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General control line discussion => Open Forum => Topic started by: Dwayne on August 13, 2010, 10:19:18 AM

Title: Challenger Mock up
Post by: Dwayne on August 13, 2010, 10:19:18 AM
Things are coming along with my Sarpollus Challenger just need to glue the wing and v-stab in place do the finish sanding and paint.
Thanks
Dwayne
Title: Re: Challenger Mock up
Post by: john e. holliday on August 13, 2010, 12:36:46 PM
Looking good. H^^
Title: Re: Challenger Mock up
Post by: Randy Powell on August 13, 2010, 01:21:42 PM
Always like the Challenger.
Title: Re: Challenger Mock up
Post by: Dwayne on August 13, 2010, 06:22:46 PM
Thanks guys
Title: Re: Challenger Mock up
Post by: ray copeland on August 13, 2010, 07:10:13 PM
D wayne, i have no background of the Challenger but it looks great. IF you don't mind post some details like wingspan and engine size.  May be something i add to the just got ta build someday list!
Title: Re: Challenger Mock up
Post by: Dwayne on August 13, 2010, 08:13:36 PM
D wayne, i have no background of the Challenger but it looks great. IF you don't mind post some details like wingspan and engine size.  May be something i add to the just got ta build someday list!

Thank you Ray
The Challenger was designed by Dick Sarpolus a very prolific designer and builder the model was featured in 12/1987 issue of Flying models magazine and the plans can still be had by going to thier web site, plan #CF0766. It has a 52.5" wing span and is for 35 to 40 size motors, I'm using a Cardinal wing and a piped OS .32F, hope this helps and thanks again.
Dwayne
Title: Re: Challenger Mock up
Post by: wwwarbird on August 13, 2010, 10:28:01 PM
 So, um, wouldn't this really be more of a Cardinal than a Challenger then? Kind of a Cardinal connected with a Challenger fuse? What moments are you using?
 By memory, I'm just thinking that the Cardinal wing must be quite a bit different than the original Challenger wing in both area and airfoil. I've got Dick Sarpolus's old Control Line book and it's got some pictures of his Challenger in it. Looking at it I just always got the feeling that the wing design was very similar in design to the old Midwest 48" Warbird series designs, which had a pretty thin airfoil along with a sharp leading edge. They also had some fairly short moments for their size in my opinion.
 Don't get me wrong, I'm always up for a "kit-bash", I was just wondering...
Title: Re: Challenger Mock up
Post by: Dan McEntee on August 13, 2010, 11:53:53 PM
  The wing on the Sarpolus Challenger is a SIG Super Chipmunk wing. I just went down to the basement and pulled the magazine to check it out. I thought I remembered that way. The Chipmunk wing is a pretty good wing to base any .40 to .51 size model on. It's pretty easy to build straight, easy to build relatively light if you watch the wood, and is pretty strong. It will carry the weight of a 45 to 55 ounce model with ease. If you robbing the wing out of a SIG kit or ordering their wing kit, I think there is an extra tip rib and with a little work you can add an extra bay or two to increase the wing area to help wing loading. I would recommend this design to anybody, especially if you use current techniques for using built up profile fuselages to keep the tail end light. Think I'll go re-read the article now! y1
   Type at you later,
   Dan McEntee
   
Title: Re: Challenger Mock up
Post by: Dwayne on August 14, 2010, 07:33:21 AM
So, um, wouldn't this really be more of a Cardinal than a Challenger then? Kind of a Cardinal connected with a Challenger fuse? What moments are you using?
 By memory, I'm just thinking that the Cardinal wing must be quite a bit different than the original Challenger wing in both area and airfoil. I've got Dick Sarpolus's old Control Line book and it's got some pictures of his Challenger in it. Looking at it I just always got the feeling that the wing design was very similar in design to the old Midwest 48" Warbird series designs, which had a pretty thin airfoil along with a sharp leading edge. They also had some fairly short moments for their size in my opinion.
 Don't get me wrong, I'm always up for a "kit-bash", I was just wondering...
Thank you for the reply
I just pulled my plans out, the airfoils of both wings are very close, my Cardinal root cord is 9.75 inch while the wing on the plans is 10 inch, the wing on the plan has a wing area of 978 sq in. and the Cardinal is 979.3 so the differences are very minor and as Dan stated you can always use a Super Chipmonk wing. I used the  numbers on the plan, nose is 8.5 and the tail is 15.
Thanks again

Dwayne
Title: Re: Challenger Mock up
Post by: Dwayne on August 14, 2010, 07:40:35 AM
Dan I agree on keeping things light, the tail feathers are all built up and I used lighter balsa glassed for the fuse, so far with the wings covered with slc and all the controls installed it wieghs 27 oz. so I should have no problems bringing it in at around 40-42 oz.
Thanks for the reply
Dwayne
Title: Re: Challenger Mock up
Post by: Steve Scott on August 14, 2010, 10:20:22 AM
When I built mine in the early '90s, I used Sig's Super Chipmunk wing kit.  My wingtips weren't like yours.  Yours look like a Cardinal treatment.

I powered mine with a stock FP 40 and probably an 11-6 prop.  Painted it all grey with US Navy decals.  It flew great (better than the pilot).

Sold it to John Hall before I moved to the midwest.  I think John Thompson published a photo of it in Flying Lines mag but had me listed as the wrong pilot.
Title: Re: Challenger Mock up
Post by: Dwayne on August 14, 2010, 11:46:25 AM
When I built mine in the early '90s, I used Sig's Super Chipmunk wing kit.  My wingtips weren't like yours.  Yours look like a Cardinal treatment.


The wing tips on the Cardinal remind me of the USA 1 that`s why I`m using them
Thanks
Dwayne