DH100 Vampire Jet - pusher prop -Second Entry 5th Sweepstakes

Started by ashok baijal, April 16, 2014, 03:08:29 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

ashok baijal

I was under the impression that the 5th Sweepstakes end on 15th April. After maiden of the Fokker DR7, I realised that it is 15th May. So I thought why not start the RC Skydiver build that I have been planning for quite some time. But then it will not get finished within the time available and moreover, my glow engines require a lot of attention after remaining packed for last 6 years. They are totally gummed up. So while I service the glow engines, I am planning to start a quick build.

So today, I have traced the components of a biofoam Vampire Jet (prop driven). The mandatory opening shots with todays newspaperare here. The plan by DZ1SFB has been taken from RCGroups forum.

K K Iyer

@ashok baijal
Add a pic from DZ1SFB. It's beautiful.

ashok baijal

The next step was to do a rough cut of all the parts. The parts were arranged to give an idea as to how the model will look once completed

ashok baijal

The wing consists of two panels, the main wing and the KFm overlay. The first step was to mark the positions of the servos on the main panel and cut slots for them. Slots  for the wires were also cut.

Next step was to make the slot for a 5mm carbon fibre rod to support the wing. Since holes were cut for the servos, to strengthen the wing a second strip of carbon fibre was also fixed on the main panel. The CF rod/strip was tacked using hot glue. To mark the location for the CF rods, the KFm panel was gently pressed on the main wing panel. Slots for the CF was cut along the impression on the KFm panel

ashok baijal

The wing panels were then stuck together and left to dry overnight. Checked this morning, the wing was still not fully dried up, so left to dry further.

I do not have a dremel so for cutting the carbon fibre rod, I tape the CF rod with masking tape on either side of the mark before cutting with a mini hacksaw. This prevents the CF rod from cracking. This trick works for me!! Just be sure to use a light hand and let the blade do the cutting. Do not press the hacksaw.

ashok baijal

Next step was to glue the fuselage pieces together. The fuselage is made up of 8 panels, 4 of which form the internal cavity.

I started by gluing the inner 4 panels together and left them to dry for the night. Today morning I separated the three pieces of the inner cavity.

The lower piece was glued to the two outer panels and left to dry for the day.

ashok baijal

The remaining components to be glued are the two booms. Each boom consists to three pieces.

A 5 mm Carbon Fibre rod is fixed inside the inner piece and covered by the two outer panel and left to dry for the night.

Today, I started sanding the booms to a nice oval profile. Photos of one boom sanded along with the un-sanded one are enclosed

ashok baijal

With all the 8 pieces laminated and dried, I sanded the fuselage to a nice oval shape. The leading edge of the wing was also sanded to give it the profile of an aerofoil.

Now, with all the components ready, I did a dry fit. Now, waiting to procure the electronics for completing the build.

sundaram


ponappa


docnayeem

Neat and clean ...... Great job

sanjayrai55


topalle

Amateur photographer ... DIY enthusiast ... Scratch Builder... Student-Innovator

ashok baijal

Thanks.  I have placed orders with HK and now waiting for the 3S lipos. Remaining build going slow for this reason.

Currently busy in cleaning my jammed glow engines. ... one engine a day!!!! Tried soaking in kerosine, methanol and WD40. All failed. Finally freed the engines by soaking them in engine coolant. so everyday one engine is having a nice hot bath. Have to wait for madam to free the kitchen before I get a chance to heat up the coolant.

ashok baijal

Slowly but surely the build continues. Today I cut off the ailerons from the wing and strengthened the edge by gluing a strip of balsa on each aileron. I also strengthened the elevator by adding a 2mm carbon fibre rod. The control surfaces were then hinged to the main body. I still prefer to use hinges over tape. Old school.  ;)

I also mounted the three servos on the wing. Since they are inserted inside cavities in the wing, I could not screw them but had to fix them using araldite. The wires were also tacked to the grove in the wing with araldite. Could have used tape though, but araldite was at hand.

Today got a email from HK that the 3S battery and propeller have been packed and sent for despatch. I hope it gets cleared by customs without any :discuss: and reaches me latest by the 10th of next month. Till them the last step of attaching all the components together remains. Will complete in the next few days. Till then  :sleepy:

docnayeem

Sir .... How have you cut the foam hot wire cutter or normal cutter and how on earth do u manage to get that shape .... I wish I could do half as neat job ...:(
The shape is by sanding it or something else ?

ashok baijal

I do not have a hot wire cutter. Planning to make one.

I use a surgical knife for cutting, blade no 11. I buy a packet of 100 blades at a time (price approx Rs 300) and frequently change the blades. If you use a dull blade the edges get torn off.

Before sanding I carve the curves with the surgical knife to a rough shape and then finally sand it to the desired shape. Sanding biofoam is easier than sanding foam as the globules in biofoam are much smaller than in normal foam.

I am in my 60s and grew up making models where you had to sand and cut all the pieces youself. And that too it used to be Japonica wood which is fairly tougher than balsa. So lot of practice under the belt. Things are much much easier with new materials now.

ponappa


ashok baijal

#18
@Ponappa
Yes. Unclogged 3 engines, another 4 to go.

Waiting for the 3S battery to come from HobbyKing. Today I joined and soldered the wires of the two aileron servos. I now do not expect the ESC that I had ordered from HK to reach me in time for the Sweepstake deadline, so I have cannibalized the same from the Hawker Hurricane that I had nearly finished making last November.

I need someone to lend me a 3S 1000mah battery for the maiden. I have already ordered 2 from HK but don't know when they will come. One has already been shipped, the second is held up as the ESC is on backorder, but none have reached me. Else I will maiden with a 2S. Will wait till 10th May  :headscratch:

ashok baijal

The wing was attached to the fuselage. The ESC was installed and engine mounting plate glued on.

I attached a magnet to the canopy.

Still waiting for the battery to arrive from HK  :(

ponappa

Looking good !!! Best of luck with the arrival of the Batt... have a 160gm 2200 3s 11.1v to borrow/lend...
Let me know

ashok baijal

@ponappa
Thanks for your offer. I have a 2200mah 3s battery but it is large and heavy for this model. Since I have already ordered 2 1000mah 3s batteries from HK, I do not want to buy it again. So keeping my fingers crossed and waiting for the parcel to arrive, if the customs release it fast enough for the sweepstakes deadline. Else last moment I will have to try to locate a store locally.

ashok baijal

Control rods were attached and the motor and prop mounted. Now waiting for the battery to arrive. Rest all is done except placing the battery and adjusting the cg.

ponappa

Hi Have you flown the beauty?
Please let me know when you are flying it I want to make it there.