brodak smoothie arf balance point?

[bob branch]

Could someone tell me the recommended cg location on the brodak smoothie arf/arc?

thanks,
bob branch

[john e. holliday]

I would start at approximately at 25% of the chord of the wing.  DOC Holliday

[Larry Fulwider]

I would start at approximately at 25% of the chord of the wing.  DOC Holliday

Classics and OTS (and their plans) are normally in the 17% to 18% of MAC range.

One place for ARF Smoothie specs is:

 http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=305669&mesg_id=305669&listing_type=search

edit: Added ARF

Larry Fulwider

[Mike Scholtes]

Since Bob expressly asks about the ARF Smoothie, the Brodak book says at 2.5" behind the LE it should be slightly nose heavy. Mine indeed balances that way at 2.5" with LA40, TT plastic prop, metal tank, plastic spinner. I built mine as a take-apart so it has an ounce or so extra in the tail for the parts and hardware. It flies very well with the CG in this location, nice level groove but very quick on the corners, without being squirrely. I fly it in OTS (I know, flaps) and Classic.

[bob branch]

Thank you gentlemen. Mine is electric and as I have changed battery packs now for the 4th time since I started flying it about 4 years ago I have lost track of the recommended cg point and wanted to refer back to it. I started with a 4000 mah pack that weighed about 13 ounces and am just changing to a 2200 mah pack that weighs about 7 oz. Experience with the plane and power system (axi 2826/12) has shown I only need 1800 mah of battery with a 12X6 apcE prop so I am doing the last battery pare down and since its a 3 once drop wanted to start my trim process from the beginning again. I usually keep all my manuals but I guess from that far back I just somehow lost track of this one. Nice to have a source as handy as this forum to always come up with what you need.

 H^^bob branch

[Phil Spillman]

The Smoothie wheels need to be moved about 1.25 inches forward; more if you fly off grass. This was accomplished on mine by adding a piece of 1/8 aluminium to the gear to move the wheels forward. Then mount the wheels with an appropriate axle to the added piece of aluminium. In addition mine had the tank lowered by routing the rails down about 1/8th inch.

Phil Spillman

[bob branch]

Phil

Thanks. I put 2 6-32 washers under the gear at the rear gear screws and that moved the axles far enough forward to stop the nose overs too.
Never have flown it with glo power, its been an electric for about 3 years now. It has continually improved as battery power has gone up and battery weights have come down. Now at about 47 ounces and with a pusher prop (turns opposite what you are used to) it flies very well.

bob branch