New 78" Vulcan for twin 90mm DF

[PeterF]

A lot of messing about cutting out the hatches, adding linings to the edges and catches to them. I have cut the radio, battery and fan hatches, the main undercarriage doors and some air inlet slots for the ESC heat sinks. I have added air outlet slots in the radio hatch and 3D printed some air scoops for the ESC inlets and outlet ducts for the radio hatch. Like everyone else, I have put the battery access hatch on the top of the plane and made it longer than the one on the plan. During the turtle deck build, I doubled up on a couple of the formers with a small gap between them, left the location marked and cut the hatch out using a hacksaw blade.

One word of warning for anyone that follows me and makes the inlet ducts to the fans longer than on the plans, the ducts will overlap the fan hatches and if like me you waited until the end to cut these hatches, then the ducts and the hatches were glued together. If you do this, then when fitting the fan inlet ducts DO NOT put glue on the bottom of the ducts in front of the fans.

I have also very lightly sanded everything in preparation for a coat of high build primer to knock back the stippled texture from the peel ply without going into the glass cloth.

I am amazed how much time I have spent on these tasks and the build does not appear a lot further forward, I suppose because there is no real visible additions to the aircraft.

Fan hatch and ESC air inlet slot cut out. Notice overlap of fan inlet duct and hatch.

Fan hatch fitted

ESC air inlet slot and start of ESC heat sink

3D printed air scoops for ESC cooling air inlet

Radio access hatch with 3D printed air outlet ducts. This is in the plan position.

Battery access hatch completed in open position

Looking forward in battery compartment to the ESCs

Battery hatch closed

Edited By PeterF on 19/04/2020 16:58:22

[PeterF]

One week since the last update, and this has consisted of 2 days applying a thick coat of high build primer (2 pack acrylic) and 5 days of sanding it down. I am now at the stage where I have to do some areas with a second coat of the high build primer to fill a few imperfections before I can apply a final light coat of primer. I was worried that the solvents in the primer would attack the PLA 3D printed parts, but that has not been the case after a test piece so this has filled the prints and has left them perfectly smooth. Since I am going nowhere it is keeping me occupied.

[patrick mcateer]

Nice work Peterf, im waiting for my edfs to come they are the 12bl 10s, i havent done much more as im waiting for them to come. im still not sure of the esc to get for them but ill keep looking. im also going to be putting the hatch on the top. i will take some photos and put them up. also peter i bought a 3d printer and bulit it so that i can print your parts out that you sent me. just having some teething problems with printer lol but ill sort it,

keep up the good work oh were did you get your primer from

[PeterF]

Patrick,

I used high build primer from Jawall, see here with the appropriate thinners, see here.

I found a lot of useful info on a thread about peel ply application earlier in the year, see here including primers and the fact that some people had brushed high build primers.I do not have spray equipment so I brushed it on, I needed to add more thinners to get a good brushable mixture without it going thick too quickly when brushed out.

The high build primer I use is an isocyanate based paint, hence has a lot of health warnings if it is being sprayed as the isocyanate is a sensitiser if inhaled or in contact with skin. As I was brushing I was less worried but still applied it wearing disposable gloves in a well ventilated area.

I will email you the air vent files in case you are also interested in these.

Edited By PeterF on 27/04/2020 10:01:53

[patrick mcateer]

Good morning Peter, yes please i will have those files. i have never covered a plane in glass clothing so i will be reading up alot and doing sample tests when i get that far.

i have had alot of triuble trying to find the 12b 10s edf but managed to get them, they are the lander units but im not sure about esc to get for them as im new to electric i usually fly petrol and nitro. your build and greggs build has being helping me alot.

thanks

Patrick

[PeterF]

I have YGE ESCs in mine, they are expensive though. You need to make sure that whatever you buy, it will need to be good for higher voltage, in your case 10S, not all ESCs are good for the higher cell counts. The higher voltage ESCs tend to not have a BEC power supply on board for the RX and servos so you will have to set up your own power feed, either a standalone BEC or separate battery for the Rx. With larger planes like this I tend to always set up a dual power system with a diode pack so either can supply the power and have a standalone BEC and a battery pack, with the BEC set to a higher voltage, so the battery acts as a back up if the BEC fails.

[Martin McIntosh]

I have a YEP 120A on a similar 10s fan. Separate 2x 1100 LiFe packs via a Failover switch.

[PeterF]

Another week of sanding, painting, sandling and painting, priming finished and the first coat of final colour has gone on, light aircraft grey with a satin finish. I will give this a very light rub down with 600 or 800 grit paper when wet before the final coat. The finish i have achieved is not the best that I have seen, but given that this is the first time I have glassed such a large plane I am happy with what I have achieved.

[ken anderson.]

hello PeterF...for a 1st go it looks spot on...

ken anderson..ne..1...spot on dept.

[PeterF]

Groundhog week!!!

Another week of sanding, painting, sanding and painting. I have now finished the light aircraft grey underside and the upper surfaces in camouflage pattern using medium sea grey and dark green. Masking tape is still on between the upper and lower surfaces. The pattern is taken from various photos and drawings, it looks about right but I have not been pedantic in getting the demarcation lines spot on, the whole model is basic scale. If it looks like a Vulcan then it must be a Vulcan.

I am glad that is over, it is 4 weeks since I completed the glassing and started sanding.

PS. I have just remembered that I have yet to paint the exhaust nozzles, and here I was thinking I had finished. Just when you think it is safe to go back in the workshop........

[Greg Minden]

loving it!

[PeterF]

Painted the exhaust nozzles, mixed some dark grey into some silver to mute it down, touched up a couple of bits, added the decals which I printed onto inkjet vinyl and cut with my wife's cutting machine (she does card making as a hobby). Attached the control surfaces and the rudder servo. Before anybody says anything, yes, I noticed I had a mismatch on the camaflage on the port wing, this will get sorted. The retracts are not yet fitted, hence I set it out on the workmate. A bit of sunshine in the garden this afternoon so I thought I would put it together.

[Gary Clark 1]

I've been following along peter and I think you've done an excellent job there.

Very impressive.

Gary

[Martin McIntosh]

Magnificent.

[Craig Carr]

Beautiful work Peter. Nice one

I must get around to painting mine

[Greg Minden]

Time to get after it Craig! People are waiting

[patrick mcateer]

very nice job done there Peter

[PeterF]

Progress on the Vulcan has slowed down as I have been able to get up to the flying field for 5 afternoons out of the last 10 since the last update. All the time since then has been spent on the undercarriage. I had a set of electric retracts with oleos in the spares box, these are larger actuators than those supplied with the kit so hopefully they should be up to the job, especially if I link some of the retract doors to them. I had to make the openings in the retract mounts slightly larger to accommodate them. The problem I had was I needed to make some adapters to length the oleos by 20mm to suit the Vulcan and then make up the twin nose wheel adapter and the 4 wheel bogies for the main u/c. I have a small lathe with a milling attachment so that was quite straight forward. I have added a spring on the main u/c as per the set Tony supplies to make sure the bogies sit correct during landing and when retracted. The springs attach to the front of the bogie and a 3D printed bracket on the oleo leg. The steering servo fits nicely on the central former.

Edited By PeterF on 22/05/2020 14:27:08

[Greg Minden]

looks good!

[PeterF]

Still progressing albeit more slowly. The control surfaces have been hooked up properly to the servos and throws etc. checked out. All the electronics and wiring has been installed and clipped into place. I have installed an igyro 3e as per the instructions on the plans and this is working OK. I have done a power test, the fans run on 8S and with freshly charged batteries at around 20°C I was seeing 28.2V under load and 101Amps per side at WOT. This equates to a total power of 5.7kW. My batteries are well used, hence the voltage sag to 3.5V per cell under load, when they were new they held up better than this at 100Amp discharge rate. I have weighed the plane and all up without batteries it is 9.04kg (19lb 15oz) and with batteries 11.38kg (25lb 2oz). This gives an impressive 227Watt/lb which should be fine for a floater of a plane. I still need to sort a final bit of wiring out, and build the battery pack retention straps / guides into place then it is ready for the maiden flight. I have as yet not installed the wheel well doors, depending on the weather and building time, they may get installed after the maiden.

Ailerons at full deflection

Elevators at full deflection (I could add more up but this is as per plan)

[Greg Minden]

very impressive! I love your finish. I used the CG as per the plan and it worked out fine.

[PeterF]

Posted by Greg Minden on 01/06/2020 18:24:53:

very impressive! I love your finish. I used the CG as per the plan and it worked out fine.

Greg,

Thanks for this, I did not state in my post that I had checked the CoG with my batteries right forward and my Rx back up battery attached to the former next to the nose leg I came out spot on the CoG per the plan. Most of the weight is on the main wheels, only about 0.5kg (1lb) on the nose wheel so it should rotate OK.

The other thing that amazed me was after all the work, the left and right wing panels weighed within 1g of each other (1137g vs. 1138g), pretty amazing.

[Greg Minden]

i can't remember if you said you measured your wingspan? Ours have all come out to 83"

[PeterF]

Yes, 83" here as well.

[PeterF]

As the weather in the UK has entered summer season (for those overseas read cold wet and windy) it has not been conducive to performing the maiden flight. Therefore I have got on with fitting the gear doors. Nothing on the plan to help out with this, just made it up as I went along. The gear doors for the main gear are the cut outs from the wing sheeting reinforced with a sheet of hard 1/16" balsa to add some more rigidity. I did not sheet the nose bay with the rest of the nose so I had to make up a couple of doors for this.

The doors have been hinged with furry cyano hinges, with the backing balsa on the doors I could cut a slot at an angle through the double sheet. For the fuselage I glued in some backing strips under the sheeting and again used an angled cut. The gear doors are operated by some mini retract servos from Logic RC, LSX260R, not sure if they are still available, similar size to the old Ripmax SD200 servos. I needed more throw so 3D printed some add on horns to fit to the disc horns. The horns on the doors are 3D printed. For the nose doors I have a servo each side, i.e. one per door, it was simpler in my view to do this than try and do a linked system with so much happening in there with the nose steering etc, and the total length of the bay is taken up by the u/c, the tyres lightly brush the rear bulkhead as they pass by it.

The trapezoidal rear doors on the main gear are connected to the main legs rather than having their own servos, hopefully the gear will be strong enough to close them against the air flow, but then my retract units are larger and more powerful than the TN items (learning from reading Greg's build log). The retract units are the XL aluminium units from Pichler Modelbau in Germany.

The retract / door control is by a retract sequencer from SM Services, now no longer trading. Plenty of photos to illustrate how I have set this up mechanically for people who may be interested. Also a video demo of the test when completed. I need to tidy up the edges of the doors / cut outs and then paint the inside of the doors.