MAC-CDL Prop Strike

[salem]

I would appreciate any information and/or advice from any MAC-CDL fundies out there.
I replaced the old Cuyuna (with V-belt reduction gear) with a Rotax 503 with gearbox. The prop is driven via a shaft direct from the gearbox. The shaft is held with a P205J bearing and housing. Whereas before the thrust line went through the root tube, it now goes through the shaft direct to the gearbox/engine assembly and to the root tube via the engine mountings.
After putting a lot of hours and effort in making the necessary changes from a Cuyuna to a Rotax I finally took the aerie this morning for a test flight. Flew the plane at ground effect height (+- 10ft) the length of the runway to check the controls and found the plane a little nose-heavy. I decided to taxi back to the hangar to make the neccessary adjustment to the tail-feathers. While taxiing, the P205J disintigrated and the prop (brand new) chewed up both trailing edges and my brand-new set of sails. The root-tube is twisted beyond repair and the prop is history. I had taxiied the aerie extensively the previous weekend without detecting any vibration or adverse torque effect.
Can anyone please give me some advice if the mod I made has an inherent flaw?

[kb]

to be honest, I have no idea, but sorry to hear about the damages.

[Duck Rogers]

3 questions here: 1) How long was the shaft?
2) What type of steel was the shaft made from?
3) How was the shaft connected to the gearbox?

[Bozz]

Hi Salem
You should try speak to CC of Bush Air in Baberton Valley.
He had a MAC CDL, while he was still in Jhb, with a Rotax 503 on and he used to do his own servicing and mods.
Maybe he can give some advice.
Web Address http://www.bushair.co.za