Simple Sailman

Roy Thompson rescues a once popular Brit kit from a clubmate's loft and launches it to lofty heights.

Back in the late 70s my then model clubmates and I were into thermal soaring, flying R/C gliders (pre-electric) at Cranford Park in West London. My club was the Hayes & District MAC. Throughout the summer Wednesday night was club competition night, with trophies to be won at the end of the year. A typical comp would be a six-minute duration event with a spot landing bonus.

At the time Bowman Model Kits of Ipswich advertised widely in the modelling magazines, being one of many small kit manufacturers in the UK. They had a good reputation for their no fuss designs and model kits supplied with good quality hardware.

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My first two proper flights were spent getting to know her, with multiple climb and glides.

My friend and clubmate, Matthew put his hand in his pocket for the Bowman Simple Sailman 110, a two channel, 110-inch span thermal soarer, which he then built and competed with. He had this habit of winning or being well placed, and often against far more sophisticated models (not mine I hasten to add). He had done the same the year before with his Graupner Amigo, so talent probably had a part to play. Year after year, or so it seemed, Matt would take home some of the club's silverware at the end of the year. Hence, we knew that the Simple Sailman was a very capable model in the right hands.

Time Flies
Roll on four decades to September 2019. It’s my current club's annual E-flight event and an old club mate from back in the day rocks up. To protect his identity we’ll call him Andy.

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Box artwork was limited to this simple illustration.

Andy brought with him the results of a loft clear out and paraphernalia rationalisation to sell at the meeting. Among the items was his Simple Sailman kit, which he had intended to build to take on Matt back in the 70s. A little bit had been started and then it had sat in his loft for almost 40 years.

Andy and I chatted about the good old days and how well Matthew had done with the Sailman. I turned down the offers to purchase the kit at a knock down price repeatedly, knowing the extent of my own future project collection. But Andy was determined not to return the kit to his loft and wanted to find it a good home - mine as it turned out!

At the end of the afternoon we had all had a great day's flying. Andy had done very well to sell or giveaway most items, except for the Simple Sailman, which sat on the ground looking unloved. Once again I declined Andy’s now give away offer, but he could see I was wilting. So, he then took the high ground, saying that he wasn’t taking it home,"It’s too nice a model to throw away, and you would be most likely to finish it."

And that’s how, in the summer of 2020 and with time on my hands, I was indeed the most likely person to finish the Simple Sailman kit.

Faded Plan
Where to start? Andy had said the kit was complete, but still my first step was to go through the kit part by part to see for myself exactly what I had. True to his word everything was there. The two fuselage sides had been started but looked a bit grubby from their time in the loft. However, they would clean up.

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Kit open and ready for inspection.

The only real issue, as Andy pointed out, was going to be the plans. The dye-line prints had become extremely wrinkled over the years. Sheet one was also very badly faded and unreadable in parts where it had been left out in the sun light.

Most of the missing details I could work out for myself and re-ink, but one part had me scratching my head. I could see it had been a drawing of a wing rib, with cut lines and some text.

This is where the modern part of this hobby comes in to its own, with an incredible wealth of knowledge that you can tap into through the online community. A search and a request for help on a couple of modelling forums, including Modelflying.co.uk, yielded a whole heap of useful information. Armed with this I was able to spend a quiet evening with a fine-line pen redrawing everything that the sun had erased.

As it turned out the missing detail was how to cut down a main wing rib to make a tip rib for the outer wing panels, so that when you make the outer wing panels ribs by the sandwich method you build in the correct washout. This still had me scratching my head as nowhere on the plan did it even mention 'washout' or how much! The joy of old kits is they assume you know all this stuff. Not that I needed this detail in the end as all the wing ribs were pre-cut. Sure enough, when I laid up the wing panel the rib trailing edges sat up in a line, as required, all bar rib no.8, which I needed to replace. In the end the washout turned out to be about 3/8 of an inch under the tips.

You forget, with today’s CNC cut kits that slot together, that back in the day sanding and finishing parts to fit was the norm, and just how much time this takes up. But it’s part of the joy of building a vintage kit, taking that extra time to get to know the personality of every part.

I must say the accuracy of the parts in this kit were on the whole very good, but every wing rib spar slot needed opening up just a little so as not to crush the ribs or spars. Better too tight than too loose though! The one big decision I needed to make with this project was do I keep it traditional or should I bring it up to date? Should I keep it as a bungee launch glider and build a power pod to fit over the wing, or convert it to electric and fit a brushless motor in the nose? There was also the temptation to add ailerons and split the centre wing panel into two. In the end I ended up somewhere in between; although I’ve fitted a brushless motor in the nose, I’ve kept very close to the plan and used as many of the original parts as possible.

She now has the convenience of being able to plug and launch, but still with the look and feel of the original. Indeed, once you stop the motor and get her into the glide you could be back in the 70s hunting down every bit of lift.

I used a 2830-1300kV motor and an 8" x 4.5" Cam prop running off a 4-Max 2200mAh 3S battery. That gives a more than ample 220 watts to play with in a glider that weighs 2.8lb (1.3kg). That’s one ounce under the original recommended build weight as a glider and includes 60g of lead in the nose for the C of G.

My Fastest Build
Now, I am not the world’s fastest builder but the build proper like started in the last week of May and with nothing else to distract me other than gardening, DIY jobs that I had been putting off, going for long walks with the wife and daughter, and quiz nights, I had the model complete and ready to go in under five weeks. As luck would have it by then our club field was again open, ready for the maiden flight. This goes down on record as my fastest ever balsa kit build; my norm would typically be five to six months - if not years in some cases!

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Ready for covering after conversion to electric power.

The model itself is as traditional as you can get, with a box type fuselage fitted with formers, doublers and triangular longerons. The tail is all built up from the strip wood supplied.

The wing is built up in four parts, with the two centre sections being joined together with a ply joiner and the two small outer panels being removable. The wing build is straightforward, with the ribs and spars being laid over the bottom leading and trailing edge sheeting before adding the top sheeting and capping strips.

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The elegant glider basks in the late summer evening sun.

I like old instructions when they say, 'Ensure the correct dihedral under each wing tip is obtained' but make no mention of what angle or the height under each tip. If you scour the notes on the plan it does give you the heights under the tip ribs, although this didn’t tally up with the main wing joiner in the kit. The plan dimensions give an angle of eight degrees, but the joiner was more like 10 degrees for the centre panels. So, which is right? Had there been a change to the kit and the plans had not been updated? Or were the tolerances for hand cutting of the joiner on the big side?

After a quick discussion on the forums with Paul (aka Cloudriderurt), my go to man for all things Simple Sailman, I made the decision to stick with the plan and eight degrees it was.

With the wings and fuselage built, covering and radio fit were next. The instructions say to use the covering of your choice, so Oracover it was. I used transparent on the wings as I didn’t want to hide all that lovely balsa, especially when I had taken the time to get it right.

Radio fit didn’t take long, with only two mini servos, a receiver and ESC to install. I did swap out the old plastic snake inners in favour of carbon rods, my last concession to current times. I don’t think there was anything wrong with the old plastic inners as on inspection they looked perfectly serviceable, but I decided not to take that chance.

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A new canopy was made to house an Eagle Tree flight logger.

All complete she weighs 45oz (1.3 kg) with 60 grams of lead to get the C of G right. I did blame George for his 4-Max 2200mAh 3S packs being too light but that didn’t wash with George, "You’re not using a big enough capacity!", being his immediate comeback! Well, 2200 mAh was enough for three decent flights that first evening, with 40% still in the tank. So, a bigger pack would mean you could go and play all day with just one pack. Speaking of her first flight, that was cut short when the second-hand prop from my spares bin shed a blade. But, fortunately, not before she had done one climb and I could check the trim and controls.

Second time out was much better, with the glider now looking resplendent fitted with new Cam Prop blades. This time I was joined by George Worley (a.k.a. Mr 4-Max) and Colin Low, whom I must thank for the flight photos. It was late evening, about an hour and a half before sunset. The sky was cloudless and there was not a breath of wind and no thermals to be had. My first two proper flights were spent getting to know her, with multiple climb and glides.

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Ready to go with the eLogger and a small camera installed.

Despite the down thrust I had added to the front bulkhead, under power she wants to pitch up, taking about half the available down elevator to keep it in check. Note to self: adjust the down thrust or add a throttle elevator mix (except that’s cheating as we didn’t have mixing back in the day. Well not on my MacGregor Digimac III anyway!)

In the glide it’s a big pussycat, with the control throws set up as per the instructions. If anything, the rudder was a bit too soft for me, needing large stick inputs to start and stop the turns. Once in a turn just a little up elevator is all that’s needed to keep the turn going, big or small.

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eLogger data showing the power and glide phases.

It’s hard to remember if control responses tended to be softer, or vintage models more stable in the past, or is it that I’m just more used to flying faster models with ailerons? But for beginners they would have been just fine. Add a little bit of power and that improves things with the rudder.

My last flight that evening was spent hauling it around, close in and low down for Colin to get the photos. So, she will hustle with the power on if you put the work in. In fact, that’s almost as much fun as chasing thermals. Loops and stall turns are also very doable if you build up the energy beforehand.

Speaking of stalls, feed in full up and nothing happens but lots of sink. There's no big pitch change or tip stall, just a gentle wallow.

A Keeper
Since then, I’ve had the Simple Sailman out at every opportunity, and I have had some good thermals, to the point that she starts getting too small for comfort. The electric conversion pays dividends when the thermals are few and far between.

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Four decades on the Simple Sailman still provides lots of entertainment.

After yet more conversation on the forums with Cloudriderurt, this time about telemetry, I dusted off my Eagle Tree Systems eLogger and fitted it for a few flights, just to see what she is capable of. She makes about 500ft/min on the way up and if there’s no lift about 140 on the way down. So, there you have it. The Bowman Model Kits Simple Sailman is a 40-year-old design that has kept me entertained all through the events of 2020 and she will be worthy of a place in my fleet for many years to come.

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