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Member postings for Tim Ballinger

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

Thread: A long time since i did this.....
19/01/2020 19:38:38

Chris,

Thanks for the kind words. The wine is indeed mine, a reward for walking round part of a very,very muddy half marathon at Doynton near bath. My other half ran the full distance , mad woman so I just do my own walk for an hour or so,.

I thought about buying some pigment when I bought the gel coat so I will revisit and colour before my next attempt.

Thanks Tim

19/01/2020 18:34:02

I’ve become a real fan of slow cure, not only 90 min pot time but no obvious heat at all in its 30 hour cure time. At least that’s how long I had left it when I released it from the mould.

I am actually pretty pleased with the result . It weighs in at 32g or 1.12 oz ( 15cmx15cmx12cm) and feels rigid enough to me, certainly pretty much the same as the original.

Surface finish I am also pleased with , its picked up a few whitish spots from the bits of filler I used on the mould but that’s ok. I can see a trapped air bubble in the nose but it’s in the solidest part so would be ok.

That said I am going to make another. Reason? I commented it was difficult to see where I had painted on the gel coat and I obviously got a bit thin on one corner right on the edge of the mould and as a result there is about a 2cmx 1 cm bit missing it’s gel coat. Again not a real show stopper but my personal mission was to do the best I could so I will have another go. I am wandering if putting some pigment in the gel coat might help ensure a more even coverage.
Chris your cowl looks to have colour , did you use a coloured gel coat?

Anyway pictures below including a close up of the offending bit of missing gel coat.


3d59ec27-a768-49e4-ada4-ca8df0dda190.jpeg65e14f7f-8319-445f-9e25-b4efe4526666.jpeg794e771e-d1ce-47da-bf29-bed7581040ef.jpeg

18/01/2020 14:53:55

It took me 80 minutes to lay up 3 layers of cloth and having mixed up 78 g of resin at 30% ratio I have about 40g unused. After 100 mins the remainder is just starting to thicken .

It was so much easier having all that time to work with. You could actually spend time working the resin into the cloth without having to spoon it on in a race to beat it curing in the middle of the job.( slight exaggeration but those that have tried this will know what I mean).

I used 2 layers of 20g and 1 of 200g cloth as planned. I used large oval shapes to cover the bottom or nose of the cowl and then just overlapping rectangles to go round the sides. A couple of small discs of 200g cloth right at the front to make sure of strength where it will be drilled out for the prop shaft.

Currently no pools of resin and no heat but then it is only just starting the long cure.

Of course I have 30 hours to wait before I find out if it even comes out of the mould let alone what sort of finish I will get.

Any way this is what it currently looks like.

894cfbc6-7f29-41d8-87a7-144952a38bf1.jpeg638e4b7c-4994-4b66-8f56-f02eed918c7d.jpeg

18/01/2020 11:03:38

Well gel coat is on. Biggest issue is seeing that everywhere is covered. You really only need about a 20g mix but to make sure I mixed the correct ratio (2% by weight) I started with 100g of resin and added the requisite 2g by pipette.

You can not see anything in the pic really except for the excess resin in the tray alongside. (It’s shallow to stop any heat build up and premature curing) .Started to go thick bang on it’s quoted 15 min pot life.)

Plan is start the lay up in around 4 hours time. Should be tough enough but still a bit sticky. Instructions reckon adhesion is excellent even after 24 hrs. 
Piers I hear your thought about upside down but I reckon I would be asking for laminates to sag if I tried that so I’ll stay the right way up.

8df4e244-c877-4190-b2f8-9a6885b337e3.jpeg

Edited By Tim Ballinger on 18/01/2020 11:07:54

Thread: FrSky Major Update for most TX and RX
18/01/2020 08:57:06

I see all the Rx’s and Tx’s on the site still list all the previous firmware as well as this latest update and just to be safe I have all the relevant Rx ‘old’ firmware files downloaded just in case I need them.

At some point I will inevitably want to upgrade the Tx firmware to take advantage of any updated features that I might find useful ( Bug fix notwithstanding, that is after all one of the benefits of being able to install new firmware) , at that point assuming all has settled down to my satisfaction I will upgrade the Rx’s.

Tim

Thread: A long time since i did this.....
18/01/2020 08:47:05

Thanks to you all for the comments. There are indeed many pitfalls when working with composites and I sense we have all experienced one or more of them. As for this project I will be starting with a 20g/m light cloth and depending how it conforms I intend to repeat with the same weight before finishing with a heavier 200g/m.

With the slow cure and the essentially quite thin ( probably around 2mm ) overall lay i am not expecting any huge heat build up. I am hoping the extra time the hour pot life gives me will allow me to stipple only the minimum necessary resin into the cloth but we shall see. As I say if it does not work out as I anticipate I will modify the process and have another go.

I will report back on the results , good or bad!

Tim

17/01/2020 19:36:30

Thanks for the comments both. I went for slow cure because I am forever having to rush jobs when using 15 min cure. However, even after being frugal with the resin, If cowl no 1 with slow cure gives me the trouble you suggest it might then I will order up a bottle of fast catalyst ( resin is the same whichever) and go for cowl no 2 !

Thanks guys and any other tips more than welcome.

Tim

17/01/2020 18:43:10

I am anticipating using 3 layers of cloth so I have already cut the pieces I think I will need.

473e3944-6380-4bc4-8c51-ec723012e433.jpegI should be able to lay three layers of cloth in 1 go as I bought epoxy laminating resin withe slow hardener which gives between 90 and 120 min pot or Working time viz the 15 mins you get with the standard or fast cure.

Next step is to brush on the gel coat. I am going to use what is shown as epoxy compatible polyester gel coat. According to the blurb this allows the epoxy laminate to laid from about 3 hours after applying the gel coat up to 24 hours afterwards so some leeway.

Accurate Mixing ratios are required so it will be out with the digital scales to orchestrate the mixing. My method of adding the catalyst will be by pipettes of which I have many and are throw away items.

Only the gel coat has the Nasty styrene content so it is on with a mask as well as gloves for that bit - windows open too.

Hope to tackle the gel coat in the morning.

Edited By Tim Ballinger on 17/01/2020 18:44:33

17/01/2020 15:25:42

Firstly here is the mould.

It has suffered a few dings over the years which I have attempted to fill then polished with carnauba wax. I’m hoping any remaining imperfections will polish/sand out of the final cowl or cowls depending on how many attempts I need to get one that is acceptable.

71193d2b-acf0-4ae1-9445-961859adadb3.jpeg

I am going to use a chemical release agent viz just wax and the first coat has been applied in the above pic. Dries very quickly but is almost invisible so you just hope it is all covered ( applied with soft cloth) . Instructions suggest 6 coats for a new mould so I will give it another 5. The release agent is meant to be multi use, hmmm.

Next pic shows most of the kit I have assembled for this task..

1ee5e830-44a4-4483-8531-1c9ee92da1c4.jpeg

17/01/2020 15:01:47

Last year I used a new GRP cowl when renovating an old Cessna 172 designed by Eric Fearnly.

I can not remember where the original came from back in 1973 but I did make a mould from it and layed up a spare just in case. That is what i used in last years refurb. I had kept the mould as well as the spare.

A fellow modeller spotted all this is also renovating his old Cessna 172. He has asked if I could make him one from my old mould. Now it is over 40 years since i used this skill set but as the weather is shall we say not conducive to flying atm . I agreed to give it a go. Maybe foolhardy given there are may of you out there who are well skilled in this area but I also said I would record my attempt in a blog. So here we go.....

Thread: New EDF Mini Jets- Jet Provost & Folland Gnat
17/01/2020 14:44:39

Dave,

Seamless is a trick of the light. After covering I just add a small strip of covering a couple of cm wide to span the gap between model and canopy. Then just use the iron on the lowest temp that causes the film to stick properly.Do not show it a hot air gun unless you are very very brave and don't mind a mess! You can add the strip before covering if you want. Not sure the result is any different.

Tim

Thread: FrSky Major Update for most TX and RX
17/01/2020 12:54:21

Andy,

I’m just reading this bit from the German report

Where benefits are known, there are also disadvantages. The modified encryption requires all receivers and transmitters/HF modules that a customer runs must receive an update at the same time.

If you don't do that, then only the recipients will work with the transmitter who got an update.

We certainly need more from Frsky but that’s the way I read it.

Tim

17/01/2020 10:56:30

Seems like folks on RC Groups are equally cynical.

Tim

17/01/2020 10:44:36

Frank,

Thanks for the link. Would have posted the translation but it so long it would have covered 2 or more posts.

if I read it all correctly there are 2 issues. 1 . Very rarely a servo in 1 random channel may twitch almost imperceptibly

2 on even rarer occasions 1 servo would be free to rotate for about 0.9 s meaning it could achieve full deflection. Control is then returned to normal in both cases.

Upshot is it is a very unlikely event but could get more common so I ,like others, am not rushing in to change anything. Problem will be when buying new Rx’s when they they start being sold with the new firmware as they will not work without the upgrade.
They certainly kept this issue very quiet. Why one can only conjecture......

Tim

16/01/2020 18:55:32

Clearly Frsky rate this as important but anyone know what the real life issue was?

Also never upgraded RX firmware before. Does it have to be upgraded to work with the upgraded Tx firmware or put another way will non upgraded RXs still work with an upgraded TX?

Tim

Thread: Your experience of Banggood delivery time?
14/01/2020 17:06:00

When things go wrong they sure go wrong! Not much more you can do other than demanding a refund from Paypal.

Tim

Thread: Forum members' new models: Let's see them.
12/01/2020 18:08:28

I have never tried control line but that is a beautiful model.

Tim

Thread: battery c rating
12/01/2020 13:39:50

Seems to be a lot of ‘weather’ about atm.

Need to have more fun ( or Sun)

Tim 🌞

Thread: Can Superphatic glue go off?
12/01/2020 09:28:18

Yes, but only after it has been standing for a long time with a modelling pin in the nozzle. Looked like the pin rusting to me.

Tim

Thread: New EDF Mini Jets- Jet Provost & Folland Gnat
11/01/2020 18:42:17

Dave,

The red and blue were HK film, the red solid Carmine and the blue pirate blue. Only the white is oracover which was because there was no white in the HK warehouse and I found MSL was selling seconds of oracover lite . Never used the lite before, it so light it is nearly transparent !

Tim

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