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Giant Astro Hog Laser Cut Kit - Jerry Bates

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Giant Astro Hog Laser Cut Kit - Jerry Bates

Old 03-31-2021, 07:08 AM
  #176  
Nece
 
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Hi Eran,

looks good. I'm glad the cowl fits. But you're exaggerating a bit ... this bonnet is no masterpiece ... it was just my first attempt. So I'm glad if I could help you with it!
I'm looking forward to your maiden flight.

Bye
Manni
Old 03-31-2021, 11:26 PM
  #177  
erans
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Today was an embarrassing day.
I was on track with the cowl fitting, making a cut-out template over the muffler and transferring it to the cowl.




Some background information is required now - For the whole period that I was waiting for the cowl to arrive, the aeroplane was in the stand (the same one I am working from now) positioned INVERTED. So for over two months, I was looking at the muffler pointing "up". Today when reinstating the muffler for the purpose of marking its location, the aeroplane was in the stand in the UPRIGHT position, and I installed the muffler pointing "up". I ended up with incorrect location markings and corresponding cutting.
I found the idiot in the room when I figured it out (and I was alone in the room, so no much challenge there...).
The correct cutting template position is below:




I now have a very large gap above the muffler. As I am usually reasonably proud of the way I fit cowls and am doing it for many of my friends, I am guttered that I managed to ruin this one, especially knowing that I would never be able to make one myself to similar quality.
As I had no good idea in my head how to fix it, I kept on and glued the retention screws brackets in.


Cheers,
Eran
Old 04-02-2021, 03:58 AM
  #178  
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Do you still have the piece you cut out?

Bob
Old 04-02-2021, 04:37 AM
  #179  
erans
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Bob - I use a Perma-Grit rotary drum tool to cut fibreglass and it literally vaporise the material in its path. Therefore what was left from the cut-out was missing roughly a centimeter of width (which was the tool path).

I would like to mention here the amazing people we have in this hobby. When Manni heard of my mishap, he reached out to me and offered to make me a new cowl. This type of generosity is humbling.
With this said, I made a small scale test of possible repair method which went reasonably OK. I then went on and applied it to the cowl. I will post some photos if it will be successful.

Cheers,
Eran


Old 04-02-2021, 06:51 PM
  #180  
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Good news, the fix came out better than expected.
What I experimented with yesterday was the ability to release the fibreglass and final finish quality when using packing tape over glass. The result was that the release was very easy and the surface area is glass smooth (except where there is an overlap of packing tape, which creates a minor impression in the finish).

I laid the cowl against the packing tape covered glass and used three layers of fibreglass (my cloth is much lighter than what was used to make the cowl) with the middle layer weave at 45 degrees. The result is amazing. Now, re-cut, it fits properly and ready for final cleaning of the lines prior to filler, sanding, etch primer and painting.
My end result may not be "perfection" as the original "out of the mold" shape was, but it is more than good enough for me.








Cheers,
Eran
Old 04-06-2021, 01:53 AM
  #181  
erans
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Final touches to the cowl prior to painting. The openings had final touch ups, making them slightly more visually pleasing.
I then drilled the cowl mounting screws and attached small washers to protect the holes from vibration.



Cheers,
Eran
Old 04-07-2021, 03:37 AM
  #182  
erans
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I fitted a 3" aluminum spinner by enlarging the hole in the back plate from 10mm to 12mm.
This was required due to the fact that the MVVS 40cc engine shaft has a 12mm "step" (as seen in the photo below).


Cheers,
Eran
Old 04-07-2021, 06:29 PM
  #183  
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I am happy it has all worked out for you, looks like you will be finishing very soon!

Bob
Old 04-08-2021, 03:30 AM
  #184  
erans
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Bob - Thank you. I tentatively arranged for the Heavy Model Inspection to take place on Sunday the 18th, however, I have just realised that my club gave the airfield on the day for a F3A competition (and therefore no club flying on the day). My plan is to run and if necessary tune the engine at home during next week after replacing the perishable items in the carburetor with new parts from a carburetor kit (the engine was in storage since September 2019), as well as completing all necessary checks prior to the HM Inspection.

Today I applied filler and did my best sanding it as smooth as I could on the area of repair. It came out good enough, definitely not a professional level. I then coated the cowl with etch primer.





Cheers,
Eran
Old 04-08-2021, 09:55 PM
  #185  
erans
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I got the cowl painted. From up close not a good finish, but from short distance it is OK.



Cheers,
Eran
Old 04-11-2021, 01:42 AM
  #186  
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I was delighted this morning to hear from Manni that he has successfully completed the maiden flight of his Giant Astro Hog and that he found the aeroplane a smooth flyer.
With his permission, bellow are photos from this flight.






Cheers,
Eran
Old 04-12-2021, 11:30 PM
  #187  
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Final checks prior to the Heavy Model Inspection.
A friend came over to assist me with test running the engine. I took a very short video of the run without the cowl holding idle:
and another video with the cowl transitioning between idle and full power -
I encountered minor issue with air leak from the fuel filter which was replaced with a brand new one which... also leaked air... I then removed the filter altogether and the problem is now resolved.
I re-checked the CG with the cowl and spinner and had to add 25g at the tail for balance.
Final dry weight is 8.1kg.








Cheers,
Eran

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