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Old Mar 30, 2008, 03:06 PM
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Matt D.'s Avatar
Greensboro, NC
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Guillow's Cessna 170 - UPDATING with new UM gear.

After three years I'm updating this thread with some changes in equipment, new tailfeathers and covering starting on post number 66.


Since the other Guillow's Cessna 170 thread is a few years old I thought I would start up a new one.

I am replacing all of the Guillow's wood with light contest grade balsa.
And using Elmer's wood glue.

I'll post more pictures tonight of the equipment.

The gear is:
2 bluebird 2.5g servos
gws 4ch rx
Hobbycity 5g outrunner
Turnigy 6am esc
small 2 cell lipo (I forgot what they were - maybe 180)

All components are directly soldered to one another. Cases removed from receiver and speed control.
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Old Mar 30, 2008, 03:09 PM
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Matt D.'s Avatar
Greensboro, NC
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780 Posts
I get tired of cutting through 20lb paper with the #11 blade so I called around and that is all everyone seems to carry. So I scanned in some of the plan, erased everything not necessary and printed on paper from an old phone book.
Works great and easy to cut through.
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Old Mar 30, 2008, 04:01 PM
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Everett Wa.
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Glad to see the 170. This and the low wingers are light in the thread offerings. I still think the Beechcraft is a little small in wing area for R/C.

The Champ and the 170 have that bulged windshield. Do you plan to do it like the plans (2 piece), pull your own from a plug, or as I have and just ignore the bulge and wrap the windshield as a single sheet.

I see that you have cut the slots for the balsa landing gear struts. I would recommend that you find some other method to make the L/G. The balsa gear even with the wire support didn't even work for the light rubber powered ships, Do think about the torsion type gear I show in my builds.

http://www.rcgroups.com/forums/showp...3&postcount=20

http://www.rcgroups.com/forums/showp...0&postcount=25

All the best,
Konrad
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Old Mar 30, 2008, 04:07 PM
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Everett Wa.
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To help hold the paper to the balsa while cutting I often use a very low tack glue stick, I think it is the purple stuff. This keeps me from making a perfect paper part only to find that the pattern moved and the balsa part is trashed.

Do look at trying your hand at laminating the outlines if you're not using the kit wood.
http://www.rcgroups.com/forums/showp...62&postcount=6

All the best,
Konrad
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Last edited by Konrad; Mar 30, 2008 at 04:22 PM. Reason: Add link
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Old Mar 30, 2008, 04:38 PM
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United States, CA, Garden Grove
Joined Oct 2000
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I have a started 170 kit but decided it was a little to small in wing area and expected weight to fly scale-like. If you can really keep the weight down by using really light covering material, power system, receiver and servos, it may fly nicely and be able to land with little damage. For example: 12mm direct drive motor, 3" DD prop, 300mah 2S lipo and two 3.6 gram servos for rudder and elevator. Use dihedral per plans. Suggest covering with Microlite silver. Try to place components forward enough so that it won't be tail heavy when covered. Avoid any extra weight in tail structure. If you have a 2.4 ghz system, it prevents glitches from receiver being too close to speed control and you don't have long antenna problems. Be sure to have a little wash out in the wing tips. A little down and right thrust will help.
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Old Mar 30, 2008, 06:37 PM
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Everett Wa.
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With all due respect to EC I donít think weight is that much of an issue with these Guillow series 300 kit other than the Beechcraft.
I can fly them at a fast walking pace to a landing. I've been able to build them to the sub 4 oz range without having to go to heroic means. I donít need to lighten the servo or RX cases nor have I had to resort to contest grade balsa. We hear good flying reports at 6oz plus.

What I am concerned about is the durability of the Guillows kit. I try to save weight were I can so I can add it back to strengthen weak points. I feel that the cabin need more support this is why I add the spreaders. I also feel that the corner longerons should be made from basswood as the covering tends to pull the balsa ones out of shape. I also know that the Guillows landing gear is inadequate. I see little strength in the large bottom spar of the Series 300 wing. This is why I go with multi bass spars It is lighter and stronger (this has been proven many times by my landings). I also like the laminated curves, as these are much stronger than the sheeted pieced parts and often times lighter. I also sheet the front of the fuselage as this helps with my nose overs and gives me a good place to glue windshield.

I prefer geared motors as it allows for a smaller motor and a bigger prop. The small motor is lighter. And the bigger prop offers many benefits while flying. First the acceleration from a stall is very good. Second you can use power to help slow down the ship in the landing approach (The large slow idle spinning prop adds a lot of drag compared to the small 3inch prop.) Also once you reach high alpha flight you can add power to slow the plane down even more by allowing the prop to carry some of the weight. This is why I have been reluctant to go with the new micro out runners. I really like the big prop of my N30 motor in a GWS LPS box. I am going to try a micro out runner in my Cub conversion

I agree with EC on the need for washout in the wing tips, like 4 degrees or more. I find that these Guillows series 300 kits have way too much decalage. This is to help the free flight ship come out of a dive. I like to lower the aft end of the stabilizer mount on the fuselage about 1mm (0.040 inches). This seems to control a lot of the zoom climbing I see with these conversions as they gain speed. I do add some right thrust in my power set-ups. Down thrust is added if the trim flight shows it is needed.

All the best, Konrad
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Last edited by Konrad; Mar 31, 2008 at 02:22 AM.
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Old Mar 30, 2008, 11:25 PM
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Matt D.'s Avatar
Greensboro, NC
Joined Jul 2002
780 Posts
Thanks for the input Konrad and EC. I haven't thought much about the windshield yet. The laminations you made look good, but not sure if I have the patience - maybe. I have been looking at the threads and I got this kit back in December as a Christmas present to myself.

Landing gear- I might make it removable as I am tentatively planning on switching back and forth between floats. I have successfully made the top hat gear held in with friction on a similar sized model.

Here is the purple glue stick I have used in the past with good results. Holds the paper without any wiggle and then you can easily peel the paper off later.

I also found a bigger syringe that is easier to refill.

The gear is:
2 bluebird 2.5g servos
gws 4ch rx
Hobbycity 5g outrunner
Turnigy 6am esc
small 2 cell lipo (I forgot what they were - maybe 180)

First time I have soldered everything directly to save weight.

I am planning to come in at 3 - 3.5 ounces.
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Old Mar 31, 2008, 12:42 AM
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Everett Wa.
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Wow, Looking real good.
Is the GWS a proven unit? I've had spotty luck with GWS RXs. I think I've had 3 good (ok) 4 ch RX out of 4 and Zero workable 6ch RXs out of 5 units tried. Have you used the 2.5 gram servos before?

You'll make the 3.5 mark easily.
Konrad
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Last edited by Konrad; Mar 31, 2008 at 01:20 AM.
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Old Mar 31, 2008, 12:53 AM
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Matt D.'s Avatar
Greensboro, NC
Joined Jul 2002
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Thanks Konrad,
First time with the 2.5 g servos and first time with the gws 4 ch rx. I have had good luck with a gws 6ch rx I bought here on the e-zone a few years ago.

I'm scratching the removable gear option - will just have to take the wheels off to convert to floats. I'll have to post pics of the removable gear I made before.
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Old Mar 31, 2008, 01:04 AM
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Everett Wa.
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I may be in error, but I did some math that showed that for scale sized floats to work the ship would need to be in the 70 gram (2.5 oz) range. Otherwise the float would look more like a submarine than floats. While doable this is a little beyond my skills. Do you have a float design in mind? I recall that for water one cc of volume (displacement) can support 1 gram of mass.

Konrad
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Old Mar 31, 2008, 01:29 AM
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Everett Wa.
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Quote:
Originally Posted by Matt D.
Thanks for the input Konrad and EC. I haven't thought much about the windshield yet. The laminations you made look good, but not sure if I have the patience - maybe. I have been looking at the threads and I got this kit back in December as a Christmas present to myself.
Patience!!! Heck the laminated stuff is dead right easy and quick. Cut out a crude foam form, tape the edges, strip some 1/32 balsa, soak for a few minutes, slather on glue, tape to form, wait for this to dry or force dry it in a microwave oven.
Believe me it is a lot easier than the conventional pieced outline. Most kits don't do it because they would have to supply a material for the form and another size of balsa sheet. It is cheeper to make us cut all those parts to form that curved outline.
I see that Dumas (Pat Tritle) is now using allot of laminated hoops in their kits.

Konrad
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Old Mar 31, 2008, 02:00 AM
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Matt D.'s Avatar
Greensboro, NC
Joined Jul 2002
780 Posts
2.5oz! Let's hope your math is wrong.

I surely doubts doing floats is beyond your skill.

I don't have any design in mind yet, although I do have some plans saved here somewhere.

OK maybe I'll try the laminations as you suggest although I will have to go with my 1/16" wood as it weighs the same as my 1/32"!

Here is a picture of the little aluminum tube glued in place for the float option.
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Old Mar 31, 2008, 02:14 AM
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Everett Wa.
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That tube is set where? Is that a broken stringer? I do like contest wood but not for stringers. At least on my covering jobs they distort badly, real bad. As to using 1/16 wood to laminate with, it might kink. Remember that even with 8 or 10lbs wood the hoops will be lighter as there is about 2/3 less wood in the hoops. True there is more glue.

Konrad
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Last edited by Konrad; Mar 31, 2008 at 03:13 AM.
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Old Mar 31, 2008, 02:31 AM
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Greensboro, NC
Joined Jul 2002
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The tube is right behind the cabin, behind former B5.

Yes I squeezed a little too much while trying to use the tube to drill through the keel and broke a stringer And I even sharpened the tube first.

I'm really not too worried, as I cut most of the stringers a little bigger than 1/16 and I don't go for max heat and shrink on the covering.

I found a carbon fiber tube that closely fits the motor so I won't be using the motor mount on this model. I am also planning on trying pull pull on this one.

I wonder what the weight difference would be between the laminations and just cutting the tail feathers out of a solid sheet of light balsa and then cutting out some holes. Any idea?
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Old Mar 31, 2008, 02:36 AM
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Everett Wa.
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I file little teeth on the ends of my tubes. Actually use a dull blade to scribe teeth on the end of the tubes this small. Makes a nice little hole saw.
I save this tool and cut a new tube for the model.

I don't like Swiss Cheese!

Pull pull another slam dunk.
Konrad
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Last edited by Konrad; Mar 31, 2008 at 03:14 AM.
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