Newbie
KingTech are a relative newcomer to the turbine manufacturing field, but have gained a strong following with their expanding range of practical, reliable and very price competitive turbines. RCJI has already tested three engines in the range, and the subject of this issue’s test is the smallest engine KingTech offer, their K-60G, which as the name suggests is nominally of 60 Newtons thrust.
There is nothing showy about the way the engine is supplied, just a sturdy cardboard box with shaped foam inner holding the turbine securely ensconced, the ancillary items being bagged and within their own smaller compartments. The long trip from the factory in Taiwan had resulted in no damage to box or components, so it was straight on to evaluating what had been supplied, commencing with the turbine itself.
The K-60G is of similar external appearance to previous KingTech engines, with a brown main casing, contrasting with the polished tailcone and red anodised intake cover and engine mounts. Quality of finish is excellent,with crisply produced components – the compressor appears to be a cast item, whilst the turbine wheel is very nicely produced.
There are a total of three connectors on the engine, two being electrical and the third the fuel input. The K-60G is a kerostart engine with the fuel and kerostart valves mounted under the front cover, thus needing only a single fuel inlet, this connector being of interest as it can be rotated to suit the installation, a very nice feature. The kerostart plug is internally mounted, so the only other item of note is the external thermocouple,which is neatly secured both front and rear.
The ECU is the well-known, compact and reliable Xicoy unit, supplied complete with its matching HDT, whilst the fuel pump is from HP-Tech GmbH of Germany. Also included is the required assortment of leads and fuel tube,fuel filter, manual fuel shut-off valve etc, as well as the very comprehensive and detailed English language manual, and some nice KingTech decals. No ECU battery is supplied,however the instructions recommend the use of a 3-cell LiFe battery or 7-cell NiMH, so for testing I used a 3-cell 9.9 volt 2100 mAh pack.
The engine comes with a ‘Limited Lifetime Warranty’ which covers the main engine components for life, with electrical and wearable components such as starter motor, fuel pump, bearings etc. having a one year warranty. If the engine is sold to a new owner within a year of original purchase then the warranty can be transferred to the new owner at no cost, after the first year the transfer of the warranty would cost $150. Like all warranties this is based on normal usage, and has exclusions for improper use, crash damage etc., etc.
The turbine itself is very compact, and has a high quality appearance with an attractive surface finish
The K-60G compressor is a nicely finished casting with excellent balance,going by the lack of balancing marks
High quality is also evident in this photo of the turbine wheel, the finish of the blades being particularly crisp
Setup of the familiar Xicoy FADEC ECU was a straightforward as ever, and with only a single fuel and twin electrical connections to the turbine the engine was soon ready for testing, which commenced with runs using my standard fuel mix of Kerosene with 5% Mobil II Jet oil. Starting from cold proved to take around 50 seconds from commencement through to the ECU handing control to the transmitter, the entire process being fuss-free and with no flames or raw fuel being ejected.
Once running at idle the test procedure was started, running through the rpm range up to full power, with timings and readings being taken at every stage. General running characteristics are excellent with the engine rpm being stable at all throttle settings, whilst vibration is almost entirely absent, even at maximum thrust.
The maximum corrected thrust figure was found to be just over 62 Newtons, a little above the 60 Newtons claimed, whilst the fuel consumption was certainly above the claimed figure of 195 grams per minute at just under 250 grams per minute.
Acceleration has always been a strong point of KingTech turbines, and the K-60 did not disappoint, with times being measured as just under four seconds from idle to full power,deceleration being similarly fast. The only slightly unusual characteristic noted was a propensity for the engine to produce a low level pulsating/fluffing sound at idle, although this did not seem to affect the idle rpm stability whilst disappearing completely as soon as the rpm rose.
Speaking to Barry Hou, my KingTech contact, he replied on behalf of the factory,that this would only occur when the engine was run on Kerosene based fuels, the noise should not be evident when using Diesel. I was further advised that this noise had no detrimental effect on the engine, and does not affect the warranty.
Following this discussion I decided that it would be worth running the engine on the recommended Diesel mix, both to confirm the elimination of the noise and to see if there were any changes in the performance of the engine. A Diesel fuel mix with 5% oil was prepared, and the engine run up so that a new batch of measurements could be taken. It was immediately apparent that the noise heard when running on Kerosene was now absent,the engine running perfectly smoothly throughout the rpm range.
Testing the full throttle performance showed that the maximum thrust has slightly increased from the original 62.1 Newtons to exactly 64 Newtons, whilst the fuel consumption had reduced from just under 250 grams per minute to 238 grams per minute.Acceleration and deceleration remained exactly the same, with the only difference from running on Kerosene being the small amount of smoke emitted during start-up and shutdown.
Based on these findings, the use of Diesel where it is readily available and price competitive would make a great deal of sense, given the slightly higher thrust and lower fuel consumption.
Note that the figures in the graphs and test result data in this report are those obtained when running on Kerosene, as this allows a level comparison with the other engines tested.
The neat fuel inlet fitting can be rotated as required to suit the turbine’s installation, note also the front mount for the thermocouple
The ECU is the well-known and easy to program Xicoy unit, this being a very lightweight and compact product
Bolted to the test rig and ready to run, the K-60G proved to be an easy to operate and smooth running engine
Data from the K-60G displayed on the screen of my Futaba 18MZ transmitter, courtesy of the Xicoy Telemetry Adapter – there will be a full review of this in the next issue
Conclusion
Once again, a very nice engine from KingTech, a turbine that is in a 60 Newton class that currently has few competitors. It is very easy to operate, able to run on a wide range of fuels, and is extremely attractive price wise. Having the fuel and kerostart valves internally mounted reduces much of the clutter and complication of the installation, making it easier and quicker to fit into the model, and this also makes things much simpler for the newcomer to turbines with less to get wrong.
The K-60G is an attractive proposition and should certainly be seriously considered for any of the smaller sport and scale jets currently available.
发表于 2020-6-8 09:00:00
千斤顶
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