K.K Senator converted to S/C

Free flight and rubber powered models
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Wayne_H
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K.K Senator converted to S/C

Post by Wayne_H »

Following on from my earlier post on re-purposing several old F/F models , I've started this thread to report on my progress converting the rubber powered KK Senator to electric powered S/C.

Upon closer inspection and the removal of some covering, the scope & scale of repair is more than first anticipated - but hey, isn't that part of the 'challenge' & ultimate satisfaction? The Senator has clearly been repaired previously, probably by at least 2 different people. There were indications that some of the repairs had also been done on the field. My biggest decisions invariably were around what to redo v's what to leave. A major consideration in my decision making was always to try and keep the Senator as original as possible while keeping the S/C & electric conversions as discrete/subtle as possible. A more practical consideration is how much tissue & dope I don't have at the moment :oops:

OK, progress so far:
The wing:
  • The spars (1/16" sq.) were all broken in the centre bay, probably due to this being where the wing bands passed over the wing, combined with compressive loads from flying and/or knocks to the wing tips. The spars were straightened and reinforced with 1/16" sheet webs. Light weight transverse sheeting will be added to better distribute forces from the rubber bands to the wing ribs.
wing repairs_2.jpg
wing repairs_3.jpg
  • The centre panel of the wing has a warp in it, so is strapped to a flat rigid board while repairs are underway. The 1/8" sq. L.E. had multiple repairs on one inboard panel, so it is currently being replaced.
Fuselage:
  • The 'propeller'(?) like fin has been removed, to be replaced with a new straight version which includes a rudder (of course).
destined for the bin!
destined for the bin!
  • The cross pieces and associated tissue covering on top of the fuse at the wing mount have been removed to allow access to the radio installation. The top longerons have been reinforced with a 1/16" x 3/8" doubler.
fuse cabin mod_1.jpg
  • The "cabin" has been extended to the rear of the wing using 1/8"sq. longitudinal inserts backed by another 1/16" x 3/8" doubler. Thin clear plastic has then been glued on as the side cabin "windows".
fuse cabin mod_3.jpg
  • There is a bit of "the hungry horse" appearance on the fuse aft of the wing. I'll leave this as it befits the age & type of model.
that "hungry horse" look
that "hungry horse" look
  • The only low KV motor I have is really too big & powerful, but I'll utilise it in the absence of anything else :x It does fit inside the nose just 8-)
    more than enough power, but a low cell count and smaller prop should tame it.
    more than enough power, but a low cell count and smaller prop should tame it.
    Power will be a 2 cell pack
The tail plane is good - doesn't need any repairs (unless I put a hole in the tissue!!)
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
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Carl
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Re: K.K Senator converted to S/C

Post by Carl »

I've loved the look of the Senator for some time and wondered if it would make a nice calm conditions S/C conversion with electric. So I'm really glad you've opted for this one first, and that you'll keep what you can of the original model.

It's great that the Senator has been included among the KK re-release kits.

Carl
Carl

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Carl
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Re: K.K Senator converted to S/C

Post by Carl »

In fact I've just gone an ordered a kit :lol: only £26.99 inc postage - one left from the same seller

https://www.ebay.co.uk/itm/323317192658

Carl
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Wayne_H
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Re: K.K Senator converted to S/C

Post by Wayne_H »

Repairs & modifications continue:
The balsa I have been using for the repairs was left over from my Veron Deacon build completed back in the 1980's. There is also the original white tissue still in the same recently 're-discovered' kit box - that is earmarked for my KK Chief build, now that I have my better than original rib set from Neil at Igull :D
The Wing repairs have been completed & the warp successfully removed. As I said in the previous post, my coloured tissue and dope are as still hiding in the 'undiscovered country'. Consequently, I've had to resort to off-cuts of coloured tissue from the florist/gift-shop (yes, it was expensive tissue!) and hair spray from the $2 shop instead of dope. Amazingly, it all worked surprisingly well - I even managed to match the brittleness of the original old tissue.... :o
I expect the purple tissue to fade quickly...
I expect the purple tissue to fade quickly...
A new fin & rudder have been built & covered. The rudder needs to be hinged & the assembly glued back onto the fuselage.
rudder yet to be hinged
rudder yet to be hinged
SENATOR Fin+Rudder.pdf
Drawing of the modified fin with s/c rudder
(193.43 KiB) Downloaded 108 times
Propulsion:
  • I re-visited the motor option & decided to re-task the GWS drive from my GG actuator experiments back into a propulsion system. The previous motor+prop option weighed 68g with spinner while the GWS unit weighs 38g with prop & spinner.
The old  GWS unit ( brushed motor) on the left is the chosen propulsion unit.
The old GWS unit ( brushed motor) on the left is the chosen propulsion unit.
  • I have a choice of either a 2S 610mah 20C (39g) or a 2S 500mah 35C (31g) battery. I'll probably try both, with the 610 mah for breezy conditions & the 500mah pack for calmer conditions.
  • AUW should come in about 145-150g.
Tomorrow will be the motor & radio installation & hopefully test flights on the weekend. :)
Last edited by Wayne_H on 03 Aug 2018, 15:11, edited 1 time in total.
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
GarydNB
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Re: K.K Senator converted to S/C

Post by GarydNB »

Wayne, I found a really good source of coloured tissue at 'Officeworks'. It's just like the tissue the Americans call 'domestic tissue', has little wet strength but is only $14 for 100 sheets.
Gary
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Wayne_H
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Re: K.K Senator converted to S/C

Post by Wayne_H »

GarydNB wrote: 01 Aug 2018, 11:08 Wayne, I found a really good source of coloured tissue at 'Officeworks'. It's just like the tissue the Americans call 'domestic tissue', has little wet strength but is only $14 for 100 sheets.
Gary
Fabulous, thanks Gary. I'll check it out at the Officeworks in Wagga Wagga on Friday. Shame they don't sell dope :lol:
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
Twitcher
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Re: K.K Senator converted to S/C

Post by Twitcher »

Hi Wayne
The KK Senator has received the EP conversion here too. It works well. If I might offer a couple of suggestions, they would be a) to balance it slightly nose-heavy, especially if you anticipate flying in anything above 3-4 mph wind. These things don't penetrate well! b) if yours is anything like mine, it will need just a whiff of power to go up like a rocket!

I've built mine with three options.1. Pure rubber power; no r/c 2. Rubber power with r/c and 3. Electric power with r/c . It's fun to ring the changes between them but be aware, this is a potent thermal-catcher! Best to have a means of D/T-ing at all times. My r/c modes both use a 45 degree rudder deflection to induce a spiral dive, but if you do this, watch out for excess speed build-up which could easily fold the wing. Also allow for a much-reduced rudder movement range for normal flight. I have that on a two-position switch.

Good luck.

David
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Wayne_H
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Re: K.K Senator converted to S/C

Post by Wayne_H »

Twitcher wrote: 01 Aug 2018, 19:39 Hi Wayne
The KK Senator has received the EP conversion here too. It works well. If I might offer a couple of suggestions, they would be a) to balance it slightly nose-heavy, especially if you anticipate flying in anything above 3-4 mph wind. These things don't penetrate well! b) if yours is anything like mine, it will need just a whiff of power to go up like a rocket!
G'day David ;)
Thanks for the info on your Senator experiences - sounds like I have some serious fun coming my way.☺ It was always my intention to move the CG forward of the FF position. How far behind the LE have you balanced yours & did you also adjust the incidence of the tailplane?
I've built mine with three options.1. Pure rubber power; no r/c 2. Rubber power with r/c and 3. Electric power with r/c . It's fun to ring the changes between them but be aware, this is a potent thermal-catcher! Best to have a means of D/T-ing at all times......

I can change back to rubber relatively easily, as I still have the original nose block & free wheeling prop. The GWS propulsion unit slides into the nose, retained by 4 screws. The Rx, servo & ESC are on rails above the line of the rubber motor.

Having previously been flown in FF competition, mine has a d/t tailplane fitted, only the timer having been removed. I could use the kick up function to release the d/t. :geek: About 10 years back, I assisted at the Australian FF Society national champs. The Senator, Achilles & the Ajax acquitted themselves well in their event, regularly maxing out but going a long way down wind in the process :( Out of curiosity, what weight does yours fly at in EP mode?
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
Twitcher
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Joined: 16 Feb 2018, 12:17

Re: K.K Senator converted to S/C

Post by Twitcher »

Just measured the Balance Point and it's 54mm behind the wing L/E. No alteration to the tailplane angle.
Weight in EP mode 124grams. I've posted a few photos that might be interesting.
Incidentally, the LiPo I use is a HK 2S 300MAh type; can't remember what the motor is, except that it it's about 2200K and cheap. It drives an Aeronaut 6" x 3" folder. I dare not give it a full can of beans - far too powerful!
To re-iterate an earlier comment, the Senator is a potent thermal-sniffer; I wouldn't risk flying it in any mode without a Dethermaliser.
Hope this helps

David
Attachments
Sen EP 1.jpg
Sen EP 2.jpg
Sen EP 4.jpg
Sen EP 5.jpg
Sen EP 6.jpg
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Wayne_H
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Re: K.K Senator converted to S/C

Post by Wayne_H »

Thanks for the additional info & pictures David - much appreciated :) I'll start with the CG location you use.

Gary - I'm now the proud owner of 112 sheets of coloured tissue :shock: - that should see me out I reckon :lol: However I'm confused by the labeling of the 100 sheet pack - called the "Rainbow pack", it contains pastel colours only but not all the colours of the rainbow, at least not the rainbows I've seen in the sky. Why do I feel like I've been PC'd??? :oops: :roll:
Cheers,

Wayne
Once a Retrobate, always a Retrobate............ ;)
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