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General control line discussion => Open Forum => Topic started by: Dan Labine on June 11, 2008, 04:38:58 PM

Title: BHM Sig Fokker D7
Post by: Dan Labine on June 11, 2008, 04:38:58 PM
I just received my BHM Sig Fokker D7 from Sams Stuff and Hobbies (great service) today.

         I am really impressed by the quality of the kit. The wood in the kit is excellent and the laser cutting is great. I have compared the plans to the original Sig plans and there is no difference in outline but BHM has incorporated some improvements in the leading edge design. Tongue and groove instead of one solid piece.. This plane should go together quickly. My original one had an Enya 35 for power and I think I will put my new Enya 35 in for power. The plans call for a 2 oz tank but I will upsize to a 3 or 4 ounce tank. If the weather doesn't improve (4 days of rain in the forecast) I may have it done by Monday.. #^ y1
Title: Re: BHM Sig Fokker D7
Post by: wwwarbird on June 11, 2008, 05:19:05 PM
Sweet! Any chance of some pics? Build photos? ;D

(BTW-I have also found Joe's service at "Sam's Stuff " to be second to none.) y1
Title: Re: BHM Sig Fokker D7
Post by: Leester on June 11, 2008, 06:47:28 PM
I never had a sig kit of this so can you show the bell crank and lead out instalation when you do it ???  Thanks
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 12, 2008, 04:59:40 AM
I'll take some photo's this weekend. On the original Sig kit the bellcrank was mounted on an aluminum bracket with the leadouts going out to the struts through a piece of spruce glued to the struts. The BHM uses a wooden bracket in lieu of the aluminum piece.

Dan.
Title: Re: BHM Sig Fokker D7
Post by: LARRY RICE on June 13, 2008, 01:07:58 PM
Dan,
         I hope that you do not mind me adding my two cents here. We had planed to use the metal bracket, bought a special cutter and even the supplies to do it, then we realized that the original kit used a 2" bellcrank. We wanted a 3" bellcrank for better performance. Using a larger metal bracket became to much, to big, to ugly and to much work to manufacture. The wood set up seemed to be more in keeping with the plane.
Larry
Black Hawk Models
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 14, 2008, 05:22:29 AM
Well the rain has not stopped so I will be able to start on the Fokker today. I guess the fish in the lake will just get a little bit bigger. Here is a picture of the kit contents. Hope to have the fuselage done today.
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 14, 2008, 07:34:54 AM
Started the fuselage and it went together well. All parts fit like a glove. The kit even has 1/16th sheet cut to act as spacers for the spruce center struts. The plywood doublers and motor mounts were glued in with epoxy as well as teh struts and balsa spacers. I had to put a 1/16th spacer behind the top motor mount as it was 1/16th to short. The tail pieces ahve been glued together and the elevator joiner has been attached to the elevator pieces. The bellcrank mount, while on the large side, will definetly hold a 3 inch bellcrank securely. I apologise for the large file size on my first picture. These should load faster..

Dan
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 14, 2008, 09:58:37 AM
First glitch!

          The stabilizer slot in the fuselage is 4 7/8 long and the stabilizer is 5 3/4 inches. The Sig plans show the same problem. Rather than lenghtening the slot I cut a piece out of the stab. Going together well so far.. Fuselage should be completed today..

Dan
Title: Re: BHM Sig Fokker D7
Post by: Larry Renger on June 14, 2008, 04:10:50 PM
As has been published, I flew Antone Kephart's model at VSC.  That is the plane on the box art.  My advice to you is to keep it as light as possible and add power!  He used a McCoy 29 (not a .35 as reported) and although adequate, being able to swing a bigger diameter prop to generate more thrust (not speed, use a lower pitch) would go a long way toward better flying in the pattern.

The problem is stalling.  You need thrust (see BiSlob threads) to pull a draggy, inadequate lift plane through those square bottoms.  Think about using the plane to aim the propeller and you won't go wrong.  Look at all the (ugh!) R/C 3-D flyers for a clue.

I scored a 404 in clearly national level competition with Antone's model, and lightened, with more low speed thrust, it could have done better.  Note that the highest I have ever scored in "good" judging is 485.  So the model has some real potential.
Title: Re: BHM Sig Fokker D7
Post by: LARRY RICE on June 14, 2008, 06:29:21 PM
Larry,
         When I started this project I was aware of a few problems with the original kit. It was heavy and tail heavy so I made some changes in the kit to correct these defects. I also found that the original hardware, shown on the plans, would not work well. These were also changed, even though I have to original hardware in stock. I may still change the control horn to a nylon one. With this kit being a little lighter and modern engines more powerful I am hoping that I have correcter all of the major problems. I am looking forward to finding out what modelers think of it.
Larry
Black Hawk Models
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 15, 2008, 04:38:06 AM
Larry..
            I agree that this plane needs to have lots of power. Dragging two wings around is a lot of work. My original Sig Fokker (1975) had an Enya 35 on it. I did not think that it was underpowered and it would do anything that I could do, which isn't much I'm afraid. I am putting in a new Enya 35 Model 5224. If it is anything like my other Enya it should be enough.. I am building the kit as per the plans and once the fuse was built I thought I might put my OS FS30 4 stroke in. It would not fit! The spacing of the motor mounts is such that only two mounting holes would be on the mounts. I did not try the FS 40 though. This kit is a joy to build. The fuselage is almost completed and I am getting ready to start the wings.. My least favorite part.. 
Title: Re: BHM Sig Fokker D7
Post by: john e. holliday on June 15, 2008, 03:22:06 PM
Dan,  if you can I would suggest using aluminum pads under the engines.  The pads are drilled and tapped for the bigger engine, then the second set of pads is made for the 4S.  The pads are mounted using mounting holes that match which are on an area outside of the mounting lugs of the engines.  I have been doing this on several planes so I can use engines of different widths.  By the way the pads stay with the engine.  Keep us posted.  DOC Holliday
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 29, 2008, 05:39:42 AM
The weather is lousy again!! It seems to rain every weekend. Oh well it let me start on the lower wing for the Fokker. The TIG(Tongue in Groove) method used goes together easily once the leading edge is glued up. One problem I had was, with the humidity, the plans stretched. Only 1/8 of an inch but enough to distort all the ribs. Good thing I noticed before gluing up. The trailing edge is 1/4 inch thick and will require a lot of sanding to get it to shape. Still have to fit the center section balsa. I've got the upper wing spar glued up and am just waiting for it to dry to start the upper wing.. Lots of fun but this weather better change soon..

Dan..
Title: Re: BHM Sig Fokker D7
Post by: Richard Grogan on June 29, 2008, 11:59:14 AM
One problem I had was, with the humidity, the plans stretched. Only 1/8 of an inch but enough to distort all the ribs. Good thing I noticed before gluing up.

Dan..

Probably should had ironed those folded plans first..Looking good!
Title: Re: BHM Sig Fokker D7
Post by: LARRY RICE on June 29, 2008, 09:22:52 PM
When we designed this "TIG" type wing we found it to be stronger and more warp free wing than any other type of wing that is on the market today. You are doing a nice job.
Larry

PS
Here is the SPAD-7.
Title: Re: BHM Sig Fokker D7
Post by: Dan Labine on June 30, 2008, 06:50:32 AM
You're right about the wing being straight and strong. The TIG method works for me. The Spad looks great! I have two on order.. When will we see them on the shelf?

Dan
Title: Re: BHM Sig Fokker D7
Post by: LARRY RICE on June 30, 2008, 06:58:22 AM
         The first order of SPAD kits are boxed and ready for shipment to the dealers and will go out either today or tomorrow. We are working double shifts to fill orders and try to stock up extra kits.  H^^