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Member postings for Jeffrey Cottrell 2

Here is a list of all the postings Jeffrey Cottrell 2 has made in our forums. Click on a thread name to jump to the thread.

Thread: 0.4mm spring steel wire
06/07/2020 23:32:49

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

06/07/2020 22:27:17

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

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

06/07/2020 19:12:23

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

Thread: Motor suggestions
06/07/2020 18:57:50

Hi Skippers

Could we have a link to the model?

Jeff

Thread: 0.4mm spring steel wire
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 milleniumsmiley

Cheers

Jeff

Thread: Mini flight stabilisers
27/06/2020 12:31:26

Hi Guys

Similar sort of subject. Recently bought one of these from Bangood. Price was the factor, nothing much to lose if it's nbg.

So, anybody used one, thoughts, opinions?

Notice the price has gone down even further. Should I grab another one before they're all gone?

Cheers

Jeff

Thread: Mystery motor ID please
26/06/2020 22:27:50

Hi Steve

The Topmodel site shows both gold and silver backplates, so I think that's just a production change.

Been refining my Motocalc entry, and I've now got 10.3a on a 6 x 3 prop, That's pretty much convinced me I have the 16/15/4.

I think the 6 x 3 is not ideal for a mini hotliner, so I'd be interested in what prop and cell count you run yours on.

Could you let me know

Jeff

26/06/2020 20:15:52

Hi Steve,spot on, thanks

Looked at this from the Topmodel site, and that's the beastie for sure.

Only question now is which one?

All the models share the same dimensions, but I'm guessing either the /3 or /4. Only difference is Kv, /3 is 2800, while the /4 is 2110.

Did find a way to measure Kv from the internet, but that made no sense at all.

So I worked backwards.

Downloaded a trial version of Motocalc., fed in what I know, and got the following results.

Static, the /3 pulls 18a and 18963 rpm

The /4 gives 8.8a and 14836 rpm.

I have pulled the motor to see if it had any labels, so I can't get rpm readings as yet, but going by my cryptic note of 10.1a on 2s, my guess is it's a /4.

Not that familiar with Motocalc, so if someone could check my figures. I'm using a Graupner Cam 6 x 3 folder, which MC doesn't list, and an old Polyquest 1450 2s LiPo which MC also does not list,

Given that, I think predicted 8.8a is closer to the measured 10.1a.

Your thoughts?

Jeff

26/06/2020 16:48:54

Hi Guys, little mystery for you.

Way back, when Methuselah's dog was a puppy, I started building a Simprop Peppo.
Don't know why but I never finished it. Got as far as fitting the motor, but now I can't remember what it was, and it has no markings to help me out.
So, here's the description. anybody recognise it?
Its an inrunner, black case, gold backplate with three solder terminals on the back. Case is 36mm long and 28mm diameter, with a 3.2mm shaft.
I suspect it's Eastern European, this was long before China took over the world.
Cryptic note on the fuz says it pulled 10.1a on a 2s pack and a 6 x 3 Cam Carbon folder.dscn0003#1.jpgdscn0002#1.jpg
Anyone help?
Jeff

Thread: New Beginner to Model Helicopters
20/06/2020 18:30:08

Hi Malcolm, now you have me puzzled.

When you say part 30 is not installed, does that mean just not fitted or missing altogether.
if it's missing altogether, how do you know it does not have grubscrew provision?
However, the problem may be more than that.
Again from the diagram, mixer arm, part number 007 has a bolt going through it which then screws into part 30 and it's this that locks the flybar in place.
If part number 30 is missing then there is nothing to bolt the mixer arm to, which means either it is floating about in mid air, or it's missing as well.
Without that part, and its associated parts, there is no link from the swash to the head, and it will never fly.
Is there any way you can get a photo of your head (the heli, that is) so we can look at what you have?

Sorry if this compounds the problem

Jeff

19/06/2020 19:01:41

Hi again, Malcolm.

Been doing a bit of research, and it seems the Mini-Pred is also known as the Falcon 3D in other parts of the world.

Found a manual for the Falcon here. Could you have a look ant tell us if your model is the same as the one in the manual?

Cheers

Jeff

19/06/2020 18:26:16

Hi Malcolm

Colin beat me to it by a short head.
Yes, what you refer to as the small rotor is the flybar.
This goes through a square frame either side of the head. Where the flybar goes through the frame there should be two grubscrews to lock it in place.
Either these screws are loose, or missing altogether.
If they're only loose, tighten up with an allen (hex) key.
If they're missing altogether you will have to source some replacements.
I'm guessing they are 3mm, so here's the place to go.
http://www.modelfixings.co.uk/steel_grub_screws.htm
What you need are MF-GS31
Anyway, here's the procedure.
I'm guessing there are two small blades on the end of the flybar. These are called 'paddles' and need to come off.
No biggy, they only screw on.
With those off, measure from the flybar frame to the outer end of the flybar.
Actual distance is not important, but they must be identical each side.
Once they are, tighten up the grubscrews, preferably using a touch of threadlock to retain them.
Now you can screw the paddles back on. There is a thread on each end of the flybar. Screw the paddles on until you can't see the thread any more.
The paddles should also be the same distance out from the frame on each side, But when you have got them as close as possible, you need to check the paddles are parallel with the flybar frame.
Look across the top of the paddle and sight it visually with the frame. Might need to turn the paddle slightly, but getting them parallel is most important.
Easier to do than to describe, but it should get you in the ballpark.

Let us know how you get on

Jeff

13/06/2020 13:07:20

Ho Malcolm

When you say the smaller rotor was sitting out towards one side, do you mean the slider which runs in and out along the tail rotor shaft?

If so, this is perfectly normal, and if you have Heading Hold on your gyro, the slider could be completely to one side.

Certainly not the cause of your vibration.

I would go with the others and suspect a bent main shaft or feathering shaft, but also possible out ob balance main blades.

Do you have a blade balancer? if not, they're not expensive and well worth having in your tool box.

Other than that, to check main shaft, pull the head off completely then spin the model up, looking at the top of the shaft from above. Easy to spot if the shaft is not running true.

Bent feathering shaft is a little more difficult, but there is an easy way. Pull one of the blades off. Inside the blade holder you will find a cap head screw that holds it on. Turn that screw with an allen key while watching the other blade holder.

If, as you turn, the other holder moves in a circular motion, then you have a bent fs.

Try these checks first then post back

Cheers

Jeff

Thread: Poor Service from Banggood- Buyer Beware!
11/06/2020 11:54:57

Hi Guys
Another +1 for Bangood, in two respects.
First of all, looking for an 8 x 4 bendy prop for a current project.
GWS do one, but I couldn't find them anywhere until I came to BG.
They were offering a pack of 10, from their UK warehouse, for the princely sum of £3.39.
Too good to be true? Well they arrived this morning, That's only 5 days from placing the order, and 3 from their despatch.
Only trouble is I don't know what to do with the other 9!
Second, placed an order with their CN warehouse for a small item.
This was shipped on 3rd June, and tracking says it is now in this country, awaiting my local courier.
Contrast this with the same item, ordered from another well known chinese retailer (no names, no pack drill)
This was supposedly shipped on the 18th April, but to this date has not even reached their local post office.
They have promised to launch an enquiry as to where my goods are, but that could take another 2 - 4 weeks.
PayPal, here I come.
Jeff

Thread: Coyote build wing sheeting question
11/06/2020 11:38:50

Hi Paul, just a quick thought.

You can use cyano or pva to join panels, however I would recommend pva. If you use cyano it leaves a hard ridge on the surface which is almost impossible to sand smooth.

I use an Aliphatic pva such as Titebond. This dries hard, rather than rubbery like ordinary pva, so the joint will practically disappear when you sand it.

Hope this helps

Jeff

Thread: Electric power for KeilKraft Gaucho.
04/06/2020 13:37:40

Hi Guys, and thanks for your help.
Here's what i have so far:
DCW
Back in the day I had an Irvine Mills .75. Little jewel of an engine, but I sold it on, along with my others, when I went electric.
Already got the plan from OZ, plus the rib link. In fact the ribs being flat bottomed, convinced me of the project.
Peter
Pretty much what I thought, thanks for the confirmation. Performance on the Mills is described as 'pottering'. Not what I have in mind. Probably won't get 'contest' performance, but I would like something more positive.
John T
That's a pretty model you have there. Notice you have quite a sizeable elevator. Do you use all of that?
Both you and DCW suggest a 2s system. What's the thinking behind that?
HK used to sell NanoTech 900ma tubular LiPos. Sadly now discontinued but I do have a spare set. These can be arranged in any format you choose, so could be tailored to fit behind the nose cheeks. A 3s pack would take up very little more space than a 2s one.
That's all I have so far. Your thoughts?
Jeff

03/06/2020 22:26:07

Hi Guys
Here's one for all you motor gurus out there.
Planning stage of my next build and I'm thinking of a KeilKraft Gaucho, 44" contest duration model from the late 50's.Just for the challenge, I'm also going electric.
Reading up on the model I find it will 'potter' about on a Mills .75, shown on the plan is a DC Sabre 1.5cc, and it has been flown on a Oliver Tiger 2.5cc.
Rooting through my old engines box, I found a motor I built many years ago, but still going strong.
Slapped it on the bench, and measured 10860 rpm on a 7 x 5 apc-e prop.
So, of the three motors listed above, which would my motor be closest to in terms of performance?
I would guess it has more oomph than the Mills, good news, I don't really want to 'potter', but how would it compare with the other two?
Only looking for a subjective opinion, not hard and fast rules, but I'd like to know if I'm on the right track.
Your thoughts
Jeff

Thread: Adventures with a Limbo Dancer
27/05/2020 18:37:08

Hi kc


Good info, but it might be a little confusing. On the Limbo Dancer, SLEC say '2826 type'.
On the Fun Fly page SLEC specify Axi 2826/10. This is where the confusion comes.
Normal practice, 2826 would denote can dia (28) x can length (26).
Axi measure theirs differently. The 28, I assume is stator dia, but the can dia on Axi's own site is 35. That's why
4-Max list a 3547 as equivalent.
I think SLEC should have said Axi on their LD page, rather than 2826 type.
Having said that, the Axi 2826/10 is £84 on Electric Wingman. That's pretty much the price of the kit.
So, summing up,
Seems to me the recommendation of 2826 should be qualified. In my mind, ignoring Axi, the recommendation should be for 35 of some type.
We have three types, based on real world experience.
Unichap himself uses 3548/900, Dan uses 3548/1100 and I use 3542/1085.
Unichap's choice should realistically be one of those three.


Just my thoughts


Jeff

Edited By Jeffrey Cottrell 2 on 27/05/2020 18:38:44

27/05/2020 14:14:25

Hi again
Don't be fooled by the wattage figures. They are only the maximum you can use before the motor goes pop.
They bear no relation to the real world.
IMHO, 1900Kv is too high for a FunFly. In general the higher Kv of a motor, the faster it will spin a smaller prop.
That's not what you need.
For Fun Fly you need a larger diameter fine pitch prop. It's all about acceleration, not top speed.
I did a google search for 2826 1900Kv. Did find one at Bangood, but that's listed for drones or fpv.
As Dan mentioned, the Fusion and the LD are very similar in their power requirements.
Since you're using 900Kv on your Fusion, that's a good indicator for the LD.
Cheers
Jeff
P.S. Btw, where did you find the recommendation for the 2826 1900?

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