Ramair 50" Ultimate Bipe.....the lead up to flying my Pitts Special.

[Mike.K 60]

Anyone having read my Cermark " Rothmans Pitts Special thread will perhaps realise how much effort went into modification and referbishment of this rare and lovely model.

Having put heart and soul into the project, I`m perhaps a little reluctant to fly the model without getting some advanced flying practice in place prior to commiting to flight. I estimate that I`ve put around five hundred hours of re-build time into this model. I`m in no hurry to fly the beast without making sure I`m up to the task. It is probably true to say that even the most experienced model pilots around would baulk at the prospect of taking charge of this Pitts for its maiden flight in my ownership. Flying a model of such intrinsic value is something that most pilots are likely fight shy of from due to the responsibility and the high risk of a flying smash at some point in the first flight.

On the basis that it would be unfair of me to ask another pilot to fly the Pitts for me, it comes directly to me to find a better solution. I regard the Pitts as a high value model that needs to be carefully managed. The answer to this conundrum is best approached by finding a model with similar flying characteristics but without its value.

So the hunt for a suitable proxy model began last week. Ideally, a Seagull Ultimate Bipe would have fitted my needs nicely. Unfortunately that model has been discontinued and I couldn`t find any used examples either locally or via the internet. Trawling the BMFA classifieds section turned up a vintage 1990`s 50" Ramair Ultimate Bipe located in Chelmsford. This was just an hours travel time and fifty miles distant from me here in Warlingham. An image and brief description detailed the model as being of foam and veneer construction similar to the Pat French designs of around forty years vintage. The construction is indeed very similar to that of my two French designed Zlin 526 models. The seller said he had run the model many years ago with a .90 two stroke fitted with a tuned pipe. The model was in sound condition and was fitted with Futaba servos but no engine. It was just what I was looking for. Although perhaps needing re-covering, a moderate overhaul and fitting of a more suitable four stroke 120, I considered the model to be suitable for my needs, a deal was done and the model collected. Added to the cost of the model was the cost of two gallons of derv for the van and Dartcharge river crossing fees. For around £100 I was on my way to getting my "Pitts trainer" requirement sorted.

The Ultimate has certainly seen some action in its previous owners hands. Upon stripping of covering, just one small restructural repair has been found in the top wing. This is indicative of the model suffering something like a cart-wheeled landing at some time in its career. The repair is well executed and doesn`t require further attention.

Stripping old covering from an airframe is a long winded and often frustrating business. Tonight I have the fuselage and upper wing cleaned a prepped for new material. The lower wing is still being cleaned. How long has it taken to get this model cleaned up....about twenty hours to date. Yes, covering removal is not for the faint hearted or for those without patience. I think of stripping a model as "digging for gold". Its down there somewhare, you just have to churn the muck until eventually the value is realised. At that point, you start to know you are beginning to make progress.

Some might ask the question as to the viability of doing refurbishment work. Yes, it can be very gutty and tedious. Faced with non availability of a new kit, referbishment of an elderly model is often the only way to obtain what you require and desire. To get to the dream, you have to put some effort into the project. I tend to forget how long it takes to clear a model of covering. Its usually the pull of obtaining what you desire that shoves all negative considerations out of the window and the grind of a "strip and clean" gets the upper hand!

Another few hours of cleaning and the model should be ready for rework and re-build. More images will be added to this thread as the model comes back together.

Mike

[Mike.K 60]

The Ultimate Bipe strip and rebuild continues at a good pace. Nothing unexpected or of any consiquence. Some control surface hinges displaced during covering removal.....ie, they just pulled out due to a slight lack of CA adhesive during the original build of the model! I don`t mind that...its better than them coming off now rather than during the early recommissioning flights. CA adhesive will fix the issue during the re-build. All the old covering has been removed from the model and the end result just needs some minor sanding, dusting off before being ready for a recover in HK material.

The cowl, spats and replacement carbon fibre landing gear have all been primed and painted with red two pack aerosol spray paint specially mixed for me to match the Hobby King covering by L E Went at Selhurst. This particular cowl is not the finest fibre glass molding ever to have been produced. Various holes have been filled and faired to tidy it up. The end result should be passable. The inverted ASP/Magnum 120FS is inverted mounted on F1. Pleasingly, the majority of the cylinder head sticks well below the bottom of the cowl. A standard exhaust without extra fittings will pertrude to the side of the port side cowl cheek. It will make for a simple and easily maintained installation with all prime parts being highly accessable. Just what I want for this little bipe which is destined to be a replacement for my aging low wing Ultra Stick as well as teaching me the basics for fast flying bi-plane experience.

The bipe came to me having two servo operation in the lower wing only. The ailerons were linked to the top wing ailerons via typical clevises and pushrods. A large degree of general slop was noted in these linkages so I decided to copy the bottom wing servo box detail onto the top wing, install two new servo power control cables within the top wing and make the model have a "one servo per control surface" system. A 3mm "trench" was cut along the bottom of the top foam and veneer wing before cables were buried within. Two 3mm balsa strips white glued back into the foam and veneer construction completed the modification. Once the glue had dried, the balsa was sanded level and any inperfections made good with quick drying balsa filler. 3M industrial strength double sided sticky pads will be used to fix two new servos into their boxes. Aileron link push-rods are now a thing of the past. Regretably, the servos cannot be screwed vertically into the wing. It just doesn`t have enough depth. Hence the box mounting and sticky tape mounting methodology.

Cleaned of residual fuel goo, the existing 16oz fuel tank fitted with new fuel tubes and pipes lives to fight another day. This is accessible via a removable lower chin panel behind F1 and before the leading edge former into which the lower wing fits using dowel pegs. The landing gear also shares this space where four 4mm HT bolts will hold the gear into the model. Fi has been doubled with3mm ply and corner gussetted to help absorb stress and vibration and effects of four stroke engine torque. Its all straight forward stuff but very necessary to give this model a new lease of life.

More images in due course but this is how the model stands this afternoon.

Mike.

[Mike.K 60]

The Ultimate overhaul continues to progress well.

The new paint has now dried but has flattened slightly with further curing. That will polish back up to a reasonable lustra. For those interested, the spats came from one of my crashed Ultra Sticks......lightly flatted, primed and repainted in two pack red paint, they have been married to a gashbox scrap carbon fibre landing gear which has again been painted in two pack red paint. The addition of the light weight spats together with some slightly larger and softer wheels certainly adds a bit of bling to the model as well as hopefully reducing the tendancy for this model to bounce upon landing.

The cowl has seen some "minor block" up work carried out to fill in redundant needle valve and air bleed holes. Any fire-glass material retained which was specific to the previous .91 two stroke installation has been worked out. I removed some further cowl fibre-glass to allow the cowl to fit around the larger 120FS motor installation. The repairs and modifications have blended in well. Paint covers up a multitude of sins!

I`ve moved the elevator servos from within the fuselage to just in front of the tail plane, building ply mounting points into the foam and veneer fuselage. The snake type pushrods and outer sheiths were completely removed from the model to save weight and to allow me to install a more direct elevator system that will use short wire pushrods and clevises. The well installed rudder pull-pull system has been retained. Althought the servo weight has gone aft, the increased weight of the four stroke 120 motor should off set that. A 2600MiMh battery pack will provide portable ballast to allow C of G adjustment during the final stages of this rebuild.

The fuselage has now been recovered in Hobby King film. It comes at a great price being about one quarter of the cost of an Oracover equivalent. That makes covering of a model quite affordable. The covering material quality is first class and is every bit as good if not rather more user friendly than Oracover. Its great stuff. If you haven`t tried the HK product, please consider doing so. You won`t be disapointed.

Tomorrow sees the wings being recovered. More images of that work shortly.

It is very heartening to see this model coming back to life. I`m well pleased with what has been achieved to date. Sticky vinyl sheet for contrasting trim has been ordered. This is exactly the same material as Emma uses to produce here wonderful model letter graphics. Its certainly cheaper than using the Oratrim product and is suitable for cutting coloured trim such as sunbursts and long panels for fuselage sides etc. Emmas graphics will adhere straight to the vinyl and make for an easy way to colour up an otherwise single coloured model.

As you will see from tonights batch of images, the model is "very, very red"! The addition of contrasting trim will add interest to the model....then its a chat with Emma to produce graphics letters. That`s the iceing on the cake and really finishes a model off.

More text and images soon.

Mike

[Mike.K 60]

Two weeks or so after my last progress report, the Ultimate is receiving the final fettles. Only the Rx aerials to locate now and a bracket to manufacture for the steerable tail wheel shock springs. The C of G was checked out at Avicraft yesterday having taken dimensions from the airframe and passing them through proprietor, Rob Newmans favoured online calculator. C of G positioning is currently at the forward end of the suggested limits and broadly equates to the position suggested by Seagull for their very slightly larger but very similar 54" version of the Ultimate.

The weight of the model is probably higher than when originally flown by the last owner. In his hands, elevator servos were internally located forward of the cockpit and the .91 two stroke motor was certainly lighter than the Magnum 120 four stroke unit I have installed. Elevator servos have been relocated in front of the tail plane to offset the weight of the heavier Magnum. A 2600NiMh power battery is located immediately above the leading edge of the lower wing also helps bring weight to the forward end of the model. Two extra aileron servos added to the top wing tend to drag the C of G aft again....its all about mass and positioning to get a decent C of G without adding additional dead weight ballast.  The C of G is well located although I shall be adding a few grams of additional forward ballast before maiden flights to ensure I don`t have a tail heavy horror on my hands.

The model now weighs in at 10.8Lbs. I`d suggest this will be rather heavier than when in the owned by the previous owner.  The weight is now broadly similar in mass to the Seagull produced ARFT kit version of the Ultimate.

The colour scheme is quite blatently "non scale" and arose as I saw opportunities during the covering process. Having two rolls of unalocated red HK covering film in stock drove the final appearance of this model.  Our Events Secretary, Emma responded to my screams for lettering and produced what you see a couple of days after I specified sizes and colours to her by email. Indeed Emma produced one of the sticky backed vinyl logos in less than two hours after I decided to change the colour scheme and layout at the last moment! My grateful thanks to her for her work on this model and also many others over the passed couple of years. A highly recommended service with very reasonable prices. Contact Emma direct for all your vinyl graphics needs.

So there we have it. A fully referbished, modified and re-lifed model of about thirty years vintage. I`ve enjoyed the re-build and challenges of reworking the model.

My grateful thanks also go to Colin, the previous owner of this Ultimate. I had to look hard to find a conveniently located used example of the model and was more than happy to travel to Chelmsford to collect it. I`ve sent Colin details about this rebuild thread and hope that he is happy with what I`ve done to his former model!

More details about this Ultimate once I get to flying stage.

Mike