Hobbyking Libero mods

[Old School]

My Libero arrived today and I set about fitting the dual water pickups and large tubing throughout. The stock motor is a 3660 2070kv. I am awaiting a 3674 which I may possibly fit coupled to a 40 mm 2-blade or possibly a 38mm three-blade propellor. Apparently, a 42 mm 2-blade is a little too much for the stock motor. The stock shaft is a 4mm one piece flex.

With the battery restrained by two hold down straps the CG is just less than 2 inches aft of the sponson. If I move the battery forward slightly then there is provision only for one strap. Oddly only two straps are able to be fitted to the battery tray. I will not be able to test run until next week, however, everything is tested and ready to go.

[T.S.Davis]

These are a riot on 4s. Bugger to race on 4s but a ton of fun just to run that way.

Ty's old boat.

https://youtu.be/mex3iFoZNuc

[Old School]

Many thanks, the boat is just for sport running. I just need to add some flotation. One thing that did surprise me was the capacitor spark when I was about to hook up the battery. All my reading stated that it does not happen on 4s, however, the T120 ESC does have a factory supplied capacitor bank as well as the capacitor on the unit itself.

I am actually quite impressed with the boat. It does look a little toyish but appears to be well built. Fortunately, I went over the boat as every mount nut was loose. The T120 ESC has a programming port and this with the programming box made for simple setting up, although the instructions are vague.

[Old School]

A recheck of the instructions and alas the shaft is the dreaded two piece stub shaft arrangement so lubricating the shaft requires disassembly of the strut. My first mod will be to hopefully obtain a one piece flex shaft to make maintenance more user friendly.

[T.S.Davis]

I wonder if it's easier to pull the motor.

You'll be re-checking screws forever. Pretty typical with TFL hardware.

I like to make plates inside the boat form aluminum. Then drill, tap, and loctite. Seems to cut down on the vibration. Less screws coming loose on me.

[Old School]

Today my SSS 3674 2075kv 4D motor arrived from OSE. I will be running 4S. I decided to fit this to the Libero and use the stock motor in another hull under construction. After changing over the motor I still prefer to have a one piece flexshaft.

[Old School]

Today was its maiden run and good news and not so good news. The boat handled beautifully, keeping a level stance on plane and smooth and straight with no drama. The boat was very, very fast with the upgraded motor and larger 40 mm 2-bladed propellor. A downside on handling is that coming out of a right hand curve and applying power the left sponson lifts momentarily to about 45 degrees as it accelerates out of the curve.

The downside as I expected is that a 4 mm shaft is not up to the task. The stock boat has a two piece 4 mm shaft. I had already purchased a single piece 4 mm flexshaft to aid post running maintenance but had not fitted it for the maiden run. However, on removal the stock flexshaft was "necked" at the strut end where the shaft had been made square to fit the stubshaft. The shaft had not separated and was still performing at full power when running even though most of the flex cables had sheared. I will need a new teflon liner as the damaged flexshaft had sheared off the last centimetre of the liner.

I still have a grin after seeing how well the boat performed. With the 40 mm prop the battery temp (45c discharge) was 59 degrees C and the motor and ESC in the mid forties. I noted that if one slowed down in a corner then the hull would bog down until it accelerated away coming out of the corner. Obviously one would maintain speed through the corner however conditions did not help and wide fast cornering was not possible. Perhaps a 3 bladed prop may assist acceleration out of a corner. I have a 38 mm 3-blade to use next outing.

[rol243]

sounds like she ran well for the first time in water. try not to hit full throttle so hard out of the turn as this is whats causing the left side to lift [ prop torque ] maybe the 3 blade prop will work better, also i would be removing the drive shaft log and fitting a suitable size without a liner plus a 5mm / 3/16 flex shaft to matching bushed strut then you will have a more reliable boat. Hobby Supplies Melbourne have what you need if you want to buy local.

[Old School]

Definitely an upgrade to a 3/16" shaft is required. I will source a 7/32" brass tube (no liner) and suitable strut to fit. I may need an adaptor 1/4" tubing to insert in the strut for a Speedmaster rotating bush.

I believe the stock 4 mm strut is a generic strut used on many TFL products including the Genesis. Thus to maintain stuffing tube depth I may use the 3/16" upgrade strut from the Genesis. The upgrade strut has a fin added below the strut barrel which may impact on handling.

Another option may be the Speedmaster 21 Strut as I would like to have the rotating bushing.

[Old School]

A further update. I decided to run a 3/16" flex without a liner due the failure of the 4 mm flex on its first outing and the stock stuffing tube is the correct size for a 3/16" shaft, so I decided to modify the original 4 mm strut to take a 1/4" O.D. tube to run a 7/32" rotating bush that I had made. As well, I positioned a short length of 7/32" O.D. tubing at either end of the stuffing tube to act as a bearing to support the 3/16" flexshaft.

I have not tested as yet as I need to purchase a flexshaft. Eventually I will upgrade to a Speedmaster strut, but for the moment the current setup seems adequate.

[rol243]

sounds like you will have reliability with the better flexshaft / brass log mod and strut bushing. try hobby supplies for a good 3/16 flexshaft [ cc racing brand ] if you want to buy local.

[Old School]

I did a quick calculation and the total length of the welded stub section (including the threaded section) of the flexshaft really needs to be less than 82 mm. I will have to investigate if such a shaft is available.

I just looked at Hobby Supplies and they have this -

3/16” x 18” Long Flex Shaft (21" total length) - $27.00 each

I assume the stub section will be around 3" (75 mm) in length which will be perfect.

[rol243]

i have the 21 inch long cc racing flexshaft on hand and the total length of stub shaft including thread is 80mm. this stub length can be set shorter as there is plenty of thread on the end so 70mm total can be done.

[Old School]

Many thanks, that seems perfect.

[Old School]

I never liked the pokey figure supplied with the Libero so purchased a 3-D printed ABS driver (1/12 scale) from the OSE store. Before I disassemble to paint the figure does he appear to be sitting too high, please? I could remove about 3 - 5 mm from the base before mounting permanently. I intend mounting his head and arms positioned as if he is in a turn. I will most likely carve some sort of backrest to fill out the cockpit behind the driver.