stunthanger.com

Building Tips and technical articles. => Building techniques => Topic started by: Perry Rose on January 11, 2018, 08:22:29 AM

Title: Engine crutch.
Post by: Perry Rose on January 11, 2018, 08:22:29 AM
Am I the only one using 3/8 x 1/2  aluminum channel for the bearers instead of maple?
Title: Re: Engine crutch.
Post by: Trevor Perry on January 11, 2018, 01:16:26 PM
Am I the only one using 3/8 x 1/2  aluminum channel for the bearers instead of maple?
I haven’t read about anyone else doing it but I’ve just bought some 10mm (3/8) square aluminium bar for exactly that purpose. I’m planning to machine a channel and a taper in the rear half of the bar (a lot like the ones they use in the combat models). The plan for Charles Mackey’s Starlight states maple or magnesium for the bearers but magnesium seems to be unobtanium.
What thickness is your channel?


Sent from my iPad using Tapatalk
Title: Re: Engine crutch.
Post by: Perry Rose on January 11, 2018, 02:44:23 PM
The wall thickness is .062 so that 1/4 inch ply and balsa fill it nicely. I get it at hardware stores or Home Depot kinda stores.
Title: Re: Engine crutch.
Post by: Trevor Perry on January 12, 2018, 12:49:40 AM
The wall thickness is .062 so that 1/4 inch ply and balsa fill it nicely. I get it at hardware stores or Home Depot kinda stores.
Ah, I think I see what you do now. So you are slipping the channel over the edge of the 1/4 sheet? I was thinking of basically using the al bar in virtually the same way you use a wooden bearer but mill it out as much as possible to reduce its weight.


Sent from my iPad using Tapatalk
Title: Re: Engine crutch.
Post by: Tim Wescott on January 12, 2018, 01:30:45 PM
Hardware store aluminum is usually pretty soft stuff.  You may be disappointed.

Trevor: I've seen pictures here of motor beams made of aluminum, tapered and riddled with lightening holes in the back (although, I've never heard of lightening inside of an airplane, so I don't know why you want special holes for it to travel through is beyond me  ;) ).
Title: Re: Engine crutch.
Post by: Trevor Perry on January 12, 2018, 03:33:24 PM
Hardware store aluminum is usually pretty soft stuff.  You may be disappointed.

Trevor: I've seen pictures here of motor beams made of aluminum, tapered and riddled with lightening holes in the back (although, I've never heard of lightening inside of an airplane, so I don't know why you want special holes for it to travel through is beyond me  ;) ).
âš¡ï¸âš¡ï¸âš¡ï¸


Sent from my iPhone using Tapatalk