bruce88123

Construction going good.

2 things:

1. When tacking with the CA, use as little as possible to leave max virgin wood for the Tite Bond to penetrate.

2. Try to put CA only where you won't be sanding as it sands tougher.

shd3920

WING REINFORCEMENT:

Plan Instructions: - - - Wrap and glue wing center joint with 4" nylon tape, top and bottom. Brush epoxy through nylon using brush.

My Explaination: - - - I have used epoxy before to reinforce the tape but it was very hard to get smooth when it was dry. Thin CA does not work too well either because it sticks to everything and causes a huge mess.

My Question: - - - What can I use in the place of those two glues mentioned that will hold nylon tape equally well, but will sand easier and smoother?

bruce88123

Did you do it this way?

use 30 min epoxy
apply tape
Use heat to thin epoxy after applied (will accelerate cure time also)
spread epoxy with plastic spatula. (old credit card, part of plastic milk jug)
Do not apply too much epoxy, remove excess
Wipe off excess from wood with alcohol before it dries too much.
Should not need too much sanding. You can place a strip of masking tape just outside where you want the epoxy to go and when done spreading (beofre dry) peel it off.

I have applied the tape with the Tite Bond before but it took several coats (applications) to fill the weave. Seems to be good and strong though. Did it on a KAOS 60 but have not flown it yet

CCRC1

My Feedback: (13)

Tigerdude426,
Could I ask you a favor, look at you plan sheet and let me know what the engine offset and thrust line is for the Skylark 56.

shd3920

No Bruce, I did it just straight from the mixing cup, going along as I pulled the tape into the epoxy. Then I just let it set, and sanded best I could. I can not use heat as I only have a covering iron and not a heat gun. Somebody mentioned in another thread (about fuel-proofing the engine compartment) about mixing epoxy with some kind of alcohol to thin it and then apply it to the engine compartment. Can the same thing be done with applying the nylon tape to the wing? If so, what kind of alcohol should I use (can 70% isopropyl alcohol be used, that is all I have at the time) to mix with the epoxy and at what mixing quantities? And if I can use that mix all I do it brush it on, let it dry, and sand it? If I have to, I may use the thin CA glue - but use it sparingly - and try to avoid the fumes to the eyes.

bruce88123

First, I'd rather see you buy a heat gun if you can afford it. It will be real handy come covering time anyway.

If not, just a few drops of the alcohol will be enough. Too much really seems to have a bad effect on epoxy as far as cure time and final quality.

Heat guns are not too expensive
http://www2.towerhobbies.com/cgi-bin...&I=LXJD39&P=ML
May be a bit higher at the LHS. And no, do not use a hair dryer. [:'(]

BTW - did I mention heat guns are nice?
Look at post #71 in this thread and view the indicated materials.
http://www.rcuniverse.com/forum/m_3260903/mpage_3/tm.ht

shd3920

CCRC1, from what I can get from the plans there is a 2% right thrust on a 10" prop.

Here is what it says on the plans word-for-word: . . . Place engine on rails. Viewing from above, measure from nosering to back of spinner, 1/8" on left side and 1/16" on right side. Tape spinner to side. Being careful not to disturb the engine position, slide rails so they are centered under engine lugs. For 2% Right thrust on a 10" prop, measure 5/16" difference from propeller tips to rear of fuselage when tips are horizontal. Mark rail locations on bearers, and engine screw locations on break away rails, then remove engine and rails.

I hope you can make something out of this, because it is going to be VERY DIFFICULT for me to follow this when it comes time for me to do this step. Will any modifications have to be done with me using the .36 engine? I hope not cause the instructions are very hard to follow as it is, and I hope I get the measurements correct.

TODAY'S WORK: All ribs on the right wing panel except rib 1 installed and glued with thin CA to hold and then reinforced throughout with Titebond II. Now just going to let it dry while I go back to work and maybe do a little more later.

Still seeking information on gluing the nylon tape to the wing center. The easiest method is appreciated. Thank you.


LATE-NIGHT EDIT: Ended the night sliding and gluing the left wing panel spars in place. Slid in kinda hard but managed quite well. But when I slid the main spar into the right wing panel a rib split and had to thin-CA it together again, nothing major - can't even see there was a crack there. Right wing panel spars not glued in place yet as instructed.

- - - - - Sorry to say but I do not see anything listed on the plans about a "downthrust" of any kind. [X(] which probably means I will not get the angle right with that not listed and the engine's setup will not be proper, I am very worried about this [sm=drowning.gif] and if anyone knows the answer to the thrust angle or downthrust or whatever else I need to know please inform me. Now that this has been brought to my attention I need to know about this myself, long before I get to that step.

bruce88123

Your .36 should make no diference. He also asked if there was any "downthrust" but not in those words. Can you see if there is any? It may just show as an angle drawn on the plans and not in text since it is built into the firewall when assembled.

shd3920

Bruce, earlier in this thread you mentioned about reduced dihedral. I am now at the insertion of the joiner braces section, and it does mention an option for a "flat" wing or the regular dihedral. With my building experience and lack of flying experience let me see if I get this right that you suggest I take the "flat" wing option. Am I correct in assuming this? What do you guys think, how does the Skylark 56 fly with a flat wing? I do not want it as a sport plane - I want it as a low-wing trainer.

CCRC1

My Feedback: (13)

Thanks for checking for me. Don't panic over the engine thrust, from what you are telling me it has 2 degrees right offset and zero degrees down thrust. The 2 degrees offset is done to compensate for the engine torque, so the airplane can fly straight when the engine is at higher rpm's. If you leave it out, you will notice the airplane pulls to the left in the air when you advance the throttle.
Thanks again

bruce88123

Leave the dihedral in. It will be easier for you to use as a trainer. I had been thinking you had more experience than you do. Even as you gain experience it will still perform well for you.

I repeat DO NOT build it flat, DO build it with dihedral.

Again, do not worry about the down thrust. I'm sure it was engineered into the construction during the assy via the tabs and things.

shd3920

Was too busy to do any work today [] but I took a trip to my local hobby store and picked up some small miscellaneous supplies such as two 2 1/2" wheels and a 2 1/4" wheel, antenna cowling w/hook and keeper, 5/32" landing gear straps and pkg of 5/32" wheel collars. I also picked up a bulk package of hinge points I plan on using for the control surfaces and something else that was included in the package of hinges. They are hinge points with attached horn that is somehow used in place of the traditional white control horns. It looks to me like you have to drill a hole like you do the hinges but would also have to cut a slit to accept the center horn part. Does anyone have any information on how these attach to the control surfaces without the gap between stabilizer/fin and elevator/rudder being too wide? I have the hinge point w/horn pictured below. Sorry if the photo is a bit blurry but the camera shots at close range is poor with this camera. I hope it is clear enough for someone to explain. Please include clear photo or graphics to show exactly how it is installed, that would be greatly appreciated. Thank you for any help anyone has to offer.

Bruce, thank you for your recommendation above, I will leave the dihedral in as instructed on plans.

bruce88123

This shaould help.
http://www.robart.com/how_to/hinge_points.aspx

shd3920

Thank you so much Bruce. You have been a great help. Thank you oh so much. Would you mind me asking, how long have you been building and flying RC airplanes? You are so helpful to me, I can really count on you. I hope to be as good as you some day.

bruce88123

I have been in and out of the hobby since the late 70's. There are a great number of knowledgeable people here on the forum, many with much more actual experience than I have due to the time I was "out". I am more than happy to help you and the others and just hope that I don't give erroneous info at times. I sincerely want to be corrected if/when I do. I make no claim to being "all knowing" by any means and have many weak areas where I try to keep quiet. It is nice to be thanked however.

CCRC1

My Feedback: (13)

tigerdude426
You helped me with that little piece of information on the engine thrust line and offset.
I am "assembling" the ARF Skylark 56 from Goldberg and noticed it had way more right thrust than I thought appropriate. ARF's don't come with plans so there was no way for me to check. Turns out mine had 5 Degrees of right thrust instead of 2 Degrees, because the firewall was improperly glued in at the factory.
I really wish I could find the kit like you have. I really prefer to build my airplanes, but the older kits are really hard to find. When you do find them, the seller wants ridiculous prices that I refuse to pay. I don't know if you realize, but the kit you are building right now, if it was in new/complete condition would easily sell for $150.00 or more. On E-Bay it would probably be closer to $200.00 .
Build it, fly it and enjoy it.

bruce88123

When I first started talking to tigerdude426 I did a little research and also found the kit was no longer in production. Quite a shame as it is such a nice plane and I don't feel that the ARF's ever are as nice even though they are OK. I have only had 1 ARF in my life as I really enjoy building. There is a real joy to seeing something you have spent so much time on fly well. Of course it hurts more when it dies but we all accept that as inevitable, just delay it as long as we can. There is a Skylark at my field and it flies great. Myself, I have built a couple of Falcon 56's and still have one that I fly. I have managed to find a few kits on EBAY but after I decide what they are worth to me I just bid that as a max and if I win or not, so be it. I NEVER go back and re-bid. Have gotten a couple of new $200 engines that way too for $50 each before too. Just need to be patient

shd3920

CCRC1 and Bruce . . . My hobby supplier in Adams, Massachusetts had this Skylark 56 sitting on his shelf and I fell in love with it's looks, so I grabbed it. $150.00 you say it can go for, I only paid $75.00. Somebody bought it at some point and evidently returned it to the supplier so maybe that's why the price was reduced. The ribs and all other parts were cut from the die-cut sheets so all the parts were loose in the box. The only part that was missing was the die-cut 1/8" bottom rear fuselage sheet, so I had to go out and buy a 1/8" sheet to replace that - I just don't have the actual outline of that piece on the plans so I will have to go by eye when I put it on.

As for the hinge points I picked up yesterday: Checked it out, bruce. Thank you so much BUT. . . I tried it out on a scrap piece of wood and the gap between the surfaces are just too great. Won't hurt to have the hinge points as spare hinges but I am not going to use them for the Skylark. Gonna use all the hardware packages that came with the kit. Thank you again.

Thus far for today only was able to temporarily install the joiners to test for fit. And when the fit satisfied me, glued the spars to the right wing panel. Hopefully later tonight after work I can permanently epoxy the two wing panels together and get the sheeting and maybe more done.

bruce88123

If the 1/8 in bottom is supposed to be all 1 piece you can probably cut the sheet to an approx length. Then apply glue as needed to the fuselage sides and set the bottom plank on there. once dry you can cut the plank down to near size and sand to final fit. Don't make it tougher than it needs to be. If you carve it down, be careful of the grain as it can cause the knife to split the wood. Start the blade at the front end and carve toward the rear. Use a sharp blade and be careful.

$75 was probably a fair retail value back when this kit came out. Add a bit for inflation and take that right back out because someone had been tampering and you have your price. Obsolete/rare kits on EBAY do go for a lot. One of the kits I was able to get on EBAY for @$55 typically is going for $120 these days. I have been watching and would buy another if the prices would be reasonable but they keep going higher than I will pay

shd3920

I think I may have found the die-cut 1/8" bottom rear fuselage sheet I mentioned as lost earlier. It looks like the right piece but it has the incorrect part number, is it possible for a kit's piece to have the wrong number marked on it. I do not see that number in use anywhere on the plans and it does look like the missing piece according to the plans. I will have to look into it further before I actually use the piece there and then find out I did need it somewhere else. But have any of you ever had a mis-marked part in a kit that had the wrong number or discription given?????

Didn't get much done today but I did get the wing panels joined, was difficult to line up but got the joiners in well enough I think (nothing is crooked anyways [sm=thumbup.gif])

PHOTOS 1 & 2 - Right wing panel joiners epoxied in and waiting for left panel to join it. PHOTOS 3 & 4 - Full-length view of the joined panels. Looks straight to me. PHOTOS 5, 6 & 7 - Closeup of center top of joiners. PHOTOS 8, 9, 10 & 11 - Closeup of center bottom of joiners.

bruce88123

That looks real good. Ya see, not as hard as you though all of this was going to be. Just don't get cocky.

As for mis-marked parts, yes that is possible but you also have to remember that someone had their hands in the box before you too. Just be careful with that part and make sure it fits well. Make a new one if you need to. Wait until you get to the appropriate step and make the final determination. It sounds like a fairly large piece and therefore there won't be too many places where it would fit. It would most likely be either the top or bottom rear fuselage piece

cwrr5

My Feedback: (32)

Looking good! [sm=thumbup.gif]

Center wing tape - My suggestion is to use Bruce's method, using credit card "squeegie" and heat gun(buy one- you need it)

Kudos to Bruce - I learn a lot from him too, lotsa little tips that I would have never thought about (and I've been doing this for 15+ years)

bruce88123

A lot of the tips I'm passing on were learned here in the forums. I'm just a storage depot.

shd3920

WELL, found a new problem today!!! The wing sheeting called for 5/64" thick balsa sheet. The kit was missing some of the sheeting (evidently the guy that bought it and returned it didn't see fit to put ALL of them back). I only have enough 5/64" sheeting to do one side (he was thoughtful enough to at least provide that much ). Only sheeting I had available on the shelves was 3/32" thick balsa sheeting. Because the underside of the wing should be the stronger side (my belief, correct me if I am wrong) because of the hold-down rubberbands (I have chosen the rubberband hold-on instead of the optional bolt-on configuration, as I can not drill the bolt holes accurately enough for them to actually work [X(]) I have used the thicker sheeting for that and saved the thinner sheeting for the top tomorrow.

QUESTION: Will the thicker sheeting on the bottom effect the Skylark in any way such as added weight or does it just mean more sanding on my part to do? Was I wrong to use the thicker stock I had on hand? Should I have just gone to the hobby store yet again to get the correct 5/64" thickness?

CCRC1

My Feedback: (13)

If it was me, I would buy enough sheeting to do all that you needed to do (top and bottom) with the same thickness. That way its uniform and you just have to sand a bit to blend it together at the leading and trailing edges. It will not effect the aircraft's flight characteristics and the weight difference will not be that significant.
If you would like to use the wing hold down bolts instead of the rubber bands, it really isn't that hard to do. I can give you some tricks to mark the holes to get it just right.