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General control line discussion => Open Forum => Topic started by: Chris Fretz on September 01, 2018, 01:31:26 PM

Title: Francherized Twister
Post by: Chris Fretz on September 01, 2018, 01:31:26 PM
After looking at the PDF under Construction Details it says Outboard Flap 1/8 wider at the tip than inboard flap. So to clarify this is it saying to make the outboard flap 1/8 wider the whole length of the flap or what?   Saying at the tip I find rather confusing.

While I'm at it under Modifications to original kit it says 3/32 plywood doublers. Then it says Replacement Doubler 1/16 plywood. I'm thinking I'll use 3/32 but is it suggesting using 3/32 or 1/16?

Finally it says to make wing jig blocks to the shape on the plans but I can't see a way for me to make them and all be identical.  So what does everyone use to build the wing? Just flat on a building table?

Thanks
Chris Fretz
Title: Re: Francherized Twister
Post by: rich gorrill on September 01, 2018, 01:51:48 PM
Hi Chris, when I modified a Twister ala "Fancherized" I built the wing flat on the table, had no problem, the leading edge needs a lot of sanding to round it off, I left the flaps stock, 1/16 stock doublers, increasing to 3/32 cant hurt. I did extend the fuselage 1 1/2 inches as per Danny B. and I did add 1/2 ribs in between reg. ribs. I use an LA 40 which is plenty of power.
worst problem I found is the landing gear. The wire gear in the kit goes into a bushing and uses little plastic clips. If I do it again I would use alum. gear like Brodak and RSM supply in their kits. Good luck.


Rich
Title: Re: Francherized Twister
Post by: Tim Wescott on September 01, 2018, 02:20:12 PM
Finally it says to make wing jig blocks to the shape on the plans but I can't see a way for me to make them and all be identical.  So what does everyone use to build the wing? Just flat on a building table?

Cut them a bit oversize, stack them, sand them.  Tacking them together with CA will help.  Sanding them square is a chore, but can be done.

I have some 1 1/4" square finish wood that came with my house, I just tucked that under the TE, like in this post (https://stunthanger.com/smf/building-techniques/fancherized-twister-build/msg275101/#msg275101).

(https://stunthanger.com/smf/building-techniques/fancherized-twister-build/?action=dlattach;attach=110687;image)
Title: Re: Francherized Twister
Post by: Steve Helmick on September 01, 2018, 03:41:11 PM
"After looking at the PDF under Construction Details it says Outboard Flap 1/8 wider at the tip than inboard flap. So to clarify this is it saying to make the outboard flap 1/8 wider the whole length of the flap or what?   Saying at the tip I find rather confusing."


It means to make the outboard flap 1/8" wider at the tip. Root chord would remain the same, so the taper is different. Adding area to the outboard flap is a common fix to older designs, to stop "hinging" with the correct tip weight. From my experience, it won't take a lot of tipweight, what with the outboard engine/tank weight.  D>K Steve
Title: Re: Francherized Twister
Post by: Chris Fretz on September 01, 2018, 05:23:24 PM
Hi Chris, when I modified a Twister ala "Fancherized" I built the wing flat on the table, had no problem, the leading edge needs a lot of sanding to round it off, I left the flaps stock, 1/16 stock doublers, increasing to 3/32 cant hurt. I did extend the fuselage 1 1/2 inches as per Danny B. and I did add 1/2 ribs in between reg. ribs. I use an LA 40 which is plenty of power.
worst problem I found is the landing gear. The wire gear in the kit goes into a bushing and uses little plastic clips. If I do it again I would use alum. gear like Brodak and RSM supply in their kits. Good luck.


Rich
Thanks for the info,  I remember your name but I can't place a face!
Title: Re: Francherized Twister
Post by: Chris Fretz on September 01, 2018, 05:25:40 PM
"After looking at the PDF under Construction Details it says Outboard Flap 1/8 wider at the tip than inboard flap. So to clarify this is it saying to make the outboard flap 1/8 wider the whole length of the flap or what?   Saying at the tip I find rather confusing."


It means to make the outboard flap 1/8" wider at the tip. Root chord would remain the same, so the taper is different. Adding area to the outboard flap is a common fix to older designs, to stop "hinging" with the correct tip weight. From my experience, it won't take a lot of tipweight, what with the outboard engine/tank weight.  D>K Steve

Well that makes a lot of sense! Guess I was thinking too much about the 1/8 and tip! Ill make my flap like that.
Title: Re: Francherized Twister
Post by: rich gorrill on September 02, 2018, 07:05:00 AM
Chris, I'm with the Philly Fliers, we met at Bernie's contest and than at our contest at Neshaminy & Benjamin Rush.
Title: Re: Francherized Twister
Post by: Chris Fretz on September 02, 2018, 07:42:25 PM
Chris, I'm with the Philly Fliers, we met at Bernie's contest and than at our contest at Neshaminy & Benjamin Rush.
I think it's coming back to me now!
Title: Re: Francherized Twister
Post by: Chris Fretz on September 02, 2018, 07:44:16 PM
Cut them a bit oversize, stack them, sand them.  Tacking them together with CA will help.  Sanding them square is a chore, but can be done.

I have some 1 1/4" square finish wood that came with my house, I just tucked that under the TE, like in this post (https://stunthanger.com/smf/building-techniques/fancherized-twister-build/msg275101/#msg275101).

(https://stunthanger.com/smf/building-techniques/fancherized-twister-build/?action=dlattach;attach=110687;image)
Thanks Tim. I can't really tell what you have going on under the spar, it don't look to be flat on the table.  How did you figure out the 1 1/4 under TE?

Chris
Title: Re: Francherized Twister
Post by: Tim Wescott on September 02, 2018, 09:26:09 PM
Thanks Tim. I can't really tell what you have going on under the spar, it don't look to be flat on the table.  How did you figure out the 1 1/4 under TE?

Chris

I can't remember what's under there -- probably scrap bits of 1/4".  I figured out what to put under the TE because that made the ribs roughly level fore and aft, along with whatever I shimmed the spar up with.

Just make it level -- all else will fall into place.
Title: Re: Francherized Twister
Post by: Chris Fretz on September 03, 2018, 08:42:40 PM
I can't remember what's under there -- probably scrap bits of 1/4".  I figured out what to put under the TE because that made the ribs roughly level fore and aft, along with whatever I shimmed the spar up with.

Just make it level -- all else will fall into place.
Would I benefit from building up the stab and elevators like you did or just stay with my 1/4 balsa pieces I already rough cut out?
Title: Re: Francherized Twister
Post by: Tim Wescott on September 04, 2018, 01:47:56 PM
Would I benefit from building up the stab and elevators like you did or just stay with my 1/4 balsa pieces I already rough cut out?

When I built that plane the kit wood was rock hard and had strange grain patterns, and I didn't have any decent wood to replace it with.  If I did it again I'd use reasonable-weight sheet.