Our structural engineer was sent seven sheets of drawings yesterday showing details of the various components of the Switchblade, and how they relate. It is amazing how much detail is in a vehicle such as this. Normally, you have a wing, a tail, and a body in any aircraft. In the Switchblade, the wings swing closed, and the tail moves forward, both locking in place. We have a center keel for bottom impacts to protect the wings.Lots of details!
The attention to detail is both a good sign, and a cross to bear, as we work to keep up with our schedule. So far, we feel we are doing about as predicted – perhaps a week off at worst. In talking with the builders in Prineville, I believe we will have a shorter build time than predicted, so should make up time there. It would be nice to fly ahead of schedule, wouldn’t it?
Samson is meeting with a mold maker in Redmond next week, and will be using the quarter scale prototype as a model to mark up like a side of beef. You have seen the pictures with the dotted lines: ‘cut here’. Same with the prototype. It is easier to see on a physical form the shape of the compound curves and predict the locations where the molds will have to be stopped and started to be able to produce the curvy outer shape of the vehicle. 3D engineering models are great, but harder to work with at times.
One thing leads to another, and we found through our engineering connections that there is one engineer who does nothing but doors. He is currently working on the door for the Honda Jet. He is being tasked to do our door as well. Not that we need pressure seals for flying above 18,000′, but he knows how to design doors that close and seal well, are structurally sound, and will hold up under use. Those are the kind of doors we wish to provide.
The transmission has been the center of attention for some time. The previous solution was a custom-designed continuously variable transmission (CVT), like a snowmobile cvt, as they are very light yet provide the power transmission and clutch operation required. When we reviewed the desires of those who might be purchasing our Limited Edition vehicles, we realized that might not be adequate.
There are several light-weight transmissions under development that would be good solutions, but they are not available yet, and obviously can’t be counted on for that reason. Our long-term goal is electric drive, but that also isn’t ready for prime time due to the battery technology available for our higher-than-average power requirement. We find that a Ford C4 automatic transmission seems to be the lightest transmission that will handle the loads, and provide the remote clutch operation we would need. We didn’t want a manual transmission, as we want to leave the opportunity open for using the wheels to assist in take-off acceleration. Operating a clutch during take-off and landing seemed too complicated. I think you would agree.
We did get a good solution for the ducted fan prop clearance, as there is the possibility that the carbon fiber ducted fan section, despite being designed ‘stoutly’ will flex on a hard landing. This would normally mean a prop strike on the ducted fan surface, and lead to prop damage and possibly engine damage as well.
To handle that, we are providing a groove in the surface of the duct at the location of the propeller to allow the prop blades and duct to deflect yet not hit one another. The groove may have a filler in it to channel airflow past the groove, or it may be left with a bare groove. I have been told that marine ducted propellers often have just a bare groove and work acceptably well. We are scheduled to do testing of both to sort out which is the best solution.
Although I feel I have barely scratched the surface of the things we are going through to produce the Switchblade, this should give at least the high points to keep you all up to speed. It is exciting to watch the team do their work, and to see that team expanding as we get other talented people offering their assistance on various aspects of the project. We are growing into a great company, even in infancy.
for The Samson Team