Weston Capiche 140 Refurb

[Adrian Smith 1]

Looking around the work shop looking for something else to do my eyes alighted on a rather dusty old airframe and wings. Nostalgia set in when I remembered the many times of flying the Capiche 140 with an OS 160 FX. When the engine finally gave up the aircraft was dismantled and set aside for the new and exciting world of my big electrics.

All looks solid enough just some re-covering, new spats removal of fuel tank and a new tail wheel. However, there is much work to be done nevertheless.

[Adrian Smith 1]

What to use as an electric set up? Well being a lazy so-and-so I zipped off am email on Saturday to George at 4-Max for some ideas. With in 3 hours his answer came back with some ideas!

**LINK**

For the motor and :-

**LINK**

for the ESC.

I have in stock already the 20A UBEC and the set up will be driven by 6S 5000 mAh lipo and I have plenty of those.

He suggests 18x8 prop for more vertical performance or a 17x10 for more straight line performance.

I will probably go for the 17x10 and see what happens, but that's a while in the future ..... When the bits arrive I will make a start.

 

Edited By Adrian Smith 1 on 06/04/2020 11:43:04

Edited By Adrian Smith 1 on 06/04/2020 11:43:49

[Adrian Smith 1]

I have now hooked out the original manual to see whats what. The recommendation for the ailerons (2) is for Hitec 5625MG with 6v producing 9.4kg stall torque. I have some of these in the workshop. I have decided to fit the Hitec 5645MG (1) to the closed loop elevators and rudder (1) which at 6v produce 12.1kg, purely because I have these on the shelf. If need be I may have to pair two servos on the rudder, but my style of flying may mean this is not necessary.

Looking at the CoG range is 180mm for normal use with up to 240-260mm for "experts". My records show that I last flew the Capiche with the CoG at 195mm which provide me with a great standard aerobatic experience. It will be interesting see where the internals need to be positioned with an electric set up if the other thread here on the smaller mini - Capiche is evident.

Edited By Adrian Smith 1 on 06/04/2020 16:27:06

Edited By Adrian Smith 1 on 06/04/2020 16:27:53

[Ron Gray]

Nice topic Adrian. I was thinking of starting a new thread (The Repair Shop) for this type of post, what do you think?

[Peter Jenkins]

Adrian, brings back memories of my Capiche 140! They are rather heavier than you would expect. Mine, with a Saito 180 tipped the scales empty at 6.5 Kg. The Saito was just not up to that and vertical lines always ended when the aircraft ran out of puff. I don't know what your Capiche weighs, but if it's like mine, the suggested power train will not do the job. Even a standard F3A power train, 10S with around 2,800 watts will probably struggle with 6.5 Kg to lug around.

My current F3A mounts are around 5.1 Kg and use around 2,600 to 2,800 watts peak to fly an FAI schedule where the vertical speed can be maintained constant with respect to the horizontal speed. The vertical performance is unlimited - something that my Saito 180 powered Capiche was woefully short of!

[Adrian Smith 1]

Hi Peter,

I take your point. According to my notes from a while ago the AUW with a OS 160 FX standard silencer was around 4.5kg, certainly well under 5kg. I don't know how the OS 2ST compares the Saito 180 weight wise I will have research that. I would expect the electric motor and ESC to weigh less than an I/C power plant, but I may be talking nonsense. I will do some sums. I know the lipo is the biggest additional weight consideration and will have to be taken account. When I spoke to George I based the weight consideration as around 11lb kitted out and that's what his recommendations were initially based on which formed part of the manual specification. I will come back on that one.

In the meantime if I used the motor recommended the motor box wall to the cowl exit is 150mm. The prop driver on the motor to the attached four wing shaped attached mount is 77mm which means I would need stand offs of a minimum of 73mm. I have some 75mm s/offs which would be suitable.

Ron,

I don't have any strong feelings, but I would say is what attracted me to your Sbach thread was the headline. If it had just been The Repair Shop I may not have read it. I can see having a Topic as the "Repair Shop" , but leaving the headline prominent as it is already is best. Anyway I don't want to go off thread here so maybe a new thread discussing subject might be appropriate.

[Adrian Smith 1]

**LINK**

This was the spec I sent to George to base his ideas on.

I have looked at a few numbers and here is what I have found:-

motor + ESC + UBEC = 500g

OS 160FX with silencer = 925g

Saito 180 = 879g.

The only other variables are weight of tank/RX battery(s) etc against the weight of my 6S 5A pack of 800g. Not sure what that all tells me other than this is very much an experiment where I may fall on my face.

[Peter Jenkins]

Ah, you may have a light Capiche. Mine was over the 5 Kg without the Saito! I spoke to the guy who did the flight report on the Weston Capiche 140 and he used a YS 140 in it which is a very powerful motor being supercharged and fuel injected. If yours came in at 4.5 Kg then you were almost 2 Kg less than mine which will make a big difference. I'd still go for a 10 S set up though because this is a 2 mtr class aerobat. In fact it is just over at 2010 mm long. Only 110 size models tend to use 8S packs. Try it by all means but I think you will be wanting in power for good aerobatic performance.

For a 10S setup, I'd use a 21 x 13 prop or thereabouts. An 18 x 10 prop is definitely a 110 class prop. That's what I used on a Wind 110 with an 8S setup and that was only just enough grunt.

[Adrian Smith 1]

Thanks for your thoughts, Peter. I may have give the 8S or 10S set ups a serious consideration. My only concern is adding more weight by using 2 lipos wired in series to achieve that end. Fuselage space might be an issue too as it is shall we say, quite sleek! I will have to check weight of these packs to see if there is much penalty. The one thing I have got is time to think about these issues at the moment.

Edited By Adrian Smith 1 on 06/04/2020 22:27:06

[Bob Cotsford]

430kv motor on 6S 5000 is what I used to replace a Laser 100, You are looking at 1300W if you cool the motor well and use something like a 15*10 prop. You are asking a lot of that 58A max motor.

[Adrian Smith 1]

Hmmmm... I see Bob. Seems strange that George suggested it. I'd be interested to understand the logic behind it. In the past i have found his advice to be spot on.

[Peter Jenkins]

As Bob says, you are looking at around 1300 watts with that setup. That's what I use for my 70 size Fantasista.

You would do better with a Turnigy G160 (if only Hobby King were still able to supply it). This is a direct replacement for a 160 glow and should provide around 2,800 watts off a 10S setup.

My 10S packs (2 x 5S as it's cheaper to charge as a 5S in parallel) weigh in at around 1.1 - 1.2 Kg so your Capiche empty weight needs to have that added to it. If you want an ESC with braking - that is adjustable braking rather than on/off, you will be looking at a more expensive ESC, typically a Jeti Spin Pro or Castle Creations stuff. I have total faith in Jeti Spin 99s which have been the go to ESC for F3A flying although they are now being challenged by others.

I have to say I'm surprised at your Capiche's weight. I found out after I'd bought my Capiche that the Weston Capiche was a bit porky and that if you wanted to crack 11 lbs then it had to be a kit built one with careful wood selection - which many achieved.

As you no doubt know, there is nothing worse than an underpowered aerobatic aircraft!

The biggest issue you will have with the Capiche will be cooling the packs. I have the same problem with a Loaded Dice that was converted to electric drive. IC models didn't need to cool something sitting on/near the CG!

[Peter Jenkins]

One other point to bear in mind. What ever results you get on power and current draw when the aircraft is on the ground and tethered is greatly reduced once the aircraft is airborne.

I have a Hacker Q80 in a Citrin biplane that recorded 3600 watts tethered but very occasionally touches 2,800 watts in flight. I use an on-board monitoring system that records max values that can be inspected on the ground or you can take a glance at the instantaneous reading while in flight - not to be recommended unless going vertically upwards at the time!

If you don't have flight pack volts/amps telemetry consider this device from SM Modelbau called the Unisens-E. If you follow this link you can download an English translation of a range of products including Unisens-E. There is also a product that carries a micro SD card that records all your flights and that you can play back on a PC.

Incidentally, this very versatile and light sensor also provides height readouts. Very useful when checking how high you went! You can also set alarms for a wide range of parameters. The sensor works with a wide range of radio equipment.

[Adrian Smith 1]

Absorbing read, Peter.

Given this project is a refurb for something that will probably be used as a go to hack I am going for simplicity rather than loading up with too much sophisticated gear. The areas where I am more interested in top line performance are with my 60cc and 100cc electric equivalents which are pretty much almost there. If it hadn't been for this period of non-flying I have admit the Capiche would have been left untouched.

That said the power train issue will need looking at again when I complete the fabric repair and clean up. In this instance I have the time to acquire the knowledge to do the sums which I should really do for my own satisfaction. Never was that good at physics and electrical current though. Anyway, she is some way from being airborne although that may change if we are all stuck on the ground for an extended period of time! I do really appreciate the time and knowledge you have put into answering this thread.

[Ron Gray]

As some aside info on motors, I have fitted the Turnigy 160 into my SIG Rascal 110 which weighs in at approx 51/2 Kg, although I haven't weighed it with the battery pack in (2 x 5s 5000mAh). It gives it spirited performance with enough power for all the basic aeros plus a flight time of 15 mins! OK not unlimited vertical but hey this isn't an F3A ship. I used eCalc to work out the requirements as I hadn't got a clue!

[Peter Jenkins]

Hi Adrian, you can swap the UnisensE from model to model very easily. So, if you get one you can use it to check the performance of all your electric fleet. For me now, it is essential equipment for setting up electric motors as ground testing has proven to give false readings. The only readings that matter are only obtainable in flight. True, the ground test errs on the side of safety but you risk losing up to 25% of power that you can safely extract but have no way of finding out about without on-board telemetry.

[Adrian Smith 1]

Well I decided to take good advice and managed to source the last Turnigy G160 motor in the UK from Rapid RC. I feel more comfortable doing this. Justin has mailed it to me today. Fortunately, I have a spare ZTW 120A ESC which while it may be overkill but will do the job and save me money. Which is just as well as I only have 6S lipos and looking at the motor spec I will need 5S lipos to run it as 6S not suitable.

Given the dimensions of the motor I will need to extend the motor box a tad as the overall can length is shorter than the 4-Max motor thereby making the stand offs inordinately too long. I will wait until the motor arrives before doing the new calculation.

Looks like the brand new 4-Max motor and ESC will be going on ebay in a day or two as I don't require them anymore ........

[Adrian Smith 1]

Right some essential items now ready to go after the refurb. The G160 Turnigy motor arrived today from Rapid RC (ordered yesterday!). Well done Rapid RC.

As far as the ESC is concerned I have at ZTW Mantis Opto 120A already. Plenty of capacity there, but saved me buying one.

 

I have used this ESC before and it very reliable - almost bullet proof.

Edited By Adrian Smith 1 on 08/04/2020 21:50:57

[Adrian Smith 1]

First job tomorrow will be to clean down the airframe and wings. Mainly dust I think, but I will see. I anticipate that I will have to cut away some of the fuselage film from the underneath, but I have plenty of covering to replace it. I will post some pictures tomorrow with all the progress. I will take some measurements of the motor box to see how much to extend the motor wall so I don't have to use stand offs that are a bit long. Shorter the better I think.

Edited By Adrian Smith 1 on 08/04/2020 21:52:22

Edited By Adrian Smith 1 on 08/04/2020 21:52:57

[Adrian Smith 1]

Down to brass tacks. I removed all the bits of extra weight I won't be using in the refurb. I will be replacing the spats from stock, however.

I have also found a spare carbon fibre U/C leg which will replace the metal one in situ. Hopefully it will save a bit of weight.

[Adrian Smith 1]

Easy jobs first. I set about opening up the pipe tunnel hatch holes to increase the airflow.

Also found a spare tail wheel assembly that will fit. Needs a bit of a clean up though before fitting.

[Adrian Smith 1]

A piece of luck today as when measuring the prop driver to the rear of the mount with the motor actually in front of me showed it is 77mm, not the shorter distance I previously thought so I should be able to fit the original stand offs which are 76mm. Given the motor wall is 150mm from the cowl exit this should suffice give or take the odd washer.

The Motor mount that came with it looks to fit within the motor wall with stand offs attached.

I will use dowel to block up the original holes drilled using epoxy resin.

[Adrian Smith 1]

It just shows you should look through the workshop drawer as I found a nice electric prop spinner and a 20x10 electric prop that will do nicely.

The one nagging doubt I have is I think fitting 2 x 5S lipos into the fuselage could be problematic if they are required to sit back from the original tank bay. The fuselage is also quite narrow too. I will address that later.

I understand the decorating paint brush is call for a couple days work so I am going to be otherwise engaged for a bit!!

[Ron Gray]

I think that you may well be massively over propped with a 20x10 on 10s!

[Adrian Smith 1]

That's what it says on the box on the spec label, Ron. What would you suggest?