spitmad

Sorry to hear Dave........that was a nice looking Spit !

well the WX here in Melborne is looking like crap this weekend (forecast is rain.......I'd almost forgotten would that looked like !) so no flying....I'll be bashing away at Spit again.....stay tuned for more pics and progress reports.

Alan

spitmad

Ok more progress

Cowl epoxied and fibre glassed in place, copious amounts of bog applied to fill the gaps and a couple of coats of high fill primer sprayed on.
After lots of snading and filling and sanding and filling yaddah yaddah.......end result looked pretty good
The underside access panel was then cut out for engine access

spitmad

The next step was to find a place for the switches and airfill valve
The radio compartment access panel was cut out and I made up a ply mounting plate for switches etc, just need to get me some piano hinges from Nelson Hobby (thanks Pete for the source info).

Working on the scale exhaust, I have opened up the three ports and hollowed out the back to allow hot air to be drawn out of the cowl.......hopefully

cheers

Alan

Peter_OZ

My Feedback: (1)

Al,
excellent work there mate.

Be pleased to get stuck in to mine once the 47 is off the boards. What weight do you think with that Spit?

Hey I'm now adealer for ESM / KMP kits, SPE, XYZ and DL donks! Plus a range of ducted fan foamies

cheers
Peter

www.petenplanes.com.au -> this is not a signature block!

rc-jg

That is looking very nice keep the good work going,im looking forward to the end result

spitmad

Thanks Jg

Hey Pete

Good news that you are now a dealer for ESM etc.............I had the guys from XYZ in China chasing me for months about signing up as dealer for their engines .....but not my thing (I was getting free donks from the guy here in Melb anyway.....he has since disapeared off the scene)...I bought a DL 50 for the Byron Mustang, it is great.....starts and runs beautifully.....still yet to fly it though.

Anyway back to the Spit..........as it stands now with the engine and retracts fitted (heaviest bits) it comes in at just under 20 lbs........so I figure it will be around 30- 32 lbs with paint and fully fitted out with servos and batteries, cockpit etc.............this should be a real floater with over 2000 squ inches of wing .
I was talking to the bloke who runs the LHS who build one of these 15 years ago and his weighed around 35 lbs with a G62 up front and he reckoned it would not land without flaps as it just hung in the ground effect !!
Anyway I have been working on those exhaust stubs, hollowing them out and opening up the exhuast ports, the plan is for them to vent hot air from the cowl thru all three exhaust stubs on either side. As these are tru 1/4 scale they are a little larger than I need so I have had to cut them down quite a bit to get them looking "right"

Peter_OZ

My Feedback: (1)

Gday Al,
I'm hoping it should work out ok. I just sold my first ESM Hurri with retracts so good start!

XYZ are good little donks, mate of mine has a26 aned loves it, has it fitted to a nieuport 17. Delightful little plane. Your going to have to get that 51 back in thair again. Did you keep the reduction drive or have you converted to direct drive? Mind you a DA-85 swinging scale solo 4 blader might be an option to consider . . .

Where did you get that foam you lined the insides with? Glue type?

Well off to pack some orders!

cheers
PEter

ticketec

My Feedback: (2)

Maybe not a big strip but enought to get some pace on the Seafury while doing engine runs

Looking great there alan, she is really starting to take shape, and with the way the Aussie dollar is looking at the moment these MD offering are looking far more attractive, now, if only they would do something german....

For your cooling issues, have you thought about an electric ducted fan? there are more than one guy out there that is using a cheap EDF setup to cool their engines. there was a guy on RUC who did it for his 1/7 scale TF spitty. check out hobby city website for motor and fan combos for $20-30. just need a small lipo and a cheap ESC, all up should cost more than $50-60.

Thanks

dave

spitmad

Pete
I bench ran a few little XYZ donks and (like most of the stuff from China) they were great, easy to start and good throttle response.........The P51 now has a direct drive DL50 installed, I still have the reduction drive but could not get is running reliably with a CDI engine and the AUW of the P51 had hit 27lbs after reglassing and patching up all the dings, I think it would have really struggled as I was still only getting 3500 rpm at the prop. The replacement blades were certainly stiffer than the old flexi blades but still not stiff enough to enspire any confidence.....The DL 50 with a 22/10 at 6500rpm should pull it around with ease .............not as visually impressive but at least it should fly with authority.

Here is shot below of the engine install, I have added a fan which I cut from an aluminum disc between the prop shaft extension, this provides cooling to the fully enclosed engine.
I need to pull my finger out and get the P51 flying again but need to get it recertified due to the engine change

G'day Dave

Yes I did have a EDF in mind for the Spit cooling, I was going to build a duct behind the cylinder head and exhaust the hot air just in fron of the wing saddle, together with a fan behind the spinner plate and vented exhaust stacks should provide enough air circulation to keep it all cool.............I'll check out that Hobby city site

The MD kits are quite cost effective however they are a hell of a lot of work, I also have a 100" P51 "in stock" I have almost completed the wing but then got side tracked with the Spit (the Tempest build is also in a holding pattern)

Anyway more progress on the Spit last night, the exhaust stacks have been cut down considerably and hollowed out, I juts need to work out a method of installing them

spitmad

Pete

The polystyrene foam in the fuse is a 3mm sandwich which was laid between the layers of cloth.....this was done by Ernie when he laid up the fuse.
The fuse had some pretty big flaws in it down towards the tail and just under the exhaust stacks which I have bogged up...............not perfect however no real warbirds were.
The front section forward of the cockpit was very soft so I added another two layers of 6 oz cloth , I will epoxy in two fuse formers made of polystyrene foam down the back of the fuse to stiffen it up and prevent drumming.....and twisting .

Stay tuned for more progress pics

Brad330l

My Feedback: (1)

Al, are you going to have to use extra extensions for you batteries because of where your switches are? The batteries will be way up front yeah?
I so want to cut out and use this hatch for my switches and air fill/gauge on my Spitty but was a bit worried about current loss through the longer leads as I was not going to use a power box, just two batteries straight into the RX and they will be right up near the nose.

Cheers,

Brad

spitmad

G'day Brad

Yep depending on where the CG comes out, the batteries will most likely by well up front, I usually use 2 x 3300 NiMi packs (5 x cell sub C's) into the Multiplex 12 chan RX (the MPX RX has two battery inputs and manages battery ouput/balance just like a power box), These are pretty weighty battery packs and last forever , I usually use the hi current gold plated and twisted silicon ext leads for all extensions, I have found these to be the lowest in power loss.

The easiest way to check if you don't have a multimeter is to plug in your Hitec bettery checker (I assume everyone has these) into you ext lead connected to your battery and see what leads perform best.

Anyway the Spit is still pretty light in the tail as I'm using a carbon push rod for the elevator and tail wheel and pull/pull on the rudder, the servos will be mounted at the rear of the wing saddle, just behind the cockpit. I also plan on fitting an electric ducted fan behind the donk to draw cooling air past the cylinder head, this will add a bit more weight up front so I should not have too much of an issue balancing the model.

cheers Alan

Peter_OZ

My Feedback: (1)

with the electric DF unit you will have a nice supercharger whistle!

spitmad

Hey I had not thought of that

Peter_OZ

My Feedback: (1)

Al,
when you build that Tempest wing take close note of how the outer panel attachs to the inner panel and how the gull butt joint is reinforced or should say little reinforcement. Had a main wheel hang up yesterday on the seafury and could not get the other down or the down one up. So landed on one main and the tail wheel. All good except the leading edge at the gull butt joint has cracked right through from top right around to the bottom.

Think the way the gull is reinforced needs to be beefed up and the dihedral braces made deeper and to extend out an extra rib bay in each direction. Leading edge needs one as well as the 1/4 x 1/4 spruce is not up to the job.

will drop a 3/16th ply brace into the leading edge on both sides and beef it up.

cheers
PEter

spitmad

Bugger !!
Thanks for the heads up Pete, the Tempest wing build is next on the list once the Spitty is done, I have all the lazer cut ribs and lumber to get it started......juts need the time

Looking at the plan it did look a little "underdone" in that area, I was also going to extend the mid section the extra 2" for the proper scale span as per Neilly's build on the RC scale builder site.


BTW

Did you end up putting a bigger donk in the Seafury ?

cheers

Alan

Peter_OZ

My Feedback: (1)

Gday Al,

i'm also going to do the extra 6" as per Neilly's.

I think a 3/16" 6 ply brace right in front of the rib ends will fix it nicely, other structures should be ok but wont be doing high G turns and pulls ups.

I still have the G62 but changed the prop to a 21x12 which made a big difference, take off roll is still long but it now climbs out nicely and in the air there is abig difference so will soldier on with the G62 for now.

That way I have the DA85 ready for the Tempest or 1/4 scale Yak 3 builds.

cheers
Peter

spitmad

Hey Pete

Hmm A 21x12 you say..........I'll keep that in mind when I fly the P51 with the DL50, I have a 22x10 on at at the moment and was going to go the other way and try a 23 x 8......

Anywaymore progress pics

The Exhaust was cut down for a better fit and hollowed out to draw hot out out of the cowl, a little more work required to clean them it, I also added the blisters to the front cowl, these were scaled off pics I took of a Mk V at Duxford and a placky model I have. I carved the blisters from balsa and laid some 3/4 oz cloth over them, just need to sand, fill and prime.

I also drilled out the position for the fuel filler, the 3W filler will be in the scale position on top of the main fuel tank............a little big but what the hell

Peter_OZ

My Feedback: (1)

good work, if you recessed that filler then no one would tell. 3W in 1941 hmmmm

spitmad

I may just do that

I had little more time in the shed last night ...........with a glass or two of a rather cheaky Shiraz

I sprayed some high fill primer over the cowl blisters and epoxied in some mounting rails for the servo tray behind the cockpit, this will mount the elevator and rudder servo.....the elevator will be actuated via a carbo push rodd and I'll use pull/pull wire on the rudder...........thinking of using a third servo for the tail wheel rather than use another pull/pull off the rudder servo......hmmm food for thought.
Next step is to finish the elevator covering and detail (dummy push rods for the trim tabs).

Anyway stay tuned for more pics

Al.

Peter_OZ

My Feedback: (1)

use a sig tiller arm like I did on the seafury and P51, arm from the servo to drive it, then the outboard holes go to rudder and the inner to tail wheel.

Have a few of those listed in my website.

See attached pic.

Brad330l

My Feedback: (1)

Al, thanks for your thoughts on the battery leads. I will get some good quality short extention leads and try the voltage drop with and with out leads.
I wont be pulling much current at any one time while flying my Spit as I am using analogue servoes not digitals so should be OK.
Hi Pete.

Cheers,

Brad

Peter_OZ

My Feedback: (1)

gday Brad, get the bloody P51 done !!

spitmad

No probs brad

Pete......I'm using a large tiller arm directly onto a servo so the result will be the same.........I'll probably use Metal 645s on the rudder and elevator....10kg of grunt should be plenty for the back end.

Al.

spitmad

Guys

progress on the Spit has been slow over the last few weeks however I have installed the pull/pull for the tail wheel and rudder and further work on the back end control surfaces..........in between getting my TF Jug and Byron P51 airworthy again........(wiping off a thick layer of dust and charging batteries and running up engines)

More progress pics to follow shortly

Al.