1/7 Harvard Conversion

Re: 1/7 Harvard Conversion

Postby Dale » Sat Jun 08, 2013 11:40 pm

Sorry about the pic quality, my SLR just went on holiday to the states, so cellphone pics from now on. (It also took the missus along with it :D )
Outer wing panels are next in the queue.
I originally had intended to just recover these (after changing the flap as per the centre section) with Solartex, for simplicity and weight, as they also have open bays, glassing of course doesn't work here.
However, thinking through the whole process, it decided in the long run it would be better to glass them. (extra support for the flap hinges, and so i can ensure the same finish all over.)
So i had to cut out the cap strips, and then sheet the open bays. Cheers John at JR Airsail, now you know where that 2mm balsa you just sent out went!
IMG_20130607_204507 (Medium).jpg

As part of this, i decided to put an extra servo in to operate the respective flap. (originally had a single centre servo, operated the outer sections by a wire joiner)
The aileron servos are mounted on sweet little plastic mount hatches, and those paying attention will appreciate why i have a "spare" set of these, so it was a pretty simple effort to simply replicate the aileron mount for the new flap servo. The new bay can be seen in the above pic, and below with the mounts.
IMG_20130608_095000 (Medium).jpg

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jun 09, 2013 12:48 pm

Was just fitting the wing securing bolts, which meant i pretty much ended up with a good opportunity to "refill the enthusiasm tank" with a photo op:
2013-06-09 12.30.37.jpg
Looks like a glider wing from this perspective!

2013-06-09 12.42.59.jpg

2013-06-09 12.31.35.jpg

Recall this is a 6ft span, so there goes the lounge taken over as well.
And yes, before anyone asks, "unyellowing" the canopy is on the list.
Centre section is in process of being filled and and smoothed at moment.
Next major job will be to replicate the wing joint fairings. (More on that later.)
(Sharp eyes will also spot the rudder is covered. Even sharper eyes will have noticed this a couple of weeks ago...)

Re: 1/7 Harvard Conversion

Postby Dale » Mon Jun 17, 2013 9:31 pm

Hasn't been much progress in the last week, was away with work.
So here's one i prepared earlier:
Control surfaces, pretty much got stripped, quick sand and fill where needed.

And using some camera tricks:

Covering is unpainted solartex. Goes on beautifully, miles easier and looks better than any plastic iron-on i've ever played with.

Regarding previous pics, had some comments about how "bad" the canopy looks, so working on something else there.
Also have a cowl former in progress.

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jun 23, 2013 8:31 pm

Wings are done, all sanded and smooth. Took quite a bit of effort, and more than one can of high-build spray, (most of which now coats the inside of the vacuum cleaner).
Next job is the wing joint fairings-
The (1:1 scale) Harvard has an interesting feature in that the outer wings are fairly easily removeable, being held on with a flange around the outside of the wing joints, with about a million bolts holding the two flanges (and thus the wings) together. This then has a simple cap over top to make it a little more aerodynamic, and a whole lot more aesthetic.
This is typical of the detail that really makes aircraft unique, and yet is missed from many ARF's, so i was determined to replicate this somehow.
What i did was sandwich a sheet of 1.5mm between the two wings, (after cutting clearance for the various joining hardware), and then gluing 6mmx6mm strip all the way around, on both sides of the sheet. Toyed with trying to bend it, but just ended up cutting in short lengths and (badly) fitting them individually.
This is then removed from the wing, and sanded to about the size and shape i wanted.
Good thing about this is completely covers the joint on the wing sections, (duh!) so hiding any misalignment or gap.
My wing joiner strip covers

And the result looks a million times better already, at the rough sanding stage.

And re canopy, i decided (after some prompting) that the factory canopy just looks crap.
Did some research on the old interwebs, and about the only one i could find of a similar size is from Top Flite.
Interestingly, Top Flite did a kit, of 69" span, which of course had the old cut it out and paint it yourself canopy.
More recently, the kit has been discontinued, but they now do a 69" ARF. You would think this was the kit, just assembled by someone else, but apparently not.
However both canopies are available for a few bucks, so i grabbed one of each.
Yes, they are different...

In silver is the Top Flite ARF version, the yellow is the World Models ARF (as seen in previous post) and behind, unpainted and uncut, is the T/F kit one. (You would have thought the two T/F canopies would be the same, but quite different in size, frame molding etc)
They are all within cooee of each other lengthwise, but the T/F ARF is around 1/2" lower in height than the other two. I haven't got the machine back together in order to to do some comparative testing, but i think i know which one i prefer.

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jun 30, 2013 5:34 pm

This week consisted of a lot more sanding and painting, including a lot of old ground. The entire wing and fuse got another going over.
I'm about to track down some pinstripe tape, (for that "painted over tape" look) and start putting panel lines on, a job for after school this week in front of tv me thinks.
Canopy, was a simple decision, going with the Top Flite silver ARF jobbie.
The control surfaces are now painted. The 1:1 machine had silver doped control surfaces, so in my case this is silver paint on the solartex.
Hinged all the surfaces (except flaps) with Robart hinge points. The pack of hinges i got included a drilling jig, which has instantly made it onto my list of how-did-i-ever-live-without-it-and-now-indispensable tools, so for the first time since it was yellow all the (main) bits are in place. (nothing glued yet till after topcoating.)
The cowl is continuing to "do my head in", i thought i would take the easy route (ha) of using the top flite corsair cowl as a male mold, but this has pretty much turned into a disaster, for several reasons. However, onwards, so working on plan B.
Unfortunately, this has held me up a bit, i gotta have this done in 4 weeks from now, so i got time to test fly prior to sending it to Forsyth.
Hopefully have something underway for the cowl this week, as well as panel lines and gear doors.


(And the jury is still out regarding pilot/cockpit).

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jul 07, 2013 8:25 pm

Spent about 8 hours applying pinstripe tape around the place. Been through 3 rolls of 3mm from Repco at $11 per roll.

Then started painting.
Barf at the RNZAF Museum, who painted the 1:1 NZ1050, has been excellent providing information, including paint codes. However, I was let down by the West Auckland automotive painting industry, several members of who told me in no uncertain terms that they just wouldn't help, or "that's not our product, go google it to find out who might have it", so i gave up trying to find the matching paint, and a trip to Mitre 10 to grab a few spraycans in the closest matches available. (at least i don't have to clean up the spray gear this way.
Wing after 1st coat. It seems that the metallic gloss definitely shows up every slight blemish. I'll probably get over that though.

Also found a cowl supplier in the US who has one perfect, so have ordered a couple.
Also started making up some gear doors, will be same idea as on the Typhoon.

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jul 14, 2013 9:08 pm

Painting has been the main goal this week, when possible.
The entire thing got the aluminium coverage, and now am into the orange (dayglo). Gotta do the rear fuse yet, and the matt black anti glare panel forward of the cockpit. All is hardware store enamels, so need a fuelproof topcoat before i can call it done.
Have also drawn up the markings, will be getting them made up soon.

Am quite pleased with the look of the "aluminium" wing and the "silver doped" aileron.
This is just one small part of the info I got from Barf at the Air Force Museum that is proving to be very helpful!
Harvard 1959 Silver-Orange Scheme-page-002.jpg

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jul 21, 2013 7:02 pm

Painting painting!
All the coloured parts are done (except for some details), am now in the process of applying a clear petrol resistant topcoat over the whole thing.
Really makes the aluminium look good in particular.
Much appreciative of the guys at Car Colours on the North Shore, these guys have been great with suggestions, test sprays etc. Although one major lesson has been learnt by me, next time i build a I/C model, i'll talk to them first and plan the whole paint process a bit more coherently, with better product/results.
Also have a cowl, i grabbed two radials, 7.5" dia x 6" long, which will be cut short to suit, from http://fiberglassspecialtiesinc.com/, arrived a few days ago, perfectly packaged and well made, only took me about half an hour of work time before i was squirting topcoat onto it.

As the bits get their clear coat, they move to the reassambly stage. Have the centre section flap in place, retracts and doors.
Pics don't do it justice, but it looks good so far!



Re: 1/7 Harvard Conversion

Postby Dale » Sun Jul 28, 2013 10:03 pm

The pile of bits is getting smaller as it turns back into a single mass.
All the control surfaces are properly reinstalled now, the hingepoints are glued in. I like these things! Definitely more work than CA hinges, but the extra work show up in a better joint. As its the first time i've used them in anger, i spend a while researching on the interwebs, and got them in no problems.
Rudder and elevator servos are in, and pushrods reconnected. These are just the supplied items reinstalled.
Tailwheel is on.
Engine mount, engine, fuel tank, throttle servo and made a carbon pushrod are all in.
Made up the Canty crest on the fin, this was a graphic supplied by the RNZAF Museum, which i printed on glossy self adhesive label paper, then put some clear tape over. Stuck in place, then clearcoated over.
Cowl fitted, used a Dubro cowl mounting system, was about to try make something similar till i spied this in the shop.
Still gotta fit the engine batt, switch, ignition system and muffler, rx batt and switch, aileron and flap pushrods, canopy, cut cowl holes, paint cowl anti-glare panel, and all those seemingly thousands of other small jobs...

Re: 1/7 Harvard Conversion

Postby DH100 » Mon Jul 29, 2013 10:23 am

It will surely look the part in it's new scheme. Great stuff.

When I was a kid the Air Force used to have an annual Open Day at Whenuapai and Hovsonville. For a couple of days during the week prior ( weather permitting) a Harvard could be see well above Auckland, skywriting an advertisement as a promo for the coming event.

Most likely they were all silver then with very little decoration.... an indication of how ancient I'm getting!

Keep up the good work.

Re: 1/7 Harvard Conversion

Postby Dale » Tue Aug 06, 2013 9:39 pm

Getting close!
The wing is done, (other than a couple of minor details that will take seconds and the markings). Wing AUW is 1938 grams. The three flap servos are all on one channel. Had to reverse one servo, which i did by opening the servo and reversing the wires. Retracts work sweet.


Fuse is also almost done, canopy has been tinted to near black and fitted, might have a further idea for that in future. To fit it, i added a small blob of car bog behind each mounting point, then drilled and tapped it, and screwed a 3mm clear plastic machine screw and washer into it.

All the radio gear is in, have put the batt switches in front of the canopy on the black anti glare panel where they blend in.

Ignition module is in, fastened it onto a small bracket below the motor. Just gotta do some slight extension to the the exhaust outlet, then can fit the cowl.

Will be endeavouring to undertake some engine runs in the next few days, and first flight within the next 2 weeks.

Re: 1/7 Harvard Conversion

Postby Dale » Sat Aug 17, 2013 3:23 pm

Been a couple of weeks since update, sorry about that.
What have i done lately? Got the exhaust finished, which consisted of a little bit of shagging around, but now is all sorted and i'm pleased. All radio gear in + tested + set, had some engine runs, and lots of little jobs done. AUW (enpty tank) is 5.2kg, and almost unbelieveably, i had to add 230g of lead to the firewall, despite this motor being heavier than anything else this machine has carried previously. I guess a little paint/epoxy down aft goes a long way!
Also made up some wing bags, the silver/foam underlay is available at Bunnings for $3.50 in the flooring section.
Really the only construction item left is to fit the vinyl markings, which have been delayed slightly.
In short, it's ready for a test flight, which has to be in the next week to prove she flies before boxing it up and sending it down south.
Watch this space!

Re: 1/7 Harvard Conversion

Postby Dale » Sat Aug 17, 2013 3:30 pm

Latest pics. Due to the crap weather today, lounge floor again.
Note the "scale" exhaust location!




Re: 1/7 Harvard Conversion

Postby Dale » Sun Aug 18, 2013 10:01 pm

Gotta have the pic, it might not ever look this good again!

First flight was a success! (Well almost, read on).
Raced down to me club this afternoon in the calm weather so spent a while spent running the engine and taxiing, and some briefing notes i gave the Tx to me old man for the honors. By this time, i had the cowl off to give the needles a slight tweak.
Off she went down the runway in a scale like fashion and climbed away nicely. By all accounts it flew nicely, without issue at all. Gear stayed extended, and flaps retracted. had around 6-7 min of good stooging around, no trimming at all required (a first!).
Carried out some landing approaches, and on the "last" one the engine quit at 20ft half way down the strip, so quickly pulled up the gear and bellied her in on the peat, with no damage other than the prop. Glided this last stage in pretty nicely actually, so looks good for proper landings! Cleaned it up a bit, new prop, and was setting the tune again for another go when the sun disappeared over the horizon and had to call it a day, but will call it a success. Home to clean it properly and give it a good going over to check all is well. Hoping to have time to give it another flight before it is packed in the box for the trip south, but more urgently i need to spend some time getting familiar with tuning 2 stroke petrol motors!

It flies!

Motor batt = 450mAh
Rx batt = 500mAh

Re: 1/7 Harvard Conversion

Postby spitfirekid » Sun Aug 18, 2013 10:08 pm

Congrats Dale! 8-) 8-) 8-)
Well done , a credit to you on the build and congrats to ya Dad for putting her in the air, Team work!!

look forward to seeing her fly
Posts: 3
Joined: Mon May 27, 2013 9:43 pm

Re: 1/7 Harvard Conversion

Postby Dale » Sun Aug 18, 2013 10:16 pm

Cheers man, was great to see her flying, can't wait to have my turn, but at this stage also happy to watch it being flown myself.

Re: 1/7 Harvard Conversion

Postby Dale » Mon Sep 02, 2013 10:23 am

She made it to Forsyth, and had 4 flights there.
Spent some time mucking around with tuning, and really getting to like the motor, mostly as i get more familiar with it, and the confidence grows.
First two were under Dad's pilotage again, then i got brave and took it for drive, and felt pretty good.
Landing was a little fast, as (i found out afterwards) the muffler had come lose, so idle speed was around 4000rpm!, however the long runway and grass overrun brought her to a stop and all was well.
Dad another flight the next day, first flight with cowl on, (sorry didn't get any pics of this one!), landing was a bit challenging due to the ever increasing winds, (had to give the undercarriage a quick realignment afterwards), but all well.
Gear retracted all 4 flights, no issues there at all. Looks heaps better with it up! Gotta start getting used to using flaps now. Takeoffs are pretty easy, doesn't have the shortest takeoff run, but is fine. Is very controllable on the ground. Currently flying on a 15x6 Xoar prop, which results in nice scale flight. Has also flown on a 14x7, but preferred to trade the speed for thrust. Once the engine loosens up a little more might try a 15x7.
I spoke with several modellers down there who have read this blog, cheers for the interest guys, and thanks for your positive comments on her. Very pleased with everything.
(Also well done to all the CRFC and the Forsyth organisers, awesome event, so pleased i went down.)
So she has 5 flights under her wings now, and looking forward to getting the final details completed, (which is mostly just the markings) and then flying her regularly.
(Note I have now already starting thinking about the next project...)


Re: 1/7 Harvard Conversion

Postby runfrcover » Wed Sep 18, 2013 6:41 pm

Very nice Dale! I think even Dave would say that's a nice looking 'halftard'. I think I may have to give my Rambler similar treatment
Im liking what I hear about that engine
Posts: 2
Joined: Tue Sep 17, 2013 10:36 pm

Re: 1/7 Harvard Conversion

Postby Dale » Wed Sep 18, 2013 8:20 pm

Cheers Mark. Has all been fairly easy, and very enjoyable.
Hopefully you'll see it at the club sometime.
I'm definitely a fan of 'glassing now, but even the solartex is miles better than the guaranteed-to-peel-off plastics.
Much enjoying the engine, I think I'm pretty much done with glow.
The Rambler is a good machine, might be worth a little work to keep it flying for a long time.

Re: 1/7 Harvard Conversion

Postby Dale » Sun Jun 15, 2014 7:44 pm

I hope this is the final post...
Finished! So very pleased with it.

Had a couple of great flights today with her, first flight in the full markings. Was enjoying flying it around so much on the first flight i ran it out of gas on approach! (In my defence, it was running quite rich, so it drank faster than i allowed for.) All good though. Really happy with the engine, a couple of clubmates have since bought one themselves, and i'm considering a larger unit from the same range for another project in future. Seems to be getting more powerful as she gets some hours on her, total running time will be under 4 hours at this stage, gonna try the 15x7 next flight.


Cheers to everyone who helped, supported and tuned in.


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