SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Aug 30, 2006, 07:45 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
Discussion
Corona Boom's

Since I have built my Corona, I have had one boom strike and the blade actually cut it right in half. It had no protection on it. Since then, I have a new boom, but at the same time, I bought a carbon fiber 4 foot tube to make my own; it was $18.

I have not cut/tried it yet, but I know it will work, fit or whatever. My question is, instead of making boom protectors why are people not using a carbon fibre boom?

Oh ya... in regards to "I know it will work". I will have to reduce the dia 1 mm at the tail to get the gearbox on. Not sure how I will do it, but I am sure it can easily be done.


-Lane
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 30, 2006, 07:55 PM
Registered User
Auckland New Zealand
Joined Oct 2003
276 Posts
Lane

There are a good number of people using carbon booms on Corona's.

If you wanted to run the wire drive tail (without further modification) you needed to find a matching carbon section on both OD and ID - that's no easy task especially if you want a spiral wrapped section - but these are available from BT.

If you are running the BT belt drive then ID is not such an issue.

I have been using a 13mm OD carbon section boom for a while (using Brett's 1/2inch gearbox and boom clamp) - works a treat

Cheers
Dave
Retro is offline Find More Posts by Retro
Reply With Quote
Old Aug 30, 2006, 08:04 PM
Big Kid / Big Toys
gruntdog's Avatar
Ontario Canada
Joined Feb 2003
269 Posts
carbon spiral wound is the way to go , can withstand the odd light blade strike

and very solid to keep vibration from affecting tail

two broken in 2 1/2 years of flying a corona and still use them repaired, one of the first mods I ever did, 100's of flights

get rid of the drive wire set-up and you will stop replacing parts as often and
the belt drive with the carbon boom is so smooth running
gruntdog is offline Find More Posts by gruntdog
Reply With Quote
Old Aug 30, 2006, 08:35 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
This CF tube I bought has an OD of .472 Not sure what the ID is, but I believe it will be fine. Sorry, I never hear much about people using CF booms. Mostly just boom protectors.

Do the blades survive a boom strike with a CF boom?

I just measured: It's 12mm OD and 10mm ID
yaremchl is offline Find More Posts by yaremchl
Last edited by yaremchl; Aug 30, 2006 at 08:41 PM.
Reply With Quote
Old Aug 30, 2006, 09:10 PM
Big Kid / Big Toys
gruntdog's Avatar
Ontario Canada
Joined Feb 2003
269 Posts
where did you get the tube of cf

I am in Ontario , I could use a new boom and would
like to play with the length a bit
gruntdog is offline Find More Posts by gruntdog
Reply With Quote
Old Aug 30, 2006, 09:14 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
I bought it from Great Hobbies (www.greathobbies.com)

Like I said thou, it's 1 mm off on the OD and ID. I still haven't figured out how to size it a bit, but if I have to, I'll take them to some shop and have just the ends sized. Someone will do it for a couple bucks.
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Old Aug 30, 2006, 09:40 PM
Big Kid / Big Toys
gruntdog's Avatar
Ontario Canada
Joined Feb 2003
269 Posts
took some more accurate measurements 11mm OD x 9mm ID and the closest at greathobbies looks to be the .472 od

the bt tubes are turned down on one end to 10 mm OD for the stk
tail case maybe
gruntdog is offline Find More Posts by gruntdog
Reply With Quote
Old Aug 30, 2006, 09:45 PM
Big Kid / Big Toys
gruntdog's Avatar
Ontario Canada
Joined Feb 2003
269 Posts
I could see it on a spindal using emery to take away some of the od

a dowel jig of some sort and a drill to rotate

lathe would be nice
gruntdog is offline Find More Posts by gruntdog
Reply With Quote
Old Aug 30, 2006, 10:23 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
That's the tubing I got from them.

I just took measurements of the CF tube with my caliper and I got this:

CF Tube: 09mm ID and 12mm OD
Orig : 10mm ID and 11mm OD

Hmm... I'll have to figure out how to bring the OD down 1mm. Well worth the time for three CF booms I think.
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Old Aug 30, 2006, 10:39 PM
Registered User
Pasadena, CA
Joined Jun 2003
3,182 Posts
Lane, the CF boom will still break in a hard boom strike. Often just cracking, and it can be repaired. But frequently breaking clear off.

It needs protection, just not as much.

I used a 7-8 inch piece of the thinnest brass tubing, that just fits over the CF, and glue it place from just in front of half way, on towards the back.

I've had a boom last years this way!

I know Matt at BT uses a belt sander to reduce the OD for the tr gb.

Don
derway is offline Find More Posts by derway
Reply With Quote
Old Aug 30, 2006, 10:43 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
A belt sander... now why didn't we think of that gruntdog

Really.. the Corona blades can still break this CF Boom. You said "but frequently clear off" I believe you meant "infrequently clear off"

How do you repair it?
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Old Aug 30, 2006, 10:48 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
Well, if I can get this to work, at $6 a boom, I don't mind breaking them. (3 out of 4' length / $18)
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Old Aug 30, 2006, 11:14 PM
Registered User
Pasadena, CA
Joined Jun 2003
3,182 Posts
Quote:
Originally Posted by yaremchl
A belt sander... now why didn't we think of that gruntdog

Really.. the Corona blades can still break this CF Boom. You said "but frequently clear off" I believe you meant "infrequently clear off"

How do you repair it?
What I meant was frequently BREAK clean off!

If they are just fractured, you can put them back together with CA.

The thing about it is flight time. Even with free parts, I would not want to be always changing the boom.

Are you using tail belt drive?
derway is offline Find More Posts by derway
Reply With Quote
Old Aug 30, 2006, 11:40 PM
Will trade wife for heli
Edmonton Alberta Canada
Joined May 2005
700 Posts
Oh.. so you are saying with a carbon fiber boom, the blades will still break it clean off?

No, my Corona is stock.

-Lane
yaremchl is offline Find More Posts by yaremchl
Reply With Quote
Old Aug 31, 2006, 12:05 AM
Registered User
chappabob's Avatar
Chappaqua, N.Y.
Joined May 2004
260 Posts
Quote:
Originally Posted by yaremchl
with a carbon fiber boom, the blades will still break it clean off?
Yup. Anything from hairline cracks, to partial breaks or complete breaks. Its funny, sometimes a hard blade strike won't do a thing and other times a simple ding will destroy the boom. You can easily CA it back together or use a CF splint. I purchased 60 inches of rolled tube .440 OD x .375 ID and made many booms. Then I finally took the advice of others and used a simple protector.

I used emery cloth to bring the OD down of the tube and to reduce the diameter of the plastic TR wire inserts.
chappabob is offline Find More Posts by chappabob
Last edited by chappabob; Aug 31, 2006 at 12:12 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Corona building ?'s hs748 Electric Heli Talk 25 Mar 15, 2004 05:00 PM
Stress Test On Matt's Corona Boom ldracer Electric Heli Talk 5 Aug 17, 2003 04:55 PM
Corona boom protection - again!! hs748 Electric Heli Talk 12 Jan 17, 2003 03:51 PM
Corona Boom Support? JoeR Electric Heli Talk 0 Oct 24, 2002 10:45 PM
Corona - What's Special About Atomic Force? 02ViperTwin Electric Heli Talk 22 Oct 11, 2002 11:04 AM