0.4mm spring steel wire

[Jeffrey Cottrell 2]

Hi Guys

Anyone know where I can get some 0.4mm dia spring steel wire in this country.

E-bay lists loads, but the all come from China, with all its attendant delays.

Really like to have it before the turn of the millenium

Cheers

Jeff

[John Wagg]

Does it have to be exactly .4 ? 4.1 is available on Ebay. but is coiled. Searched using 0.4 mm piano wire.

https://www.ebay.co.uk/itm/Superior-Grade-Piano-Wire-Spring-Steel-0-23mm-0-41mm-0-8mm-1mm-1-2mm-1-4mm-1-6mm/323981491647?hash=item4b6ecd3dbf:g:Z4MAAOSwSkpeT8KC

https://www.ebay.co.uk/itm/3-metre-length-9ft-10-ROSLAU-Finest-Polished-German-Piano-Wire-Spring-Steel/383064633534?hash=item59306e70be:g:rnkAAOSwUP5eRVsu

 

 

Edited By John Wagg on 06/07/2020 19:08:00

[Jeffrey Cottrell 2]

Hi John, thanks for the quick reply

Doesn't need to be exactly 0.4mm. I am making up a spring return rudder system, as in this video.

Must admit I did look on e-bay, but didn't notice those.

Looks like I'm in business.

Cheers

Jeff

[John Wagg]

Hi Jeff; I got some off Ebay about 6 weeks back and it came in a coil. Mine was a bit thicker for a push rod inner. Not easy to straighten out but can be done.

Glad I could help.

P.S. interesting video.

And interested in what you are building.

Edited By John Wagg on 06/07/2020 19:24:50

Edited By John Wagg on 06/07/2020 19:39:36

[Stuart C]

I keep my replaced guitar strings for such purposes. Just measured the 3rd from a light set - exactly 0.4mm.

[Jeffrey Cottrell 2]

Posted by John Wagg on 06/07/2020 19:22:22:

And interested in what you are building.

Hi John

It's a Keilkraft Gaucho, from the Outerzone plan.

Fancied one since I was a lad, long time ago, finally got round to building it.

Just at the covering stage. soon to appear in a New Models thread, I hope

Jeff

[flight1]

well have you tried hyperflight they sell music wire which i believe will do

[John Wagg]

Posted by Jeffrey Cottrell 2 on 06/07/2020 20:50:13:

Posted by John Wagg on 06/07/2020 19:22:22:

And interested in what you are building.

Hi John

It's a Keilkraft Gaucho, from the Outerzone plan.

Fancied one since I was a lad, long time ago, finally got round to building it.

Just at the covering stage. soon to appear in a New Models thread, I hope

Jeff

Look forward to seeing it.

IC or Electric.? I have thoughts of something similar for electric with a 2s inline battery to fit in the slim fuselage..

John

[Jeffrey Cottrell 2]

Hi John

This one's electric, as is all my fleet now.

Did think about 2s, but eventually went with 3s so I could use a motor I built many years ago, but never found a use for.

Hobbyking do (or rather did) do Nanotech single cells in tubular format. Similar size to an AA dry cell, but a little longer. Made up three of those into a 'Toblerone ' style pack and cut a recess in the fuz to take the extra cell, leaving only two on the surface.

Might have to enlarge the side cheeks a little, and make them built up rather than block, but hopefully not enough to spoil the character of the model.

Being electric, I can test fly it without the cheeks, and then decide.

Static test shows 10860 rpm on a 7 x 5 APC-E prop, pulling about 11 a. Since switched to a GWS DD prop at 8 x 4.

Not sure how it will perform in the real world, but on the static test, let's just say I won't need to dust my workshop for a while.

Could do you some pictures if you're interested in the install.

Have to mention my original thread here, and all the help from John T who has one up and running.

Other than that, build it and let the gods decide.

Cheers

Jeff

[John Wagg]

Downloaded plan from Outerzone and printed it off. Now have 15 sheets of A4 to sellotape together.

Thanks for the post and will now study it for viability. Just might be a future project.

Cheers. John

[Jeffrey Cottrell 2]

Hi John

Same page on Outerzone has a link to an Italian website which has the wing and tail rib shapes. They are in pdf format at reduced size so need a bit of experimenting to print off full size.

Well worth doing.

The inner panel ribs are all pretty much the same size, so I made a ply template to cut round. For the tapered outer panels and the tail, printed off a couple of copies, cut out the shapes and glued them to the balsa.

Probably ended up more accurate than would have been in the original kit.

Hope you decide to build it. The world needs another Gaucho.

Will keep you in touch with progress on mine.

Jeff

[Richard Clark 2]

Jeffrey,

Don't forget it's supposed to be a real rocketship.

These things went up in an incredibly fast vertical 'rotating on its axis' or tight spiral ciimb reaching several hundred feet in a few seconds. Junior 60's or Ladybirds they aren't. (At our site we have a few free flight enthusiasts who still build such things and it is still an active competition class.)

That guy making the OZ comment about a 'reduced thrust' Mills 0.75 is losing the whole idea, though he does mention they sometimes used a Oliver Tiger 2.5 cc (though the ultimate would have been a Super Tigre G15 glow). The Gaucho is what we would call a 'hotliner' today. and a very hot one at that.

You need about a 300-500 Watt motor to get the correct 'historical' (and still existant today) performance, it's the entire point of 'pylon' models.

[Michael Barclay]

Posted by Jeffrey Cottrell 2 on 06/07/2020 18:40:23:

Hi Guys

Anyone know where I can get some 0.4mm dia spring steel wire in this country.

E-bay lists loads, but the all come from China, with all its attendant delays.

Really like to have it before the turn of the millenium

Cheers

Jeff

It's listed on AMAZON UK.

[Jeffrey Cottrell 2]

Hi Guys

Thanks for all your help. I now have enough links to this material to start my own shop. Time to pull the curtain down on this one.

Meanwhile, Richard.

Agree with everything you say, except it was never going to be a competition model. The reason I am building it is to scratch an itch I have had for many years.

If it performs well at the end of it, that's icing on the cake.

Having said that, did have a look through some competitions and found this one.

Could have been made for the Gaucho.

Mine would come in power band A, so 20 second motor run and 5 minute max. If mine doesn't get to a decent height in 20 seconds, that will be a disappointment. Whether i can achieve a 5min glide is another matter.

Just done a quick and dirty weigh in of all the components. Came to 330 g or 11oz. With a wing area of 1.95 sq ft, that gives a loading of less than 6 oz/sq ft., firmly in the floater category.

Would also question you referring to the Gaucho as a 'hotliner'. True, they both climb fast, but the hotliner also glides fast as well, witness the distance task in multitask events.

With such a low wing loading and thick wing section, couldn't get the Gaucho to fly fast, even with a cattle prod behind it.

Horses for courses, I suppose

Jeff

[Keith Berriman]

I see Model Shop Leeds have a 0.35mm spring steel wire in 1 mtrs lengths

[Richard Clark 2]

Posted by Jeffrey Cottrell 2 on 07/07/2020 18:18:17:

Hi Guys

Thanks for all your help. I now have enough links to this material to start my own shop. Time to pull the curtain down on this one.

Meanwhile, Richard.

Agree with everything you say, except it was never going to be a competition model. The reason I am building it is to scratch an itch I have had for many years.

If it performs well at the end of it, that's icing on the cake.

Having said that, did have a look through some competitions and found this one.

Could have been made for the Gaucho.

Mine would come in power band A, so 20 second motor run and 5 minute max. If mine doesn't get to a decent height in 20 seconds, that will be a disappointment. Whether i can achieve a 5min glide is another matter.

Just done a quick and dirty weigh in of all the components. Came to 330 g or 11oz. With a wing area of 1.95 sq ft, that gives a loading of less than 6 oz/sq ft., firmly in the floater category.

Would also question you referring to the Gaucho as a 'hotliner'. True, they both climb fast, but the hotliner also glides fast as well, witness the distance task in multitask events.

With such a low wing loading and thick wing section, couldn't get the Gaucho to fly fast, even with a cattle prod behind it.

Horses for courses, I suppose

Jeff

Well, yes. I admit I wasn't thinking about speed on the glide. Which is the last thing you want. I called it 'like a hotliner' so people who have never seen these things would get an idea how fast they climb.

The idea was to get a vertical climb. There were two ways of doing it. One way was a lot of washIN on one wing and launch it vertically. No 'power on' rudder offset. Thus it climbed while rotating on its axis. If you didn't do this it would do a series of full power tight loops until it crashed very violently. The alternative, favoured by some, was much less washin and a small rudder offset the other way and launch at a 45 degree angle in both roll and pitch. Then it went up in a tight spiral.

The concept was to do a full power climb on a lightly loaded high lift wing flying very fast under power. The rotation or the spiral was to prevent its 'natural' looping tendency at such speeds by constantly changing the orientation of the loop so it never had time to develop into an actual loop.

The rudder was freed by the same timer that cut the engine and a spring or rubber band pulled it to the correct angle for the aircraft to go into gentle tums so it stayed in sight. if the washin was on, say, the left wing causing a right power on roll or spiral, the rudder was set to the left during the glide enough to overpower the washin and give a left turn. Thus the washin and the rudder didn't work together which could result in spiral dive.

(The best kit one was the Contest Kits Calypso.)

PS: the modern FAI competition class for these things is 'F1C'. Engine 2.5 cc max,  engine run 7 seconds max. No radio of course. The top engines will give about 1 horsepower (750 Watts), maybe a bit  more.

Edited By Richard Clark 2 on 07/07/2020 22:15:49

[PatMc]

Posted by Richard Clark 2 on 07/07/2020 06:29:47:

Jeffrey,

Don't forget it's supposed to be a real rocketship.

These things went up in an incredibly fast vertical 'rotating on its axis' or tight spiral ciimb reaching several hundred feet in a few seconds. Junior 60's or Ladybirds they aren't. (At our site we have a few free flight enthusiasts who still build such things and it is still an active competition class.)

That guy making the OZ comment about a 'reduced thrust' Mills 0.75 is losing the whole idea, though he does mention they sometimes used a Oliver Tiger 2.5 cc (though the ultimate would have been a Super Tigre G15 glow). The Gaucho is what we would call a 'hotliner' today. and a very hot one at that.

You need about a 300-500 Watt motor to get the correct 'historical' (and still existant today) performance, it's the entire point of 'pylon' models.

Richard, I think you're being a bit over-enthusiastic on the engine power level of the day. The Gaucho had a long nose compared with most other FF power duration models of the time, which ruled out the favourite competition 1.5cc Olly Tiger Cub. This meant either shortening the nose or using a lighter 1.5cc. Most keen competition flyers would have turned their noses at a KK kit anyway but the average occasional competitors would have used a cooking pb 1.5.
The AM10 & AM15 were the most powerful PB 1 - 1.5 engines commonly available (the AM10 was actually more powerful than most 1.5's) they were about 80W & 120W max respectively, even an Olly Cub was only around 130 - 150W. A few keener people used one of the lighter .09 or .15 glows. I never flew FF much (CL combat & Stunt were my main interests) but remember lending a mate my KB Torp 15 & Fox .15 ( Around 190W on a good day & using 15% nitro) for a pair of Gaucho's he used in a local comp.

I agree the Contest Kit's Calypso 50 was a better comp model than the Gaucho.

[Richard Clark 2]

Posted by PatMc on 08/07/2020 00:59:56:

Posted by Richard Clark 2 on 07/07/2020 06:29:47:

Jeffrey,

Don't forget it's supposed to be a real rocketship.

These things went up in an incredibly fast vertical 'rotating on its axis' or tight spiral ciimb reaching several hundred feet in a few seconds. Junior 60's or Ladybirds they aren't. (At our site we have a few free flight enthusiasts who still build such things and it is still an active competition class.)

That guy making the OZ comment about a 'reduced thrust' Mills 0.75 is losing the whole idea, though he does mention they sometimes used a Oliver Tiger 2.5 cc (though the ultimate would have been a Super Tigre G15 glow). The Gaucho is what we would call a 'hotliner' today. and a very hot one at that.

You need about a 300-500 Watt motor to get the correct 'historical' (and still existant today) performance, it's the entire point of 'pylon' models.

Richard, I think you're being a bit over-enthusiastic on the engine power level of the day. The Gaucho had a long nose compared with most other FF power duration models of the time, which ruled out the favourite competition 1.5cc Olly Tiger Cub. This meant either shortening the nose or using a lighter 1.5cc. Most keen competition flyers would have turned their noses at a KK kit anyway but the average occasional competitors would have used a cooking pb 1.5.
The AM10 & AM15 were the most powerful PB 1 - 1.5 engines commonly available (the AM10 was actually more powerful than most 1.5's) they were about 80W & 120W max respectively, even an Olly Cub was only around 130 - 150W. A few keener people used one of the lighter .09 or .15 glows. I never flew FF much (CL combat & Stunt were my main interests) but remember lending a mate my KB Torp 15 & Fox .15 ( Around 190W on a good day & using 15% nitro) for a pair of Gaucho's he used in a local comp.

I agree the Contest Kit's Calypso 50 was a better comp model than the Gaucho.

Maybe. I like vintage models (being vintage myself) and currently have a Junior 60, Mercury Aeronca Sedan, Juri Sirotkin's 'Spacehound' 1963 world championship winning c/l stunter, and a KK Spectre c/l stunter all flown with rc.

I don't think KK ever made a serious competition model of any sort, The 'Talon' supposed combat model I had certainly wasn't, though I did put a Super Tigre G15 in it for a laugh.

And the 'ferocious' (for the time) Eta 29 was often used in the Calypso Major, even at 'club level' competition. I had the last version, the Mk 6c, in mine.

I think Jeffrey understands, both with his "horses for courses" comment, his link to SAM, and his using a rudder spring perhaps indicates that he is actually flying it free flight, but I suspect the average radio modeller who builds a 'vintage' pylon model, puts a low powered IC engine or low powered electric in it and potters gently around hasn't the foggiest idea how they were intended to fly.

[Former Member]

[This posting has been removed]

[Jeffrey Cottrell 2]

Hi Guys

Sorry to drag the conversation back to where I started, but I have some good news.

My spring steel arrived today, so I lost no time trying it out.

I followed the instructions in Andrew's video, and it worked a treat.

Surprised how much force the spring exerts. Did wonder whether airflow would cause the rudder to blow back, but that's not going to happen.

So, on with the next task.

Cheers

Jeff

[John Wagg]

Hi' Jeff, that's good news.

Funnily enough just an hour ago I was thinking, with the spring system, there will always be some force on the servo. Even at centre there must be some force from the spring and what effect on current draw would this cause ?

P.S. Assembled the Gaucho plan but having a problem getting the wing ribs to the right length. I downloaded the PDF ribs from the site you suggested and printed them out. But first print came out too small and the second lot are too big. Just need Goldilocks to come along and sort out some just right.

Keep us informed on your progress.

Regards

John

Edited By John Wagg on 08/07/2020 21:21:21

[Richard Clark 2]

Posted by Barrie Lever on 08/07/2020 08:52:52:

Richard

How did the Sirotkin Spacehound fly as an RC model?

I have not heard of Sirotkin much in the last 20 years but at best he was a formidable character at worst he was something quite nasty.

B.

It's fine, very light too, which I don't usually achieve.. I enlarged it by about 10% and lengthened the tail moment slightly.

It flies exactly the same as the equally thick winged Wolfgang Matt Superstar RC pattern model - I've built three of them over the years.

[Jeffrey Cottrell 2]

Hi Dave

Racking my brains trying to remember how I got mine to the right size.

Must have involved screenshots somewhere along the line. Can only imagine I downloaded the screenshot into paint, and then adjusted the image size from there.

Trouble is I found a page which allowed me to adjust the zoom percentage one point at a time. Darned if I can remember how I got to it.

You say you downloaded a pdf version. The original drawings are in jpeg, so how did you get to pdf?

Might jog my memory.

About the servo, had the same thought myself.

I am using one of the new Plush32 esc, which has a 4a sbec, so I don't think current draw is going to be an issue from that point.

I pinched a slim wing servo from a stalled project which would fit in the pylon. The one I used is this,showing as 1.4Kg @4,8v.

Knowing I would complete the stalled project sometime I cast about for a replacement, and came across these, seem to be the same servo.

Will do some experimenting to see how much pull I actually need.

Jeff

Further to the rib size issue.

I have a Canon iP1800 printer. If I go to print from the original page (not the screenshot) I get a page set up choice, which does include changing zoom percentages one point at a time.

Dug out the prints I did originally to find correct setting, On one I have a cryptic note saying 130%=136mm

The rib size you want is 138mm. I very seldom use page set up, so when I looked at it it had 133% as scale.

I'm guessing if 130% is a fraction short, maybe 133% is the magic number.

You may have noticed I'm not the most computer literate person in the world, but this might help.

Good luck

Jeff

Edited By Jeffrey Cottrell 2 on 08/07/2020 22:48:55

[Jeffrey Cottrell 2]

Hi Again

Things I do in the cause of science.

So, clamped the rudder down to my bench, attached a length of Kevlar thread, over the edge of the bench and tied to a milk bottle.

Kept adding water until I got figures for rudder central, and full deflection against the spring, then weighed the bottle and contents.

Results I got were surprising, but in a good way.

To move the rudder to its central position only took 137g, and to full deflection was 328g.

Both well within the rating of the servo.

I would say good to go.

Any thoughts?

Jeff

[John Wagg]

Ribs - Finally got a print off matching the rib lengths to the plan. (13 tries) On the .jpg (not PDF as I thought) page there is a drop down box to resize. It gives the option to keep the "define custom size" and to "maintain aspect ratio". So with a bit of hit & miss I managed to print off a set of rib patterns.

Jeff - with such a small rudder I have no idea of the air pressure on it. As long as the "spring" will withstand it then all good. We will wait for the report to see what effect on turning control you will end up with. Same goes for elevator and what effect that has.

I'm still perusing the plan and thinking about the practicalities of electrifying it.

Thanks for all the info' so far.

John

Edited By John Wagg on 09/07/2020 11:06:58