01:08 PM
  #31
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[ATTACH]2170522[/IMG]
Just maidened my Etude. Fantastic airplane. Very little trim needed. 1 click on ailerons and 1 click on rudder. That was it. My CG is about 265-270 or so. need to fly with the lighter battery packs and play with cg again. I started out at 285... WOW and WOW. I love this airplane.
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Old 10-19-2016, 06:40 AM
  #32
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Quote:
Originally Posted by Rudy View Post
A few more flights and Iím excited about the performance of the Etude. CG is at 265mm and feels good now. The only mix is a little downline mix. It was windy today and it is rock solid in the air. A pleasure to fly such a stable plane.
How do you think the snap roll and spin performance of the Etude compares to the Nuance?
Happy Landings

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Old 10-19-2016, 07:55 AM
  #33
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It has a lot of rudder authority. That was a good improvement over the Nuance. Etude snaps as good as any plane out there that Iíve seen. Spins are easy and nice with the Etude.
Look for the newer discussion on the Etude from yesterday, too.
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Old 10-20-2016, 06:09 AM
  #34
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I just started construction of an Etude for my father, I took the time to weight everything.
Fuse 1035
Right wing 293
Left wing 291
Right stab 72
Left stab 74
Rudder 68
Wing tube 52
Landing gear, Wheel pants and Miscellaneous hardware: 273
Total 2158. I believe the weights posted on the website do not include Landing gear and hardware.

I plan on using the equipment from a nuance that had a close encounter with the ground.
So far I got the following:
Q-80 11S: 665g
2 X BLS 173: 58g
BLS 175: 68g
2X BLS 571: 101g
Mezon 95 w/ arming assembly: 135g
Receiver: 15g
3 blade prop: 60g
CF spinner: 20g
2 X receiver batt: 98g
extentions: 80g
Smart fly reg with F/S switch: 60g
pushrods and BB ball links: 49g
Firewall+battery tray: 65g
Total equipment will be 1463g for a plane weight of 3621g. My build could be much lighter by using the stock pushrods, lighter regulator and single rec battery though I don't see the need for it since the airframe will easily make weight.
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Old 10-20-2016, 07:58 AM
  #35
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Rudy - Thanks for all your information on the Etude. I just received mine from Mike yesterday and have a couple of questions before I dig in. First, the canopy has no latching mechanism installed, was that your experience as well? Second, the canopy overall is very "flimsy", to the point of making it difficult to install on the model and line up the little tabs. Was yours this way, too? Next, you've provided the CG point that is working for you, but I'm not sure which index point you're using. Some measure from the back of the canopy opening forward, others measure from the leading edge of the wing back. What are you using? Finally, are you using the canopy opening of the fuselage as your index point for setting the incidence on the wing and stab and did you replace the stock wing incidence adjusters with an after market set?

I apologize for bombarding you with questions, but I want to get this one right and I've only built a few other 2M models. Thanks in advance for your answering my questions.
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Old 10-20-2016, 08:44 AM
  #36
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1. canopy has no latching mechanism – there is a carbon rod and a couple of white round knobs. You’ll notice the canopy alignment tabs at the rear have a cut out/notch. The rod goes through to rectangle cut out on the side of the fuselage at the rear of the canopy. To open the canopy pull the two outside white knobs at the ends of the carbon rod and ease the canopy up with your fingers or thumb. I installed a spring and pin latch at the top of the canopy because I have one hand. A work on aligning the two canopy pins in the front and the tab hole in the fuselage. Mine need a little filing in the hole to get the fit I likes. Canopy is light, yes. It works for me. On my Nuance I added a small light cross piece of balsa where I handled it.
2. Next, you've provided the CG point - The CG is measured at the back lower edge of the canopy corner.
3. index point for setting the incidence – I measure my incidence off of the stabilizer without the elevators installed. First assure the stabs are exactly the same. I use paper that is stiff enough to have some body. You see what I mean. Slid the stabs on the two carbon rods on the fuselage. Next slide a piece of your paper behind the stab. Then cut a little out for the carbon rods. Next tighten up on the paper with the stab. Trace the stab ends and on top on the paper. Next align two sheets of paper and then cut out the stab leaving enough some paper below at the stab ends. Next, snog up the stabs. Put the paper on the stabs and check the corners. They need to be aligned. That will determine zero incidence of the stabs.
The wing can now have the incidence set off of the stab witch is zero. Remember no elevators or ailerons installed during the incidence set up.
4. stock wing incidence adjusters – no I like the Gator ones from F3A Unlimited. I install then at the rear of the wing. I think the stock ones would work. The stock ones are good for the front.


Hope this is helpful
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Old 10-20-2016, 09:04 AM
  #37
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Thanks Rudy, I appreciate your reply. Adding the mechanical spring latch and the balsa cross-members to the canopy is a good idea. The picture of the CG measurement on the BJ Craft website was a little confusing to me, but your explanation makes it make sense. I really enjoy my little 70 BJ Craft Fantasista and am looking forward to this model too.
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Old 10-20-2016, 09:42 AM
  #38
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deleted duplicate

Last edited by cactusblues; 10-20-2016 at 09:44 AM. Reason: duplicate post
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Old 10-21-2016, 05:06 AM
  #39
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Also, remember the A.J. Acuity 2M will be coming soon!!

Bill
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Old 10-21-2016, 06:23 AM
  #40
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For what it's worth, I have about 25 flights on my Etude with 0 problems with the canopy latch. Works just fine. Just make sure that you press the white knobs aft to lock the latch into the slots. Simple, yet effective...
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Old 10-21-2016, 06:46 AM
  #41
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I've taken a look at the RCOne photos showing assembly of the Essence and other models in an attempt to get some clue on assembly of this Etude, given the lack of an assembly instruction manual. Where have you guys gone for information when you were assembling your model? When I purchased my Fantasista, there was a pretty decent pictorial available with Japanese (I think) characters explaining the assembly process. I used Google Translate to convert the instructions to English with mixed results, but got enough information to put it together correctly. I haven't had a chance to go through the included materials yet, but hope there are the little plywood templates included to help with locating control horn slots and Dremeling out vent holes, etc....
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Old 10-21-2016, 07:04 AM
  #42
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Quote:
Originally Posted by cactusblues View Post
I've taken a look at the RCOne photos showing assembly of the Essence and other models in an attempt to get some clue on assembly of this Etude, given the lack of an assembly instruction manual. Where have you guys gone for information when you were assembling your model? When I purchased my Fantasista, there was a pretty decent pictorial available with Japanese (I think) characters explaining the assembly process. I used Google Translate to convert the instructions to English with mixed results, but got enough information to put it together correctly. I haven't had a chance to go through the included materials yet, but hope there are the little plywood templates included to help with locating control horn slots and Dremeling out vent holes, etc....
I have one from the very first batch. At the time I followed the Nuance and other info at this website to get hints.
http://rcone.kr/board/index.html?id=bjreference1&no=11

Subsequent to my build he uploaded more pictures including one that totally showed a completely different CG location that what he has on his nuance and prolog page (280 Etude vs 260 earlier similar airframes)

http://rcone.kr/board/index.html?id=bjair1&no=144

between these two links and maybe mulling some more on his website you should be able to figure it out. It's not a complicated plane to put together if you go with fixed wings. If you go ahead and make the wings adjustable you'll have to get additional wing adjusters. He only gives one set and they are for the back wing tube. I used spare ones I happened to have for the forward wing tubes. I found no BJ guidance for the wing incidence so I used info Arch Stafford had somewhere on how he changed his set up from BJs to more 'traditional' on the Nuance and copied that. Turns out for the CG of 280 as a starting point (equals the rear quarter or so of the wing tube) that was a good move as BJ later came out with a picture of the same thing as you can see from the link I added. I also put the wing about 0.5 positive incidence to the stab. Tip, remove the stab halves but keep the stab tubes in and use the tubes to measure the incidence off of. Kept the motor so the spinner was symmetrical to the front of the airframe.

I also installed a quick release on the canopy instead of BJs thingy. I much prefer that. I also put scotch tape on the side of the canopy mid way from the front because as noted it's a large canopy and has some play in it that the scotch tape puts an end to.

Fill all the poorly glued landing gear wood to the fuse with Hysol. I made hysol filets and they have worked awesome.

I'll post some pictures of my install later.

Last edited by luckymacy; 10-21-2016 at 07:06 AM.
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Old 10-21-2016, 08:07 AM
  #43
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Thanks for all the info. I had already to decided to Hysol in some cross bracing balsa for the canopy and to install a mechanical canopy latching mechanism. I will certainly look at all the pictures you've suggested, and have Google Translate handy to try to decipher any Asian character instructions.

On the incidence adjustment topic though, I've got a question. In the past, I've used the fuselage canopy line as my index point to establish level for the airframe, then used my Robart incidence gauge to set a starting incidence in relation to that index for both the stab and wings. Does that seem reasonable to you guys? I'm installing the Gator incidence adjusters to the forward fuselage points, versus the rear ones that are installed.

As you have suggested, I Hysol a lot of the interior (landing gear box, firewall, battery tray, wing tube support, etc..) in these composite models. Experience, mostly bad, has taught me not to trust the factory glue and glue joints. Hysol just keeps everything where it belongs on those windy contest day landings.

Thanks again for the useful input. Keep it coming.
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Old 10-21-2016, 08:17 AM
  #44
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Quote:
Originally Posted by cactusblues View Post
Thanks for all the info. I had already to decided to Hysol in some cross bracing balsa for the canopy and to install a mechanical canopy latching mechanism. I will certainly look at all the pictures you've suggested, and have Google Translate handy to try to decipher any Asian character instructions.

On the incidence adjustment topic though, I've got a question. In the past, I've used the fuselage canopy line as my index point to establish level for the airframe, then used my Robart incidence gauge to set a starting incidence in relation to that index for both the stab and wings. Does that seem reasonable to you guys? I'm installing the Gator incidence adjusters to the forward fuselage points, versus the rear ones that are installed.

As you have suggested, I Hysol a lot of the interior (landing gear box, firewall, battery tray, wing tube support, etc..) in these composite models. Experience, mostly bad, has taught me not to trust the factory glue and glue joints. Hysol just keeps everything where it belongs on those windy contest day landings.

Thanks again for the useful input. Keep it coming.
don't over complicate the setting up of the fuselage to then take the incidences from. it's not relevant what the airframe is at when you do this as long as it's reasonably level but more importantly it's fixed in place and doesn't move as you go back and forth as you take measurements or make adjustments with the wing adjustors. The measurements are between the stab, wing and motor. The stab is fixed. while I did move the back of the airframe up and down so the incident meter read 0 on the stab, that's not critical because all you need to know is the relative difference in degrees between them and it's not only irrelevant but maybe completely impractical to read what the canopy opening is because there's no requirement by the design that it is flat or has the same incidence as anything else that is important measure.
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Old 10-21-2016, 08:44 AM
  #45
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Thank you. I'm not at my home to look over the model at present. I assembled a Caelus a few months back, and both the stab and the wings were adjustable, so I leveled the fuselage to use as the index to set the stab to 0, then moved to the wings. I assumed the Etude also had an adjustable stab, but wrongly so I'm learning. I appreciate your input.
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Old 12-10-2016, 11:22 AM
  #46
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Rudy,
I find that my Etude also has a slight misalignment between the left and right stabs, the left stab has around .5 deg pos incidence and I'm wondering how you were able to correct it without some major surgery since the carbon fiber sockets through the fuselage and in the horizontal stabs are almost cast in concrete. I certainly wish that the horizontal stab incidence was adjustable. Any recommendation for zeroing out the error would be appreciated.
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Old 12-10-2016, 12:43 PM
  #47
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What I did was sand the tube and the socket in opposites until it aligned up. Thin on the opposite side that was sanded on the tube I applied a light coat of epoxy. Once set up, I sanded the epoxy down until I had a firm fit in the tube socket. On my plane I could see where they had a tough time getting the socket tube right. Not all the Etude's have that problem. Good luck.
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Old 12-10-2016, 08:51 PM
  #48
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Thanks for the info Rudy, I will see what I can do.
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Old 12-14-2016, 05:40 PM
  #49
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Anyone have any pics of their unboxing of the newer shipment of etudes? Does this incidence issue apply to all of the models? I've also read about some coupling issues on this airframe. I'm considering ordering one but I want a straight and true flying airframe. Thanks!
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Old 12-15-2016, 06:37 PM
  #50
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I ordered one from Mike at F3A last week. They are currently out of stock until later this month. When mine does arrive I will post several photos to assist others in their decision process.
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