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Who Else Wants a 63" Lavochkin La7 kit?

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Tim Flyer01/05/2018 10:16:44
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1296 forum posts
236 photos

I hope you are feeling better Bob. I just thought I would update all on progress. I’m still finishing little bits but am nearly at painting stage, but waiting for some warmer weather. I will be brush painting with white Solarac which is a cellulose paint so will certainly need shed doors open! . I will connect up elevator and rudder after that. I cut the spinner last night too. It’s a lovely big shiny metal one from Sarik Hobbies . They seem to have a great range. This spinner fits the cowl well leaving just about 3/8 of an inch all round to collect air. I put my SLEC pilot in for fun and made a cardboard instrument panel . Here is a pre spinner photo . I 0b166055-9b6a-4462-a366-0766de6cbb0f.jpegmust admit that I’m enjoying this bit. As long as I don’t rush it’s still fun...

Tim Flyer01/05/2018 10:26:07
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1296 forum posts
236 photos

Oops I forgot to ask what if anyone had any advice on C of G ? How far back. I think I will use15mm up 15mm down at full travel at trailing edge as maximum on ailerons and elevators . Any opinions welcome!

Edited By Timothy Harris 1 on 01/05/2018 10:26:39

Bob Cotsford01/05/2018 14:24:16
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8642 forum posts
483 photos

Thanks Tim, I am having a better week. Maybe the promise of some sun is helpingsmiley

The plan shows the CofG as being 122mm back from F2 iirc, and 15mm is what Richard recommends in the book for ailerons and elevators, though he rather oddly goes imperial with 1" each way for the rudder. It will be interesting to see if the moderately sized ailerons are as effective as the ones on my late Ta152 (RIP), that rolled at a phenomenal rate at full bore.

Tim Flyer01/05/2018 14:50:07
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1296 forum posts
236 photos

Cheers Bob good to hear things looking better. Sun is so welcome! It does change everything and I think we should soon be in for a better spell! I had put the plans away so missed that! I will do as it said and use the rates switch as usual to give me choice on first few flights . I wanted to start thinking of c of g so I can start thinking where my two Life batteries go. I’m set to mount them after painting, on the fuel tank base just behind F1 but may put the smaller retract battery further rearwards if needed. My cowl is heavy and I’m using a big metal spinner, plus I went light on the tail so hopefully no lead will be required up front . Have a good week all 😊

Edited By Timothy Harris 1 on 01/05/2018 14:51:02

Jon - Laser Engines01/05/2018 15:04:16
5560 forum posts
270 photos

Looks great Tim, cant be long now before shes ready to go?

Bob, the ailerons on my bigger one are pretty powerful so i wouldnt be too worried.

Bob Cotsford01/05/2018 15:29:01
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8642 forum posts
483 photos

yes Jon, it's surprising how relatively small ailerons can be very effective at warbird speeds. The other way of looking at it is perhaps how ineffective the root sections of strip ailerons are!

Jon - Laser Engines01/05/2018 15:31:10
5560 forum posts
270 photos

too true! I made the elevators on my Hurricane scale size and they are still extremely powerful. My sea fury has really powerful controls all round as well. I think that is why so many people run in to trouble when moving to their first warbird. They set control deflections similar to their sport models and its just way too much

Tim Flyer01/05/2018 16:25:00
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1296 forum posts
236 photos

Agreed Bob as well as the root being ineffective I think the last bit of the trailing edge is the important bit especially at speed so they don’t need to be very deep unless it’s for “kite flying 😉3d” low speed design. Cheers Jon hopefully it will fly well and the engine definitely won’t overheat. There is really just the painting ahead now and then installing the bits and pieces after. Im leaving engine out and control wires to make painting and sanding easier . Should be in the air within a month if the weather stays sunny!

Tim Flyer14/05/2018 08:43:41
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1296 forum posts
236 photos

Hi all I hope you are all well and getting on ok with your builds? I have progressed further and hope to have it finished within the next 2 weeks. It’s mostly painted but I have a question on fuel proofing the decals. Will I be ok painting them with Solarac clearcoat? This is a cellulose based lacquer. I also have Deluxe two pack Tuff Kote that I used over the paint on the front to make it extra fuel proof. If that’s not ok I do have Spectra polyurethane varnish. I’m keen to avoid wrinkling up the decals so advice appreciated!

Bob Cotsford14/05/2018 09:57:46
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8642 forum posts
483 photos

I've not had any problems using Clearcoat over vynil decals, I have had problems with Spectra fuel proofer being anything but!

It may be a bit late in the day, but I'm thinking of going electric. Looking at the model I'd just need to cut a section of the top deck off from behind the cowl to just in front of the cockpit and face everything with 1/32" ply. A few magnets and dowels to hold it on, a liteply battery box sloping down through F2, fill in the cylinder head hole I cut in the cowl and I'm in business. I have a 5055 430kv motor and 80A esc along with various 6S packs. Flog the OS91 Surpass IIP and buy even more batteries. No mess, no starting gear or fuel, no running motor to carry across the pits - unfortunately no noise either crying

That or add it to the list of IC models for sale.

Tim Flyer14/05/2018 10:30:48
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1296 forum posts
236 photos

Thanks again Bob. Agree with you re Spectra. It certainly needs s fair bit of baking before resisting fuel. In my Acrowot it’s very sticky in patches . I will use the clearcoat I think then .. hopefully no wrinkles. If you use the electric on the LA 7 might be worth having a sound system...

Bob Cotsford14/05/2018 10:37:02
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8642 forum posts
483 photos

Are you using the flatting agent with the clearcoat Tim? I have a can but i've yet to try it. Hmmm - sound systems. That could be an interesting area. I think there are various radial engine sound tracks available. If all else fails I can play the sound on my tx!

Tim Flyer14/05/2018 11:08:53
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1296 forum posts
236 photos

Hi Bob ..Yes I have been using the flatting agent with the solarac paints. It works quite well. I have been using about 20/25%. That was as much as I could fit in a new tin of paint as they have a small gap at the top. The 20% mix seems to have a “silk mild sheen” but certainly not gloss . But I think it looks fine plus silk will be much more durable I think than Matt. One thing I noticed is that the flatting agent needs a lot of stirring before adding to the main pot of paint as it has a lot of tiny particles. ..Regards. Tim

Edited By Timothy Harris 1 on 14/05/2018 11:10:19

Tim Flyer14/05/2018 11:14:40
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1296 forum posts
236 photos

I think I’m going to paint the canopy edge lines with Spectra Matt black. I’m not too keen on the red colour there and I would rather not use solarac red in case it reacts with the plastic being cellulose. Oil based Spectra enamel isn’t that fuel proof but I think perfectly good enough for the canopy.

Tim Flyer16/05/2018 09:23:18
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1296 forum posts
236 photos

Nearly finished now. I need to next apply decals. I might later paint the spinner light grey to match canopy. b913385b-76e6-4a20-a7ff-7ab5ee757052.jpeg

Jon - Laser Engines16/05/2018 10:22:59
5560 forum posts
270 photos

ooo pretty

Tim Flyer16/05/2018 10:39:43
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1296 forum posts
236 photos

Cheers Jon. I’m looking forward to finishing it . The only annoying thing is that a small spider has taken up residence the cockpit and a bit of its web has picked up a grain of foam! 😊 .

Tim Flyer17/05/2018 09:33:30
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1296 forum posts
236 photos

Drat! Too much haste! I put in the HK retracts last night . First one went in fine and worked well . Bit of a disaster on the second one . I screwed it in without checking if there was any tension from the thick oleo resting on the wing. When I tested it it went up ok but jammed going back ! I should have shimmed it slightly but rushed. Anyway I couldn’t disconnect fast enough and it has fused/ burnt out the motor. It’s a shame but I don’t have the skill to repair electronics. Anyway I ordered a new pair of the 10kg “large heavy plane” retracts from HK in Hong Kong. These are the ones I use on my Laser 100 powered P 47 and will use the same. This will delay the maiden flight by a week or so 😧....but i’ll Be back!

Bob Cotsford17/05/2018 10:34:39
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8642 forum posts
483 photos

I'm surprised at that Tim, the HK retracts that I've used have had stall protection built in to the amplifiers. In fact I've found that a more reliable way of setting the movement than relying on the microswitches. Maybe it was a faulty unit?

Ron Gray17/05/2018 11:29:33
2235 forum posts
978 photos

I had the same issue with HK retracts, they're supposed to have stall protection but I've been through 3 or 4 different ones where it's been obvious that they haven't! I now am of the opinion that it is better to pay more to get quality legs,, after all, you don't want one packing up in flight!

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