Amateur Build. HAYA Centurion KIT

[Herr Dr. Professor]

These are not YouTube reviews, but printed in the monthly Toy Farmer magazine: https://www.toyfarmer.com/. I tried to find an online sample, but no luck. Nor do I know if legally the reviews are my property after they are published each month. So I am putting in a brief sample here, just a few sentences excerpted from the September 2024 issue:

The reviews start with a bit about the real machine, in this case the Fendt 728 Vario. Fendt is a long-established German brand available in the U.S. for some time via AGCO Corp.

What is unusual is what Fendt calls its “iD Low Engine Speed Concept.” The Fendt engine’s working range is 700–1,700 RPM and “peak torque [is] achieved and sustained from 1,100–1,400 RPM.” The results, Fendt advertisers claim, are lower fuel consumption, a quieter tractor, and longer engine life (Fendt 700 Vario Series 10). Given the lower engine speed, the Fendt 700 tractors are capable of the kind of creepy crawly ground speeds one would expect from a vegetable tractor or a guy my age: 65 ft./hr. (0.02 km/h) (Fendt 700 Vario Series 22).

And then the reviews go into the model or toy itself, often comparing its authenticity against the real one. In this case the model is the 1/32 Fendt 728 Vario by Wiking NordAmerika (ACP0835750):

As for the driver’s seat, the model replicates Fendt’s “New Premium Driver's Seat” with the horse-in-a-triangle logo on the upper seat back. It might be a bit difficult to try out the seat’s features on the model, but Fendt says the real seat features “electric adjustment of the backrest, side bolsters and lumbar support” as well as electric longitudinal adjustment. There’s also a “Massage function” (Whoopie!), “Multi-stage seat heating and air conditioning” and a “Memory function.” (I could especially use that last one.) (Fendt 700 Vario Series 8 ).

[zooma]

Thanks Prof - that is very interesting!

[zooma]

Followers of this kit build will be aware that I had a problem when I glued the front light covers onto the gracis plate - prior to inserting the LED bulb legs. I had to use a cyno dissolving fluid to remove them and this damaged the cover mouldings and the surface of the glacis plate itself.

Unfortunately Andrew at HAYA had no spare bulb covers but sold me a pair of used ones that he had managed to remove from a used model - but these covers were also broken and damaged so I ordered a new pair - to be delivered whenever they may become available again.

These new light covers are still not available, so the build had effectively stopped.

Today I decided to use the best two of my damaged and broken headlamp covers and get on and use what I had - not an ideal situation - but hopefully with filler and paint I can make the best out of what is a bit of a bodge-up.

I found a short length of small brass tube and cut two lengths to cover the + (positive) legs of the upper and lower LED bulbs and soldered them together. I repeated this with the - (negative) LED legs to join both pairs of legs together.

I cut the brass tube to length by rolling it under my craft knife blade to almost cut it through and then snapped it off to give a nice clean and square end. I rolled the knife tip into the end of the cut tube to make a small chamfer to allow the LED legs to slide in easier. They are a reasonably close fit!

Supplied in the kit was the yellow and black wire with the correct type of small white plug fitted to plug into the CLARK board.

The yellow wire was soldered onto the + (positive) leg joint and the black wire was soldered onto the - (negative) legs joint.

I was worried about holding the soldering iron so close to the plastic upper deck moulding, so I snapped a wooden toothpick into two halves and pushed them under the legs of the LED bulbs at each end just to lift them clear of the plastic. This seemed to work OK and no plastic was melted during the soldering process.

The toothpicks were removed and the finished soldered joint looks OK.

The RTR HAYA Centurions come with a big blob of not melt glue covering these soldered joints - presumably to strengthen the joints and to insulate them?

The brass tube holds the LED legs apart, so I will consider what to do about this as I do not own a hot melt gun - and this could possibly be my only use for one!

[zooma]

I need to buy an inexpensive hot melt gun to smother the soldered LED legs and the thin connection wires with hot-melt glue.

Following some enquires, I have found out (as suspected) that this application of hot melt has multiple benefits from holding the fragile wires more firmly onto the joint (helps to stop them being pulled-off as the deck is removed from the chassis for regular battery changes etc) and to give an insulated covering to the LED legs and brass connecting tubes that I have used.

I forgot to mention previously, that the two long LED legs (both + positive) and the two short legs (both - negative) from both headlight bulbs were aligned with each other to make sure they were being connected with the same polarity.

The inside of the deck was marked with a "+" and a "-" using a felt tip pen because once I had soldered them together I would not be able to see which LED legs were the longest or shortest!

Once the two pairs of LED legs had been soldered together I could refer to my felt tip markings to make sure I soldered the connection wires to the correct sides.......and maybe just as importantly - in the future when my memory has faded even more, I can refer to these simple markings as they will stay on the underside of the deck for the life of the tank.

[tankme]

They sell hot glue guns all over the place. Any craft store or hardware store should have them. They all pretty much work the same except for the glue stick size. I sometimes use a dab of glue on the tops of the connectors to help stabilize small wires going into the tops of JST connectors. Wires tend to break off right at the end of the crimp area on the pins and the glue stops the bending of the wire there which makes it break.

[zooma]

They sell hot glue guns all over the place. Any craft store or hardware store should have them. They all pretty much work the same except for the glue stick size. I sometimes use a dab of glue on the tops of the connectors to help stabilize small wires going into the tops of JST connectors. Wires tend to break off right at the end of the crimp area on the pins and the glue stops the bending of the wire there which makes it break.

Thanks Derek,

I am sold on the idea of using a hot melt gun to reinforce the thin wire joints, and have ordered one from Amazon - it should be delivered here tomorrow .

Bob.

[zooma]

My hot melt glue gun has arrived - and only just in time!

I notice that both wires that came pre-soldered onto the main on/off switch (included in the kit) had both sheared off !

These two wires were soldered back into place and then became the first to receive a coating of hot melt glue!

Next, my two LED headlamp joints were covered with hot melt glue so these two first applications have covered these two wire joints to strengthen them and (in the case of the headlamp joints) it has insulated the bare LED legs as well.

I think this little hot melt glue gun is likely to find a lot of similar applications!

[zooma]

The next job is to connect-up the Clark board that I bought from HAYA pre-loaded with the correct Rolls Royce engine sound for the Centurion - and then the basic KIT build will be completed.

This will be the first "board" of any type that I have fitted to any r/c model tank from scratch, so I am a little nervous about the process as none of the ports on the board are actually marked in any way.

I thought that I could refer to my RTR Centurion and more or less copy the plug positions, but that tank is not quite the same as this one as it has barrel flash and gun smoke fitted and so it has a small additional supplementary board fitted (for the smoke function) that my KIT Centurion does not have.

Maybe in the future I will add the barrel smoke feature as I do like to see the smoke combined with the muzzle flash (and I have already "hollowed-out" the BB firing mechanism to make space for the gun flash LED) but for now I just want to get the basic functions working - plus a muzzle flash LED to give a basic Tamiya "full option" type working specification.

The first thing I have done is to remove the Tamiya type battery plug from the power supply lead and replace it with an XT60 plug. I prefer the XT60 plugs to the Tamiya type and it will also make it possible to share all my battery packs between any of my tanks as they have all been converted to XT60 previously.

[zooma]

Tentative start - optional gun flash plugged in

8179B102-9276-4EAB-81AF-108CDB283948.jpeg (803.07 KiB) Viewed 255 times

As an Amateur Builder (and first time board fitter) I have decided to add labels to each lead as I identify their function and then mark the board where they should fit - nothing special - just small strips of masking tape on the leads marked with a ball point pen.

Hopefully when I have completed my first Clark board installation and recognise the socket functions I won't need to do this, but as I 'first-timer" I think it will be helpful.

I bought a pair of red motors from HAYA with the kit, but as I discovered early-on in the build they were too long to fit safely in the comparatively narrow Centurion chassis (!) so I acquired a pair of blue motors that are a little shorter and will hopefully improve the "marginal" power that I experienced with my RTR HAYA Centurion as its performance was disappointing.

Unfortunately neither the red or the blue motors come fitted with a plug that will fit into the Clark board, so I have ordered two pairs of connecting wires (with suitable plugs fitted) so I can fit them on the "option" motors.

I think I will need to remove the motor/gearbox assemblies from my KIT Centurion to gain access to the solder tags on the motors, but this will also allow me to test everything outside of the tank once it is all connected and powered-up. If I can re-solder the motor wires "in situ" then I will just remove the tracks so I can safely run the motors without the tank moving and avoid the risk of pulling any other sub-assembles (such as the main gun etc) off of the table.

[Ludwig von wigbearer]

Its coming on a treat, Its great to watch a build such as this moving along

Regards John