Building the new Bushbaby SAFARI

[Oupa-G]

Stefan I'm trying to record as much as possible because I want to write as good a manual as possible. A good static port is part of accurate evaluation. Factory test aircraft fly with these enormous probes and pitot tubes etc because they have the same problems and then they make two holes on the side of the fuselage at the right spot. Finding the spot is not easy


Cheers Oupa-G

[KFA]

Hi Oupa, with the fiddling I was more referring to the engine tuning part I am just pulling your leg, we are all anciously awaiting that 40hr mark to arrive

[Oupa-G]

Stefan this engine is a beauty and is running like a clock will tune and fiddle after 40 hrs it is called fine tuning

Cheers Oupa-G

[Oupa-G]

The wind was not blowing today it was pumping, spent time modifying the fuel cap spanner added a wooden grip it will be engraved with the fuel quantity information. Another calibration coming up. I love fuel dipsticks. Just a quick photo.

Cheers Oupa-G

[AndyCAP]

Hi Oupa - Thats a nice looking tool!

My only concern would be that it gives one the opportunity to overtighten the fuel cap - and possibly damage it.(I know you wont - but someone who is less technically inclined may do so)

I suggest that you make the handle as short as possible to limit the moment that one can exert on the cap. I presume you intend using the handle as a dipstick? Nice idea!

Glad to see your testing is back on track

Best regards

A

[Oupa-G]

Dear Andy the Cap (no pun intended) is turned back on till the vent tube is showing forward. It is not my design I think it was Ranger's idea I stand to be corrected. The material of the cap and the filler neck have binding properties. I spoke to your boet the other day when I was visiting FAFK.

Cheers Oupa-G

[AndyCAP]

LOL! Pun is funny none the less!

I guessed that the plastic Caps would be inclined to bind - so the tool will be very handy.


Good to hear you met my boet again. He will be very interested to try OTT out when the time is right.

I am actually very proud of him for safely handling the emergency landing in his first ever twin flight at FACT the other day. Both him and Instructor walked away. that was one day after my boet's 2nd child was born!

good luck with the rest of your testing!

[Oupa-G]

This week was spent on changing the spring quality of the tail wheel. I am flying the approach at slower speeds so the touchdown is tail wheel first. So the dynamic of the spring had to be adjusted I made a new spring bent it to the correct radius and went to my friendly spring maker and had them heat treated like the main gear. On the Vansin I replaced the master cylinders with locally produced products new pads new O-rings on the slave cylinder and while I'm in the process the Baron also received new O-rings in the brake system.I will take photo's tomorrow and post them. I hope the wind is going to play game , so that I continue the testing.


Cheers Oupa-G

[Oupa-G]

Have been quite busy the tail spring was to soft and the reshaping of the rudder happened. I do not know if the temper of the spring was correct but I remade the spring, made it from 8mm EN45 bent it in my press shaped the spring fitting snug into the Matco base and made sure there were no sharp stress inducing corners and edges. The wheel now works well.

I finished the silencer exhaust of Bosvark II and did the final fitting of the exhaust stubs. Also played around with the static source placed the adjust-able O-ring around the pipe and it seems to do the job. Suddenly I have an accurate airspeed at cruise and in the landing configuration. On quiet days I will fine tune this set up I'm glad it has saved me placing a static source in the tail .

[Mogas]

"Also played around with the static source placed the adjust-able O-ring around the pipe and it seems to do the job"
Brilliant!

[Oupa-G]

Mogas if I have the right place I will turn it out of teflon then it will be a permanent fixture. Looking on the net I saw the NASA boffins also reshaped the aerodynamics on the their probe. On a quiet day i will calibrate it against the GPS. This morning I had a wonderful flight bit bumpy because of the east wind, but the engine is purring.

Cheers Oupa-G

[Trikenut]

Hey Oupa G.
I was Flying with Louis in his gyro and and we saw you puting away the bushbaby. It looks AWESOME from the air! It looks great!

[Oupa-G]

Here are some figures the new engine is running like a turbine and the temperatures are "cool". I'm showing a snapshot of the Voyager. I have not connected the fuel flow and the virtual fuel tanks. Sofar I have concentrated on the temperatures and the static system. The sump oil temp's is 71c the cylinder heads are 70 and 71 C remember the heads are oil cooled. The EGT's are 716C each. The inlet of the oil cooler is 76C that oil comes directly from the exhaust valves hence it is slightly higher then the sump oil temp of 71C. The oil cooler outlet is 63C so we know the oil cooler is dumping heat. The gearbox temp is 42C should there be a problem in the gearbox this probe should tell us the story. As soon as I have the revs over 6000rpm the speed goes well over 100mph this is still on the 72X54 prop, I'm waiting for the 74X60 prop. In the very left upper corner is the GPS speed but that day there was a slight southerly wind. The highest temp I have seen sofar was 102C on the inlet of the oil cooler and on that day it was 42C and everybody flying was complaining of high temperatures. 100 degrees C for oil is a walk in the park. The baffles Boet and myself with a healthy bit of cross pollination worked out are doing their job. More flying will tell. The Bosvark is becoming a get in start and fly machine. Last weekend it was nice and hot and I had a go at hot starts. Waiting 2 min and then 5 min and 10 min I tried starting on the main system and on the backup system. The starting is immediate and the 3.5 Bar pressure prevents air locks. If you try to do that with either a Lycoming or a Continental you would end up with a dead battery and a burnt-out starter. This is all for tonight



Cheers Oupa-G

[Dusty Eagle]

Hi Oupa-G.

Love your fuel cap spanner. My cap was turned smooth on a lathe and I had to use a large visegrip to open or close due to the binding. I put on a little copper slip on the threads and it now easily turns by hand and seals nicely. Guess it will wash off over time, just add as needed.

How do you measure the fuel level in the bottom /rear of the tank with a vertical gauge when standing in the tail dragger position.

I made a gauge as per the attached pics and it shows the fuel level down to the last 5L. It makes very little difference if the plane is not quite level.

Very sad about your rudder damage, but we Bushbaby owners are now forwarned. My spring is also very sloppy. Need to change before it happens to me.

Happy flying.
Regards,
Nico

[Oupa-G]

Nico

Very clever mine was only for the full half part. I will definitely construct something like that, I'm a great fuel dip believer. I absolutely love the cross pollination on the web. The exhange of data is stunning. I can imagine that your dipstick will be very accurate. Thanks for the tip.


Cheers Oupa-G