SIG's airfoils

Ken Cook wrote:              A sharp block plane yields one in no time at all.

And probably at half the price. But, my "eye" left me about 15 years ago.

rsv1cox wrote:

And probably at half the price.  But, my "eye" left me about 15 years ago.  

Boy, do I understand that -- a lot of things left me some time back.

Were mere shells of our former selves; but hey, at least were retired and can get out and play every day.

I had my eye back in 1971 when I built this thing from scratch scaled to a 26 1/4" wing with a root chord of 5 1/2" and a tip chord of 1 1/4", something that I though two Cox Black Widows would haul around.  Although I didn't really build it to fly, sticking to scale mostly, it did fly and on many occasions.  

My only referance:









Not trusting again to rulers and calipers, this time I'm bringing it to Staples and have them enlarge it to plans for a 26" wing.  

Not going to complicate the wing this time, no ribs and stringers just the SIG airfoil. But I'm thinking to get the thickness in need I might glue two SIG airfoils together, one over the other to get the root to tip taper correct????





It's true, the P-38's wing was just a scaled up Super Connies wing.  No surprise they were both made by Lockheed.

Tell me THAT is a piece of Pine // That airfoil looks terrible Darn , I had my finger on purchase the other day when you said they had sent the inventory (finely) to you .. Was going to get with you to see how it turned out , shipping and all . Thanks for posting ! So your getting ready for a big build ?

Yes, my cutting board. I just wanted to get a look at the sweep-back of the wing.

I'm stilll a big fan of SIG, I think I might have just got some poor balsa and a bad rendering of the airfoil. The P-38 used a semi-symmetrical wing, so I'm going to join the 4" and 3" together like this.






I will still have to add an inch and one-half section to the wings trailing edge to get the width I need and sand to scale. It probably will wind up lighter than the built up wing I used on the original. Thinking about profile for the pilots pod and twin booms. I have the perfect pair of Cox horseshoes for engines, but will probably resort to Black Widows to avoid the tank issues.

The problem with buying balsa sight unseen is that you have to rely on someone else to make your selection. Hand selection is the best way to go however, very few hobby shops carry balsa anymore and there are even fewer hobby shops to choose from.

Almost nobody builds with balsa these days. Most new kits are foam. We are just in an age where you get what you get. Maybe next time you can contact SIG and request certain pieces and order over the phone so they can put notes in your order.

Ron

I stopped by Staples (yes, they were open on Labor Day) and had the P-38's sketch blown up. $3.45 cheap enough. Nice enough to hang on the wall but I'm going to cut it up and use the templates for my new build.

I just eyeballed it 50 years ago when I made the original. Seems I shortened the twin booms a bit. Can't remember why.

My last purchase from Sig was about a year and a half ago.
The shipment had fuel, castor, some building supplies, and some 3x36 and 4x36 airfoils.
The airfoils were broken in half like someone had a very bad day and decided to break the balsa over their knee.
I called Sig but they seemed to be in turmoil and had no idea when more balsa was coming.
I hung up and have not placed an order since.
Over the years I've bought a lot from them like kits and a lot of Norvel stuff before it was all gone.
Great company but apparently poor management now...
FWIW Steve

66 Malibu wrote:My last purchase from Sig was about a year and a half ago....

Over the years I've bought a lot from them like kits and a lot of Norvel stuff before it was all gone.
Great company but apparently poor management now...
FWIW Steve

I haven’t purchased anything from them either, but don’t want to see a good name go down in flames. “ New” owners/management took over and were sending out updates on the SiG Facebook page. The guy was investing tons of time and money to update inventory and operations. It’s all work and no play when you try to turn your hobby into a profitable business. Sounds and looks like they’re fixing the shipping as best as they can to keep the content of packages from being damaged. But you know those delivery guys sometimes have bad days, not the employees of SiG.  If you’re in or on FB go here and see what the new guy is up to:    https://www.facebook.com/SIG-Mfg-Co-355006604526046/?ref=page_internal

The damaged balsa airfoils were professionally wrapped in paper inside the heavy over carton.
The over carton didn't have a mark on it so no possible way it was done except the Sig packer did it or just the packer pulled broken pieces from inventory to ship to me.
BTW the over carton was more than 36 inches long so it was not a jam fit into the box.
I've always liked Sig and have bought my share them and I hope the new owner brings Sig back.
He needs have a "training" session with the packers if it is still a problem.

I have 5 of the 4" wide in the mail will report my findings.
Have made quite a few projects with the airfoiled balsa.

It's raw shape is enough to help speed up sculpting the rest of the wing.
I use semi to fully symmetrical airfoils for RC flying. My examples below.
The last two at the bottom are double planks fully symmetrical by nature.
Even the vertical stab on the checkered wing plane is doubled up.

All hale the simple balsa plank racers.

What did you use to glue the two together?  I'm thinking Gorilla or titebond maybe thinned a bit?  But I'm afraid of distortion.  I hadn't thought of doing the vertical stab too.  Had no problem with breakage, if anything the box and padding were over-done but the box was to short as the ends were jammed up against it's insides.  





I have done maybe six of these altogether.  Most appealing perhaps the Mexican "Black Widow."

I used Titebond to glue the two fuse halves together on my SM 23….. I also dimpled the gluing surface with an awl to give a little more bite to the joint…. Used very thin coats on both halves but was applied full strength….. Clamped between two flat plates and 24 hr cure…. It has stayed straight and stiff…


Looking forward to your ‘38 build…. The original is beautiful…

I really enjoyed the Viuda Negra thread as well…

Robert

Thanks, I will use your dimple idea.

Thanks also for the P-38 compliment, but I'm a hack at this especially when compared with the two "L"'s here, Lieven and Levent. I would love to see a P-38 that they turned out. I'm not even close to their league.

50 years ago I had this canopy and esscentially built the airplane around it. It was my base measurement. If the canopy isn't right, the whole model is off as mine is but not by much. This time, if I don't go profile I'm working with this.




At one time a popular kit on eaby. I have used the contents alot.

The canopy is not as close as my original, but close enough. I will have to structure the pilots pod accordingly.




I could make a buck and draw plastic across it, but where do I get the example that would fit my needs. SIG makes canopys but even they are less close to what I already have. The best one is from Russia but I'm not going there.

My lot showed up same type of packing.

Speaking of SIG, I was going through some of my old control line stuff the other day and came across this:



Cleaned it up a bit losing somew of the lettering in the process and stuffed it in my display case.  SIG offered a lot of different things back in the day. I tossed the kinked/broken line in the trash. Saved the connectors though.

I am in dismay of the quality of the cut on the airfoil , I would say somebody didn't give the right measurements for the cut ? Found the only other airfoil I can find is 12" long and would need to bee scalped together to make up something useable for 1/2 A . I Am sure it can bee worked (sanded) to make better but that's not what you buy it for ! This looks good but again 12" https://www.vernier.com/product/kidwind-airfoil-balsa-blade-sheets-10-pack/ Just one of a few.. These people may even cut to shape what you want !?!? >> https://specializedbalsa.com/products/balsa_scraps.php Cost ?? $$$

getback wrote:I am in dismay of the quality of the cut on the airfoil , I would say somebody didn't give the right measurements for the cut ? Found the only other airfoil I can find is 12" long and would need to bee scalped together to make up something useable for 1/2 A . I Am sure it can bee worked (sanded) to make better but that's not what you buy it for ! This looks good but again 12" https://www.vernier.com/product/kidwind-airfoil-balsa-blade-sheets-10-pack/ Just one of a few.. These people may even cut to shape what you want !?!? >> https://specializedbalsa.com/products/balsa_scraps.php  Cost ?? $$$

12" might work Eric, joined together gives 24" more than enough for 1/2A.  I will have to cut mine anyway to add dihedral.  

Under all that crap is 36" of SIG 4 an 3" airfoil glued by Gorilla.  Leading edge didn't turn out.  Still have to reglue and clamp.  



Somewhere in there is a P-38 wing.




Nuff of this, I got lawn to mow!

Nuff of this, I got lawn to mow! wrote: