Building the new Bushbaby SAFARI

[Aerosan]

Oupa, KFA and others....

The issue around fairings on these aircraft should never be to increase the speed. You can never make a F1 racer from a 1970 Beetle by putting on more fins.

But, having said that, the aerodynamic boffins will tell you that the drag from a round tube, say 25mm in diameter, is equal to drag of an aerofoil with SEVEN to EIGHT times that diameter
My knowledge about Aero D is limited, but common sense tells me that, by putting fairings on the lift struts and landing gear, the amount of overall drag is hugely reduced. Drag roughly increases with the square of speed, a small increase in speed results in a large increase in drag.
Remember, any decrease in drag will always come with a penalty (weight), but on this aircraft the benefits FAR outweigh the penalty. I believe when fairings were first introduced to the Bushbaby, the guys gained between 8-10 mph on there cruise speed. For an aerrie only doing 80-90 mph, that is a gain of roughly 10%. . In Aero D terms, that is light years

I know, I said you don't put fairings on to gain speed. a 10% increase in speed is huge, but the difference between 85 and 95 mph is not earth shattering. THE BIG GAIN IS IN EFFICIENCY AND ECONOMY OF THE WHOLE OPERATION. Hope this make sense....

Well said sire

[Oupa-G]

Not everything in life does have to make sense, sometimes the joy of building and making something is enough. What however what is the most important about any project is the critical evaluation afterward's, and honest reporting otherwise there is no advance. Not doing the same thing again is not negative , you only place knowledge in the right perspective. So for future Bushbaby builders stick to the conventional gear but bring the axles a bit further forward. The Grove gear have the section in the middle to make the spring longer because aluminium is not the ideal spring. On the steel gear the centre section makes the spring to long, that is why Cessna have two seperate legs bolted onto the airframe. So a conventional gear with bungees is a very good compromise.


Cheers Oupa-G

[Oupa-G]

The Bosvark is done awaiting the paperwork from CAA. Exhaust and Oil cooler handed over to Boet for the Banana boys Explorer , I must say I'm proud of the final result of these two components for the BMW conversion. So finally I got stuck into my trike that was quietly waiting for attention, I had taken it out of service for some tender love and care and foremost to replace the Hall sensor pickup EboXi version 1 with the later 60-2 version. The bolt spacing on my 1100BMW fly wheel is different to the 1200 GS so I had cut a new 60-2 ring fitted it also with a new longer gearbox for the 1100 which has a different Bell housing.
Then came the truck through the wall drama and shambles etc etc that explains the 7 months. On the trike I flew with the circuit board unprotected in dusty environment a killer for electronics but during the operation the system worked 100% from the photo you can see the difference between the old and the new EboXi. I cut out a lot of wire because the first EboXi was still mated to the original Gotech loom. I could never get the Gotech to function stable it had Windows like behaviour not suitable for aviation. Luckily Ystervark7 is helping he cuts wires and I label when he cuts it looks as if he was a barber in his previous life. So in the near future trike ZU-DCM will be flying with a BMW Motronic and EboXi systems.


Cheers Oupa-G

[Rudi Pretorius]

Hi Oupa-G
I did read and follow a bit on this project, maybe I missed it if it was in the tread
What is the possibility of a video clip on the engine from idling till the propeller stars to turn
As you mentioned the propeller only starts turning @ about 2000rpm and if those exhaust pipe look that good I can just imagine the sound coming out there
So if possible can you please make a video clip and put it on the tread?

[Oupa-G]

This weekend I will give it a go the sound is awesome.

Cheers Oupa-G

[Oupa-G]

This weekend ran the Whisper Eboxi on the loom of the Bosvark. Ystervark7 made some changes to the software just some minor finesse changes making the starting cycle more slick. Also made a loom so that I can run the tested EboXi in the cabin, as I was busy Ystervark came round the corner with also an intermediate loom. As they say great minds think alike and fools seldom differ. Still awaiting the final papers from CAA. Patience is a virtue.

Cheers Oupa-G

[Boet]

Ze peppes she`s a goin ina tomorrow, I has been told. Like you so rightly mentioned. Patience is indeed one of the great virtues of life. Let`s hold thumbs!!!!

[KFA]

Problem with the papers is that it is not just the Safari papers, Monty is redoing all three type acceptances to comply with the ATA 100 system. This will smooth the way forward. Patience. Getting there

[Oupa-G]

I will wait and work on my trike which was seriously neglected over the past 6 months.

Cheers Oupa-G

[Oupa-G]

While waiting for the paperwork I'm doing some refinements on the gear, I have changed the geometry mainly because I have located a machine shop that can roll the gear to the desired shape. This geometry should work better, but as always time will tell.


Cheers Oupa-G

[Oupa-G]

This weekend was buzzing. Saturday morning the wind was north and a miserable day for flying . I jacked up the Bosvark and took the present gear of and hung the new rolled gear. As it has not been tempered yet I slowly lowered the aircraft and took measurements as to the amount in degrees that the gear must still be rolled to give the correct angles and I want the toe-in to be as close as possible that makes the final shimming easier. Also helped Anton and Tommy on the final wiring of the Bosvark II which is very quickly going to be finished. It is going to be another race between finishing and paperwork. I think there is another vertical taxiing coming up. However the final acceptance of the Safari paperwork is happening on Tuesday. That is why I took the gear of so I'm not tempted. This morning we filled the gearbox with oil the engine with oil filled up the header tank and Bingo Bosvark II started and ran like clockwork small adjustments on the throttle cables, but the wiring Tommy had done was superb and much neater then Bosvark I, he will have to come back and tidy up my prototype wiring, where things get added and changed etc. The main system ran well and when I switched to the back-up all was well. The day was beautiful and I grabbed the first and closest Trike put on a helmet and flew in the beautiful Cape weather, these winter days when they are nice, they are really nice. Enclosed the Bosvark in retractable form and then with the new gear fitted.


Cheers Oupa-G

[KFA]

The papers went in on Friday, apparently we will have the verdict tmrw. On the face of it the powers that be are happy with things (paperwork)

[Oupa-G]

KFA thanks for the news . I really hope so it will be a long paper path I hope that my efforts helped a bit. Meanwhile I'm playing around with my Voyager it went to MGL for upgrading the new Graphics I must say it is a big improvement on an already superb instrument. The weekend was cold and I sat in front of the computer adapting the instrument lay-out to fit the probes I have in the Bosvark. Also got back the next batch of exhausts, I must really compliment the welder with superb welding. The jig was adapted to the new dimensions for the Banana boy's Explorer the Bosvark exhaust did not fit exactly because the Explorer is smaller I did not want to cut the Safari exhaust and opted for a new Explorer exhaust. A modified thing is never so good. Ystervark is busy making looms that will include the switches and in future a builder will be able to just connect a wire to positive and a wire to negative. For most builders the wiring seems to be a problem and mistakes creep in to easily.

The new under carriage is again at the rollers to make adjustments. Time flies but I hope all the paper and refinements of the build will all come together. When Tommy returns from Loeriesfontein he will have another job to clean up the wiring of because a prototype tends to become an Afro- hairstyle or maybe some of the other modern hairstyles you see that looks like instead of a comb they use crackers.

Sorry for not being on this site lately but things are happening to fast.


Cheers Oupa-G

[Oupa-G]

I see 99000 views on this site and it is difficult to believe the interest in this topic. I will go a little bit more technical and I will talk tonight on the application of torque values how they are worked out and how the the values are calculated and recommended. I had a discussion with a very experienced person ,and it happens that sometimes we miss some information I will try to help and fill in.


Cheers Oupa-G

[Boet]

BMW in the Banana boy`s Explorer fired uo for the first time this evening. A bit of a steep learning curve for me! After some burps and farts, she runs beeautifull. We will try out the scales tomorrow, and try to get the papers going.......