CARF Pitts 12 Build Thread

All types of aerobatic airframes, questions, builds or general info

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Sun Jul 07, 2019 5:19 pm

Images from Friday evening at Nick's workshop. Machining the parts and beautiful Engel 34x18 carbon prop.

B.
Attachments
IMG_1802.jpg
IMG_1801.jpg
IMG_1800.jpg
IMG_1799.jpg
IMG_1798.jpg
IMG_1797.jpg
IMG_1793.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Sun Jul 07, 2019 5:22 pm

Images from today: laying up a carbo joiner piece to go inside the top front half of the engine cowling. This will be used to join the cowl pieces together, after I cut the front off!

Made up using two layers of 200gsm carbon cloth and West Systems epoxy resin.

B.
Attachments
IMG_1824.jpg
IMG_1819.jpg
IMG_1818.jpg
IMG_1817.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Sun Jul 07, 2019 5:26 pm

After taking a double shot of single malt scotch ( to steady myself!), I took a razor saw to the nose of the cowl to cut it off. I decided to cut along the edge of a paint line, to help hide the cut. Came out fairly well! :D

B.
Attachments
IMG_1808.jpg
IMG_1809.jpg
IMG_1820.jpg
IMG_1822.jpg
IMG_1823.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Sun Jul 07, 2019 5:29 pm

Final job today was then gluing the joiner onto the fuselage side of the cut, using grey Hysol. Finish off the photography by taking a few images of the fuselage outside. Very pleased with how the surgery to the nose of the Pitts has come out. :dance:

B.
Attachments
IMG_1825.jpg
IMG_1827.jpg
IMG_1826.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Sun Jul 07, 2019 5:31 pm

I'll sign off today with a few random fuselage images.

B.
Attachments
IMG_1829.jpg
Image of the inside of the cowl, showing the carbon joiner glued in position.
IMG_1833.jpg
IMG_1830.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Andrew Bird on Wed Jul 17, 2019 3:28 pm

Looks good.

Now get the bugger waxed :lol:
User avatar
Andrew Bird
HA Sponsor
HA Sponsor
 
Posts: 3107
Joined: Sun Nov 16, 2008 11:08 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Wed Jul 17, 2019 3:32 pm

Thank you, Andrew. Its on my 'to-do' list for the end of the build.

I've been busy getting on with this and not posting any progress here on HA, so, I'll now stop and post a series of updates.

B.
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Wed Jul 17, 2019 3:37 pm

After returning to Nick's workshop, I was able to collected the new set of machined wooden spacer mounts. I found that I needed x6, 6mm thick spacers to get a 1 & 1/4 inch gap between the front of the cowl and the back edge of the prop.

B.
Attachments
IMG_1834.jpg
IMG_1835.jpg
IMG_1836.jpg
IMG_1838.jpg
IMG_1841.jpg
IMG_1842.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Wed Jul 17, 2019 3:40 pm

I got the rudder servos fitted into the tail. A couple of picture frame inserts were cut out to glue inside the servo openings, which I could then screw the securing screws into. I also cut out a Herex former to glue onto either side of the fuselage (on the inside) above the servos. The idea being to take out any fuselage flex with big rudder inputs.

B.
Attachments
IMG_1856.jpg
IMG_1847.jpg
IMG_1848.jpg
IMG_1849.jpg
IMG_1850.jpg
IMG_1852.jpg
Last edited by Billy Bunter on Wed Jul 17, 2019 3:47 pm, edited 1 time in total.
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

Re: CARF Pitts 12 Build Thread

Postby Billy Bunter on Wed Jul 17, 2019 3:46 pm

Getting back to installing the engine, I removed it so I could glue the spacer rings together and then wrap them in carbon to add strength and stiffness. The Moki 300 is quite a lump at 6.3 kilos in weight. So, under aerobatic loads the forces on the engine and its mounting could be high. Hence gluing the spacers together and reinforcing them (And not using 4 standoffs instead).

Quite pleased with how the mount came out. Looks pretty nice with the gloss carbon finish! 8-)

I also added a layer of 200gsm carbon cloth to the firewall, to account for the hole I have made in it. The hole is there because the Miko has the carb in the rear, facing rearward. Thus, It will be drawing air from inside the fuselage.

The front of the mount is machined from a 5mm thick sheet of carbon plate. Very strong, stiff and yet light weight.

B.
Attachments
IMG_1853.jpg
IMG_1854.jpg
IMG_1858.jpg
IMG_1859.jpg
IMG_1860.jpg
IMG_1862.jpg
User avatar
Billy Bunter
Squadron Leader
Squadron Leader
 
Posts: 714
Joined: Sat Nov 28, 2009 6:26 pm

PreviousNext

Return to Aerobatic Airframes

Who is online

Users browsing this forum: No registered users and 6 guests