HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 20, 2012, 11:42 PM
Carbon User
Pilebuck's Avatar
YAL
Joined Jun 2005
729 Posts
"If you want that quick J sub second launch experience then I strongly recommend the full mega bungee that Keith and Joe W are using."

I thought that was what it was all about? Otherwise I would just be getting/suggesting a "B" winch.

As for the safety, I've worked with Keith's bungee, and I can assure you that the danger is real for anyone between the model and the stake (in adjacent lanes.)
Pilebuck is offline Find More Posts by Pilebuck
RCG Plus Member
Latest blog entry: HF Ventus
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 22, 2012, 09:13 PM
Win=span\massXpractice+lu ck
webbsolution's Avatar
Joined Jul 2007
3,097 Posts
Quote:
Originally Posted by Pilebuck View Post
"If you want that quick J sub second launch experience then I strongly recommend the full mega bungee that Keith and Joe W are using."

I thought that was what it was all about? Otherwise I would just be getting/suggesting a "B" winch.

As for the safety, I've worked with Keith's bungee, and I can assure you that the danger is real for anyone between the model and the stake (in adjacent lanes.)
No its not - the purpose of the effort was among other things to find a launch solution that would lower the effort required to hold a team select and potentially avail itself to a lasting MOM based contest format. There has been a lot of interest in the format.

B winches are great for those of us willing to invest - hey if you have the bug you make the time and money. I looked at purchasing several B winches to hold a significant event. It's just not practical.

If your interest is moderate or you are just curious and you see that a winch, battery and mono is a requirement for competitions... it's a barrier. I want to remove barriers and increase exposure. I don't want to drag 2k worth of gear to a high school and listen to the kids basically tell me that they will not even tell their parents about the sport because of the money involved when in reality they could build killer skills with $50 worth of rubber.

This last summer I attended a couple MOM bungee powered events - they were so much fun - we got so many more flights in and the concept just made an impact.

Most serious pilots don't drag their winch to the field either. I don't, Keith doesn't Arend, JW - we are all using a bungee already for practice. The practice solution currently seems to be a really powerful burst solution that eliminates a lot of walking - this is a factor when you want to do 10-15 launches back to back but a contest solution should be a little easier to manage. So in that light I have been experimenting with a larger than average bungee that delivers serious launching potential but does not require holding above 60 lbs of force.

I am making obvious concessions. We will not have the kind of J power from a 2 man tow. We will however have a MOM format and standardized gear that can:

- be duplicated at any club for very little investment

- Be duplicated by individuals for less than some people pay for a single servo.

- Seriously expose the pilot skills given that launches are going to be 150-250 meters instead of 300 meters.

- reduce barriers to new pilots.

- promote the MOM format

if we can accomplish these things and increase our numbers so that we have a critical mass of pilots then I would be all for going back to a pure F3J approach. Right now however we are in a different world.


In terms of danger regardless if it's a bungee or a J tow you are going to be exposed to some danger if you are hanging around between the plane and the stake. Right now in a typical J format we have 10-20 people down there already and the stats on injury from aircraft collisions with towers seems to be very low.

In the format described with bungees, the amount of people between the spike and the plane should be reduced to just those doing relites at the same time, pulling out of coordination and in adjacent lanes....and even then the chances of mishap are pretty low - the same as in F3J but lower power. Most perceived danger could be resolved by using wider lanes or even an extra lane with a spare bungee for larger safety margins.
webbsolution is offline Find More Posts by webbsolution
Reply With Quote
Old Jul 20, 2013, 10:18 PM
Win=span\massXpractice+lu ck
webbsolution's Avatar
Joined Jul 2007
3,097 Posts
Event completed!

We completed the Canadian F3J team team selects today using said bungee format. The event went off without a hitch aside from a lower than expected pilot turnout. Ron Turner had his timer through for him. His timer had never thrown an open class plane under decent tension and I am happy to report after just one test launch he had it down with ease.

The conditions were really challenging with really significant cycles moving through. Relites were as common in our rounds as any major J event I have been at regardless of launch solution.

All the typical F3J strategy was still as applicable using this launch format and most important we all had a lot of fun.

We had a consistent 8-12 KPH head wind all day - I ballasted for 50% of the rounds because the sink cycles were fairly strong and I wanted to punch through them quickly. The decent head wind was a boon to our launch height.

The qualified CDN Team pilots along with me were Ron Turner of BC and Simon Thompson of Edmonton Alberta.
webbsolution is offline Find More Posts by webbsolution
Reply With Quote
Old Jul 20, 2013, 10:58 PM
Sailplane Flyer
Berthoud CO
Joined Oct 2007
368 Posts
Congratulations All.

Thanks for the update David.

Did Arend attend? How about any Juniors?
mikeverzuh is offline Find More Posts by mikeverzuh
Reply With Quote
Old Jul 21, 2013, 12:00 AM
Win=span\massXpractice+lu ck
webbsolution's Avatar
Joined Jul 2007
3,097 Posts
Unfortunately Arend did not attend and this coming WC we will have no juniors flying for Canada. We may have a junior for the next cycle though...

Quote:
Originally Posted by mikeverzuh View Post
Congratulations All.

Thanks for the update David.

Did Arend attend? How about any Juniors?
webbsolution is offline Find More Posts by webbsolution
Reply With Quote
Old Jul 22, 2013, 12:55 AM
Registered User
Joined Jun 2004
210 Posts
Question

Hi
For safety how would you keep the stake in the ground and not have it come flying back at you under max pull in soft soil
mack5 is offline Find More Posts by mack5
Reply With Quote
Old Jul 22, 2013, 01:10 AM
Win=span\massXpractice+lu ck
webbsolution's Avatar
Joined Jul 2007
3,097 Posts
Quote:
Originally Posted by mack5 View Post
Hi
For safety how would you keep the stake in the ground and not have it come flying back at you under max pull in soft soil
We used a 2 foot 1.5 inch pipe with a flange for attaching the bungee - I have used far smaller spikes as small as 18 inches without pulling them out but these would never come out and are FAI legal -
webbsolution is offline Find More Posts by webbsolution
Reply With Quote
Old Jul 22, 2013, 07:49 AM
Registered User
Australia, VIC, Paynesville
Joined Apr 2007
192 Posts
Just getting back into F3J and found this a great read - we mostly winch here in Oz and a $1500-plus winch is a big turn off. These bungees you refer to sound alot stronger than my old surgical latex one - can you provide more detail on the materials you are using and maybe a source? Thanks, Cam.
camdyson is offline Find More Posts by camdyson
Reply With Quote
Old Jul 22, 2013, 08:58 AM
Registered User
Tuomo's Avatar
Jyvaskyla, Finland
Joined Aug 2003
2,449 Posts
I think webbsolution is refering to these bungees. Definately stiffer than surgical tube of the old days and also feels different as a material.
http://www.emc-vega.de/de/Hochstartt...Megarubber/F3B
Tuomo is offline Find More Posts by Tuomo
Reply With Quote
Old Jul 22, 2013, 09:05 AM
Registered User
lesterpk's Avatar
Australia, WA, Perth
Joined Oct 2003
909 Posts
@camdyson - check rctrader, there is a decent winch there for $500.
lesterpk is offline Find More Posts by lesterpk
Reply With Quote
Old Jul 22, 2013, 10:05 AM
Registered User
Australia, VIC, Paynesville
Joined Apr 2007
192 Posts
Thanks Tuomo, Lots of good stuff there. Looks like an easy way to practice on weekends.

Lesterpk - yeah, spotted that the other day. Thanks for the heads up tho'.

Cam
camdyson is offline Find More Posts by camdyson
Reply With Quote
Old Jul 22, 2013, 01:12 PM
Win=span\massXpractice+lu ck
webbsolution's Avatar
Joined Jul 2007
3,097 Posts
Quote:
Originally Posted by Tuomo View Post
I think webbsolution is refering to these bungees. Definately stiffer than surgical tube of the old days and also feels different as a material.
http://www.emc-vega.de/de/Hochstartt...Megarubber/F3B
No I am not referring to those bungees - these were created for the task by March Mech at aerofoam Composites -

We used a test bungee, measured the results and then spec'd the specific tension range to elongation. You will not find these anywhere else to date -

PM me and ill give you the email address - if you are interested in obtaining one for practice.

Given that you are so far away its not going to be a massive problem if you simply use whatever you can get assuming its relatively stout - if you are holding 40- 70 lbs at peak you are in the zone. These bungees will probably hold much higher tension but thats not something everyone can replicate safely.
webbsolution is offline Find More Posts by webbsolution
Reply With Quote
Old Jul 22, 2013, 02:32 PM
Registered User
wakumann's Avatar
Canada
Joined Jul 2003
2,546 Posts
Hi David

were there more as 3 attendees, a competitor list would be appropiate and easy to post?

Tks
Thomas
wakumann is offline Find More Posts by wakumann
RCG Plus Member
Old Jul 23, 2013, 01:38 AM
kdt
Registered User
kdt's Avatar
Joined Feb 2007
433 Posts
Team Selects

Congratulations to the new team members. I would also be interested to know who competed and what the scores were.
kdt is offline Find More Posts by kdt
Reply With Quote
Old Jul 23, 2013, 07:58 AM
Registered User
Tuomo's Avatar
Jyvaskyla, Finland
Joined Aug 2003
2,449 Posts
Quote:
Originally Posted by webbsolution View Post
No I am not referring to those bungees - these were created for the task by March Mech at aerofoam Composites -

We used a test bungee, measured the results and then spec'd the specific tension range to elongation. You will not find these anywhere else to date -
Ok, I just got confused since "Mega" is also the band name for EMC Vega bungees.

I am 99% sure that EMC Vega stuff is just rebranded Thera Band. My bungee is Thera Band and it looks and feels exactly same as EMC Vega bungees.

I undestand that for the sake of competition you want to buy your bungees from one single supplier.
Tuomo is offline Find More Posts by Tuomo
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Contest 2012 US Team Select Contest djensen Hand Launch 927 Jan 08, 2014 03:05 PM
Contest CRRC Hand Launch Classic July 7 + 8 Sudbury, MA - Team Selection Qualifier for 2015 Fly2High Hand Launch 64 Jul 14, 2012 11:06 AM
Discussion Conditioning for the team selection contest GaryO Hand Launch 19 Jul 13, 2012 11:54 PM
Discussion Qualifying for the US F3K Team Selection, 2013-2015 glidermang Hand Launch 14 Jul 11, 2012 10:28 AM