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Request for comments....

n468ac

n468ac

Well Known Member
I'm looking for comments about the attached picture ... I want to have the square tube mounted to the firewall on our RV6A the "pins" will be on the passenger side, outside of the cowl. Do you think this will have an major effect on the flying characteristics? As the pins will be in the airstream ... it will be mounted in the middle of the firewall (top to bottom).

thanks for you input.

RV6a-1.JPG
 
Uh, sounds/appears a little unusual if you wouldn't mind the characterization. What do you have in mind for this attachment?
 
Given your fabrication skills, it would be very easy to dummy up some protruding pins for a quick flight test. Just mount dummy arm and pin assemblies on small, thin flat plates suitable for taping to the cowl/fuselage skin.

I'll fly it on the -8 if you want. Obviously a -6 would be better. Do we have a -6 owner out there who can help?
 
DanH said:
Given your fabrication skills, it would be very easy to dummy up some protruding pins for a quick flight test. Just mount dummy arm and pin assemblies on small, thin flat plates suitable for taping to the cowl/fuselage skin.

I'll fly it on the -8 if you want. Obviously a -6 would be better. Do we have a -6 owner out there who can help?
Click to expand...

I was thinking about that ... but didn't want to lose it in flight and have it damage the tail, if anyone thinks it will have too much drag for tape.

but that sure going to be this weekends project.

:eek:
 
Another thought ....................

Would it be possible to mount a receiver or socket inside the cowl, and plug in the lift mount when needed?? Or, screw it in-----or plug in and quarter turn to lock etc.

The access holes can be covered by a snap plug or some kind of door when not in use.

Think along the lines of how a trailer hitch on some cars is done, hidden behind the license plate until needed............

Just something you might consider thinking about.

Good luck with the project.
 
Mike S said:
Would it be possible to mount a receiver ... the access holes can be covered by a snap plug or some kind of door when not in use.
Click to expand...

I was noodling just such a design. It could be made just as solid and not impact the airplane when not in use.
 
Have you see how they fly the Super Cubs in Alaska? I absolutely would not worry one bit about that fitting. Unless the caribu that you mount to it is over 500 lbs. Then you'll need a second for the other side to keep from flying in circles.

I would of course add significant structure on the inside to support the loads.
 
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Mike S said:
Would it be possible to mount a receiver or socket inside the cowl, and plug in the lift mount when needed?? Or, screw it in-----or plug in and quarter turn to lock etc.

The access holes can be covered by a snap plug or some kind of door when not in use.

Think along the lines of how a trailer hitch on some cars is done, hidden behind the license plate until needed............

Just something you might consider thinking about.

Good luck with the project.
Click to expand...

Thanks! good idea
 
While doing a story for KitPlanes some back, I interviewed a guy who made an aluminum hoist for his son. The cool thing was it came apart and would fit in the baggage compartment of his Highlander.

Let me know if you want his contact info.
 
N941WR said:
While doing a story for KitPlanes some back, I interviewed a guy who made an aluminum hoist for his son. The cool thing was it came apart and would fit in the baggage compartment of his Highlander.

Let me know if you want his contact info.
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thanks, the system we are looking into will come apart and fit in the baggage compartment of the RV6, it is fully contained and self powered. So far the total weight looks to be around 36 lbs. We are in the discussions with the manufacture ... our only real hurdle is the system mount on the firewall.

As we work the issues I will post more information for everyone.
 
Any chance of posting a photo of the apparatus that will attach to the pins?

I also like Mike's idea.

Regards,
 
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Another idea...temporarily secure the dual pin bracket through the cowl like a tie-down fitting. Have two bolts running thru the vertical bracket and engine cowl passing into a threaded anchor block affixed to the firewall. Then you would only have two bolt holes through the cowl which could be covered with snap in caps for flight. Then you can detach the pin apparatus for flight.
 
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TomVal said:
Another idea...temporarily secure the dual pin bracket through the cowl like a tie-down fitting. Have two bolts running thru the vertical bracket and engine cowl passing into a threaded anchor block affixed to the firewall. Then you would only have two bolt holes through the cowl which could be covered with snap in caps for flight. Then you can detach the pin apparatus for flight.
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I really like this idea!!!
 
n468ac said:
I really like this idea!!!
Click to expand...

This is a better idea. Should be fairly straightforward to do something inside the fuselage/cowling envelope. But to answer your original question, based on the size, shapes and locations of camera mounts I've stuck to my plane, you'll ever know that bracket was there when flying.
 
n468ac said:
thanks, the system we are looking into will come apart and fit in the baggage compartment of the RV6, it is fully contained and self powered. So far the total weight looks to be around 36 lbs. We are in the discussions with the manufacture ... our only real hurdle is the system mount on the firewall.

As we work the issues I will post more information for everyone.
Click to expand...

Been thinking about the loads and stresses that something like this will impart to the airframe. Lots of questions/concerns floating around between my ears:eek::confused:

Question-------is there going to be a support leg/outrigger that sits on the ground?? or is the entire load going to be cantilevered off the mount attached to the firewall??

A ground leg to carry the vertical load, and a firewall mount to locate the lift, and stabilize the loads seems like it may be a good way to go.

Are you looking to hoist someone up in front of the wing, then swing them around to above the wing, then finally to the cockpit?? If so, the load vectors go all over the place. How many pounds do you plan to lift?? How far from the mount will the arm go??

I would suggest you have an aeronautical engineer take a look at this, and how to transfer the load to the airframe safely. Both safety for the person being hoisted, and safety for the aircraft.

Good luck, homebuilt/experimental aviation at its best.
 
N941WR said:
While doing a story for KitPlanes some back, I interviewed a guy who made an aluminum hoist for his son. The cool thing was it came apart and would fit in the baggage compartment of his Highlander.

Let me know if you want his contact info.
Click to expand...

Is this the one that was behind the Vans tent at OSH?

The base was mounted to the bulkhead behind the seat, and carbon fiber tubes were sections that fit within each other. A skyhook hung out of the top and had an electric hoist. The Aluminum section was a ball bearing pivot.

Yes, Mike, it picked up the passenger from a wheel chair, hooked onto the hooks you see hoisted. It then perfectly fit right over the seat. I did not see it in use, but the owner used it for a paraplegic passenger. It did not look very heavy and he erected it from the baggage compartment in a few minutes with no tools.
That section of the fuse forward is pretty torsionally stiff. Think of the weight just on the steps.
photo-4.JPG
 
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Question-------is there going to be a support leg/outrigger that sits on the ground?? or is the entire load going to be cantilevered off the mount attached to the firewall??

--> not sure at this point ... but I've too though about this


Are you looking to hoist someone up in front of the wing, then swing them around to above the wing, then finally to the cockpit?? If so, the load vectors go all over the place. How many pounds do you plan to lift?? How far from the mount will the arm go??

--> correct in front of the wing, swing over the wing, then into the cockpit. the mount will be braced across the front of the firewall, maybe in a "<" v connecting to the far side engine mounts. The arm will be between 45 and 54 inches long to allow for the lift from a wheel chair and then lower into the seat. Lifting weight will be 180lbs.

I would suggest you have an aeronautical engineer take a look at this, and how to transfer the load to the airframe safely. Both safety for the person being hoisted, and safety for the aircraft.

--> point taken
 
BillL said:
Is this the one that was behind the Vans tent at OSH?

The base was mounted to the bulkhead behind the seat, and carbon fiber tubes were sections that fit within each other. A skyhook hung out of the top and had an electric hoist. The Aluminum section was a ball bearing pivot.

Yes, Mike, it picked up the passenger from a wheel chair, hooked onto the hooks you see hoisted. It then perfectly fit right over the seat. I did not see it in use, but the owner used it for a paraplegic passenger. It did not look very heavy and he erected it from the baggage compartment in a few minutes with no tools.
That section of the fuse forward is pretty torsionally stiff. Think of the weight just on the steps.
photo-4.JPG
Click to expand...


Ours will be a different design, but his setup got me thinking! I've also talked to that gentleman last week and have gotten more pictures from him.
 
thanks everyone ... I love VAF ... these are all great points, ideas and suggestions. We have such a brain trust working here.

I can't wait to get dad back to flying to all the great events.
 
Photos of RV Handicapped Lift available

If anyone is interested in more photos of the RV Handicapped Lift displayed at KOSH and its various components let me know at fraziernv at earthlink dot net. I have a dropbox site set up and can send you the link.:D
 
Pax Lift

1: Flight characteristics- I don't believe you will ever know that bracket is on the outside of the airframe. I ran a Maint operation for a while that included seaplanes and have seen them and landplanes return to base with all manner of damage and they usually flew absolutely normal. Additionally we used to tie all sorts of things externally to the floats and other than a slight speed penalty no adverse effects noted.
2: Structure: Not sure what your plans are for mounting the square tube but the firewall itself is not very strong. I would try to incorporate the upper and lower engine mount attach bolts as hard points for attaching your lift structure.

Don B. Always up for a cool project!
A&P, IA, ATP

RV 9. Rebuild in Progress
 
Lift

Saw your Mom and Dad at Menards the other day and he mentioned you were working on this. Keep in mind that my son, Matt, is an aeronautical engineer and might be able to help you on the structural part and definitely the mechanical part of making this work.
 
pdecraene7a said:
Saw your Mom and Dad at Menards the other day and he mentioned you were working on this. Keep in mind that my son, Matt, is an aeronautical engineer and might be able to help you on the structural part and definitely the mechanical part of making this work.
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I almost forgot about Matt ... thanks im sure we will need his help.
 
Why not reverse the mount so that the pin half in on the lift and the eye half is mounted to the plane. I say that not having seen the rest of the assembly or knowing if that is even an option. It seems like having just two eyes protruding from the cowl would be less to deal with than the pins....
 
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