Pre-owned Seagull Zlin Z50LS overhaul and re-birth.

[Mike.K 60]

If you are an Avicraft customer and have ever glanced up towards the ceiling in the shop, you may well have spotted a rather down at heel and unloved Seagull Zlin Z50LS. It was particularly notable due its baggy and wrinkled covering and neglected appearance. Emma told me it had been hanging there in the shop for something like two years. People had looked at it and walked away. I did that same thing at least three times myself before looking harder at this model which was badly in need of some TLC. Structurally, the airframe appeared sound and undamaged. That gave some cause to consider the model further. Research indicated that a complete new kit retailed at £225, plus of course the additional costs of an engine, servos, receiver, propeller and battery, etc. Another £250 or so would perhaps have to be added to the cost of a build to make a flying model. The total cost might possibly accumulate to about £475.

I`d watched a few You Tube vids which showed this Seagull model to be quite a performer as well as having fairly benign landing characteristics. My search was for a model that could become a hack for my learning curve and completion of the B-test later this year. I wanted something a little more lively than an Ultra Stick and something that looked more like a full sized aircraft. I also wanted to find an economical alternative to buying a fresh new kit. In other words, I wanted a bargain with some potential at a rock bottom price! I wasn`t too concerned that the model might have usage rash or be a bit unsightly in places. It just had to be sound, usable and perhaps expendable without too much outlay being involved.

Rob offered me the model for £100. It included Futaba servos but no engine. Removing the model from the ceiling showered us both with a quarter inch thick layer of Avicraft dust. The model was filthy! Rob and I cleaned it up a bit so that we could examine it further. I was told it was a commission sale. I never haggle with Rob on prices as I know he always gives me a reasonable deal. Back home, the model was washed down with a damp cloth, dried and then given the once over with vehicle waterless cleaning fluid. This made it look rather more presentable. Yes, the covering had slackened badly and required a re-tighten with a hot covering iron. That done, it looked vastly better. The wing tightened to almost new appearance but the fuselage which had many self adhesive decal stickers applied to it, was a bit of a headache. I persisted and eventually ended up with an 80% good appearance. Ideally, the fuselage could do with a strip and recover but the current state is good enough for my purposes. I removed the fuel tank which was contaminated with solidified fuel residue together with its fouled fuel pipes. Tanks and pipes are cheap enough, so I`ve not wasted my time on cleaning it out. It went straight in the bin. A replacement tank was sourced from my ever-increasing stock of unused Seagull kit parts and a length of new fuel pipe was obtained. All simple stuff. The spares box also supplied a new pair of engine mounts, new blind nuts and a new throttle rod.

Set to one side, I had a low use SC120 FS ear marked for my Fly Baby bipe build. This was re-directed to this Zlin.  Another replacement ASP/SC 120FS "new in box" is due for collection next week and that unit will be directed at the Fly Baby unless a more suitable 90 sized unit becomes available via eBay or some other source. My power units get moved periodically from airframe to airframe. Again from stock, I pulled a new seven channel FrSky FASST receiver which is fully compatible with Futaba FASST transmitters. At a humble £25 each from Rapid RC, they make a reliable alternative to the Futaba 617 receiver which costs double the price. Other modellers speak highly of this budget priced FrSky receiver. I also replaced two terrible old cheapo light weight switches with a decent unit which has the benefit of an external charge port. How I hate and distrust low cost switches.

Apart from some localized silver Oracover covering repairs being needed, I`ve only had to block up a few blind nut holes and a badly executed throttle rod exit through the engine mounting bulkhead before disguising the work with a few Oracover off cuts. The cowl was in reasonable condition but any cut outs for the previously fitted engine or silencer placement were badly carried out by the original owner. Fortunately, the cut outs required for my chunky large ASP120FS removed the clumsy previous work for ever. This large motor installation made the model slightly nose heavy. Correction to attain the correct C of G position was easily accomplished by placing the 2600NiMh battery pack aft of the servos. No problem with that. All clevises, push rods and control horns were checked for security. Essentially, this Zlin received a full check over, re-work and overhaul over a space of a weekend. What has been achieved has pleased me greatly. The Zlin is of better appearance than I predicted or thought possible. It is a long way from perfect but my total outlay to get this neglected model operational again, amounts to a total spend of just £270. Its certainly the cheapest model in my collection although perhaps not being the tidiest! Value for money, it's a half price model rebuilt for a purpose. Certainly, it was worth what I paid for it and the twenty or so hours I've spent nailing it back together. Good enough for  Government job!....yes, and it is the first model that I`ve placed my shiny new CAA OP label on....Legal it may be, nonsensical it almost certainly is! (My opinion)

The finished weight is a very acceptable 8.4Lb/3.4Kg. The manufacturer states 8.6Lb -9.4Lb. This Zlin then is the first ever model that I`ve been involved with that weighs LESS than the manufacturers spec. Pleasing, I think you might agree.

Anyway, here are some images.

All comments appreciated.

Mike

[Mike.K 60]

Its been under the modifying torch before its even flown!

I needed the SC120FS for my forthcoming Seagull Steen Skybolt. Out came the engine and in went a low time ASP/SC 1.08 two stroke which I bought with a gummed up carburettor for just £11 at one of the Club actions a couple of years ago. As I confidently expect this Zlin to have a fairly short life, it seemed a good idea to fit a cheap engine rather than one of my prized and valued four strokes! Conversion of the air-frame was accomplished in about three hours. It was worth doing.

Mike