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-   -   The Scratch Plane featured in Fly Rc (https://www.rcuniverse.com/forum/scratch-building-aircraft-design-3d-cad-174/7250867-scratch-plane-featured-fly-rc.html)

lrglnman 03-19-2008 05:00 PM

The Scratch Plane featured in Fly Rc
May 2008 issue #54 . Is anyone planning on building this little plane? Several in my club are planning to start at least 6 next monday. If you have built this plane please post your results and any mods you may have made. This is going to be most of us first build like this and need some advice.

BMatthews 03-19-2008 11:36 PM

RE: The Scratch Plane featured in Fly Rc
You might want to post which design it is and the month of the magazine. Fly RC has full size plans on a regular basis and no one will know which you are reffering to in a few weeks. I seldom see the magazine so I don't know either.

lrglnman 03-20-2008 06:17 AM

RE: The Scratch Plane featured in Fly Rc
Good idea Bruce I edited my first post to add the Issue info . A club member who has been doing this for along time and who is going to be guiding us in the ways of the plane building force, came up with a bill of materials. Looks like it going to come togeather

rsteffen42 03-21-2008 12:08 AM

RE: The Scratch Plane featured in Fly Rc
I'm planning on building my own "Scratch". I just got the plans enlarged today, and I'm going to get the wood this weekend.

This will be my first scratch build. I've studied the plans, and I don't see anything particularly difficult. This seems like a good plane to start with. I'm thinking it would be nice to have a build thread here for collaboration.

BMatthews 03-21-2008 12:20 AM

RE: The Scratch Plane featured in Fly Rc
Oh great... now I need to go check out the newstand. The FlyRC website is still showing the current issue as April.

All I can say is that this better be good.... :D

lrglnman 03-21-2008 09:36 AM

RE: The Scratch Plane featured in Fly Rc
RSteffen, Thats a great idea I will post our clubs progress with pics. We are not slated to start till Monday, March 31. We are already planning a few mods to the plane. Such as no daheadrial and 1 servo in each wing half. The latter is a great way to learn how to set up flapperons for different types of flying. Please post your progress as well.

lrglnman 03-21-2008 09:39 AM

RE: The Scratch Plane featured in Fly Rc
Bruce I just got mine the other day. Its a simple plane that will teach basic tecniques.

jg95762 03-25-2008 12:12 AM

RE: The Scratch Plane featured in Fly Rc
I too am planing on build the Scratch as my first airplane. 25 years ago I got close to finishing a balsa/ply sailplane but moved away to college and never came back to it. 3 months ago I purchased a simulator, which I flew 2 hours a day for two weeks before flying the Parkzone T28 that I also bought, which I can now fly fairly competently.
Anyway, I would really appreciate any tips, and photos that you folks can share as you go through the build process. I will start in a couple of weeks once I have cleared out my garage and finished installing a whole house fan in the attic!

lrglnman 03-25-2008 06:18 AM

RE: The Scratch Plane featured in Fly Rc
Jg, As soon as I can I will post pics. Next Monday is when we plan to start the wing. I have a bill of materials list that we made up. It should get you very close to a completed plane. We decided to built this plane in order to teach some of us new comers techniques that we can find helpful in modeling. There is more to it than just buying ARF's which is fine if you have alot of money. I plan on building 2 . 1 gas , 1 electric.

Sheet balsa
(6) 1/16x3x36" balsa
(1) 1/4x3x36" balsa
(2) 1/8x3x36" balsa
Stick balsa
(1) 1/4x 1/2x36" balsa
(2) 1/8x3/8x36" balsa
(2) 1/8x1/4x36" hard balsa
(1) 1/4x3/16x36" balsa
(1) 3/8x36 balsa triangle stock
(2) 1/4x1 1/4" aileron stock
Spruce stock
(1) 1/4x1/4x36" spruce stock
(3) 1/8x1/8x36" spruce stock
(1) 3/16x36 dowel
1/8x4x6" liteply
(1) Sheet 1/64 ply
(3) sheets 3/32 ply
(1) 8-32 nylon bolt
(4) Dubro 1/2a control horns
1 pack EZ hinges
Tools and glue
(1) 1/4" foam core poster board (can be found and Hobby Lobby or Office Max)
Xacto knife and # 11 blades
Good quality 3' metal yardstick
(1) bottle thin ca super glue
30 min epoxy.

jg95762 03-25-2008 11:23 PM

RE: The Scratch Plane featured in Fly Rc
lrglnman, I really appreciate the bill of materials. I had a stressful day and decided to stop by the LHS tonight and got a real kick out of looking at the balsa sheets, finding the airleron control kit, looking at the monokote.

Is the poster board for creating templates??

I was also looking at the Spektrum 6i radio. Currently the only radio I have is the one that came with my Parkzone T28, so I need something new. Any input on whether this would a be good choice for a good radio system for me, for the next couple of years.

lrglnman 03-26-2008 06:00 AM

RE: The Scratch Plane featured in Fly Rc
Jg, no the foamcore poster board is for laying on the table . then you lay the plans over that so you can pin the wood down on the plans. you can use an old celing tile as well. just something flat that you can push t pins in . As for radios go, I would look at nothing less than a 7 channel. If you ase sure that you are going to be in this for a good while get at least a 7 channel. that way when you are ready you have the option for a lot more mixes that you can do.

jg95762 03-26-2008 11:46 AM

RE: The Scratch Plane featured in Fly Rc
thanks for the feedback on the radio. It is hard to imagine using 7 channels but I definitely expect to stay with this hobby so I will go with what you say. Is 2.4ghz the way to go?

How did you go about getting the plans enlarged? I am thinking of just taking it to Kinkos and getting at least 2 copies, one to cut up to make templates. Does this make sense?

BMatthews 03-26-2008 01:09 PM

RE: The Scratch Plane featured in Fly Rc
I'm from a simpler school of thought in many ways. 7 channels is nice if you ever expect to fly camber altering sailplanes or similar designs where you need a separate channel for every surface rather than one per control. But if you don't expect to need that any time soon then a 4 or 5 channels is fine. But the all singing/all dancing 7 channel rigs DO come with lots of nice model memory and mixing options so that can often be worth the extra cost.

I recently got my first 2.4 set and I won't be going back. The freedom from worry about being shot down or accidentally shooting someone else down is well worth the price. It IS the way of the future. I'll continue to use my old sets for the time being but as they fail or get sold off all my new ones will be 2.4.

Kinkos or similar would be fine. If you're lucky enough to have a copier at work that handles 11x17 that's another option. Or even just with legal size. Keep in mind that you don't need to blow up the entire plan. An edge joined tiled strip with the wings and another for the fuselage will keep the seams and alignment issues to a minimum. From there just spot copy/enlarge for the specific parts and tail surfaces. There's no need at all to tile enlarge the whole plan.

lrglnman 03-26-2008 06:42 PM

RE: The Scratch Plane featured in Fly Rc
JG, Bruce has a good point on the radios. However if you want to do mixing, which I find extreamly useful, then 7 channels or mor is better. Alot of your planes in the ARF lines are comming out with 2 servos on the wings. I find this fantastic because I can turn the ailerons into flaps and mix a bit of elevator so my landings are super smooth I can program this to any switch on the radio I want to. each servo has its on channel.I have no experience with 2.4 but as Bruce stasted it is the future of radios. I will wear out my Futaba 7 cap first then get the 2.4 . As for the plans , here in my town their is some folks that have a CAD business which does drawings for buildings or an computer aided drawing. They inlarged my plans 250% which is to scale for $ 4.50 a copy. super cheep I think. I think Kinkos or ofice max will do it as well. Or look in your local phone book for CAD services they will be able to do it for sure.

WPee 03-30-2008 03:39 PM

RE: The Scratch Plane featured in Fly Rc
I agree with the 2.4 and extra channels and features.

But the 2.4 receivers are too large for small scale foam. [&o]

I would like to hear that my 2.4 transmitter could support small CD-ROM motor driven foamies.

My new 2.4 has room for storing multiable setups <hum?>

And the 2.4 receivers are not cheapies either.

rsteffen42 04-01-2008 10:34 PM

RE: The Scratch Plane featured in Fly Rc
1 Attachment(s)
Since the thread kind of wandered a bit, I thought I post some pics of the progress I've made on mine. One wing basically constructed, the second one about halfway done.

jg95762 04-02-2008 12:53 AM

RE: The Scratch Plane featured in Fly Rc
It looks like you are making good progress. I have basic questions because I haven't built anything from balsa in 30 years.

I have cut out and sanded the 1/16 ribs and they look ok. It was harder work cutting these out than I expected. I think I need to get a larger xacto knife - maybe I am just getting weak in my old age! So I am now wondering how best to cut the 1/4 ribs??

Also, looking at the fuselage the ply doubler has nice circular cut outs - how do you go about cutting those.

Are you pinning the wing directly to the plans or do you have plastic or something in between? Dare I ask what the syringe is for?

What glue are you using and do you use CA activator?

rsteffen42 04-02-2008 02:39 AM

RE: The Scratch Plane featured in Fly Rc
Well, I'm learning as I go along. Cutting the 1/4" ribs wasn't as hard as I thought it was going to be. The trick is that the grain of the wood is going from leading edge to trailing edge on the rib, so your longest cuts are going with the grain, so a knife blade only has to split the grain. I just used a fresh #11 XActo blade, and made the cut larger than my template (I made a rib template out of 1/8" lite-ply and used it to cut out all of the ribs). Then I just sanded the ribs down to match the template.

Looking at the fuselage plan, I see circular holes in the bottom sheet, which is 1/16" balsa. Shouldn't be hard to cut those with a sharp knife. And, in the sides I see rectangular holes with rounded corners in the ply doubler. However, the plan says that doubler is 1/64" ply, which is very thin and seems like it should be an easy cut with a good knife and a straightedge.

My building surface is a Great Planes 36" building board. The plans are pinned to the board, and a layer of Great Planes plan protector is pinned on top of the plans. In retrospect, the plan protector is nice but wax paper or plastic wrap would do the job pretty well, too.

For glue, I'm using Titebond (Aliphatic Resin), which is what is in the syringe. The syringe is a "drywall syringe" from the hardware store. I have no idea what you'd use it for with drywall, but it seems tailor made for this job.

I have used a bit of medium CA on the first wing. Got a little over enthusiastic while sanding the trailing edge spar and cracked two ribs - fixed with medium CA.

jg95762 04-02-2008 10:22 AM

RE: The Scratch Plane featured in Fly Rc
Thanks for the feedback. I will pick up some more xacto blades on the way home tonight and see if I can get the 1/4 inch ribs cut out. I too made a rib template out of ply and epoxied two small brass tubes following what the author showed in his picture - this allowed me to essentially punch holes in the ribs - this actually worked well because it held the balsa in place while I cut around the ribs.

Is there a reason you are using Titebond rather than CA? Which type of Titebond are you using - I was looking at it in the store and there are several kinds.

lrglnman 04-02-2008 09:25 PM

RE: The Scratch Plane featured in Fly Rc
I got 1 wing built monday nite. Dont forget to allow for your servo wires if you use 2 servos in the wings. I did not put any diheadril in mine and built one wing. We will have another build next monday and I hope to get some pics then. I used thin ca only in my wing build. get you some of those ca applicators to put on the tip of the ca bottle .that way you place the ca just right. there is nothing wrong with tightbond. its the best a/r glue on the market. use wax paper to protect the plans. if you sand a rib a tad bit too much and you need t stretch it you can sprinkel some bakeing soda in the crack and hit it with thin ca. crack gone and a pretty good fix. pain to sand though. I will build my next wing with diheadrial in it.

rsteffen42 04-03-2008 01:41 AM

RE: The Scratch Plane featured in Fly Rc
I'm using Titebond over CA for 2 reasons - longer working time (plenty of time to get things aligned), and sandability. There a trade off in build time though, it's a bit slower to build this way.

As for which formula, I'm using the original Titebond, mostly because that's what I had on hand. I spend a fair amount of time reading build threads in the Kit building forum and here and most people seemed to recommend Titebond or Titebond II, and honestly I don't really see a huge difference between the two. Titebond III's major feature is water resistance, which I didn't think very important for this.

jg95762 04-03-2008 09:54 AM

RE: The Scratch Plane featured in Fly Rc
Thanks for the feedback on glues. I was concerned I would get the hole thing built and then find out I had used the wrong glue! However, with my current flying skills it wont be long before I am building a second version! I think I am going to use a combination of Titebond where I need the additional time to move stuff around and CA with activator where it is easier to lock stuff in place immediately.

As an experiment last night I used some Elmers carpenter glue on a couple of scraps of balsa - it dried in under an hour and seems very strong. All the modern glues seem to be so much better than the crap that was around when I was a kid. I did some renovation work on a sailboat a few years ago and was amazed at the strength of epoxy.

Last night I finished up the wing ribs - using a larger xacto knife with a more comfortable handle made a huge difference - the 1/4 ribs came out easily.

I took a few photos last night which I will post soon

lrglnman 04-03-2008 04:57 PM

RE: The Scratch Plane featured in Fly Rc
jg if you use thin ca you won't need to use activator as it sets almost instantly. I and all my club buddies used thin ca entirely on the wing. fantastic results.

jg95762 04-05-2008 01:19 AM

RE: The Scratch Plane featured in Fly Rc
1 Attachment(s)
Here are some pics of the first wing. I am now half way through building the second wing which is going much faster. The thin CA seems to work well - it certainly glues my fingers to the balsa very effectively!

lrglnman 04-05-2008 06:10 AM

RE: The Scratch Plane featured in Fly Rc
fantastic looks as good as mine!!:D

jg95762 04-09-2008 12:28 AM

RE: The Scratch Plane featured in Fly Rc
1 Attachment(s)
The second wing went together much more quickly, partly because I discover the razor plane for shaping the 1/4 leading edge!

Here are some pictures of my partially complete fuselage. It took longer than I expected to glue the 1/64 ply and 3/32 wing supports and then sand the wing support to shape. I could certainly do it faster next time.

To make sure the wings sit correctly in the fuselage I ended up drawing some lines on the plan to see that a line through the two holes in the ribs should be parallel with the top line of the fuselage extended. I then drew a line on the ribs and a line of the fuse and carefully sanded until I could get the wing to fit in with these lines parallel. I am not sure how critical this is, but it obviously effects the angle of attack.

I then extended the lines on the plans that show where the formers go so that I could put the fuselage halfs on the plan an mark where the formers go.

It was a little tricky gluing it all together. I cracked on of the formers because the CA set so quickly and I didn't have the former square. But some additional CA fixed that! I managed to round off the top of the fuselage where the horizontal tail feather goes but fixed it but glue on some 1/16 balsa and sanding it down.

Tonight I put most of the skin on the fuse and am happy to see that it is square and seems strong.

Anyway, so far no major screw ups. At least not that I am aware of.

I was trying to figure out how to glue the 1/4 wing tips to the wings but wasn't sure how best to do it. Has anyone done this yet?

When it comes to putting on the monocote or whatever the covering is I am clueless - are there any good forums that someone can point me at?

lrglnman 04-09-2008 04:20 AM

RE: The Scratch Plane featured in Fly Rc
Jg I got my wing tips glued on monday. all you have to do is center the leading edge and trailing edge with your tips and glue with thin ca. after it is glued in place , come in at the main spar and glue in some wing tip angle bracing on top and bottom. thats it! my wing looks real nice . the razor plane make easy work of the leading edge. also a balsa strip cutter is real nice as well.

jg95762 04-09-2008 02:55 PM

RE: The Scratch Plane featured in Fly Rc
When you say wing tip angle bracing is this a piece of triangular shaped balsa or something special? If balsa, what dimension (1/4, 1/8, 1/16) did you use? Any photos??

I have a balsa strip cutter - it is great tool. I also had the razor plane when I built the first wing but was too dumb to think to use it!

lrglnman 04-09-2008 07:57 PM

RE: The Scratch Plane featured in Fly Rc
1 Attachment(s)
I hope this drawing will help. I will post pics as soon as I can.

lrglnman 04-09-2008 07:59 PM

RE: The Scratch Plane featured in Fly Rc
well It did not turn out like it was suppose to. Sorry. As soon as our club photographer sends me the photos I will post them here.

jg95762 04-09-2008 11:32 PM

RE: The Scratch Plane featured in Fly Rc
Thanks - Your drawing is plenty good enough for me to see what you did. I will add the same type of 1/4 inch wing braces in line with the spars, top and bottom. They make a lot of sense and I am surprised they were not called for on the original plan.

I epoxied my two wing halfs together tonight - took quite a while to get set up to glue them, but I am hopeful they will come out straight! If they don't I wont be happy.

I found a good series of videos on how to apply ultracote - http://www.rcuniverse.com/magazine/a...article_id=726
Now I need to go buy and iron and heat gun. Any recommendations on what to get? Also is there particular covering material that I should use or not use?

lrglnman 04-10-2008 06:03 AM

RE: The Scratch Plane featured in Fly Rc
This is the set up I use not too expensive. I like this one better http://www3.towerhobbies.com/cgi-bin...?&I=LXB361&P=0
Ultracoat is the easiest to use any of that will do fine. one thing though make sure you drill a small hole in each rib so hot air can escape as you install the covering. 1/8" hole will work fine. The trick to ultracoat is getting the iron hot enough to lay down the covering but minimize the shrinkage . Then come back with the iron hotter and shrink the covering. Any trouble spots hit with the heat gun. thats my method of doing it. work slow , take your time.

cdnarcher 04-10-2008 08:58 AM

RE: The Scratch Plane featured in Fly Rc
I just picked up the rag yesterday and got the plans resized. I will start on it next week. Should be fun.

jg95762 04-14-2008 02:50 PM

RE: The Scratch Plane featured in Fly Rc
huh - it looks like there were some server issues over the weekend and some entries were lost. I will repost the pictures that I added Friday night.

One of the questions I had was about the Trailing Edge, which is a fair bit deeper than the 1/4 deep aileron stock that I purchased per the plan. I am not sure if this is because I messed up or what. Anyway, I can glue some sheeting on to the bottom of the airleron to make it the same depth/thickness as the trailing edge, but I am not sure if this will change the flight characteristics???

jg95762 04-20-2008 12:09 PM

RE: The Scratch Plane featured in Fly Rc
1 Attachment(s)
Here are some pictures from a week or so ago that show how I glued to two wing halfs together. I used two 1/4 inch pieces of wood under the outer ribs, then used a big clamp that I built from a home depot yard stick. I put packing tape on the underneath of the wing halves before putting the epoxy on. I then put packing tape over the top of the wing and put a one-by-four on top of the whole thing to keep pressure on it while it dried. The result was good. I also put the nylon bolt through the wing into two pieces of 1/4 ply. I used a metal bolt of the same size with a notch in it to cut the thread and then ran thin-CA down the thread of the metal bolt and screwed it in and out to make the thread hard. Once I got the wing on with the dowel and the bolt there was small (1/16) gap under the wing. I guess this is due to the dihedral. Anyway, the last picture shows how I glued some 1/16 sheeting on to 'fill' this gap.

larrypaul 04-25-2008 09:33 AM

RE: The Scratch Plane featured in Fly Rc
Finished my scratch, right after I got the magazine, built it with lighter materials, such as changing sizes in fuse sides and and fillers,also added landing gear, and this model does fly great, :Dfully airobatic as well, built a lot of models but the scratch is #1 now, monokote covering, and a cf2812 Emax, with 7x6 prop:)

larrypaul 04-25-2008 09:35 AM

RE: The Scratch Plane featured in Fly Rc
11 volt 1000 ma battery supplys the power LiPo[&:]

larrypaul 04-25-2008 09:37 AM

RE: The Scratch Plane featured in Fly Rc
Great simple club project!!!!!!!![>:]

Flash1940 04-25-2008 10:11 AM

RE: The Scratch Plane featured in Fly Rc
I wouldn't wish to bust anybody's bubble....but it looks to me as though there's a lot of space between ribs.....too wide for me anyway. Wide rib spacing causes excessive covering sag between ribs. Maybe I'm off base here....but if it were me.... I'd probably stick a half rib in between each of them....


carlosponti 04-25-2008 11:17 AM

RE: The Scratch Plane featured in Fly Rc
flash in the article the covering doesnt sag at all between those sections because of the sheeting on the d-tube and the rib caps and the trailing edge sheeting.

ps i kept article for these plans so i may build them sometime in the future looks like a cool sporty kind of plane.

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