Register

If this is your first visit, please click the Sign Up now button to begin the process of creating your account so you can begin posting on our forums! The Sign Up process will only take up about a minute of two of your time.

Page 1 of 13 12311 ... LastLast
Results 1 to 25 of 307

  1. #1
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208

    AMR Trainer 26 - (my) official build thread

    I've been in the hobby a few years now and it's time to build my first kit. I chose an AMR Trainer 26 because a used one was for sale at the time I was ready and it looked suitable for a beginning builder. The kit was already partially built (most of the fuselage) which would not be my first choice. But the price was right and to my inexperienced eye it looked good.

    The AMR 26 has an 84.5" wingspan and a 66" fuselage. Is is supposed to come in at 12-14 lbs and specified power is a 26-32 cc gasser. I have a DLE 30 to put in it.

    I have created a page for this plane on my website (http://www.grosbeakrc.ca/aircraft/amr26/amr26.html) and will update it as I go.

    Overview

    The AMR Trainer 26 consists mostly of laser cut 1/8" ply with tabs, slots and notches to aid in construction. The wing is built in a supplied jig and the empennage is cut from 3/8" balsa sheet. From a technical writing perspective the manual could use improvement, but with the help of AMR staff, forum members and my own stubborn determination I don't foresee any problems.

    My adhesive of choice is Lee Valley Cabinetmaker's Glue 2002 GF; I will be using that unless otherwise specified. The wing will be built on my main workbench atop a section of Sonopan acoustic panel.

    Documentation

    Manual
    My kit is an older edition; the hardcopy of the manual is dated 2008-11-30. The closest available electronic copy is a .pdf file dated 2010-01-10. The significant difference between the two versions is the empennage construction: 3/8" balsa sheet in both cases but laser cut in the latter version and manually cut in the former.

    I will be using the electronic copy (2010-01-10) for the build because I will be making references to page, step and part numbers and I want the document to be accessible. Though the empennage construction has changed again since, the rest of my build is still relevant to today's version.

    AMR Trainer 26 manual

    In addition to the manual I have created a few documents to help me along. The documents are hosted on Google Docs and are shared for viewing; all are subject to change throughout the build.

    Questions and Issues
    In reading the manual I have run into several snags in my understanding. Many were resolved during the build process or by reading ahead; in some cases I asked AMR for help directly. I have attempted to document all of my questions, answers, issues, resolutions, deviations from the build procedure and explanations therefore.

    AMR Trainer 26 - Questions and issues

    This document will change often as I progress through the build.

    Parts index
    There are a large number of laser cut parts in six sheets of 1/8" plywood. Most (not all) are identified on diagrams in the manual on pages 6, 7 and 8. Each page shows a two sheets of parts, one (A) above the other (B). Therefore, my own sheet IDs are 6A, 6B, 7A, 7B, 8A and 8B. Below is a link to a spreadsheet that lists the part number, sheet ID and the steps in which the part is explicitly mentioned.

    AMR Trainer 26 - Laser cut parts list

    I hope to update the sheet diagrams to reflect the parts that are unidentified. If and when I do I will post links here and wherever relevant throughout the build pages.

    Lamination
    Most of the parts are 1/8" ply but in many cases they need to be thicker for strength. Such cases require lamination - the bonding of two or more identical parts to improve strength. Most of the build reviews I've read mention that there's a lot of it to be done, and it's scattered throughout the manual. Below is a link a spreadsheet that lists the steps and the parts involved.

    AMR Trainer 26 - Lamination steps

    It's my plan to do one or two laminations at the end of each build session so that the parts are properly cured and ready when I need them.


    First look



    You may notice the hangar rash - one of the cheeks was accidentally broken off by the previous owner. No worries - I'll be fabricating a cowl.


    Almost all of the parts are laser cut from 1/8" ply; there's a lot of lamination throughout the process so I'm going to identify and tend to that early on. There are a lot of tabs, slots and notches to aid in the building process.

    The first step I took was to cut off the remaining cheek. I love the flush-cut saw for jobs like this.




    Next, I added some glue where it was missing from the joint on the sides of the fuselage. Here's where the glue went.



    Last edited by grosbeak; 10-31-2014 at 08:13 AM.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  2. #2

    Join Date
    Jan 2006
    Location
    China, MI
    Posts
    735
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback
    I have mine ready to cover, nice kit had fun building it, have a DL30 on mine too. Will tag along on your build.
    Ken
    Wherever conversion engines are outlawed, only outlaws will have conversion engines.

    ULTA SPORT BROTHERHOOD #8

  3. #3
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Quote Originally Posted by box car View Post
    I have mine ready to cover, nice kit had fun building it, have a DL30 on mine too. Will tag along on your build.
    Good to know, Ken. I'm sure I'll have questions!

    The first thing I installed myself was the paper servo lead tube, from the cockpit to the tail. Cutting it to length:







    Routed from front to back and secured at each bulkhead with cabinetmaker's glue.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  4. #4
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Next - the servo tray. It's not mentioned in the manual; Dany tells me that's because a lot of builders choose to put elevator and rudder servos in the tail. I'm planning on a pull-pull rudder, so I'll use the tray.







    After I had glued the tray in I noticed a part, also unidentified in the manual, that looked like a backplate for the tray. I figure it'll work equally well on the top or bottom so I used a pair of servos to mark the hole. Holes drilled, I glued it in place and used servo screws to clamp it for curing.







    The next thing I installed was a brace. The doublers forward of the brace push the fuselage out at the top; this part pulls it back together. Identified as F4A in the manual, it was not cut out of the specified sheet for whatever reason. Easy enough to fabricate, though. 1/8" ply.







    I ran a thin bead of cabinetmaker's glue along the edges of the joint for a little extra holding power.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  5. #5
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    I struggled with understanding how the empennage is built but the light bulb clicked on last night - it's made from 3/8" balsa sheet. There are three 48" sheets in the kit; two get edge-glued together and the last is cut in half; the resulting 24" pieces are also edge-glued.





    The next step is to attach the relevant plan sections to the sheets with contact cement. Before I could do that, I needed to cut the plan to fit.





    It was only after I'd cut the plans that I got the advice to have them copied first, but the only plans are for the empannage - the wing is framed up in jig provided in the kit.




    One of the next steps is to sheet the top of the fuselage aft of the cockpit. As I was contemplating this step I noticed these notches.







    Not sure what they're for - perhaps another stiffener to keep the top of the fuse in line? Once again, no mention in the manual and I welcome your opinions. I cut a piece to fit but I haven't glued it in place yet.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  6. #6

    Join Date
    Aug 2005
    Location
    SOUTH EAST PA, PA
    Posts
    76
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback
    Click image for larger version. 

Name:	Trainer 26 Oct  7 2011 016.JPG 
Views:	151 
Size:	873.6 KB 
ID:	2042151Here is my Trainer 26 RCGF 26cc power it was a pleasant building project and flies like a trainer should. I have built a second one but did not fly it yet.Click image for larger version. 

Name:	Trainer 26 Oct  7 2011 002.JPG 
Views:	162 
Size:	936.5 KB 
ID:	2042152

  7. #7
    Melchizedek's Avatar
    Join Date
    Jul 2012
    Location
    Missouri
    Posts
    771
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback
    Grosbeak,

    It seams to me, that a full pain would go where your notch outs are. The pain would have tabs to match those notch outs.
    If you don't have that part it may be missing. Looks like it would make a shoulder for the wing saddle.
    That's my guess anyway.

    Kevin
    Taking over the world one plane at a time.

  8. #8
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Quote Originally Posted by overbuild View Post
    Click image for larger version. 

Name:	Trainer 26 Oct  7 2011 016.JPG 
Views:	151 
Size:	873.6 KB 
ID:	2042151Here is my Trainer 26 RCGF 26cc power it was a pleasant building project and flies like a trainer should. I have built a second one but did not fly it yet.Click image for larger version. 

Name:	Trainer 26 Oct  7 2011 002.JPG 
Views:	162 
Size:	936.5 KB 
ID:	2042152
    Nice!

    Quote Originally Posted by Melchizedek View Post
    Grosbeak,

    It seams to me, that a full pain would go where your notch outs are. The pain would have tabs to match those notch outs.
    If you don't have that part it may be missing. Looks like it would make a shoulder for the wing saddle.
    That's my guess anyway.

    Kevin
    Thanks Kevin, I'll take another look at the sheets to see if there are any parts I haven't accounted for.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  9. #9
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Good progress today. First, I installed that piece I cut for the fuselage notches. I did find a piece that appeared to match but it was much too narrow. No worries.







    Next came the sheeting of the upper fuselage.





    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  10. #10
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    While the sheeting glue cured I turned my attention to the 3/8" balsa I edge-glued several days before. Time for the empennage parts.


    Smaller sheet first. I taped the plans along one edge after checking for straightness.







    I bought this spray adhesive at a local craft store.







    With the plans hanging from the tape I sprayed the sheet with the adhesive.







    After waiting for one minute per the instructions on the can I pulled the plans taut, smoothed them out and stuck them down. Luckily this adhesive allows some repositioning so I was able to deal with the few small wrinkles that occurred.





    The lines on the drawings are fine and hard to see in photographs - this sheet holds the vertical stabilizer, its forward fairing, and one elevator.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  11. #11
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    The longer sheet was done in the same fashion.







    While the adhesive cured I turned my attention back to the sheeting on the fuselage. I cut off the overhang with a flush cut saw.







    After a first go with some coarse sandpaper it looked pretty good.







    I added a little glue the joint after the cockpit where the angle changes. Smoothed down with a finger - one of the reasons I love working with Lee Valley Cabinetmaker's Glue 2002 GF.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  12. #12
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    While that glue cured I took the empennage parts to the band saw to cut them out.







    Then over to the sander to shape the edges.







    Horizontal parts...







    and vertical parts.





    There is still a bit of shaping to be done but apparently that is supposed to come later.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  13. #13
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    I bagged the small tail parts and put them aside for now. Back to sanding the fuselage.


    There was some tearing from the sawing.







    Time for some filler.







    Mixed up.





    I've applied the filler and will sand that down in my next shop session.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  14. #14
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    I'll be starting the wing soon but before I can do that I need to address a gap in my understanding.


    There are two pieces of ply that are stapled to the work table at the beginning of the building (red arrows). From the instructions: "Locate the wing rib support plate W14 and staple it to your work table through the wax paper." The long piece that extends to the right is W14 on the plans sheet; the short piece at the wing root is not identified; in fact, no reference to this piece is ever made in the manual (scrap?).







    At first I assumed they were part of the jig; I still think that's the case for the piece at the wing root. However, the notch in the long piece (blue arrow) appears again later, apparently part of the wing. So now I'm pretty sure that W14 does become part of the wing.







    At no point in the manual does it state anything like, "Remove W14 from the work table by prying up the staples".




    If I had to guess I'd say that by "work table" they were referring to a large piece of something flat from which W14 could easily be separated - like drywall. Does this sound reasonable?
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  15. #15

    Join Date
    Nov 2002
    Location
    Lahaina, HI
    Posts
    1,622
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback
    Hay Grosbeak,
    Nice build so far. I have been building an AMR kit myself and surprised at the ease of the build.
    Soft Landings Always,
    Bobby of Maui
    AMA 15016
    Hellcat Brotherhood #21
    P-38 Brotherhood #51
    Skyraider Brotherhood #11
    Say what you mean, mean what you say...and !#$& it if you can\'\'t take a joke.

  16. #16
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Quote Originally Posted by Bob Paris View Post
    Hay Grosbeak,
    Nice build so far. I have been building an AMR kit myself and surprised at the ease of the build.
    Soft Landings Always,
    Bobby of Maui
    Thanks Bobby. I'm enjoying the build.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  17. #17
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    After a little research I came across acoustic panel as an option so I decided to try that. I found some at Rona here in Ottawa. I wasn't sure what to expect but it is dense, flat and takes staples well so I'll give it a try.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  18. #18

    Join Date
    Nov 2002
    Location
    Lahaina, HI
    Posts
    1,622
    Gallery
    My Gallery
    Models
    My Models
    Ratings
    My Feedback
    Hay Grosebeak,
    Your building area is way to clean and organized. That's gotta change... : )
    Soft Landings Always,
    Bobby of Maui
    AMA 15016
    Hellcat Brotherhood #21
    P-38 Brotherhood #51
    Skyraider Brotherhood #11
    Say what you mean, mean what you say...and !#$& it if you can\'\'t take a joke.

  19. #19
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Quote Originally Posted by Bob Paris View Post
    Hay Grosebeak,
    Your building area is way to clean and organized. That's gotta change... : )
    Soft Landings Always,
    Bobby of Maui
    That's the exception, not the rule!
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  20. #20
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Not a very exciting shop session tonight - laminating wing ribs...










    As other builders of this kit have mentioned, there's a ton of laminating to do. Do yourself a favour - search the .pdf version of the manual for instances of the word "laminate" and make a list of the steps in which it appears and the parts to which it refers. Going forward, my plan is to laminate a few pieces several steps ahead at the end of every build session in the hopes that I can stay ahead of the game.




    More excitement - cutting balsa sticks. This razor saw mitre box came in very handy for trim when we re-did the floor in our travel trailer this spring - it's great for all kinds of fine work.





    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  21. #21
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Due to my malfunctioning internal alarm clock I had some time before work in the shop this morning. Got the first wing panel properly started - the first step is stapling part W14 to the work surface.




    In this kit the wing is fully dry fitted (save for one exception and a couple of pieces that are tack-glued), then disassembled and built up again with glue. The manual doesn't give a reason but it seems to me that this method allows the builder to make sure everything fits before making a commitment.

    The one exception is a length of 1/4" square balsa stock, which gets bonded to W14 at the outset. Before gluing I set the balsa against W14 and traced a line to mark where the glue goes. In this photo W14 is on top and the balsa stock is in the centre. The piece below the balsa is a length of straight scrap from one of the laser-cut sheets. It will be used with staples to hold the balsa in place while the glue cures.



    The manual does not specify the required length per se, but pictures in subsequent steps show the balsa ending at wing root W11, which attaches to the end of W14 - so I cut the balsa stock to the same length as W14.


    Here's the balsa glued and curing with the clamp in place. I did not intend for the pen to have any meaning in this photo but it does happen to point to the large opening where the servo wire will exit the wing.




    A little wider...

    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  22. #22
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    A little more progress on the wing tonight, still in dry fitting mode.


    Dihedral protractor clamped to the root rib. Still a little skeptical of this thing.







    Tack glued in place.







    Ribs 1 to 4 in place.







    Ribs 5 to 10 ready for prep (knocking out the holes, cleaning up the sheet attachment points).


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  23. #23
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Ribs 1 to 10 in place. The laminated parts that make up rib 11 can be seen off to the right; the manual tells you not to fit those yet.







    Preliminary leading edge fitted.







    Rear longeron fitted.







    So far I'm impressed. The parts are a snug fit and go together well.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  24. #24
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Lesson learned: laminated parts don't snap together well when there's squeeze-out in the notches.





    Luckily it's perfect fodder for a #11 blade.




    Here's the wing with all of the ribs, upper spars and the main lower spar in place.







    Here, in between the main spars, is the small webbing plate that joins the half ribs at the root. There's another on the other side for the forward half ribs. The 2 dihedral is cut into the left side of the plate.







    A larger webbing plate goes over the small one. Looks like this one will tie the spars and small plate together. The 2 dihedral is cut into the left side of this plate as well, and there an identical plate on the other side of the spars.


    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK

  25. #25
    grosbeak's Avatar
    Join Date
    Dec 2010
    Location
    Ottawa, ON, CANADA
    Posts
    1,208
    Here's a look at the spars, webbing and root ribs from the side.







    Sighting along the root from the trailing edge the dihedral looks good. I'm going to be paying a lot of attention to that during the glue-up.







    The manual does not speak volumes on the glue-up procedure:




    "You can now bond the wing pieces together."




    Obviously with cabinetmaker's glue this will require disassembly first. I will be giving careful thought to the order in which I do things; I plan to use the dry fit steps as a guide but will deviate as necessary. And I'm going to make a more robust version of that dihedral protractor.
    MAAC 83386
    Stetson Flyers, Ottawa
    G-RSBK


Page 1 of 13 12311 ... LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
All times are GMT -6. The time now is 09:28 AM.

SEO by vBSEO 3.6.1 ©2011, Crawlability, Inc.