Paul,

Very nice Kit ! Cant wait to see it fly at the field. You are one of our last of the great pioneers and we dont see too many guys like you nowdays. You have inspired me and many other St Louis guys with the "jet side" of the hobby. Keep up the good work!

Paul, did you test flew the model yet?.

If so, hope everything went well and if not, still waiting everything goes well.

Best Regards,

Jesus Cardin

I currently have six flights on the BD-10. It still seems a bit nose heavy on take off due to the fact that 80% of the fuel is forward of the CG. The power curve of the 44 is a little hard to get use to since all the power seems to be in the 90% and above range. I will have somebody video the next flight so I can post it.

Paul Appelbaum

Congratulations Paul. Sure you will be able of solving the issues and make it an enjoiable model. What a great model if just a bit bigger and full composite a BD-10 kit would do it today.

We await your flying videos, Paul.

Best Regards,

Jesus Cardin

I too have one of the Wren 44's, the manual start version, and love it. If your power curve "problem" is what I think it is, it's just the fact that the thrust output from the turbine is not linear to it's rpm. Most of the thrust comes from the high end towards red line rpm. I use Futaba transmitters and on both my Wren and Simjet I have a big, healthy dose of positive expo on the throttle chanels. I reached it thru trial and error over a few flights until I got to where it 'feels' linear on the throttle stick. Afterwards just out of curiosity I checked my Simjet 1200 with the data terminal and full throttle and max rpm is 160,000 and at half stick it's at about 130,000. The numbers may not look right but the proof is in the flying. At half throttle my plane is flying at what feels like half power. Try it and see how it works. If you use JR tx's I think they call it negative expo, not sure though.

Paul, What a cool little plane!!!----I remember your work from back in the day of ducted fans....Produce a kit that is rated for P-120 size turbines and I'll put down a deposit for one of those!!!!----I just don't have any small turbines laying around...So---How about it---Think you'll ever make one for the popular 120 size engines!?!?!?!???

Kevin

You could always buy one


Paul, it's really good to hear that the plane has flown. The thrust isn't linear, and it's not possible to adjust the engine in any way, so quite a number of customers do as r3bldr suggests and set up expo in the transmitter to compensate.

Sara Parish
Wren Turbines

Working on my scratch build BD -10 and found this thread. Old thread but hoping fellow modeler can recommend c/g range? Mine is
version of Bob Thackers BD-10 reduced to 70 inches long.

"dwhorn" I still monitor this thread for any new entry or comment and I was very glad to find yours!

As previously commented, I own one original Appelbaum kit as well as the Thacker foam plans. I have never compared the proposed C.G. positions for each design, but as you are working from the Thacker plans I will take a photo of the Appelbaunīs one and will post here so you may compare. I am quite sure they will be very close and both quite safe knowing the designers!

Unfortunatelly I will be out of home for some weeks as I have to assist my elderly mother in South Spain and I keep my "model hangar" at my home in Madrid, so I will only able to post the photo when I am back ato home. In the other hand, I will be very pleased to see photos and details of your model.

Best Regards!

Thank you ! Will be posting pictures shortly of my build. Need to mount the stabs and its ready for primer.

Kindest regards
Dennis

I do not know if you got Col. Thackerīs article together with the plan but if not, here you a have a link to other thread here in RC Universe where you may read it while I am able of getting access to the plans:

BD-10J

Best Regards,