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Author Topic: 1/16 Trent Refurb  (Read 16173 times)

IKB

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1/16 Trent Refurb
« on: May 10, 2016, 10:27:57 pm »

 Hi Guys,

So looking around eBay a few months ago, I came across a 1/16th scale Trent for sale, I really like this particular design of boat and have always quite fancied one, so took the plunge and bought it.
The model itself is in relatively good order, the seller was very honest about it being used weekly, but even so the it is still in quite good nick, it also came with an Mtroniks sound module, two 5000mah 3s Lipos, ESC and twin brushed 850s for drive... yes you read that correctly, twin 850s in a 1/16th scale boat, this thing shifts.
It also has working GOW navigation lights, a blue flashing LED and a motor for the radar, all of which kind of work, but the wiring is suspect and I will be replacing everything with new LEDs and other assorted hardware.

The problem with the big 850s is that they have very little fine control at low RPM, as the shaft jumps 1/3 of a revolution between magnets, it also only had the one esc, so no tank steering in harbour. Based on my recent exploits with my home built jetdrive, (http://www.modelboatmayhem.co.uk/forum/index.php/topic,53340.0.html) I decided brushless was the way to go, so after a quick search through this section of the forum, I came across someone else who had also installed brushless motors in a Trent and just bought the same ones, they would spin at the same RPM as my current 850s, which I was very happy with, I also bought two water cooled Turnigy Marine Esc’s, which I will run on the original 5000mah 3s Lipo packs.
Installing the brushless motors was easy enough, removing the old motors and examining the mounts, I quickly figured that I could bolt the supplied brushless mounting plate to the original mount and it would practically be a straight swap over. I turned up an Aluminium plug at work to centre the two mounting brackets before drilling, in order to preserve the original motor’s centre line with the shaft coupling, as the attached photo shows, the size comparison between old and new is remarkable, with the new motors being just as powerful as the old ones.
For the first test run I quickly wired in the esc’s, but didn't have time to connect the water cooling system, but as the runs were going to be short, I was not really concerned, I did however setup he esc's using a Turnigy programming card, which makes the whole process a breeze compared to trying to decipher beep codes from the motor and esc.
Here is the onboard footage from the test run, the motors have plenty of get up and go and even without the aid of water cooling, the esc's didn't get that warm: https://youtu.be/hRX-lkXMdfE
Progressing from here I am planning the following changes:
 
  • Proper installation of the internal electronics
  • Removal & refitting of propshafts, which will allow for new grease packing to take place and hopefully stop water ingress
  • Installation of esc water cooling system, this will be combined with a water vapour exhaust smoke effect, so the cooling water will constantly feed the vapour tank using a pump, which will overflow out of the exhausts, this will be based upon my Clyde Puffer smoke system: http://www.modelboatmayhem.co.uk/forum/index.php/topic,52469.0.html
  • 3D printed bolt on fans for the brushless outrunners, the Overlander motors are great, but they have no inbuilt fan on the rear
  • Replacement of all lights with LEDs
  • Conversion of all deck flood lights to working ones using LEDs
  • Internal cabin instrument lighting
  • New radar motor
  • General clean and tidy of some of the paint work and fittings that have suffered during the many trips to the lake
  • New multi-function high power LED rotating blue beacon
  • Trim tab rebuild, as the current setup is unbalanced and boat tries to roll at high speed, may install a servo operated setup
More updates as they happen.
Alex

 

 
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derekwarner

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Re: 1/16 Trent Refurb
« Reply #1 on: May 10, 2016, 11:09:18 pm »

That's a very neat retrofit motor conversion Alex :-))....the concentric aluminium spacer plug certainly did the trick...

The vessel displays a good turn of speed O0.......were you using tank steering for the berthing in the last 15 seconds?

just one thing....the video picked up a semi interment intermittent noise at lower speeds that didn't sound drive line related ....more like a constant sharp rattle or electrical interference :o ...am sure you know & will resolve it....... Derek
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IKB

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Re: 1/16 Trent Refurb
« Reply #2 on: May 10, 2016, 11:25:09 pm »

Hi Derek,

I am pretty sure that the intermittent noise is from the waterproof casing of the GoPro, resonating against the handrails of the flying bridge.

Yes, I believe I was tank steering at the end.

Alex
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IKB

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Re: 1/16 Trent Refurb
« Reply #3 on: August 15, 2016, 10:10:57 pm »

Hi Guys,


The other week I got around to spending some time on my Trent refurb, so far the modifications have been to the power train, replacing the twin 850s with Overlander 3548/05 900KV Outrunners, paired with Turnigy Marine 60A ESCs.
This time the modifications were all about adding functionality:


  • Water vapor smoke system routed through the exhaust ports
  • Water cooling system for ESCs, which in turn feeds the water vapor tank
  • Power distribution board
  • 12v Pb power source
  • Battery monitor
  • Mtroniks sound system
  • Expanded functionality relay board
Up in the bow a speaker is installed with the water pump hanging below, this is a diaphragm pump which sucks lake water through an inlet in the keel, passes it through both ESCs and then into the vapor tank.
As the tank fills, it over flows through two pipes connected to the exhaust ports, which gives the look of cooling water being ejected by the engines, an ultrasonic vaporiser, driven by a DC-DC converter produces water vapor in the tank, which in turn is pushed out of the exhaust ports by a fan along with the over flow water.
All of the extra functions of the boat are relay controlled via the expanded functionality unit, this is built into the my Robbe F14 Navy, which allows eight switches to control sixteen functions, the system I am using is not the original version, but a cheaper and more robust system made by an individual in Germany trading as CP-Elektronik, their website can be found here:


https://cp-elektronik.de/index.php/en/16-channel-decoder.html


This is the build thread I did about converting my handset to the new system: http://www.modelboatmayhem.co.uk/forum/index.php/topic,52951.msg544729.html#msg544729


Eventually I will have all of the extra functions hooked up through this relay function.
Up until now I have been running the boat on twin Lipo batteries, but I wanted to see if lead acid could be a suitable candidate, the problem with the vapor system is that it is quite power intensive and I wanted to have the longest possible run time with the model. To get the model to handle better and to pull it down to the correct water line, with the Lipos, I had been adding in a foot length of inch square steel bar, this makes for great handling as it really lowers the centre of gravity of the model, lead however is much heavier than steel and comparing the two options on the scales showed a significant increase in the all up weight of the model,
but I thought I would give it ago.
Down at the lake I eagerly lowered the boat into the water and the first fail of the day, the pump doesn't want to prime for some reason, so after back filling the pipe work, water started to flow through the system and fill the tank, which lead to the second fail, the pump filled the tank too fast and water was only just about creeping it's way out of the exhaust overflows. So before the pump could overfill the tank and sink the boat it was quickly disconnected, which lead me onto the third fail, flicking the switch on the TX activated the appropriate relay in the boat, but the vaporiser was suspiciously dormant, at this point I gave up, drained the vapor tank and tried to set sail, or so I thought. Fourth fail, the underside of the superstructure is fouling on the power distribution board, I had earlier removed the broken radar motor as that was really getting in the way, so quickly onto fail number five, the Trent is one of my favourite models, it is fast, handles well in all conditions and looks simply stunning on the water, at least it used to, although it was only sitting slightly lower than usual, I have never seen a lifeboat do an impersonation of a tug boat at speed, not cutting gracefully through the water, but beating it into submission before pushing it to the side, it was a very short trip out for fear of sinking.
Suffice to say I have learnt a lot and have plans to redo what I have and many  ways to improve, that can wait for a future post.


Alex
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IKB

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Re: 1/16 Trent Refurb
« Reply #4 on: August 30, 2016, 12:07:35 am »

Hi Guys,


Got some time this weekend to work on the Trent refurb and address some of the failures from last time, this is what I got up to:


  • Fixed wiring for sound system, I can now operate the horn and turn the engine noise on and off remotely
  • Added logic relay driven float switch to vapor tank fill system to prevent overfilling
  • Moved exhaust vapor outlets to be higher up in tank to prevent clogging with water
  • Worked on superstructure clearance issues
On the bench the exhaust smoke system works just fine, got to the lake today, the fan packed in so never got to see it working, video from bench test: https://youtu.be/9M_OeXEXtaw
On a more positive note, I replicated the fill system I have in my Clyde Puffer, which uses a float switch to drive the logic input of a relay module using the 5V BEC feed from the power distribution board, this turns the pump on and off as need to top up the vapor tank. Another modification made was to swap back to Lipos as a power source, this makes the boat much lighter and sit much better on the water, but all of the extra kit is still weighing it down and the heaviest thing in there is the vapor tank, so my next line of action is to make the smallest tank I can get away with, which will use the smallest amount of water possible, as at the moment, the vapor tank is about the same size as a 9Ah 12v Pb battery.


Alex
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IKB

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Re: 1/16 Trent Refurb
« Reply #5 on: November 19, 2016, 12:03:38 am »

Hey Guys,


So been working on this for a while now and normally I post updates as I tune and test at the lake, but this time the modifications came one after another without even leaving the work bench because, hey, that's just the way it goes sometimes, you look at what you've done, immediately see a way to improve it, rip it out and start again... at least that's the way I work sometimes.
My aim from the beginning was to add extra functionality to a one of my favourite boats, it has amazing presence on the lake and performs well in all conditions, I'd be really worried if it didn't being a lifeboat n' all!  {-)  But unfortunately, even with all the best intentions, I completely ruined that majestic glide that a Trent has across the water and turned it into a big orange tug, so it was back to basics, out came everything I had added and I reset the boat back to it's last good sailing trim, then out with the scales to see what kind of all up weight I had to stick to and in last good trim the max dry weight was 5970g, (minus batteries) I have removed the batteries as the scales can't cope with the added weight and thy are also a constant in this equation, not going to leave them out after all.
One of my first modifications to the boat was to do a brushless motor upgrade to replace the twin 3 pole 850's that had zero low speed manoeuvrability, they are also really heavy at half a kilo each, so heavy in fact, that when I did the swap, I had to add 1470g of ballast to get the boat to sit back down in the water, (when I bought the boat it was ballasted very lightly and sat too high in the water) so as I am adding a ton of kit, if I can get everything to work within my budget of 1470g, give or take, all should be right in the world again, so out with the scales again to make a list of each component I had installed on a quest to ether improve or junk it, major savings had to be made somewhere:


  • MK1 Vapor Tank (includng fogger, float switch & fan) 650g
  • Power Distribution Board 420g
  • Pump & Mounting Board 180g
  • Speaker & Mounting Board 355g
  • Multi Function Decoder Board & Relay Board 80g
  • Mounting Board for Above 140g
  • Relay for Pump 20g
As we can see from the above figures, that is a whole lot of weight, 1845g of stuff and that is not even including the water for the vapor tank which holds around about an additional 250g, savings have to be made, in the above list, anything that is green cannot be reduced in weight, so I have to decide to keep it, junk it or replace with something better and lighter.
Looking at the original install pictures I posted, I realised that my placement and use of space was very poor, partly due to the very rushed nature of the install to prep the boat for a cub event, I had the speaker and pump right up in the bow, a great open space for bulky kit, but a terrible choice of placement in regards to trim, as the extra weight was pushing the bow down into the waves instead of letting it rise above them, next for judgement was the size of the vapor tank, it was gargantuan, great for a puffer, terrible for a lifeboat, it held too much water and really needed re-thinking, for some unknown reason I had also elected to construct the tank and all the other mounting boards from 6mm thick clear Acrylic, obviously a poor choice on my part and a major source of potential savings.
Right, to work, I re-designed the vapor tank, not only shrinking the size I also decided to 3D print it which would make for a strong yet light weight construction, opting for a wall thickness of 2mm, the new tank was a considerable improvement over the old one, weighing in with an all up dry weight of 332g, (including hardware) no sooner had I finished bench testing the new tank, I thought, "Hey, the float switch in this tank is huge compared to the one in my Clyde Puffer, why don't I get another one of those and that will allow me to make the tank even smaller an if I decrease the wall thickness to just 1mm, I can save even more weight, with the added bonus that it will take less time to print"
One swift print and a delivery from Mr. Postie later, the new and improved MK3 tank was ready and weighed in at an all up dry weight of 232g, saving 418g over the MK1 tank and 100g over the MK2 tank, happy with the savings so far I turned my attention to the water distribution system in the boat, which originally had a 12v pump sucking water out of the lake through a pipe in the keel, this was then pumped through both ESCs before filling up the vapor tank. The original idea was that the boat would have a combined cooling water / exhaust smoke effect coming out of the exhaust ports, this is great in theory, but alas the water only ever dribbled out of the exhaust ports, completely blocking the vapor from escaping and on the first outing to the lake, the pump nearly sank the boat by over filling the tank, clearly a re-think was in order.
In my Clyde Puffer I have a pump, that like the lifeboat, draws water from the lake and fills up the vapor tank, except in this instance, there is a float switch driving a relay, which turns the pump on and off as is necessary, the vapor system consumes very little water and the pump runs mostly to replace water escaping out of the tank back through the pump when it is switched off.
Even though the ESCs in the Trent are water cooled,  even without water cooling, they have never gotten hot, even on extended high speed runs, so this time I am going to take a slightly different approach, this time doing away with the pump altogether and instead placing the cooling inlet pipe just behind the prop, taking advantage of the high positive water pressure produced to cool the ESCs when they need it most, before the water is dumped back into the lake back through the original keel inlet, a pair of one way relay controlled solenoid valves will divert cooling water to fill the vapor tank as and when the float switch demands it, now this does mean that the vapor tank may take a little time to prime at the beginning of a run, but I can always over come that by pre-filling with a drain syringe.
Other small improvements include relocating the speaker to a new thinner mounting plate in between the motors, so as to preserve the original trim's centre of gravity, all of the mounting panels have also been re-cut from lighter 2mm Acrylic and last but not least, as part of the complete rewire, I have started on upgrading all of the lights on board with LEDs as well as making all of the feature lighting functional.


Hopefully more to come tomorrow after much successful tinkering in the Shedshop!


Alex

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rnli12

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Re: 1/16 Trent Refurb
« Reply #6 on: November 19, 2016, 07:23:05 am »

Hi,
 
Looks great, wish I kept mine, but if anyone has one going drop me a pm.
 
Rich
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Rich

IKB

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Re: 1/16 Trent Refurb
« Reply #7 on: November 20, 2016, 11:05:26 pm »

Hi Guys,


Back tinkering in the ShedShop this afternoon and man it is a much more pleasant place to work now that I have some effective heating, so to work I set looking at the final install of the vapor tank which just sits as low down into the hull as it's width will allow, but something was off, the tank wasn't quite sitting right and then I noticed that the side mounted inlet sticks out to act like a pivot point, doh!
One quick redesign later had relocated the inlet, I also took the chance to draw up some mounting brackets for the twin solenoid valves which I had decided to mount onto the front of bow end of the tank, these will sit nicely in between the twin battery boxes and their associated supporting brackets that I had designed previously and was already in the process of mocking up.
So the new parts will get printed whilst I am at work tomorrow and if all goes to plan I can post some more progress photos in the evening.


Alex
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Re: 1/16 Trent Refurb
« Reply #8 on: November 21, 2016, 11:07:40 pm »

Hi Guys,


Not spent a huge amount of time out in the ShedShop tonight, but enough to get the new tank design glued together and trial fitted in the hull and I am very happy with the way things are turning out so far, next will be to install the new water inlets behind the props, wiring and then plumbing.


Alex
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Re: 1/16 Trent Refurb
« Reply #9 on: November 22, 2016, 05:00:54 pm »

John Walravens have you seen this post? Just what I would like please!!!
Mick F
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Re: 1/16 Trent Refurb
« Reply #10 on: November 22, 2016, 06:09:03 pm »

Alex,


just curious...   you are using a 12+2 encoder/decoder combo on an f-14...  are you using 35/40/41mhz or are you using 2.4ghz, and if 2.4ghz, which version of 2.4ghz are you using?




Tim
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IKB

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Re: 1/16 Trent Refurb
« Reply #11 on: November 22, 2016, 10:22:52 pm »

Hi Tim,


I am using an after market encoder / decoder setup with my F14, it works well on 2.4G & 40M, details for both can be found here:


Alex
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Re: 1/16 Trent Refurb
« Reply #12 on: November 22, 2016, 10:44:43 pm »

thank you alex for the links on your upgrades...  i ask, because i have a Robbe FC-28 with both an original robbe multi-prop 4+4, and a wetronic multi-prop 8...  and i had tried using it with the Assan 2.4ghz and Futaba 2.4ghz modules... neither of which work correctly with the multi-props.  i have not tried it with a Corona 2.4ghz module...  i will have to test that.   your links give me hope :)
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IKB

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Re: 1/16 Trent Refurb
« Reply #13 on: November 28, 2016, 11:48:41 pm »

Hi Guys,


Quick update, managed to get enough done to enable me to do some lake trials of the new vapor tank system, since the last update I have added a water inlet scoop behind the port prop, run all the plumbing, wired in the float valve system that controls the solenoid tank fill valve, wired the vapor unit and re-installed the main power circuit so I can sail.
Onto the water and first impressions were good, boat sat nicely on the water, I held the hull still whilst running the port motor so I could watch water flowing through the system and it all flows like it should, ESCs are kept cool, the solenoid water take off works as it should, so out onto the lake I sailed and was underwhelmed by the lack of visible exhaust vapor, so back it came for some adjustment of the vapor tank fan speed control, which helped a bit, by speeding up the fan, the vapor was forced out of the exhausts ports more vigorously.
What was noted is that the exhausts ports are very close to the surface of the water and with the flaps only partly open, the vapor exits and is immediately deflected down onto the water where it condenses and dissipates, ruining the effect, what I will try next time is to open the flaps more to allow the exhaust vapor a better chance of escape.
So not a 100% successful test of the new system, but a massive improvement over the old one that nearly sank the boat, plus it performs like it used to once again, with a bit more tweeking I am confident I can achieve the effect that I want, that means I can move onto concentrating on the LED refit.


Alex
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Re: 1/16 Trent Refurb
« Reply #14 on: March 19, 2017, 06:07:15 pm »

Hi Guys,


Been doing some work on the Trent this weekend and this time focusing on further improving the drive system, which although great with the brushless motors, the top end is unusable and the low end makes for very lively maneuvering in the harbor, to remedy this I have decided to design and build custom reduction gearboxes, following on from my recent success with reduction drive in my jet drive project.
At the moment the motors run off 3S Lipos giving a top end speed of, 900KV x 11.1v = 9990RPM, now because of the way sensorless brushless motors are driven by the ESC, when you apply throttle, unlike their brushed counterparts, they have a tendency to burst into life, great for power boats / planes & quadcopters, terrible for low speed harbor maneuvers as the the props suddenly start spinning at a slow cruise speed, which can be throttled back, but it makes the whole process very jerky and a bit unpredictable.
So with top end to spare a reduction drive is the way to go, after mulling this over for a while, I have decided to use a pair of MOD 1 24T & 30T gears, giving me a drive ratio of, 24 / 30 = 0.8, this will give me a new top end of 9990RPM x 0.8 = 7992RPM, I arrived at this figure after observing that full scale speed was achieved at about 3/4 throttle input and I am not really fussed by the loss of top end, the boat doesn't look right standing on it's stern and the bow wave created means swamping smaller boats is a very real danger.
I set about designing a new combined motor / gearbox based around the old motor mount, as I wanted this to as much as a drop in replacement as I could, it was at this point I realised I could also incorporate an integral mount for the ESC of each motor, making the whole installation much neater and would stop the cables chaffing on the rotating motor body.
The new mounts have been successfully printed, however I inadvertently ordered the wrong bearings, so I will have to wait for new ones to arrive in the post, hopefully I will have photos showing the install later in the week.


Alex
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Re: 1/16 Trent Refurb
« Reply #15 on: March 19, 2017, 08:35:02 pm »

Hi Alex,

Nice to see you back on the Trent.
Looking forward to seeing your progress, would you consider producing another pair of your gearboxes for another Trent??

I've managed to source an unstarted kit, it's one of the older ones with precut wheelhouse parts.
It also has 45mm props.

Regards
Adam
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Re: 1/16 Trent Refurb
« Reply #16 on: March 19, 2017, 10:20:57 pm »

Alex....the speed reducer body appears robust with the two shaft mounted ball bearings  :-))...& I see you have re-ordered alternate sizes.........are they also stainless shielded ZZ type?

Is the mechanical strength of the synthetic printed material of the speed reducer body sufficient to provide resistance to flexing?

When I searched on MOD 1 24T & 30T gears, I see they are available in steel, hardened steel and composite materials [the latter which I assume are extremely high in tooth surface and shaft mounting tapping hardness]

The gear width is certainly very generous, however this also dictates good alignment [and also looks at the axial alignment of the motor rotor]...is there any end float in these brushless motor rotors?

Considering the rotational speed you plan [sub 10,000 shaft RPM], have you considered steel against composite gearing?......and what about the issue of gear lubrication, or non-lube composites?

Derek


 
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Re: 1/16 Trent Refurb
« Reply #17 on: March 19, 2017, 10:24:21 pm »

Hi Adam,


I might be persuaded to produce another set, you may want to wait until I have tested the design first though, the main issue is going to be the gear ratio, it may be just right, it may need to be lower still, the problem is, until I actually test it on the water, this is all just an educated guess and if the ratio changes, then the 3D printed part has to be adjusted in CAD & re-printed to accommodate the new centre spacing of the motor and output shaft required by the different gears.


Alex
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Re: 1/16 Trent Refurb
« Reply #18 on: March 19, 2017, 10:37:56 pm »

Alex,


I will wait until you have conducted testing and come to a conclusion as to the best setup.
I was planning on using 12v Nimh, so that's going to have an effect.
Still good to see you back at it though, all information and testing appreciated
Kind regards
Adam
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Re: 1/16 Trent Refurb
« Reply #19 on: March 19, 2017, 10:43:36 pm »

Hi Derek,


Answers to your questions below:


Alex
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Re: 1/16 Trent Refurb
« Reply #20 on: March 19, 2017, 10:51:04 pm »

Hi Adam,


No worries, glad you are enjoying the thread and you are right, 12v will have an impact if you are using the same motors, for example:


  • Alex - 11.1v (3S) x 900Kv = 9990 RPM
  • Adam - 12v (NiMh) x 900Kv - 10800 RPM
So you are already, on paper at least, 810 RPM up on my setup, of course we all know that actual battery voltage is not exactly as advertised at the start of a run and will trail off as the battery empties, but it is enough of a difference to be noticeable out on the water, which means you may indeed may require a lower ratio in your Trent than I do in mine


Alex
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Re: 1/16 Trent Refurb
« Reply #21 on: March 19, 2017, 11:12:52 pm »

Those CNC produced pinions from Grade 4340M is an absolute top of industrial grade class of material  :-))

To 55 RC via case hardening then Nitrided is beyond model comprehension

The polishing of the pinion tooth surface is polishing only and not wear

If the composite is Nylon, I doubt if it would be of suitable strength or compatible in the drive considering the power transmitted, and the speed

Derek
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Re: 1/16 Trent Refurb
« Reply #22 on: March 19, 2017, 11:39:53 pm »

Hi Derek,


Nylon was just an example, if I was going plastic, then I would more than likely go for something like this out of Delrin:


http://www.motionco.co.uk/spur-gear-bore-setscrew-p-681.html


Alex
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Re: 1/16 Trent Refurb
« Reply #23 on: March 23, 2017, 10:20:59 pm »

Hi Guys,


Quick update on the gearbox, the new bearings finally arrived in the post today, so I quickly threw one of the units together to see if everything was going to work as planned and as far as I can tell this should all work rather nicely, the ESC is held nicely in place, the shaft needs cutting down and I think I will print a shroud for the gears to stop any grease I put on covering the inside of the hull, but more importantly, the gears mesh nicely, the shaft isn't binding and everything appears good and solid, I plan to work on the Trent tomorrow night with the aim to hopefully to get in some lake trials this weekend.


Alex
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Canterbury Coxswain

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Re: 1/16 Trent Refurb
« Reply #24 on: March 23, 2017, 11:24:31 pm »

Hi Alex,
A couple of observations on what looks to be a superb assembly you have designed and made there.
  • If you need more control maybe you could use the programming of the ESC to have a 'soft' start up and also to either downgrade or upgrade the power output by using the facility of 'tweeking' the power output. In some cases this can also be done via the Tx, in those that allow an exponential adjustment.
  • I also note the ESC seems to be 'fixed' rigidly in position. I am no expert in this area, but quite a few manufacturers and other electrical experts I know say that both the servos and ESCs should be fixed using the soft [foam] servo type tape so that vibration 'feedback' is kept to a minimum. Please keep us informed.
This is not meant as a criticism of a great refurbishment project - keep up the good work and continue to share it with us.
Many thanks for this insight.
Kim [C.C.].
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