Simprop Raz Faz - RC Groups
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Apr 22, 2014, 07:29 AM
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Ben D Wing's Avatar
Build Log

Simprop Raz Faz


Having competed in the UK's Speed 400 pylon racing series back in the 90's I've always had soft spot for small fast models, so when this untouched kit of the discontinued Simprop Raz Faz appeared for sale I just had to have it! For those that remember this kit it was released back in the late summer of '96 and was very similar to Graupner's Race Rat, albeit slightly smaller. One well known, but unfortunate trait of the Raz Faz was to flick in during fast pylon turns, which isn't very useful for a pylon racer and may explain why it wasn't overly popular with serious racers. Anyway, I think I may have found the reason for this behaviour, but more on that later.
My intention is to build this kit mainly as intended with the exception of the centrally mounted aileron servo and power train. I won't go into a blow-by-blow account of how to stick part A to B etc, but just show photos of the progress with accompanying notes, so let's make a start:
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Apr 22, 2014, 07:55 AM
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The kit itself is nicely presented with the die cutting of the ply parts extremely sharp, the glass fibre fuselage is nicely moulded and true (unlike some kits!), and the pressure formed Obechi/foam wing seems very tough and warp free.
The initial tasks included cutting the ailerons free, assembling the tail parts and bonding in the die cut ply motor mount. After that the two pre-formed NACA ducts in the fuselage were opened to allow motor/ESC/battery cooling, and a hole drilled through the fin to allow the elevator control snake through.
Apr 22, 2014, 08:29 AM
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Ben D Wing's Avatar
As stated earlier I don't intend to use a central servo for aileron control as designed, but instead use two nano servos to enable flapperon control. The ply plate designed to mount the original mini servo was perfect for me to place the two small servos in tandem. I used the kit supplied ball links, pushrods and torque rods, and the servos were simply wrapped in masking tape and fixed in place with UHU Por.
The rest of the ply canopy frame work was assembled with cyano and the wing securing bolt hole drilled and tapped into the fuselage. When I trial bolted the wing in place I noticed that there seemed very little strength in the design, even with the GRP canopy in place. If pressure was placed under the wing, as in a high 'G' turn, the whole wing/canopy assembly flexed and lifted off the fuselage. This gives the effect of negative wing incidence and I wondered if this was the problem for all those Raz Faz's that flicked in during WOT turns. In any case, flexing like this is not an option with the power plant I intend to use, so I simply cut a brace from the scrap ply left overs and bonded it into place (see photo). This has totally
stiffened up the whole assembly and only adds a gramme of extra weight.
Apr 23, 2014, 04:48 AM
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Having fallen foul of incorrect incidence settings between wing and tail on too many kits over the years I decided to make the tail removable. This serves two purposes, one is to easily replace the tail should it suffer an accident, the other is to make incidence adjustments if necessary. The fin was simply drilled and tapped for an M3 screw and a suitable hole and locating peg added to the tail.
The elevator servo simply lays on the supplied ply plate and is secured with UHU Por, but I'm not sure that the very thin piano wire pushrod as supplied is going to be up to the power plant I have in mind! Anyway, this concludes the very simple build of the Raz Faz and all that's left is to add some colour to the wing and tail prior to final setting up of the motor/batt/ESC, and adjusting the CG. As I have plenty of Oracover scraps I'll be using those for the covering, but I'll try and keep it to something that resembles the box artwork.
Apr 23, 2014, 01:03 PM
Annoying people since 1970 :)
Nice find, looking forward to the flight report.
Apr 23, 2014, 02:04 PM
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Ben D Wing's Avatar
Hmm, having researched this model on various forums I can almost guarrantee it'll be exciting, but maybe not for the right reasons!
Apr 23, 2014, 02:47 PM
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I had one when they were new, flew it on a speed 400 race and it was pretty good for the time. put it in the loft and forgot about it for a bit. Eventually got it back out of the loft and fitted brushless n' lipo's to it and it was sooo much more fun. From memory it was something like a Mega 16/15/xx and 3s 1600 ish. One thing I do seem to remember is once I got it going faster than the old speed 400 would take it it needed the CG pulling forward from the recommended point to stop it tucking and I think half throttle launches were the way to go. This was about 6 ish years ago but worth remembering for your maiden.

Steve.

Oh yeah just remembered I won a bottle of wine with it at a fly in cuz it scared the bejesus out of the old guys running the flight line
Apr 23, 2014, 04:12 PM
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Ben D Wing's Avatar
Thanks for heads up Steve and it's purely by coincidence I'm fitting a Mega 16/15/3, 4.75" x 4.75" APCe prop and a 3s 1400mAh battery. This is the same set up as my Voodoo so I know roughly what I'm letting myself in for, although the 'Faz has a more draggy airframe. It's interesting that you mention moving the CG forward with a hotter set up because most of the reports I read about the bad behaviour in the turn was attributed to the CG being too far forward. Also, on the plan it shows +2 incidence on the wing which I find strange as all previous racers I've flown have been set up 0 - 0 with about -1 down and 1 side thrust, and this is what I'm aiming for with the Raz Faz. Time will soon tell if my set up will be successful........or not!
Last edited by Ben D Wing; Apr 23, 2014 at 05:59 PM. Reason: Wrong prop size, senior moment!
Apr 25, 2014, 05:49 AM
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Not much done today due to me being well out of practise with a covering iron (I've had too many foamies recently methinks), so it's taken most of the morning to cover the worlds smallest tail assembly!
Anyhoo, I eventually managed to cover the tail pieces, hinge the elevator, set it all up and install the motor & ESC. The covering material is some left over Oracover from many years ago and it's almost a direct match for the box artwork colours. Lucky or what!
Apr 25, 2014, 10:38 AM
#who gives a rats a**?
feefo's Avatar
Nice covering colour, I like it.
Apr 28, 2014, 09:55 AM
1ONkar, Satnaam
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Here is mine


I just tested yesterday and flew great. HET 3W 4600KV motor and Catsle 45 ESC with 4.4X4.1 prop. Thunder power 2S battery.
I like it. fast.

satnaam
Apr 28, 2014, 11:42 AM
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Ben D Wing's Avatar
I like the colour, it's nice and easy to see! What speed do you estimate with that setup?

I'm in the process of covering the wings, but work is getting in the way of further progress at the moment.
Apr 28, 2014, 04:02 PM
1ONkar, Satnaam
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Speed wise?


I fly high speed EDF's and this thing is ballistic on 2S. It gets away very fast. I would say at least 100 to 125 MPH. My wings are glassed top and bottom with fiberglass cloth with WBPU and I glassed the elevator as well. The colours are easy to see in the air.
I am just getting into these fast pylon racers. I just bought a 1 Meter Rifle.
satnaam
PS I am going to try a 3S battery after some experience on this type of aircraft.
These are fast. Love it.


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