Espritmodel.com Telemetry Radio
Reply
Thread Tools
Old Jul 16, 2009, 11:15 AM
where did my wings go?
estlin76's Avatar
livingston, tx
Joined Jun 2009
103 Posts
Ken, what prop are you running on that little machine? I love the way it performs in the vid so i ordered the power setup you listed in the beginning, as i am still learning to fly and love how at lower throttle that thing seems to just float along.
estlin76 is offline Find More Posts by estlin76
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 16, 2009, 12:27 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Quote:
Originally Posted by estlin76
Ken, what prop are you running on that little machine? I love the way it performs in the vid so i ordered the power setup you listed in the beginning, as i am still learning to fly and love how at lower throttle that thing seems to just float along.
Estlin76,

I use a GWS 9x4.7 SF. According the seller it only draws around 11.5 A on 2s with this prop. That along with the 900Mah 2s Mystery Lipo, which is a 15C battery and reasonably light, you get a nice run time of around 25 minutes with some power management.

I will try to get the plans up tonight.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 16, 2009, 12:30 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Quote:
Originally Posted by rbrown3rd
If you seriously have too many, one too many, I would love to have it. :-)
R,

Karl is local to me so that would have been convienient. Postage would be more costly than the part is worth I think.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 16, 2009, 12:34 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Advanced non foam detail parts

Attached is the plan for the landing gear wire, motor mount firewall, and control horns.

The rest is forthcoming.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 16, 2009, 10:26 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Fleet construction progress

Launched the assembly of these birds this past Sunday. Had my Uncle and a friend for helpers. They did a great job, and I am deeply indebted to them.

I will let the pictures tell the story.

Its getting late. Takes too long to do this on dial up. Will post the remainder of the pictures tomorrow.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 16, 2009, 10:39 PM
treefinder
springer's Avatar
SE MI
Joined Oct 2004
9,442 Posts
Messy? looks about right to me!
springer is offline Find More Posts by springer
RCG Plus Member
Old Jul 17, 2009, 07:35 AM
dizzy yet?
Kap'n Karl's Avatar
Chesterfield, MI
Joined Jun 2009
225 Posts
Thanks again for posting all this info, Ken. It was really interesting to see your build process. Man! It's a Oshkosh Special factory!

The fleet is impressive!

Your picture answered my question about the landing gear block. but you bake your wings? do you mean that you use a heat gun after cold rolling them or do you have a form you actually bake them on?

-Karl
Kap'n Karl is offline Find More Posts by Kap'n Karl
Last edited by Kap'n Karl; Jul 17, 2009 at 07:43 AM.
Reply With Quote
Old Jul 17, 2009, 08:07 AM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Quote:
Originally Posted by Kap'n Karl
Thanks again for posting all this info, Ken. It was really interesting to see your build process. Man! It's a Oshkosh Special factory!

The fleet is impressive!

Your picture answered my question about the landing gear block. but you bake your wings? do you mean that you use a heat gun after cold rolling them or do you have a form you actually bake them on?

-Karl
Karl,

I have a form I built that holds the foam to the airfoil shape. Then the entire package goes into a 200 degree oven for 10 minutes. This sets the foam and seems to give some temper to the material as well.

It is possible and practical to cold form the airfoil as well. You can get excellent results, but there is tendancy for the foam wanting to go back some. Not a game changer, but baking just makes a good thing even better.

BTW I am bringing the Prototype Oshkosh Special to the field this afternoon. I want you to give it a go. The winds are supposed to be about 10 Mph, but that should not be a problem. Need to know for Oshkosh. There always seems to be some wind. Also want see how you handle it as well. Using you as a test subject to get a feel for what might happen with the new folks at the camporee. Hope thats okay! I would not do it if I was worried about the model. You are going to love it.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 17, 2009, 09:45 AM
Addicted to flight since 1944
rbrown3rd's Avatar
southern Florida
Joined Feb 2004
1,750 Posts
Beautiful work. Also makes a nice how-to build thread. What I like is the precision you get having each piece cut so precisely. I see now that what I failed to do on my first Blu Baby is to detail the mono bloc before assembly. Cutting out that motor wire tunnel the way you did would have saved me a lot of anguish after assembly. You are inspiring me to convert my garage to a shop but first I must resolve the 100 degree temperatures out there.
rbrown3rd is offline Find More Posts by rbrown3rd
Reply With Quote
Old Jul 17, 2009, 07:19 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Rbrown3rd,

Glad you like it. They say "the devil is in the details". So best to take care of as many as possible while its easy to do. Makes the final assembly go quickly.

FLIGHT REPORT

Stopped by one of the fields the SEMFF folks frequent this afternoon. Wind was supposed to be 10 mph, but was more like 15 at times. What to do? Send it up thats what. I was interested in how she might handle a stiff breeze. Well she had plenty of power to stay into and ahead of the wind. Also had some low time friends from RCGroups try there hands at the sticks under these conditions. These were extreme conditions, but both Kap'n Karl and JolleyRogerF4u did a fine job and commented on how smooth the Oshkosh Special was in such bumpy air. This was a good indicator of how this may do in Wisconsin and gave me a baseline from which to make good judgement about the aircraft and pilots limits. Flew out 3 batteries.

Special Thanks to Kap'n Karl and JolleyRogerF4u for being brave and having faith. Just need to get Springer behind the sticks. Somehow missed that opportunity twice now. Sorry Mike.

Ken
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Latest blog entry: Mini H Quad Project
Reply With Quote
Old Jul 18, 2009, 12:16 PM
Addicted to flight since 1944
rbrown3rd's Avatar
southern Florida
Joined Feb 2004
1,750 Posts
Quote:
Originally Posted by dz1sfb
You are right on! I wanted to be able to utilize one thickness of material for the entire airframe. Even thought about engineering the monoblock out of it, but after playing with the idea awhile, the laminated monoblock is simpler to design and manufacture. Of course the number of layers of foam dictates the width of the fuselage. Seven layers was just right to make up for the 1-1/2" foam using PB3.

Ken
Ken,
Congratulations on turning out a very nice looking fleet of BBs. Your work has inspired me to investigate the Phlatprinter. I even went so far as to add the Phlatscript to my Sketchup installation. Looks really interesting. My wife even said, "Well, that is the way to go." after watching the Phlatprinter video. Ah, another project to think about. Meanwhile, I think I will build an Oshkosh version of the BB for a friend of mine. That one will have to be cut with my Xacto.
Bob
rbrown3rd is offline Find More Posts by rbrown3rd
Reply With Quote
Old Jul 18, 2009, 11:47 PM
Slipping the Surly Bonds
dz1sfb's Avatar
Attica, MI
Joined Dec 2006
10,323 Posts
Oshkosh Special Plans

Well here they are!

I have kept these plans relatively simple. Since they have been proved out I did not develop a 3D math model, but kept this to 2D only. The parts look a bit spread out on the sheet, but that was to help with the tiled output of the plans.

You should be able to use the photos as a guide to construction. More photos will be posted.

Freely I have received, so freely I give.

Ken

Edit: 02-DEC-2009 - Added KFm3 plans to this plane.

Edit: 08-FEB-2010 - Added build instructions.

Build instructions:
1. Glue bulkhead to fuselage side (there is only one bulkhead and it does not matter which side you start with).
2. Add the other side to this assembly and glue the tail ends together and hold with tape.
3. Add fuselage top and hold in place with tape, taking care not to tape a bend in the tail.
4. Add fuselage bottom and hold together with tape until the glue is set. Likewise take care not to put a bend or twist in the tail as you tape it together.

Steps 1-4 are done one right after the other. That way if you get a twist or bend from taping it can be corrected before the glue sets up. With the tabbed construction, the sides are self jigging for alignment. This is why I do not start with the monoblock to the sides on this build.

5. Prepare monoblock while the glue is setting up from the previous steps. That means get you firewall mounted to the monoblock and all wire channels and cavities done prior to installation. You have time to do it while the glue sets.
6. Untape fuselage and install monoblock. Please clamp flat from the nose to the bulkhead, this will prevent you from getting any unwanted bends in the fuselage. I like to use a piece of 1 x 6 on each side. If you happen to have CNC cut parts, install the front wing hold down dowel at this time to help keep things in place.
7. Add the tail skid at this time as well. This complete the fuselage structure. Allow to dry for at least 30 minutes. Here in Michigan as I am sure in other cold weather climates, the humidity is low and this slows the cure time for the Poly Urethane type glues (i. e. Gorilla Glue, Sumo Glue, etc...). I highly recommend this glue for FFF type builds.

While the fuselage is curing its time to move to the wings.

8. Sand the wing center joint bevel to obtain the specified dihedral.
9. Glue and tape together the wing center joint, and allow to dry.
10. Finish control surface hinging on horizontal and vertical stabilizers.

By this time you should be able to unclamp the fuselage and remove all tape if you have not already done so.

11. Add servo rails to fuselage. To glue these in I use a simple and clean technique. Push the servo rails into the fuselage sides. Install the servos (this is optional at this time, but it does help to hold the sides of the fuselage out to the correct place relative to the length of the servo rails.) to the rails. Then put a bead of glue on the outside of the fuselage over the ends of the servo rails (not alot of glue). Now place a piece of tape over the glue. Use enough tape so that the glue does not leak out under the edge. This forces the glue into the joint and forces exspansion inboard. This is why you don't need too much.

At this point, it is really good to know what you are going to do for trim. If you are painting it does not really matter, but if you are useing colored packing tape, this is where you get started.

12. Add tape trim to the tail surfaces.

Lets get back to the wing for a moment.

13. Remove tape from center joint on wing, and it should look beautiful.
14. Using a small rat tail file or dowel rod with sandpaper create the grooove in the LE and TE of the wing to receive the dowel rod reinforcement. This allows you to use less glue and therefore build a lighter better flying model.
15. Now add the prebent wing dowels per the mini tutorial. http://www.rcgroups.com/forums/showp...postcount=8031

Lets get back to trimming now by way of the fuselage.

16. Remove any remaining painters tape from the fuselage and do any finish sanding.
17. Add trim and colored packing tape as desired. I have found it best to keep the schemes simple when using colored packing tape since it does not like to go around bends well.

Now that the fuselage and tail feathers are complete, it is time to join them together.

18. Start by slitting the fuselage out the rear of the horizontal stabilizer location to allow you to slide the stab into the fuselage.
19. Now check the stab for squareness in the front and top views. If it is not, then you will need to make some adjustments to the stab slot in the fuselage to allow it to be square.
20. Now glue the horizontal stab in place and glue the cut that was made to allow the insertion of the stab shut. Using painters tape hold this assembly together and to control the foaming of the glue. We want it to be pretty.

Back to the wing while this dries.

21. Untape and sand out the tips of the dowels to blend into the wing. Now your wing is ready for trim tape or paint or Sharpies or all of that. I used a single strip of colored packing tape even with the leading edge and a line from a Sharpie permanent marker to set off the edge. Then I put one strip of clear packing tape around the wing center joint top and bottom. That completes the wing.

Back the fuselage assembly once it is dry.

22. Now line up the vertical stabilizer assembly and glue to fuselage, making sure it is square and straight to the fuselage. Use painters tape agian to hold in place and control the foaming of the glue.

Tip: Using just enough glue to do the job is key to building a light strong structure. You will get to know by doing it. The rule is, the tighter the joint the less glue is required. Not as much room to fill.

23. You are almost done. Now you can add your landing gear assembly to the fuselage. Add glue to the slot and install the gear. Make sure you have enough glue here, as you need to fill the cavity by foaming action of the glue. Place tape over the slot so as not to get foamed glue all over your wonderful creation.

This finishes the basic airframe. You need only make and install your pushrods, and control horns, Then install your ESC and motor, along with the RX, and your are ready to go. Remember to check the CG.

This entire sequence assumes you are using Gorilla Glue and painters tape.
dz1sfb is offline Find More Posts by dz1sfb
RCG Plus Member
Last edited by dz1sfb; Jul 01, 2010 at 06:53 AM. Reason: corrected typo's on steps 11 and 23
Reply With Quote
Old Jul 19, 2009, 09:05 AM
Addicted to flight since 1944
rbrown3rd's Avatar
southern Florida
Joined Feb 2004
1,750 Posts
Quote:
Originally Posted by dz1sfb
Well here they are!

I have kept these plans relatively simple. Since they have been proved out I did not develop a 3D math model, but kept this to 2D only. The parts look a bit spread out on the sheet, but that was to help with the tiled output of the plans.

You should be able to use the photos as a guide to construction. More photos will be posted.

Freely I have received, so freely I give.

Ken
Thank you so much Ken. I have a couple of questions if you don't mind. I am considering cutting my monobloc out of FFF but since I don't have a Phlatprinter (yet) I thought I would stack some sheets and cut them with my dremel tool and router bit. Would that be a good way to go or would a bandsaw or scroll saw be better? If Dremel router would work then what bit works best and what speed?

Sorry for so many questions but I am trying to get setup to make a few planes as you did for any friends that might want one.
rbrown3rd is offline Find More Posts by rbrown3rd
Reply With Quote
Old Jul 19, 2009, 09:16 AM
Addicted to flight since 1944
rbrown3rd's Avatar
southern Florida
Joined Feb 2004
1,750 Posts
I overlaid the standard monobloc outline with the Oshkosh one and they seem close enough that I could use the BB monoblock for stick mount to make this version. May I also ask, full of questions today, what package you use to draw your plans and for tiling? Thanks very much Ken.
rbrown3rd is offline Find More Posts by rbrown3rd
Reply With Quote
Reply


Thread Tools