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General control line discussion => Open Forum => Topic started by: Peter in Fairfax, VA on July 21, 2020, 01:59:07 PM

Title: Pathfinder ARF Tip Weight
Post by: Peter in Fairfax, VA on July 21, 2020, 01:59:07 PM

Just acquired a Pathfinder ARF which will get an LA 46.  It has a weight box, which appears empty.  Yet, when I balance the fuse on the table, the outboard wing falls, weighing down the scale half an ounce.

Two questions:

1.  How much tip weight is good?

2.  What type of weight is best?

thanks,

Peter

Title: Re: Pathfinder ARF Tip Weight
Post by: Steve Helmick on July 21, 2020, 03:07:44 PM

I'd first measure the wing panel lengths to see how much offset there is, if any. The less offset, the more tip weight, but don't forget the engine likely has the engine weight outboard, which makes up some of the tipweight. Other that that, IMO it's best to start with too much TW, so you are less likely to need the broom and dustpan. Sometimes, lack of adequate tipweight can be noticed on the takeoff roll. Remember that the TW will yaw the model outward as the model accelerates. Lack of TW will make takeoff dodgey at best.   y1 Steve

Title: Re: Pathfinder ARF Tip Weight
Post by: John Paris on July 21, 2020, 07:45:07 PM

Instructions say an ounce and a half.  Looks to have about one inch longer inboard panel.  Would not hurt to start as recommended and pull it out as you fly it.  Box is set up for the 1/4 ounce lead plates that Brodak sells, but really any lead that will fit in the box will work.  You will need to put in some foam to hold it in place.

Good luck and let us know how it flies.  I am assembling one now and will most likely use an LA 46 on it as well.

John

Title: Re: Pathfinder ARF Tip Weight
Post by: Perry Rose on July 23, 2020, 05:16:00 AM

The Pathfinder and the Evo .60 is a great combination.

Title: Re: Pathfinder ARF Tip Weight
Post by: Peter in Fairfax, VA on July 23, 2020, 06:22:39 AM

Perry,

I can see that a big, heavy engine would be just fine.  At present, I have both the heavy stock OS LA 6 muffler installed and a Harry Higley heavy hub, yet the balance point is about 1/4" rear of the spar.  John sent me info that the balance point should be 2-3/8", which is the spar.  I'm 100% ready to try it as set up now.

I have an OS SF 46 Stunt that might work.

Prop clearance is just OK with my standard 11-1/2" prop, but not great.  A 13" prop would be too much.

thanks for the info and ideas,

Peter

Title: Re: Pathfinder ARF Tip Weight
Post by: Perry Rose on July 23, 2020, 08:41:56 AM

Peter:  I just checked and mine balances at the spar with Evo tongue muffler and no tail weight. I did build it tail heavy though. With a 2 inch nose wheel and a 12 x 6 prop I have 3/4 inch of ground clearance. The nose strut sticks below the fuselage 3 3/8 inches. I built it for a Stalker .51 but it was way too light.

Title: Re: Pathfinder ARF Tip Weight
Post by: Peter in Fairfax, VA on July 24, 2020, 12:03:50 PM

Flew just fine with the balance point 1/4" behind the spar and overall tip weight 1.5 oz.  Good pull, turned well, tracked well in level flight.

Peter