Scratcho - Page 5 - RC Groups
Thread Tools
Nov 09, 2012, 02:14 AM
AvB
AvB
Wind, hill, ... I'm keen ...
AvB's Avatar
Problem with cutting back in is that with most gelcoats, only the very surface is perfectly solid and sealed. When you start cutting back into the gelcoat you expose microporosity. Unless you use a soft polishable gelcoat like SW18. Problems around every corner. If I was happy with "within 1mm" I'd keep the moulds as-is. But it's no good having the TE not closing together. New moulds needed ... somehow.
Sign up now
to remove ads between posts
Nov 09, 2012, 05:36 AM
making my own planes...
decones's Avatar
Andrew, about the damage moulds, you sad that you did some repairs and then sanded with 800, 1200, 2000, polish,... Didn't you sand the TE? Sometimes we focus in a specific part and don't pay attention that the sand is touching another part of the mould... Any mould edge should not be sanded, if you sand it starts to become round and when closing you will have a gap, exactly like you described....

I like your Scratcho's colour scheme based on your Shockwave hehe...
congrats!

André
Nov 09, 2012, 05:37 AM
608 km/h!
josh18's Avatar
hey Andrew, sorry to hear about your moulds! Before you chuck them, how about using a long flat sanding block and sanding the whole flange area down by however much you need to get your TE back to size. You could leave the LE flange alone and taper the flanges towards the back too. did this to the trailing edge of my full wing mould because there was originally too much material there and it worked a treat.
Cheers mate
Nov 09, 2012, 05:54 AM
AvB
AvB
Wind, hill, ... I'm keen ...
AvB's Avatar
Yeah might be worth a try Josh, thanks. But I'm lusting after new fin and stab moulds now!
Nov 09, 2012, 06:21 PM
Everything's A Compromise
Larrikin's Avatar
Another consideration with CNC at home is the noise. Unless you're in a bunker, hour after hour of a screaming router is seriously going to annoy the neighbours.
Unless, of course, they're modellers too.
Geoff, who milled the Sniper plugs, moved to an industrial area from his back yard for that very reason.
D.
Nov 09, 2012, 11:30 PM
AvB
AvB
Wind, hill, ... I'm keen ...
AvB's Avatar
Some Hobby King stuff just turned up, and I'm a bit excited about the pushrods/ snakes that I got. Must be new because I'm always on the hunt for pushrod systems and have never seen these before. Nice thin plastic tubes and springy wire rods. Just the right length for the Scratcho. I'd post a pic but the kids stole the camera!
Nov 10, 2012, 02:31 PM
Remember... Fly for fun!
ALEX HEWSON's Avatar
Here is some good scratcho action:

Foamies and Scratchos at Wainui (10 min 47 sec)
Nov 10, 2012, 03:48 PM
AvB
AvB
Wind, hill, ... I'm keen ...
AvB's Avatar
I wanna move to Christchurch. Cheesh, Wainui 30 - 35 knots SW .... Having been there now, that's like code words for "DS Heaven". Really nice vid and love the music. Looks like it's still pretty cold up there!
Nov 10, 2012, 04:12 PM
Auzzie built planks
timbuck's Avatar
Cool vid Alex.... Great start to my day.. Good vibes.

Tim
Latest blog entry: More colours
Nov 10, 2012, 05:26 PM
608 km/h!
josh18's Avatar
Nice one Alex. Was that foamy one of your homebrews? It was super slick!
Nov 10, 2012, 05:50 PM
Remember... Fly for fun!
ALEX HEWSON's Avatar
Cheers guys! Hopefully there will be at least 6 of my foamies on the hill in Dec.

Green Foamy is a R60 Reaper. Blew up at 169mph, but video was rolling. Lost fuselage, but have made a new one. Wing was fine. This is now a dedicated light-medium wind foamy.
Nov 21, 2012, 10:08 PM
Brettski
SoarPilot's Avatar

Pushrods...


Quote:
Originally Posted by AvB
Some Hobby King stuff just turned up, and I'm a bit excited about the pushrods/ snakes that I got. Must be new because I'm always on the hunt for pushrod systems and have never seen these before. Nice thin plastic tubes and springy wire rods. Just the right length for the Scratcho. I'd post a pic but the kids stole the camera!
Andrew,

I was planning on calling you about pushrods. Do you have a HK part number? Initial thoughts?

Brettski
Nov 21, 2012, 11:17 PM
AvB
AvB
Wind, hill, ... I'm keen ...
AvB's Avatar
Haven't looked at them again Brett.

I just got a message from Alex saying he's in 45 - 60mph winds at Cass Ridge right now and had the old Ampreg Scratcho fluttering and it was the fastest it's ever been. Considering it was gunned at 267 at Tekapo, and he reckoned the fast laps were missed , it sounds like it just went pretty fast. Cass seems to have a lot of power.
Nov 21, 2012, 11:47 PM
Brettski
SoarPilot's Avatar
Quote:
Originally Posted by AvB
Haven't looked at them again Brett.

I just got a message from Alex saying he's in 45 - 60mph winds at Cass Ridge right now and had the old Ampreg Scratcho fluttering and it was the fastest it's ever been. Considering it was gunned at 267 at Tekapo, and he reckoned the fast laps were missed , it sounds like it just went pretty fast. Cass seems to have a lot of power.
I've got a strong feeling that you'll be back in NZ bending sticks before too long....

It's a fantastic spot for any flying..

Brettski
Nov 22, 2012, 12:02 AM
Remember... Fly for fun!
ALEX HEWSON's Avatar
Probably was going 270mph odd. Cass is slightly smaller than Tekapo so would seem like it is going faster. Report in the NZ DS thread


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Building a heavy Scratcho for US DS trip. AvB Dynamic Soaring 114 Mar 31, 2012 04:39 AM