stunthanger.com

Speed,Combat,Scale,Racing => Speed Talk => Topic started by: GregArdill on July 15, 2021, 11:22:32 PM

Title: Dolly
Post by: GregArdill on July 15, 2021, 11:22:32 PM
I'm about to begin making a dolly for a vintage New Devil (by Ugo Rossi). I have the general layout for a Pink Lady dolly from Speed Times, but need advice on general construction tips.

All help will be greatly received.
Title: Re: Dolly
Post by: Dennis Toth on July 16, 2021, 07:53:25 AM
Greg,
Years back when I was an active speed flier I used both the mousetrap type and pin type dollies. Both worked for me. The pin type is easier to build but you need a smooth surface to prevent bouncing out. I liked having the vertical pins close to the fuse. The ship should sit flat/level in the dolly no nose up. You need to build either type so you can put the ship in the dolly and hold the ship and dolly around the fuse to start the engine. You need to have access to the needle valve and be able to set it and safely set the whole assemble on the ground for release. Use rounded profile wheels not thin pointy one to allow it to roll over little bumps/ruts without getting railroad tracked. Remember to slowly walk back as the ship starts moving to keep the lines tight and off the ground. Don't hold up elevator coming off the dolly, hold neutral or very slight down (like a stunt ship smooth take-off roll).

Most speed designs are high wing and will have a nose up pitching moment plus the nose up torque reaction so be ready to ease in the down to keep it from getting to high in the hemisphere (we use to hand launch them and you had to hold significant down elevator at launch to get the nose to come over flat, once it got flat back to neutral, see attached pic of John Kukon father hand launching his speed ship in 1962). Basic trick is once the ship gets to the low point of its path pump the down to kick the nose flat, always control at the bottom, up elevator doesn't do much except stall the wing.

Best,   DennisT
Title: Re: Dolly
Post by: Dennis Toth on July 16, 2021, 08:35:53 AM
Greg,
Got the attached plan from Barton site in the speed section shows good pin dolly design (personally I don't care for the tail hook arrangement as the ship needs to go nose up to clear the dolly and tail hooks rather then just come up flat). If you go to this link it has other photos of a few different layouts.

http://controlline.org.uk/phpBB2/viewtopic.php?t=12711&highlight=dolly

Best,   DennisT
Title: Re: Dolly
Post by: GregArdill on July 16, 2021, 06:26:59 PM
Greg,
Got the attached plan from Barton site in the speed section shows good pin dolly design (personally I don't care for the tail hook arrangement as the ship needs to go nose up to clear the dolly and tail hooks rather then just come up flat). If you go to this link it has other photos of a few different layouts.

http://controlline.org.uk/phpBB2/viewtopic.php?t=12711&highlight=dolly

Best,   DennisT
Thanks Dennis,
Thatís the schematic that I have, Iím after construction tips and details of any jigs used in construction.
Title: Re: Dolly
Post by: Dennis Toth on August 03, 2021, 07:00:16 AM
Greg,
You can lay it out on a scrap piece of cheap 1/4" plywood. Use some small 3/8 by 2" ish blocks with saw cuts across them to hold the main axial and frame wire, do the soft copper wraps at the joints and solder, then add the upper frame and pins.

Best,    DennisT
Title: Re: Dolly
Post by: GregArdill on August 11, 2021, 09:01:56 PM
Greg,
You can lay it out on a scrap piece of cheap 1/4" plywood. Use some small 3/8 by 2" ish blocks with saw cuts across them to hold the main axial and frame wire, do the soft copper wraps at the joints and solder, then add the upper frame and pins.

Best,    DennisT
Thanks Dennis