Monday, November 22, 2004

Gert Nieuwoudt on "where next?"

Seems like most builders have disappeared in the jump to moldies. With a limited budget it IS possible to build a competitive glider in your ownworkshop. There are still a few builders around and some with lots more experience than me, like Theo Woluters and co. You will laugh if you see myworkshop. I have a bench in a space of 1.8m x 2m where I work and if I make dust I get a hiding from the wife. I have a few primitive tools and a fridge compressor for bagging. If I had more energy I would have built parts forothers as well, but I am always willing to help with the limited experience I have. There are other options as well, like buying parts. A Mantis fuz fromTerry Luckenback and a set of bagged foam wings from Phil Barns can save you some time. Pity we can not get similar deals around here.
We calculated the past weekend you can build a foam and glass 3m Bubble Dancer for less than R800, including the CNC cutting of Wings. The only difficult part is the wing spar, but hope to solve this problem with the next wing to start soon.
Willem brought a 2.5m Thermic from Art hobbie in and the quality of the kitis pretty neat. I do not think it was maidened yet, but will report back. Think the Art hobbie kits is a good choice, but the landed cost vs. what you get is debatable.


Tuesday, November 16, 2004

Andre Kilian on electric conversion

I converted a standard Shotgun 5000 to electric as a proof of concept, asone of my objectives was to prove that I can have similar weight and performance to glow by using electric power. The only change I made to astandard off the shelf Shotgun kit was to ask Mike Hirst not to cut off thenose but to leave it the length of a standard balsa plank (I wanted to keepthe distance between the prop and the wing leading edge the same as on aglow model, and to provide space for batteries in the nose just in case I ran into CG problems.)

An Aveox motor (1200rpm/v) was bolted to the nose, and I started with 10 CP1700 cells, which I had available. On this combo the CG was no problem, anda 13X4 APC electric worked fine (it hardly flew with the same wooden prop),with the amp draw about 30A max. Only problem was that I was slightly heavier than a glow version (although the CP1700s are a 4/5 sub-C size andweight), and flight times were about 5 mins. Next move was to install 3S3PKokam 1500 packs. Performance was up (prop hangs very easily, fantasticacceleration) and flight time was about 30 mins. Only problem was cooling on the motor, which overheats when prop hanging continuously. With hindsight it was not a good idea to use the plastic Robbe mount (very easyto mount, but shields about 50% of the motor from any airflow). A standard540 motor RC car heat sink solved the problem of overheating, but I also sourced some alu tube mounts that I intend using.

The greatest performance improvement came when Mike showed me how to set up the plane. It really helps when you know how, and whichever version you build it would be worthwhile getting some expert assistance with the setup!

My conclusion was that electrics are now able to compete on an even footing with the glow versions, and I suspect that it will not be long before ourtop pilots realize the advantages of electrics and start competing using electrics.

The only problem is that the Shotgun really shows up my lack of flying skills, which I am now working at with a Shockflyer (fantastic way to improve flying skills at very low risk and costs).

For the serious competition flyer I would recommend using a Axi 28/20/12o utrunner motor(new version) or similar, and Kokam 2000 packs, which will bring the all-up weight down well below the glow versions and have better performance on a 4S pack. The cheaper option would be to use a Jeti 30/3 motor with 3S2P Kokam 1500 batteries, which would enable you to have similar weight and performance to the glow versions, and about 15-20 mins of flying time.



Friday, November 05, 2004

Rudolph du Toit on the 2004 Fun Fly Masters

Hi guys I would just like to mention to the members of the group some of the results of the masters which was held at Welkom model aircraft club over the past weekend. Guess the reason for sharing this info is also mainly attributed to the fact that the winner is one of if not the youngest to our knowledge to ever win it and well because he is a friend of mine and a valuable member to our club Rosslyn Aero Modelers. It was a very stressfull competition for all of us as the top 6 pilots were a really close knit group considering the scores in the last 6 or so rounds of the 15 flown over the weekend.

I have to apologize if I do not exactly have all the facts correct but I was also competing and with this being my first year flying a shotgun and flying in the competition I was so consumed by the madness I might have missed a couple of things. Well onto the facts our own Ricardo da Silva at only 13 years of age managed to pull through at the last moments and snatch 1st place this year. It is hes 3rd year competing. The top 3 pilots were seperated by very little points so much so that there was something like an 8 point difference between 1st and 2nd place. A big congratulations goes out from me to everyone that participated in the competition this year. Out of the 21 pilots that qualified for the masters we really got to see alot of skill this weekend. Weather conditions had us all really nervous throughout the weekend with wind blowing 25kmp/h plus the entire event. I think at some stages it could have easily gusted close to 40 or 50 kilometers per hour but I didn't have a windmeter handy so maybe Dave Armitage will help me out on this one some time.

Anyways this is what I could remember from the standings and I'm sure it will be posted somewhere soon so we could get the exact positions of all the pilots soon. Unfortunately I am unsure of all the exact positions and would rather not lie to anyone. I do recall where all our pilots ended up and I'm very proud to say that I think RAM also had the biggest number of competitors this year. Maybe Dave will correct me on this one as well if I am wrong? :-)

1) Ricardo da Silva (RAM)
2) Mathew Hirst (Barnstormers)
3) Hennie Viljoen (Barnstormers)
4,5) Christopher Harris and Rob Hurlin (Not sure which way around)
6) S. Frazer
7) Rudolf du Toit (RAM)
8) Arney Sieling (RAM)
15) Herman Smit (RAM)
21) Johan Sieling (RAM)

Like I said I can not remember the correct placings of all the pilots and I apologize for that. The results should be posted soon so we would have the correct positions of everyone. I guess most importantly I wrote this message to congratulate and spread the word about Ricardo who managed to pull such an amazing accomplishment off at hes young age.

The fun fly is the most attended competition I know of in the country where after only the first two rounds already 67 pilots were participating. I'm sure more pilots joined in the fun in the 3rd round as only the 2 best rounds out of 4 counted.

As soon as I get more if I'm not beaten to it I will post the full list of results.

RegardsRudolf du Toit

Dave Armitage on the 2004 Fun Fly Masters

I measured windspeed at a maximum of 30 Kms/hour on the Saturday morning and 28 on Sunday morning. On both days the wind abated.
Minimum I measuredwas 11 Kms/hour during Saturday afternoon.
Positions were:
Ricardo da Silva 1091.3184
Matthew Hirst 1084.6120
Hennie Viljoen 1035.6490
Chritopher Harris 1026.3267
Rob Hurlin 1012.3979
A full report will be in SAMAA NewsRegardsDave A

Jet newsletter from Boet Denysschen


Once again a big thank you to all modelers and dealers that participated in making the expo such a great success.
The feedback received from every dealer was that they enjoyed it tremendously. It was not all about sales but mainly about exposure to the modelers, public and possible future modelers. Watch the press for a date for 2005. We have learned a lot from the first and it can only get better next time around.


The time has come that we Jet pilots in the Gauteng area get a field suitable for Jets to fly on a regular basis. At present we have to travel great distances to far away areas or have to get permission to fly at certain venues with a lot of red tape involved.There is also the occasional flight at O.D.I but it is tied to a great security risk.
A proposal was put to the R.M.A.C committee to develop their runways and make them suitable for flying jets. As the club is fairly central to the Vaal Triangle as well as P.T.A and all the necessary infrastructure already exists, we feel this will be the most suitable venue.
A request is being made to all Jet pilots interested in fund raising for this project to contact Boet 082 449 4623.
The idea is to extend the main runway to 200m and a width of 10m as well as re surfacing the existing runway no 1. The run off towards the existing quarry will be filled and smoothened off.
I will keep everyone informed on the progress of negotiations with R.M.A.C
The year is drawing to a close and we have come to the end of our organized flying programme. The Jet weekend that was arranged for 20th - 21st November has been cancelled. The dates for Tedderfield for 2005 will be published in due course.
The Jet modelers in the Cape have put together a qualifying round for this coming weekend at Bredasdorp. For any further information regarding the event you can contact Ross on 082 881 3183.Well done to the guys in the Cape for taking the initiative to get the ball rolling in another Province.


Second qualifier is on the 14th November at AFB Zwartkops. The pilots briefing will start at 09h00 with the first flight directly afterwards.
Third qualifying is on Sunday 30th January 2005 at Witbank Model flying field.
S.A invitational Masters is on 5th - 6h March 2005 A.F.B Zwartkops
S.A National championship 25th - 28th March 2005 A.F.B Zwartkops


1 Dominator - OS 91 completes ready to fly only needs receiverContact Awie Muller 083 32276204
Sparrow - OS91 ready to fly contact Hugh Wylie 082 892 8539
Byron F16 kit in box contact Juni 082 514 3024

Blog Archive

Total Pageviews


Web site terms and conditions

Copyright of material on all the pages of this site is vested in the SAMAA or the original authors. You may use the material in terms of the Creative Commons license for non-commercial purposes on the condition that you acknowledge its origin.

This work is licensed under a Creative Commons License

The views expressed on this web site, or on any directly or indirectly linked site, are not necessarily those of the SAMAA Committee, or the web editor. The information provided on this site is provided for recreational purposes only. The SAMAA and the authors of presented content assume no liability whatsoever on the use of information contained in this site. The information on this site is provided on an "as-is" basis, without warrantee of any kind. Links provided on this site will let you leave the SAMAA web site. The linked sites are not under the control of the SAMAA, and the SAMAA is not responsible for the contents of any linked site, or any link contained within a linked site, or updates to such sites.