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Roteseri

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I bought two Harbor Freight engine stands, about $35 each. Removed the third leg and ran a board between them to keep them from splaying out. Used the engine mount holes on the firewall. Built a plywood box around the wing spar. The wingtip and the fuselage tail are sandwiched with plywood.
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Note: The third picture is temporary, the board has not been added.
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How did you determine where the axis of rotation relative to the firewall and aft bulkhead should be?
 
How did you determine where the axis of rotation relative to the firewall and aft bulkhead should be?

I lined up the bottom of the engine stand plate with the bottom of the firewall. So the access of rotation would mimic rolling the fuselage on flat table. I then laid the aft end of the fuselage on an adjustable height sawhorse I bought from Lowe's. Whenever I rotated the fuselage the aft end would just roll a few inches on the sawhorse.

You can see the sawhorse at the aft end of the fuselage in the pic below

2017-03-24%2019.37.16.jpg
 
Really? Seems to me if you rigidly attach an engine stand with a single degree of freedom (roll) at both ends of the aircraft and the axis of rotation does not accurately align and go through both, then you run the risk of tweaking/bending the fuselage. If you only attach an engine stand at one end, presumably at the firewall, and simply let the aft end rotate on an adjustable height table or saw horse, then I would agree with you that there isn't much thought that needs to go into how to align the rotation axis.
Although now that I think about it some more, you can have a single degree of freedom on one end, but you will need 3 degrees of freedom on the aft end, hence the offset attachment from the OP's photos.
 
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Agreed

Really? Seems to me if you rigidly attach an engine stand with a single degree of freedom (roll) at both ends of the aircraft and the axis of rotation does not accurately align and go through both, then you run the risk of tweaking/bending the fuselage. If you only attach an engine stand at one end, presumably at the firewall, and simply let the aft end rotate on an adjustable height table or saw horse, then I would agree with you that there isn't much thought that needs to go into how to align the rotation axis.

That's why is left the back of the fuselage on a saw horse :)
 
It appears the rotisserie manufacturer that Larry suggested is not in business any longer. At least the web link seems to be dead.
 
If you only attach an engine stand at one end, presumably at the firewall, and simply let the aft end rotate on an adjustable height table or saw horse, then I would agree with you that there isn't much thought that needs to go into how to align the rotation axis.

Very true. :)

Different airplane but same use of the engine stand/sawhorse:

fuse-17.jpg


The Legal Eagle was a fun build.
 
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I lined up the bottom of the engine stand plate with the bottom of the firewall. So the access of rotation would mimic rolling the fuselage on flat table. I then laid the aft end of the fuselage on an adjustable height sawhorse I bought from Lowe's. Whenever I rotated the fuselage the aft end would just roll a few inches on the sawhorse.

You can see the sawhorse at the aft end of the fuselage in the pic below

2017-03-24%2019.37.16.jpg

How did you fabricate the angles attaching the firewall to the engine stand?
 
Really? Seems to me if you rigidly attach an engine stand with a single degree of freedom (roll) at both ends of the aircraft and the axis of rotation does not accurately align and go through both, then you run the risk of tweaking/bending the fuselage. If you only attach an engine stand at one end, presumably at the firewall, and simply let the aft end rotate on an adjustable height table or saw horse, then I would agree with you that there isn't much thought that needs to go into how to align the rotation axis.
Although now that I think about it some more, you can have a single degree of freedom on one end, but you will need 3 degrees of freedom on the aft end, hence the offset attachment from the OP's photos.

Regarding the rigidity, I found that there was more than enough 'slop' in the shaft of the rotating head that allowed the fuselage to move up and down as required during rotation. The slop in the engine stand equated for about 6 inches of up and down free movement at the rear of the fuselage, which was more than enough to allow the fuselage to rotate unhindered.
 
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