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Thread: Builders Guide Model Y Gee Bee (Electric)

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  1. Builders Guide Model Y Gee Bee (Electric) 
    #1
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    My Model Y Gee Bee design effort previously covered in an earlier forum will be coming out in the April edition of M.A.N.. This is a first for me so don't mind my big head

    The original forum was a work in progress showing many twist and turns as I worked out the design so it is a little hard to follow.

    After the test flights I pulled all the changes together and finalised the plans along with changing just about every piece of the short kit that had been cut by Top Notch Products (TNP).

    I purchase a proof kit from TNP which should arrive in the mail today. Its purpose is to support this thread and to also replace the original which has been hung in the Den of greats (Ok I am afraid I will crash it so I am building a second one to fly)

    After talking with the Model Airplane News editor, Jerry Yarrish I decided to start this new forum showing the final methods used.

    I thougt I would group the assemblies to show the basics of any contruction so that a new builder would not get lost. I hate to say it but the article is too short to be of help and as I am not a professional at this the plans can be a little vague also.

    I would like to say from the get go that this is also a place for other builders to come and ask for clarification on my work. Any feed back on clarification of the plans or short kit will go onto the plans and back to the kit cutter.
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  2. The Plans 
    #2
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    I went back thru the plans and made a lot of changes based on the prototype along with changes that worked out well with earlier designs

    Most of these were in the wing area where I tried to move all the parts into the short kit to make it easer of a beginner who may not have access to a local hobby shop still carrying building materiels

    The plans are on two sheets, both on 3 x 5 foot paper.

    Model airplane news will sell them thru thier plan service.

    If you should go with the short kit from John Valentine at Top Notch you can ask that they be added to the short kit. If you have previously purchased them be sure to tell John not to include them.
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  3. Cowl Ring and Radial 
    #3
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    As I do not have the new kit to start I thought I would start with the cowl ring and radial.

    The model could be built with a Williams Bros Cyclone Radial as the model is 1/8th scale. But due to its high cost (Over 40.00) and my fear of crashing (Only three kinds of model airplanes, Those that are going to chrash, those that have crashed and those hung on the ceiling) As I have the engine I may make a mount for it and put it on the Prototype as It is retired.

    The radial on the prototype was purchased from Dare Enterprises (Dare Design-Po Box 521, Cumberland Maryland, 21501, www.darehobby.com) with the concept that the cylinders are glued to the front and back of of the ring support (RS-1). I realised very early the plastic engine itself would not hold the ring in place on a nose over.
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  4. Cowl Ring and Radial 
    #4
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    The ring support assemby is made up of RS-1, (4) RS-3 and RS-2

    The do not have to be assembled over the plans as any flat surface protected with wax paper will do.

    The RS-2 that is shown is changed slightly from the original to cut weight and add cooling holes into the fuselage for the battery.

    NOTE: pay sepecial attention to the orientation of RS-1 and RS-2 to ensure the number one cylinder is straight up when the assembly is finished.

    RS-1 has an arrow pointing up and the new RS-2 has a flat top line now.
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  5. Cowl Ring and Radial 
    #5
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    The plastic radial is cleaned up as a whole and the front section glued to the front of RS-1. The aft sections of the radial were cleaned up and glued individually to the back of RS-1.

    One thing I did not do when I finished this part was to take a dremel and clean up the excess plywood from around the cylinders. It would greatly improve the looks.

    The original plywood was drawn by simply laying the Dare Hobby radial on a scanner and importing it into AutoCAD to draw out the profile. I fudged a little to ensure there would be enough matereil should the radials have any variation

    Later you will find you have to remove most of the radial gearbox to allow cooling air but not to worry as the nose bowl covers it up.
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  6. Radial Mount 
    #6
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    The radial/cowl is attached to F-1 around the motor using 3 4-40 cap headed screws and washers. They are accessed thru the space between cylinders using a ball driver.

    Prior to gluing F-1 into the fuselage T nuts are epoxied into it to accept the motor mount and radial mount screws.

    NOTE: Do not fly the Model Y with the cowl off unless you make adustments for the Center of Gravity.
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  7.  
    #7
    Nice to see the new thread - I'll be watching. Looking forward to getting one started.
     

  8. Hello 
    #8
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    Glad to see you found the thread Shnokey

    You had mentioned jumping in and I will say John is cutting and has sent me two kits which I am going to do and the other is going to a model builder in Maryland to proof out.

    Anyone jumping in now may have to make corrections as we go because I have yet to get a design perfect the first time.

    I will be talking with John at the end of this proof build to go ahead and make it a full kit as it will really only need the balsa for the stringers and fuselage planking, along with some hardware.
     

  9. Landing Gear and Pants 
    #9
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    I was checking the back door until the time when the mail should have delivered the new kit, only to have the wife remind me it was New years day and there would be no mail.

    To make matters worse, She drug me to Walmart which was like rubbing salt in a wound.

    Decided to discuss the Landing gear as it was not changed.

    The gear is a carry over from the Model D which I did just prior to the Model Y.

    The gear is all 1/4 inch balsa built up around the main gear that is formed from 1/8 music wire.

    Some of the photos may show the Model D as like I say there was no change in the procedure only the scale.
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  10. Kit Arrived Today 
    #10
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Kit arrived today but I did not get to spend about an hour on it. Wife took me to a sale to buy more clothes.

    I thought I would slip it in here before I go to far.

    John ships USPS priority mail so I would have had it thursday or in three days if the holiday had not gotten in the way. (Remember I live in Lester Alabama and there is no such thing as next day mail).

    Cost was 115.00 which was higher than I was expectiing but it was a large increase in parts since the original. I added over 150 parts to the list. It turns out it is more of a kit than the usual shortkit with over 350 parts including the wingspars. With the cowl jig and everything but the 1/16 inch planking and stringers in the box it is pretty close to complete.
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  11. Back to the Gear 
    #11
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    The leg fairing and wheel pants are built up as an assembly and then glued around the main landing gear wire.

    The assembly is started by gluing together MG-3A and MG-3B for each main gear.

    This assembly along with MG-1 and MG-2 are glued to MG-4.

    NOTE: Two of the MG-4 have alignment markings to assist in aligning MG-1 thru MG-3AB. Using these assures you end up with a left and right main gear.
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  12.  
    #12
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
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    476
    This is a good point on the fuselage to put in the push rods. I used .047 Dubro pushrods with the white nyloy sleeves. They need to be well supported to keep

    I usually mount the two servos and actually run the wire out the back.

    I have added the cutouts for exit points on the box sides but to be truthfull they are a best guess on the runs and will need to be proved out.

    After putting the wires in I felt a need to route out the cutouts a little more forward to lesson the angle to the control horns. I willl change the parts on the cut order.

    NOTE: Ensure you anchor the pushrod guide at every frame to keep out play in the rods.

    I also added a brace under the front edge of the servo tray to stiffin it up.
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    Last edited by PipesCS; 01-04-2009 at 10:27 AM.
     

  13. Tail Surfaces 
    #13
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    It has just struck me that the tail surfaces have to be installed prior to the rear fuselage stringers as they nest around the tail.

    The horizontal and vertical stabs. are bult flat over the plans
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  14. Battery Hatch 
    #14
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    The battery hatch is built on a flat surface such as a table with an edge. The only critical part on the first steps is to ensure the two ends are perpendicular.

    There is extra material on the base that you will need to bevel sand into the shape of the frames. This is to ensure the skin marries up with it.

    Stringers should be stiff balsa or bass.
    Attached Images
    Last edited by PipesCS; 01-04-2009 at 11:02 PM.
     

  15. More Hatch 
    #15
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    The skin is joined on a flat surface covered with wax paper.

    The skin has square holes to line up with the square pegs located at the top of the framing.

    1. Tack glue the skin to the alignment pegs.

    2. Wet the upper surface of one side to help is bend around the curves. (I cracked mine trying to do it dry)

    3. Put slow CA on the frames and along the one edge of the base piece.

    4. Place the assembly on the edge of the table and slowly form the skin to the frames and base letting the excess skin overhang.

    5. Remove the excess so that the assembly can be reversed to do the
    other side.

    6. Repeat on other side
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  16. Hatch 
    #16
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Once the hatch is formed clean it up and sand the ends till they are a good slip fit. (My hatch started out too tight)

    Add alignment pins to the bottom.

    The hatch on the prototype was secured with a rare earth magnet in each of the four corners
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  17. Question Price of the short kit 
    #17
    Join Date
    08-29-2009
    Location
    Clovis, CA, USA
    Posts
    8
    John quoted me $89.95 last week for the Gee Bee Sport short kit. Would this be the same kit that you paid $115 a few months ago or is the a different version. As I write this I realize that it would just be easier to just give John a call. That said I want to thank you for modeling one of my all time favorites.

    Has anyone mention building this as a gas powered plane...how can you fly a "silent" Gee Bee?!!

    During you initial flights the plane nosed over...I will fly off of an asphalt runway but was wondering if fudging the gear a little forward would make it less likely to nose over?

    Thanks again, Gary
     

  18.  
    #18
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Once the pushrods are installed its time to put in the stringers. They must go on before the forward planking due to the way the stringers need to be notched for the planking.
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    Last edited by PipesCS; 01-04-2009 at 10:41 AM.
     

  19.  
    #19
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Stuck in a hotel in Arizona. Hopefully Bob is working on the wing and can post photos soon.
     

  20. Wings 
    #20
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    While I was working in Arizona John started his wing.

    He sent me three emails with comments but no photos to show you.

    I flew home to night and checked out some of his notes.

    One was that his plans were smaller than the parts. Both his set and the set I am building from came with the short kit from Top Notch.

    First I checked out the parts to find they match the cad drawings perfectly.

    Sure enough when I laid laser cut leading edge on the paper plans there was an eighth inch difference with the plans being shorter.

    I took the part to the prints I had done here ( Also the ones I sent to Model Airplane news for copy) only to find the parts fit with no distortion in the plan. I do not know at this point if the plans that come off the printer at MAN will have a problem.

    Looks like paper printers have some variation.
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  21. Building the Wing 
    #21
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Decided to build the wing on the short set of plans to see what the issues would be.

    As the ribs are tabed and the leading and trailing edges are slotted the wing will come out fine if the first rib is aligned to the plans and the spar is pinned staight over the plans. Bob and I both built over the short plans to make sure it would work.

    NOTE: THE LEADING AND TRAILING EDGE PIECES HAVE A BEVELED END THAT IS FOR THE CENTER SECTION TO ALLOW FOR THE DIHEDRAL. THEY ARE MADE TO BE INSTALLED WITH THE LETTERING (FTE, LE) ON THE PART. UP RIGHT.
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    Last edited by PipesCS; 01-09-2009 at 10:39 PM.
     

  22. Cutting Spar 
    #22
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Some how I double posted this. The steps are below
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    Last edited by PipesCS; 01-09-2009 at 11:36 PM.
     

  23. Cutting the Spar 
    #23
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    One concern with the plans being off was spar length. If cut per the plan it would come up short.

    I used the leading edge stock to mark and cut mine to length.

    1. The lower spar is pinned to the plans using the center line as a reference.

    2. All the ribs were double checked and put in to position without glue.

    3. The false leading ad trailing edges were dry fitted.

    4. Using R-1 as a reference the wing was aligned to the plans.

    5. Once the wing was trued up it was pinned into position and glued using thin CA.
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  24. Shear Webs 
    #24
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Once the glue has dried I added the top spar.

    Once the top spar was dried I added the shear webs that are part of the short kit.

    Mine were a good press fit between the two spars but Bob complained his were a little short and that he could see light. He ended up replacing his. I would advise that you make sure you have the spars in the rib notchs before gluing. (Note they may need to be trimed to length between the ribs as I made them a little over length.)

    When I glued the spars on, I matched the ends which come to think of it will need to be sanded to match the dihedral later.
    Attached Images
    Last edited by PipesCS; 01-10-2009 at 12:21 AM.
     

  25.  
    #25
    Join Date
    01-25-2007
    Location
    Lester Alabama, USA
    Posts
    476
    Looking at these photos, I now realize the problem was not with the part but that Bob and I both let the last rib get a warp in it and it is bowed in at the spars.
     

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