Everybody's micro 757-200

[Dentar]

Hello again,

Since I finished up my Cessna 150 today, I started to go for a 27 inch 757 using two KP-440 Fan from Knight & Pridham.

I started this thread so I could get suggestions while I build this beauty, from the ones that have been there before. So Your comments might be implemented into this build making it partly Yours. ;)

I just finished assembling the two wing's, and here I am looking for the first suggestion.

How should I mount the wing's ??? permanently ???

[keven64]

That's Knight and Pridham... (http://www.businessmagnet.co.uk/company/Knight%20%20Pridham%20Engineering%20Ltd-41555.htm) ;) :)

Does a micro model need removable wings ?

If you make the wings removable for tansport, or for access to the internal components, be sure that your method of attatching them is such that there is only one place in which they will fit...

Are you fitting an undercarriage - that will affect the integrity of the wing mountings ?

Oh - any idea of a colour scheme yet ?

Keven. :)

[Dentar]

oops, I pasted it from a previous thread cause I didnt know how to spell it. Looks like Im not the only one:)

Undercarriage, You bet. I have ten 16mm wheels that should look scale. I forgot about the U/C when I assembled the wings, Im very new to building.

No problem though, I will glue some wood between the inside spars and leave some sticking out to attach the wing. Then I will build a wing attachment for the fuselage that is angled appropriately at both sides, then glue each wing in place. Glue some more wood onto the wing attach. and fuselage, and mount the wings with screws.

I wanted the UPS color sheme but they switched and I dont like it anymore.
Then there's Condor, American Airlines, or the good old Boeing rollout color sheme. Dont know?

[Dentar]

After another night of airliner insomnia.....

What is a good dehidral for a model??? 5 degrees looks right to me, but I dont know the advantages or disadvantages of more or less dehidral.

The wings do have ailerons if that matters much.

I test covered the top of the fuselage with paper (underside is EPS foam) and think I might actually go with that. Has anyone else covered in paper?
Would spraying on multiple light coats of clear coat make the paper stiffer?

Heres what I have so far (around 100 grams) and the tail & nose arent even sanded down yet.

Thanks

[pacro]

looks good. how did you make the fuse

[Dentar]

Very simply:)

Its all sturdy board with the paper removed, and the bottom is sanded down EPS foam.

[pacro]

it just looks very thin

[scratchandbash]

Looks good Dennis, I'd like to see the Cessna also. I just finished my Yak23, and still need to fly it, and get my Arado sorted out. See you love this foam thing like I do. As for wings, I've been using solid carbon fiber rod reinforcement. It can even be glued in place, with dihedral. I almost always build removable wings, for the serviceability. Depends on the plane, whether or not you need to get in there again. The rubber band attachment with removable wing can absorb much shock. I've picked up mine with the wing knocked over 1 inch. Think about how much crash impact that can absorb.

[Dentar]

Thanks

I will make the wings removable but I wont be able to get to the inside untill I crash it. I dont plan on it though so I dont care about how forgiving it is on crashes. The cessna I built to better my flying skills, and is the first plane I've built that flies. Well for a second at least, I just took her up and down on my street. I havent flown in three years and I'll have a better pilot fly the 757 on its maiden.

Scratch, Heres the Cessna housing Your 300 motor. Thanks again for those.

Got any pics of the yak?

[keven64]

Dennis,

The 757 looks GREAT ! :D

I was mocked when I suggested to someone that paper would work... :rolleyes:
Foam and paper - brilliant. :)

You could print most of the colour scheme onto the paper before sticking it to the rest of the airframe ! ;)

For the lightest of colour schemes, something like this example in Continental (http://www.airliners.net/search/photo.search?&regsearch=N14118&nr_of_rows=19&first_this_page=0&page_limit=15&sort_order=photo_id+DESC&nr_pages=2) colours would be worth considering... simple, striking, and LIGHTWEIGHT ! ?

Eyeball the dihedral until it looks right - you don't need much with ailerons... something around 3/4" under each tip.
It looks like you have built aileron linkages into the wings - so that both are operated by one central servo ( the flaps and ailerons are to be added later I guess ) ?
Your tailplane looks like it will have seperate elevators ?

From my experience, at the weight your model will turn out ( less than a pound - surely ? ) it'll not be slow...!

Keven. :)

P.S. Have you got a construction thread somewhere about your 300 powered Cessna ?

[Dentar]

Exactly, using paper would be brilliant if the color sheme is printed on it.

I think You have won me over on the Continental colors too.

The dihedral is at 5 degrees and I did build the aileron linkages into the wing. That obviously has its advantages in more than one way, like only needing one servo.

The ailerons and flaps wiill be added onto the already 10% bigger wing, thats ok since I want this puppy to fly as slow as possible.

The tailplane might or might not have seperate elevators, depends on whats lighter.

I really dont want this plane to be fast at all, but I guess thats unavoidable with the wing loading of a airliner without flaps.

The Cessna thread is here, http://www.rcgroups.com/forums/showthread.php?t=391250

Thanks

[scratchandbash]

Dennis, Dessna looks good. I did a build thread on my Yak23.
http://www.rcgroups.com/forums/showthread.php?t=388374

[Dentar]

Ohh yeah, Saw it before and its outstanding. What did You use to cover the plane with. I need that chrome look on the wings and nacelles, it looks awesome. I could die a happy man with those building skills.

[scratchandbash]

Chrome Monokote. Probably the most difficult color to get the wrinkles out of, like the flat colors. Not too bad, once you get the hang of it. Just stretch the crap out of it, to avoid wrinkles, and then use the heat to re-shrink the leading edge of the material not yet applied, since it has been stretched, and needs to shrink again.

[Dentar]

Here is the distinctive face of the 757, please stay tuned :D

[DiabloKid]

nice work Dennis

any chance of getting plans/templates for novices like me to give a try to build :)

matt

[Dentar]

Well, All Im using is a 3-view drawing for the measurements so There is no plan. I want to see how well she turns out and flies first, then I might make some plans and or templates or even sell the premade parts for cheap.

There are 91 parts to the aircraft as I have it planned out, 40 for undercarriage alone!

Thats the goal here to have a great looking airliner thats cheap :)

Thanks for the interest.

[keven64]

Dentar said
Here is distinctive face of the 757, please stay tuned :D
Looking good Dennis ! ;)

Keven. :)

[Dentar]

OK, now all the major components are ready to be assembled.

I have layed the motor wiring inside my 757's wings but it seems very heavy.

Does the gauge of the wire matter for powering these little fans, or could I use a very thin wire like ribbon cable or telephone wire??? The thinner and lighter, the better of course.

Keven why do You like Continental so much???

[keven64]

wire the same size as that fitted to standard servos is what I use with my small models... I buy 1 metre ( 39" ) lengths of servo wire ( ribbon ) from the local model shop for a few £'s.

I strip off the white wire if using brushed motors - and leave it on for brushless motors... ;)
I've not had a problem - yet... :)

I use it for models powered with the following:
KP-44 fans, GWS EDF-50 fans and DX gearboxes ( with either the std. or brushless IPS motors fitted ), Speed 280 motors... etc.etc.

Continental... that's just a nice and simple colour scheme...
I assumed you're in the country that it originates from... and so should suit you ? :D

Keven. :)

[Dentar]

Maybe someone can answer this for me.

I want to install four "rice" light in the plane without adding another battery.
How do I do it??? Could I just cut into the positive negative wires of the ESC that go to the receiver since it is supplied with less power???

Or where do I connect them?

Thanks

[Dentar]

I made a mistake with the scale, looks like 40mm or 30mm fan's are needed for the scale look. I made a nacelle for the KP fan and it's almost as wide as the fuselage itself. ooops

I decided to permanently attach the wing. Total weight as seen is at 100g.

[thailandboy2]

nice work dentar, if i could suggest for future, try to hollow out your nose and tail sections..this would cut down on your weight...tom

[Dentar]

Thanks Tom, I might do that but the weight savings will be minimal.

[thailandboy2]

dennis, have you tried depron usa? they have grey depron too, but unfortunatly not in 1 or 1/2mm yet...

[Dentar]

Yeah, I will order some here shortly, although I cant cover this 757 with any(other than 1/2mm) since the overlap of the nose and tail arent enough.

I'll finish the nacelles today and the gear, then I'll finish the tail surfaces and then see what I'll use to cover the fuse. Gonna try the printed paint sheme and windows ect. on plastic sheet or paper, and spray it with a couple of clear coats.

Gonna go and maiden the Cessna 150 now, wish her luck.

Thanks,

Dennis

[Dentar]

The cessna flew well, until I lost controll in the sun and the prop came off from the hard landing. Nothing elese is broken though and I'll take her up again.

Being only the first plane I have built that flies :D

Now my confidence is way up there, and Im sure the 757 will be a hit.

[thailandboy2]

congradulations on your maiden..hope your 757 goes good too..tom

[Dentar]

Because of some free time finally, work will resume on this puppy :D

[Dentar]

Here are the rough parts for the EDF nacelles. I think that two 4mm thick posterboard pylons are strong enough to support the small KP-44.

I also hollowed out the nose and tail sections to save weight. Now its on to the landing gear so I can mount the engines to the wings.

Im also considering installing permanent 15 degrees down inner outer flaps.
I really dont want this to be a fast runner.

[thailandboy2]

looks good denis....

[Dentar]

Thanks Tom

I have had a request from someone to build another one. If Anyone else is interested and I get enough requests, I will take the steps in order to make some ARF versions for sale. So if anyone is interested let me know so I could figure out a price of production. The nose cone and tail would then be out of molded plastic, and all that would be left to do for the buyer is install the EDF's and servos.

For anyone interested, please send me a Private Message.

[keven64]

You got the Continental scheme for yours, Dennis ? ;)

Keven. :)

[Dentar]

I'm looking through color shemes right now.

I might go with the new UPS colors since its mostly white, the underside of the wing especialy. Wish I knew what the top looks like though :confused:

[Dentar]

Well, shes not done yet but I took her for a taxi test. It looks like at 9 oz. The plane is underpowered for a runway takeoff. So a lipoly battery is necessary in order to save 2 whole oz's. I will also order a couple of edf 40's to replace the older KP fans.

Here a few pics with temp. covering.

[thailandboy2]

looking good dennis..keep going...tom

[embraer 145]

any updates?

[Dentar]

No updates sorry!

I need a new power setup for this airliner. some EDF40's a lipo and charger.

Since there wasen't a overwhelming intrest in this plane, I decided not to go further and invest in it. I still have the interest to finish it though.

[IWC]

I'm interested

[Dentar]

Hi everyone.

I am going to build the second version of this airliner with improvements learned from mistakes i made on this one.

Glass nose and tail, flaps, retracts, and a brushless GWS 40mm fan setup are planned for now. Im starting the build tonight so look for an update soon.

hope ya will like it.

Thanks,

DT

[FEDEXDC10]

keep me update

[FEDEXDC10]

Hey Check Your P.m Asap

[FEDEXDC10]

Hey Den

Do You Have Many Update Hey P.m Me

[Dentar]

Im currently working on the tail molds. The fuselage will be made up of 11 parts, including the elevators and ruder. As for the wings im waiting on depron but in the mean time am also working on the flap system. As soon as I comlete the molds, make a few castings, and cut out some parts, I will send you a kit:) Sorry but all this takes time and patience, after all I want a quality result.

Thanks for your interest.

DT

[FEDEXDC10]

Do You Have Some Update ?

[57_KID]

Dentar
I think that there is more interest than you might know, The subject came up last Friday when we were out flying and we were saying that you probably got bombarded with requests to do a build, I think people were just not responding because they felt that a LOT of people would be sending you pm's I could be wrong but this project sounds cool keep going and post as often as you can just my .02
Steve

[FEDEXDC10]

Hey Den


Any update ?

[FEDEXDC10]

Any Update On The 757

[Dentar]

HI, Sorry I havent checked this thread or any for a while. I was going to build a larger scale 787, now though im thinking 757 again.

I think i'll build it to be fit with some 55mm fans....?
A 40mm fan version might also be in the works.....?

DT

[Dentar]

And the building has begun on another 757 housing GWS40's.... just finished the right side wing. I used depron for the spars and covered them with a 1/32 balsa sheet. Like in my previous model a flexible pushrod running through the wing will activate the eilerons.

The fuselage will most likely be foam cut via hot wire and the tail, nose, and nacelles will be plastic pulls.

I can see more airliner insomnia in my future.

Sorry cant take any pictures yet.... hopefully tomorrow.

ttyl

[scratchandbash]

Dennis, if you haven't seen it yet, here's a scratch built airliner that flies on BRUSHED 12 EDF50 fans. Well mostly scratched. The nose is from a Cox Airlifter that got a new nose to become an Arado.
Love those micro fans,

Bill

[Dentar]

Hi Bill, nice to hear from ya!

I have seen you airliner, its nice and always nice to see a edf that flies on a stock setup. That DHL truck tha needed a drink of water was also amusing.

I hope to have this airliner fly on stock 40's and if too heavy then BL of course. Am in the process of covering the other wing and then ill work on the fuse.

I could not find a balsa block to carve out the nose and tail sections though.

Is there any other wood good for carving? To make a plug?

Thanks for the help,

DT

[scratchandbash]

Hi Bill, nice to hear from ya!

I have seen you airliner, its nice and always nice to see a edf that flies on a stock setup. That DHL truck tha needed a drink of water was also amusing.

I hope to have this airliner fly on stock 40's and if too heavy then BL of course. Am in the process of covering the other wing and then ill work on the fuse.

I could not find a balsa block to carve out the nose and tail sections though.

Is there any other wood good for carving? To make a plug?

Thanks for the help,

DT

I've made plugs from foam, and then coated them with filler. You'll spend a few bucks on cans of filler, since it uses a lot to fill the foam surface well. The filler hardens the surface of the foam mold, and also give you a little latitude for finish sanding, to get the plug really straight.

Depending on how you make the sections plane over the mold, if you made the parts in halves for examply, you could keep reusing the molds, since they wouldn't have to be destroyed to get the glassed parts off.

Just by coincidence, I was taking the 12V motors out of a set of EDF40 fans last night, to use them for a small micro FlyZone Mosquito project. The fans will get Feigaos for what I'm planning to use them for. Figured I'd play with the fans a bit, before dissasembling them. I was impressed with the difference between them, and the 7.2 volt motors. These little fans on 12V should easily power something as twins, as long as the wing loading's light enough, granted they don't burn up. So far, the 12V motors are holding up on the DHL plane.

Bill

[Dentar]

Awesome craftsmanship bill.... I need plugs to not be covered by glass but plastic vacu forming. Maybe foam would work for a plug if covered in fiberglass. Ill ask the nice gentelman who will do the plastic molds for me.

What aircraft are you planning for the BL 40's ???

on a nother note... I expect to have the beta 757 ready by friday. Sorry for not having any pics...ill upload them ASAP.

The quality of this plane will be a huge improvement over the last one.... love the foam and balsa mehod for a build up!


If anyone is interested, I'll be more than happy to build kits, or RTF versions.

Pm me if interested.

DT

[scratchandbash]

Awesome craftsmanship bill.... I need plugs to not be covered by glass but plastic vacu forming. Maybe foam would work for a plug if covered in fiberglass. Ill ask the nice gentelman who will do the plastic molds for me.

What aircraft are you planning for the BL 40's ???

on a nother note... I expect to have the beta 757 ready by friday. Sorry for not having any pics...ill upload them ASAP.

The quality of this plane will be a huge improvement over the last one.... love the foam and balsa mehod for a build up!


If anyone is interested, I'll be more than happy to build kits, or RTF versions.

Pm me if interested.

DTMaybe thinking of an F14. One of the few "modern era" jets I like.

I'm assuming these plastic molds must not be too terribly expensive to have made for you in low volume custom production?
What's the weight of them?

Bill

[Dentar]

I dont know how much the weight will be yet, not much since the thinest plastic will be used. The nose will only be 4'' long and 3.5'' in diameter, the tail will be 8'' long and the diameter tapers at the aft end of course. First need the plugs to have a set made and then ill no more. Im hoping the parts will weigh around 1 ounce. No they should not be too expensive to have made... will ahve to work out a deal with the vaccum former gentleman.

Today the middle fuselage will be completed, foam formers and covered in balsa. both wings weigh around 35g. I should have the beta ready by friday.

RTF Airliners should be ready for orders in a month or two.
I really need to borrow a digi cam to take pictures.

[MustangAce17]

Dennis,would love to build one of these and getting a DX 7 soon,so will have the flap option:)

[Dentar]

Why build one when you can buy one from me... :D

Im also thinking about installing flaps using the very light 2.5g servos on the production version, maybe not triple but double slotted. On this prototype I will not though, to see how well it perform without. Or just add a ittle more balso to the trailing edge of the wing to simulate a 5 degree take off flap setting.

Ill have pictures posted by tonight of my progress.

[Dentar]

Im having some tech. difficulties with the camera..............Arrrrrgggghhh

But i got one of the wing to upload, and more to come.

Both wings still need to be sanded and primed and sealed ect. ect.ect.

The fuse is also comming along well, i have done nothing but build this week :D

[Dentar]

Well, I have changed my mind and will install retracts in this 757. The GWS nano retracts and gear door sequencer will be here tomorrow. This sequencer is capable of anything at only 10 grams:) Took me a while to find it though.... I cant wait.

http://www.wingspanmodels.com/Products/Electronics/LG.html

Any suggestions on retracts in small models is very welcome.

[Dentar]

Here are some pics...... still having problems with the damn camera though.
Progress is further along then these pics show.

The empty weight of the complete aircraft is around 110 grams. This can and will still be improved though by using different covering for the fuselage.

Next major step is installing the retracts and all those tiny linkages for the doors ect. ect. ect.

[MustangAce17]

looking good Dennis!

[Dentar]

Thanks Ace,

Now im also debating if i should go for the works and add flaps as well. Since the landing gear will add so much weight i figure the extra lift will come in handy for takeoffs and landings. Cant make up me mind...

[FEDEXDC10]

Good Progress Dentar

[scratchandbash]

Looks good. Just keep target specs and weight constantly in mind.
I've built through total TLAR, and through adhering closely to a spec, and you can guess which builds were more successful. :D

The best example of building to spec was my micro brushed EDF50 airliner.
I followed Dave Ramsey's specs for wing loading with brushed fans, and read everything he had to offer, since I was going brushed.

As the build progressed, I constantly weighed everything, and I mean everything, to stay on track. I had to cut the Coverlite covering sections, and even make close estimates for remaining glue and paint to be used, when I got to the point of designing the wing. When I could hit the target AUW almost dead on, I THEN laid out the wing, accounting for its weight/covering weight too, of course. I laid out the desired profile and continued to enlarge it, until I reached my target wing loading. In other words, the wing told me how big it was going to be. :D Well the wing was not exactly scale, and had less than scale taper, but it all worked.

The more I build EDF, the more I will continue to build to spec. The Yak I just got flying is another perfect example of non-spec building. It was not built to spec, and is heavy. Flys well, but needs power, and I'd love it, if I could go back and built it 3 ounces lighter or so. Could have been achieved, if I used thinner sheeting and was more conservative with heavy filler, etc.

Bill

[Dentar]

Always nice to get your input scratch.
This is the closest to scale model compared with all my other aircraft. Building to scale is much more rewarding, instead of just winging it.

more pics of progress comming tonight...

Thanks for everyones thoughts...

[Dentar]

No further progress was able to be made, the edf40's and the retracts have not arrived yet:( I did however buy some rare earth magnets that will be utilized on the engine pods to hold the fans in place. Works like a charm and gives the ability to just snap the fan off in case a motor or rotor needs replacing. It will aso allow for different fans to be used as they become available in that size, or the KP-44 could be used also wich is currently available and only a fraction bigger. More to come soon...

[scratchandbash]

No further progress was able to be made, the edf40's and the retracts have not arrived yet:( I did however buy some rare earth magnets that will be utilized on the engine pods to hold the fans in place. Works like a charm and gives the ability to just snap the fan off in case a motor or rotor needs replacing. It will aso allow for different fans to be used as they become available in that size, or the KP-44 could be used also wich is currently available and only a fraction bigger. More to come soon...
I used Velco to hold my nacelles and engines in place on the DHL micro airliner. The idea was to have breakaway nacelles. After solving the problem of the velcro mounting plates breaking away too :D , it worked quite well.

Bill

[Dentar]

Theres a different idea... I never would have thought that velcro would be strong enough to support a fan... certainly not a larger one. What about the wing attachment? what did you use to hold the wing in place? Im also thinking magnetsfor that, or your velcro idea, or anything else?

[scratchandbash]

Theres a different idea... I never would have thought that velcro would be strong enough to support a fan... certainly not a larger one. What about the wing attachment? what did you use to hold the wing in place? Im also thinking magnetsfor that, or your velcro idea, or anything else?
My little airliner has epoxy to hold the wing in place. I.E. it don't come off. :D
I use a lot of the GWS pin locators for foam wings, at the LE. You can buy the replacement plastic parts bag for about 2 bucks. I use a variety of different methods for the rear wing hold down.

The velcro strips on the nacelles are about 5/8" x 1-1/2" long. Plenty to hold the nacelles on. Any more, and it would be too strong, and not break away when needed. Wing was the first of my hand sculpted wings, like your Cessna.

Bill

[Dentar]

Thanks again scratch...

I got the main retracts installed and am now working on the doors and setting up the gear controller. Comming along slowly but surely.

[Dentar]

Just another progress update...video this time:)

http://www.rcgroups.com/forums/showthread.php?t=716765#post7846030

Certainly not easy installing retracts in this size model and get them to work...but i got er done...

[scratchandbash]

I see you actually went with the correct airliner wheel setup too. Looks nice.
I'm visiting my sister's at 1 mile from Dulles international. Really enjoying watching all the airliners come in. Where I normally live, I see them at 30 thousand feet, and finally hear them when they are almost over the horizon. :D

Bill

[CarreraGTSCS]

Dentar-- What brand are the retracts? Very nice job.

[Blaze.45]

You've got to be kidding me :eek:... that's some mighty fine work on those retracts for a model of this size and weight. My lower jaw actually dropped watching that video clip. :o

-Chris

[Dentar]

Thanks guys,

I had to go with the real wheel bogey setup... want this plane to look as close as a replica as possible. And tommorow the fans will get here so i can finish up this plane and fly her:)

The retracts are GWS pico landing gear, these are really tiny... smaller than i thought. The gear controllers is from wingspannmodels.

[FEDEXDC10]

look good

[FEDEXDC10]

dentar


can you build me a set of landing gear ?