Cookies used in this website are gluten free, wheat free and dairy free. By using this website you agree to our use of cookies. More Info
Guest
Login Below
Join Us On Social Media!
   
Get The Model Boats App!
Apple App Store
Android app on Google Play


Help Support This Website
£
or enter custom amount

(Non Contributor)

Help support this free
website and donate.



£285 a year is needed to keep the website and apps online. Please consider donating £5 or more to help towards these fees.
All donations are securely managed through PayPal. Amounts donated are not published online.

Many thanks for your kind support.

Model Boats Website Team


Donation History
August 2018: 3 people
July 2018: 8 people
June 2018: 8 people
May 2018: 7 people
April 2018: 24 people
March 2018: 13 people
February 2018: 8 people
January 2018: 25 people
December 2017: 4 people


Unique Visitors This Month

Website Members

Terms and Conditions
Privacy Policy
Advertising
Contact


Model Boats Website
Active Users (10)
Login or Register
To Remove This Ad

Login or Register
To Remove This Ad
>> Home > Forum > Boat Specific Chit Chat! > Aerokits Patrol Torpedo Boat
Aerokits Patrol Torpedo Boat
(2923 views)
Author Message
MouldBuilder
(Commander)





Forum Posts: 25
4th Mar 2018 18:32  
>> Permalink
mdlbt.com/39443

Hi. I have just joined the forum to try to learn, and possibly help, although I consider my knowledge to be `limited`.
Many years ago I bought the Aerokits Patrol Torpedo Boat. More than 30 years I think. Ten years later I decided to build it. I think the construction is ok, except for the Captains view being blocked by a turret. The boat runs well, although a little slow. It has a 12 volt MFA Marlin motor running from two 6 volt batteries in series.
I have several items that I would like some advice on but they can wait for a while whilst I prepare the boat for a refurbishment. I intend to replace all of the fittings with new and possibly try to improve the performance. The boat is driven by a 35mm diameter propellor with quite a heavy pitch. My question for today is whether a change in motor to a MFA Torpedo 850 would be wise. There is only one motor.
Thanks.😊


Attached Files - Click To View Large

canabus
(Fleet Admiral!)





Forum Posts: 123
4th Mar 2018 22:28  
>> Permalink
mdlbt.com/39457

Hi MouldBuilder
As for motor upgrade a 35mm brushless motor with an ESC and lipo battery would be a far better choice.
These motors are far more powerful and the Lipo batteries, less weight and delivery the power the brushless motors require.
As for a prop a 2 blade 40mm or 3 blade 35/37mm.
Canabus

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
5th Mar 2018 05:42  
>> Permalink
mdlbt.com/39463

Agreed Canabus👍 That Hi Torque /Low 5100rpm looks more suitable for a tug! And the weight of the 2 SLAs won't help the speed🤔

Hi MouldBuilder; Welcome Aboard 😊
Unusual position for the forward gun tub 😲 Thought they were always offset to starboard. Build looks very tidy though - lots of potential!
Attached pics of a 28" ELCO 80 PTB I bought last year from a fellow member. I am going to refit her as Kennedy's PT109. She has 2 x 28xx Brushless and 2 x 30mm 3 blade screws.
Happy Refurb, cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
canabus
(Fleet Admiral!)





Forum Posts: 123
5th Mar 2018 08:54  
>> Permalink
mdlbt.com/39464

Hi Guys
Looking at the motor 5,100 rpm @12 volts is 60 Watts of power.
We use Hobbyking gear in our club mainly.
As they have a special on a present with free delivery over $50 US.
3639-1100kv(800 Watts)(170 grams) is cheaper than the sister motor 3639-750kv(600Watts).
ESC car 100 Amp is near half price.
A programming card is required but these are cheap.
We used a MFA Spearfish as a test boat with the 1100 and on
Zippy Compact 3S 5800mah 60C(449grams) clock 27KPH.
Changing to a Zippy Compact 4S 5800mah(567grams) 40C clock 37KPH.
Run time a good half hour or more depending how fast you push it.
We do not watercooling on this motor which will work out OK in your setup.
The Hobbyking car ESC(part No.HK100A)(106 grams) has a fan for cooling and with the large interior of you boat heating will not be a problem.
I am using this setup in both my Sea Commander and 1920 Gentleman's Runabout.
My little Sea Hornet is using a 1900kv 28mm motor on a smaller 3S 2650mah.
If you have no plans for your boat, I have a PDF copy(free of course).
If you wish to go faster, a straight change over to the 3648 1450kv(1600 Watt) beast!!!!

Canabus


Attached Files - Click To View Large

MouldBuilder
(Commander)





Forum Posts: 25
5th Mar 2018 19:12  
>> Permalink
mdlbt.com/39473

Thanks for the help. The tech on the motors and battery is a little beyond me at the moment but I will research and work it out.
Thanks RNinMunich. The first thing I noticed about my build was where I had positioned the forward gun tub. I cannot imagine when I thought that was a good idea. It has now been removed.
Thanks for the offer of the plans canabus. I think I have the originals here somewhere but yet to be found. I have found the build instructions and small plans for the deck parts.
Reading just these comments has made me understand that I have a lot to learn. Well, here goes. The research begins.
Thanks for your help so far. I am sure I will be back very soon as I really am keen to improve the boats looks and your experience will be invaluable.😊.

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
5th Mar 2018 20:06  
>> Permalink
mdlbt.com/39474

Hi MB, Attached are two extracts from the official USN Bureau of Ship plans for an MTB. Kindly sent to me by the colleague I bought the PT Boat from.
Also a pic of the forward (starboard!) gun tub on a model, showing what can be done these days with some photo etch upgrades😉 Not mine I'm afraid🤔 I get the impression that the Aerokits version is somewhat stylised. Have fun, cheers Doug 😎
BTW: If you don't want to tackle LiPos just yet you could use Hi Power NiMH.
LiPos do involve some investment when you first start using them: Lithium safe charger, relatively expensive battery packs and LiPo safe ESC. The latter can be preset to stop if the LipO is discharged to it's lowest safe voltage, i.e. 3.2V per cell. Below that the LiPo cells will most likely (99.9%) be irreparably damaged.😡 Cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
6th Mar 2018 16:28  
>> Permalink
mdlbt.com/39506

Thanks Doug.
I have been in touch with BattleCrafts regarding etched guns and other deck items and unfortunately I have fallen at the first question. Is my boat based on an American design. Would you know a classification for it, forgetting the forward Tub of course😊
Thanks.

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
6th Mar 2018 21:51  
>> Permalink
mdlbt.com/39517

HiMB, sorry for delay replying, just got back from a Ten Pin Bowling League Cup match, we won 4:2 and through to Round 5 😊
Ooops! I can't think of any type with a gun tub slap bang in the middle of the bridge. 😲
Otherwise I think yours is a simplified version pretty much based on the US produced ELCO PTB. Probably the 80 foot version, known as ELCO 80 (wonder why 😉). Modified from the original Vosper / British Power Boats designs. More of these were built than any other version and most used in the Pacific.
The USN called these boats PTBs while ever other navy at the time called them MTBs. Also suggesting that your model is based on the US ELCO version.
Here you can find oodles of photos of MTBs, MGBs and PTBs.
https://www.pinterest.de/pin/417145984205535643/
Attached is a photo from this site showing the bridge, foredeck and forward gun tub. I have loads more like this. If you like I'll sort out a bunch and post them here or email them as you wish.
Battlecrafts are good, well detailed. BUT, I was disappointed when I bought a set of 4.7" for my destroyer that nothing moved 😡
Now trying to figure out how to mod them without wrecking them.
The guns in the tubs are Twin Browning 0.5" calibre, 50 CAL (for barrel length =50xCalibre). Means that the barrel length was 50 times the bullet calibre! I.e. 25".
Cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
jarvo
(Fleet Admiral!)





Forum Posts: 550
8th Mar 2018 07:18  
>> Permalink
mdlbt.com/39585

Hi Doug, alway wondered what the 50cal meant, learn something new every day.

Mark


Etherow Model Boat Club
RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
8th Mar 2018 08:56  
>> Permalink
mdlbt.com/39592

Hi Mark, we sure do!
Tootling about for 30 odd years with all sorts of ships in navies and yards around the world had to come in handy for something 😉
Carry on learning! cheers Doug 😎


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
8th Mar 2018 21:04  
>> Permalink
mdlbt.com/39641

Thanks Doug. The pictures will help me a great deal.
The ELCO sounds right. The boat is 80 feet at 1;24 scale. 40 inches.
I think that my radio gear is a little old. The talk of ESO`s made me do research. I will post a picture of my servo set up tomorrow. I think that area will need updating too. It will make most people laugh I expect.
I have bought a 20mm gun from BattleCraft to see how it looks. Will post a picture when it arrives.
Thanks for your help.
Peter.😊

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
8th Mar 2018 21:42  
>> Permalink
mdlbt.com/39643

Hi Peter, Only those who don't know better laugh!😉
I suppose you mean ESC (Electronic Speed Controller)!
What radio gear do you have?
FYI: I still have an old (25 years) 40MHz set for my submarines, 2.4GHz don't like going under the wet stuff, it turns it's toes up, wrinkles it's nose and whizzes off into the sky 🤔 Also a pair of ancient 'standard' servos in the Type 1A U-Boat. See pic.
I also have an even more ancient (35 years!) 35MHz set I'm going to use with my Catalina flying boat. They both still work great so why dump 'em?
Look forward to the 20mm pic, I could use some, but ONLY if the guns are movable! Carry on Modelling, cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
9th Mar 2018 18:23  
>> Permalink
mdlbt.com/39683

Looks busy in there.
I would like to consider a motor upgrade to brushless. This would require a new electronic speed controller. I assume this migt need a radio upgrade as well. I read above that the NiPo battery would be required for a brushless motor. Is this correct or is there a safer alternative.
The pictures below show my current radio set up. I run on 27Mhz.
Please also not that my Captain thanks you as he can now see ahead.
Will post a picture of the gun when it arrives. I think it does not move though.😊


Attached Files - Click To View Large

MouldBuilder
(Commander)





Forum Posts: 25
10th Mar 2018 06:40  
>> Permalink
mdlbt.com/39703

Hi Doug. I have just noticed that you have already answered my battery question in an earlier post.
Do you have, by any chance, a legend for the MTB drawings you posted earlier. I cannot recognise some of the parts.
The machine guns in the other picture look superb. I have found them on a website but it states they are brittle. Is this your experience with this kind of 3d printed item?
Thanks.😉

canabus
(Fleet Admiral!)





Forum Posts: 123
10th Mar 2018 07:51  
>> Permalink
mdlbt.com/39704

Hi MouldBuilder

I use the Hobbyking Turnigy IA6 which is the same as the Banggood Flysky I6 2.4G 6 channel sets.
You can set up 20 different models of the one transmitter.
I have both and are great units.
I was scarce of this Lipo stuff years ago, but, a good balance charger with a safety bag you will be OK.
A battery alarm is a cheap handy little unit or add a sensor unit into the boat so you can monitor the battery voltage at the transmitter.
Check out you tube about the radio.
Canabus

MouldBuilder
(Commander)





Forum Posts: 25
11th Mar 2018 16:14  
>> Permalink
mdlbt.com/39758

Thanks Canabus.
I have just checked out the transmitter/receiver sets. Very reasonably priced. I really do want to upgrade. The Turnigy is around £40 whilst the Flysky is around £34. Do you have a preference?😊 Would my Futaba servos still work or would I need to change these also.
I know this might be a strange question, but as you can see from one of my pictures above, I have a servo operating the speed controller. How do you control an electronic speed controller with the radio.
As for the battery, is the safety bag used to put the battery in for charging in case it catches fire? I am a little wary about using things that I may not have control over.
I have been looking at brushless motors. Can you say a kv range I should be looking for to possibly increase the speed issue. You have mentioned 1100kv and others above but was just wondering what you would cosider to be sensible bearing in mind only one motor is practical witout major hull surgery. Can I assume that if a motor is given a kv rating that all motors are based on the same criteria, or are there other variables.
Thanks. 👍

canabus
(Fleet Admiral!)





Forum Posts: 123
12th Mar 2018 00:00  
>> Permalink
mdlbt.com/39772

Hi MouldBuilder
As for radios they are the same, go for the Flysky.
As for servos I think Futaba ones will work, but, the price of these from Hobbyking are cheap.
The good balance will have auto cutout, but, check out club members to see what they use or model car clubs.
The 1100kv has power to drive the boat.
The kv rating is the base and multi by the voltage to get unloaded revs.
1100 x 11.1 volts(3s) 12210 and 4S(14-8volts) 16480rpm.
Canabus

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
12th Mar 2018 02:14  
>> Permalink
mdlbt.com/39780

Hi MB, Sorry for late response, I've been occupied with varnishing and painting of my Sea Scout renovation.
The Turnigy i6 and Flysky FS-6 are hardware identical but have slightly different software, not critical I understand. I have the German branded version of the Turnigy i6, called here HT-6. Attached is the excellent German / English User / Programming manual without the Chenglish gobbledygook! Flysky Chenglish manual also attached for comparison.
Only mistake I found in the manual is re Binding (see pic); they mention Binding button on the RX when it is on the TX at bottom left Item 13 in the attached pic of my German branded Reely version.
BTW; iA6 is the RX type number. The TX is TGY-I6 or FS-6 for Flysky.
Pics 4 & 5 show my Reely HT-6 and Turnigy TGY-I6 versions. Identical except for labelling, same goes for the Flysky - see manual.

Re: Servos: I have tested my TX and an iA-6 RX with all sorts of servos; Sanwa, Futaba, Hitec amongst others some going back 30 years and they all work fine. I currently have an iA-6 RX and ancient Hitec standard rudder servo in my Sea Scout and it works just fine.

Re: controlling the ESC; it just plugs into the RX like a servo. Usually channel 1 or 3 depending on whether you want throttle on the right or left stick respectively.

Re: 3D printed stuff 'brittle or not'; depends on what type of filament they use for the print so can't really say. Up to now have not had problems. What I have noticed with some 3D plastic and resin items is surface defects, pits etc, which need some treatment before fitting. Resin also tends to be more brittle than 3D plastic prints. Resin don't bend well and don't like knocks! As I discovered with the resin gun barrels on my Graf Spee 😡 Will be replaced shortly with turned brass or Alu!

Re: LiPos; attached is a file from Model Boats mag of Hints and Tips for using LiPos. It also explains the tech jargon surrounding brushless motors, i.e. interpreting model numbers and parameters😉

All for now, cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
12th Mar 2018 21:02  
>> Permalink
mdlbt.com/39826

Thanks for all the information.
I have purchased the motor, ESC, Tx and Rx for starters.
I will sort out the batteries next week. Still considering the LiPo option.
Thanks again for all the help.
Peter.😊

MouldBuilder
(Commander)





Forum Posts: 25
16th Mar 2018 20:15  
>> Permalink
mdlbt.com/39999

Hello RNM and others.
The 20mm gun arrived today. I am really pleased with it. To my surprise, it does move up and down. It has no rotational movement. I will attach pictures at the end.
I bought the "beast" motor that you suggested Canabus. I will have to see how it fits in. Do you think the universal joints I am using now are suitable or should I upgrade these considering the RPM.
One other question I have for today is about paint. Can you suggest a suitable paint to use on my boat. I am not concerned about the colour, just the type/make at this stage. I read an article here earlier that suggested to use Holts car spray cans. What are your thoughts on this. I have an air brush if this is more suitable, but would like help on a suitable paint choice.
I will attach the gun pictures now. If there is a particular angle you would like, please reply and I will try to add tomorrow.
Thanks.
Peter.😉


Attached Files - Click To View Large

canabus
(Fleet Admiral!)





Forum Posts: 123
16th Mar 2018 21:14  
>> Permalink
mdlbt.com/40006

Hi MouldBuilder
I use solid joints for motor to shaft coupling, but, Banggood have metal universal joints which come in different hole sizes.
Canbus

Biggles
(Sub-Lieutenant)





Forum Posts: 25
18th Mar 2018 10:26  
>> Permalink
mdlbt.com/40067

I have an Aerokits Fast Patrol Boat, what scale 20mm deck gun did you buy is it 1/24? Also I was thinking of powering mine with a Graupner 700BB Turbo motor and Nicad battery packs or Lipo batteries. My hull doesn't have spray rails, should I fit some?
Sorry for all the questions but I'm returning to powered model boats after a long absence! Thank you for any help received.

MouldBuilder
(Commander)





Forum Posts: 25
18th Mar 2018 11:17  
>> Permalink
mdlbt.com/40071

Hi Biggles.
I am at a very similar level to you. I am seeking help from the kind members so that I can improve my skills. I built this boat in 1993, which by the way, I had no idea about until I removed one of the life rafts to find I had painted the completion date on the bottom. I am currently stripping the paint and trying to get advice on the painting method. At present I am tending to favour air brushing Revell aqua paint but I am open to other views.
As for the spray rail, my boat has never gone fast enough to need them. To be clear, is this the rail around the joint between the hull and deck which my boat has. Told you I was a beginner as well. With the more powerful motor, anything that keeps water from the electrics must be good.
The gun was supplied by Battlecraft in Bideford. It is in 1:24 scale. I have just purchased a 40mm Bofors for the stern. Nothing like a lot of weapons. Perhaps I should have some torpedoes one day.😁
I have just bought a 3648 1450kv motor from Hobbyking for mine. I am advised that this will sort out my slow speed problem. I have also been advised to fit Lipo batteries. I probably will once I get over the thought of a large fireball on the river or in my house during charging.😉
Would love to hear how the renovation goes. I am considering starting a build blog as it might be a good source of gaining extra knowledge. I am not sure if a restoration will be ok on the build blog so I would appreciate if a member in the know could comment on this.
Work keeps getting in the way of my plans but one day!!
Peter.😊

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
18th Mar 2018 11:45  
>> Permalink
mdlbt.com/40074

Hi Peter, of course restorations are OK blogs! 👍
There are several on the site, including my Sea Scout 'Jessica'.
It's sometimes more awkward than a new build. Look forward to yours. Cheers Doug 😎


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
19th Mar 2018 20:41  
>> Permalink
mdlbt.com/40144

Hello. I hope I can get a little help with battery choice.
I have been reading the comments above and elsewhere on the site, and have decided to go along the LiPo route. I purchased the Turnigy 3648 1450kv brushless motor along with the Hobbyking brushless car ESC 100A w/reverse. I have done a little research on this battery but still do not know the exact battery I should be looking for. Please can you help with the following:
What voltage should I be looking for.
To have a reasonable useage period, can you advise on a suitable mAh rating.
Please can you recommend a charger.
Should I have a charge alarm.
Should I have a monitor for cell voltage.
Are there any other accessories I should have.
Thanks in advance.
Peter.😊

jarvo
(Fleet Admiral!)





Forum Posts: 550
19th Mar 2018 21:44  
>> Permalink
mdlbt.com/40148

Hi MB, the motor you have would go well on 3S lipo's, as to the Ah rating, cheepish 2200mah in parallel is the way i went using a Y lead, others may say go for larger capacity !!! your choice.

Mark


Etherow Model Boat Club
MouldBuilder
(Commander)





Forum Posts: 25
20th Mar 2018 21:36  
>> Permalink
mdlbt.com/40182

Thanks Mark.
Is there an advantage in using two 2200mAh batteries in parallel instead of one 5000mAh or is it price.
Do you have any views regarding a particular charger.
I have never used LiPo batteries before and I read they can be problematic if not used correctly.😊

jarvo
(Fleet Admiral!)





Forum Posts: 550
20th Mar 2018 21:48  
>> Permalink
mdlbt.com/40184

Hi Mate, there was an offer on ebay £5 each for 2200mah 3s lipo's, so i took the plunge, bought 8 of the beasts, 2x2 in my Fireboat, with twin 700BB motors, thinking of swapping to brushless but SWIMBO has ideas for the garden!!!!

Mark


Etherow Model Boat Club
RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
20th Mar 2018 21:51  
>> Permalink
mdlbt.com/40185

Hi MB, don't recommend you use ANY kind of batteries in parallel, esp. LiPos, unless you have a connection / distribution board in between that will stop one battery trying to charge the other. This will happen if the two batteries do not have identical charge levels! Component shop have such a board (from Action Electronics) to do this.
Also, you will probably find that, for example, 2 x 2500mAH batts will weigh more than one 5000mAH batt🤔 and be more expensive.
Only advantage I can see in using two instead of one is that you can put them either side of the keel to help reduce any rolling tendency. Effect is minimal I think though.
Cheers Doug 😎
PS: One per ESC and Motor as Jarvo is doing - Fine. Two in parallel feeding one ESC - not so fine! 😉


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
20th Mar 2018 21:58  
>> Permalink
mdlbt.com/40186

Thanks Doug.
Do you have a preference on a charger and is the monitor I saw you mentioned in an earlier post important.
Finally, for now😁, would a 5000mAh battery 3s be about right for the 1450kv brushless motor I bought.
Thanks.
Peter.

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
20th Mar 2018 22:43  
>> Permalink
mdlbt.com/40187

Hi MB, can only say what I have which works and I ain't set the house on fire yet 😉 Not surprisingly for someone living in Munich both mine are from German companies!
Robbe Power peak Uni 7 and Graupner Unimat 14. There are later versions of both around nowadays but you can still find these on Amazon / Ebay etc.
Both of them have automated programmes for various Lithium types, NiMH / NiCad (not recommended these days!) and SLAs.
Robbe is now defunct and their Marine stuff taken over by Graupner and marketed as RoMarin! Pics also show the Balancer Adaptor Boards, necessary to connect the balancer cable of the battery. This ensures that each cell is equally charged 😊
I also included in the pics the little battery Capacity Testers I use. They cost around a tenner and are very useful for checking the capacity before a run or charging, as well as the voltage and capacity of each cell, which gives an indication of the battery condition.
I found some duff cells with the tester in a few batteries I'd only just bought 😡
When looking for / buying a charger look also for a LiPo Safe bag to charge them in. E.g. LiPo Guard.
Charger may cost 50 quid upwards depending on how many charging outlets you want and how many Bells & Whistles. But I get on well with these two 😉 I like the Robbe version cos I can charge two LiPos at the same time.
Also in the pics are a few of the charging cables I made up with gold 4mm bullet plugs for the charger end and Tamiya and BEC (for my Plastic magic stuff!) at the batt end.
Such adaptor cables are also available 'ready made' but I just like fiddlin' 😊 Hope this helps, Cheers Doug 😎
Nearly forgot! Can't say for sure what current your motor will draw cos I don't know all the other details, but a 40" boat will need some shove! So I wouldn't go below the 5000mAH if you want a half decent run time.
A 40" boat can carry a bit of weight! And batt power is more useful than pure ballast 😉 Recommend a little Wattmeter to check the max current draw - see last pic.
Basic theory!
A fully charged 5000mAh (or 5AH) batt can theoretically deliver 5A for one hour, or 10A for half an hour and so on!
Say your set up draws 20A with the 'pedal to the metal' then a 5000mAH batt will 'theoretically' last 15 minutes. Theoretically cos other factors are in play; initial charge state, temperature, internal resistance of the cells, cable losses etc. The latter is why I only use gold connectors!
The higher the batt capacity the higher the price and weight. So suggest you start with the 5000 and see how (long) it goes. Then check the weights of higher capacity batts (and the bank account / management approval😉) Bon chance mon ami!


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
20th Mar 2018 23:18  
>> Permalink
mdlbt.com/40189

PS re Monitor!
There are separate 'Alarm' devices (i.e. Monitor) on the market for warning you if the Lipo is approaching the critical low voltage; 3.0 - 3.2V.
Look on the sites selling batteries, they usually have the Monitors as well.
Some can allegedly be coupled to the feedback telemetry to warn you on the TX display, but i ain't tried that yet 😉
LiPo Safe ESCs can also be programmed to slow down or Stop when the voltage is low. This is (to me) about the only reason to buy a programming card for the ESC. Everything else; stick positions for Full Ahead, Full Astern and All Stop you can do with the TX! 😎
PPS: Before Canabus jumps on me about programming cards! 😲
There is one other reason they can be useful: If you have a Car Escape as Canabus recommends! I discovered that they are usually delivered set up to 'Brake on reverse', which means that you have to shove the gas stick backwards twice to engage reverse. Otherwise it just STOPS!!
The programming card enables resetting this to 'Boat Mode' so that the motors reverse immediately you pull the stick back.
If you use Marine ESCs this isn't a problem as there ain't no Brake!


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
21st Mar 2018 10:42  
>> Permalink
mdlbt.com/40203

Thanks Doug. That really helps me. I have read a lot about LiPo batteries and now have a better understanding. This experienced help is perfect.
I did buy the 100A car ESC as recommended by Canabus but Hobbyking did not have the suitable programmer. I have left a message so they will respond when a new supply arrives. I have looked elsewhere for the programmer but all of the stockists I found do not have any stock. Supply problem?
Thanks again for all of your help. A lot of sanding down and painting awaits me for the next few weeks. I plan to drive to Cornwall Model Boats this weekend to see how it looks. I am getting that hollow feeling that I should get a new kit to run alongside this rebuild. Just for a change now and again you understand😁. We will see.
Peter.😊

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
21st Mar 2018 11:04  
>> Permalink
mdlbt.com/40205

Glad to help Peter,
I was a Brushless & LiPo newbie last year, guys like Canabus, Dave_M and co helped me make the quantum leap. Being a retired electronics engineer helped as well 😉
Know what you mean about 'a change now and again'!
Did I mention that renovations / upgrades are often more awkward and time consuming than a new build? 🤔
I have a few other 'odds n ends' on the go for a break from the Sea Scout renovation. A Deans Marine HMS Manxman, an Alexander Engel GmbH AKULA II sub, and a Dynam PBY Catalina kit are queued up in the planning and research stages. Kit boxes are clogging up the cellar!
Bits and pieces for various 1/350 Plastic Magic projects are being collected and prepared! It's all Go folks😊
Happy hunting at CMB, longish drive for me 🤔
Cheers Doug 😎


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
21st Mar 2018 11:25  
>> Permalink
mdlbt.com/40206

PS: Attached is the user manual for a typical Quickrun Car brushless ESC.
Par 3 shows how to program it using the TX.
Para 5 shows a table of the options available and the presets marked with black background! I used the programmer to set the Running Mode to Mode 3, i.e. No Brake between forward and reverse!
the programmer is also useful for setting other parameters; esp number of battery cells and Low Voltage cut off.
Hope this helps to know what to expect😉
Cheers Doug 😎


Attached Files - Click To View Large


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
23rd Mar 2018 19:10  
>> Permalink
mdlbt.com/40316

Hi Doug.
Would you mind giving me your thoughts on this charger please.
Thanks. Peter.😊
Charsoon Antimatter 2X300W
Had to think twice about going to Cornwall model boats. It is a warehouse and not a shop.😡

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
24th Mar 2018 01:19  
>> Permalink
mdlbt.com/40328

Hi Peter, seems a bit pricey to me.
For me two disadvantages-
1 Only a titchy 2 line display for setting up and reading the batt status, can't put much info in that,
2 External DC supply only.
The Robbe version I use can be either 12V DC at the lakeside, or mains at home.
Personally I wouldn't buy it for that money, but that's just my opinion and wadda I know😉
Surprised about CMB 😲 I always thought it was a real shop!
Ciao, Doug 😎


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
figtree7nts
(Fleet Admiral!)





Forum Posts: 434
24th Mar 2018 01:43  
>> Permalink
mdlbt.com/40332

Hi Doug,

Here is the coded message that Steve's ship send of using flash Morse "#T#TTT ##EE 5#E ##E #TG## # 7# S". This is all it says. I'm an amateur radio operator...


"Fair winds calm Seas"
RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
24th Mar 2018 01:46  
>> Permalink
mdlbt.com/40334

Maybe we need an Enigma machine 😉


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
24th Mar 2018 06:26  
>> Permalink
mdlbt.com/40335

Thanks Doug. Finally found the Robbe on Amazon for £42 plus delivery.
I took your advice and ordered it as it appears to be the only one left anywhere.
I will leave the battery until I get nearer to the re-launch. I also purchased the monitors and balance unit. There is no point in starting from total scratch. Thought it safer to follow your lead.
Thanks. 😊Peter.

RNinMunich
(Fleet Admiral!)





Forum Posts: 2064
24th Mar 2018 10:55  
>> Permalink
mdlbt.com/40337

Hi Peter, we are all 'Standing on the shoulders of Giants'!
Folks like Canabus, Dave_M and Jarvo, to mention but a few, showed me the way last year.
Couple that with my insatiable desire to know 'How Things Work'! and here we are 😉 The Robbe should give you years of trouble free service. Have fun, Doug 😎
PS the 20A rating of the other charger is 'marketing blurb'! No one charges at 20A, unless they are into pyrotechnics and demolition😲


Young at heart - slightly older in other places 😉 cheers Doug
Grant me the Serenity to accept things I can't change,
the Courage to change things that I can, and
the Wisdom to know the difference!
MouldBuilder
(Commander)





Forum Posts: 25
25th Mar 2018 20:26  
>> Permalink
mdlbt.com/40395

Hello Canabus.
Please can I take you up on the pdf files of the plans for my boat. I have an A0 printer so should be able to print them full size. I have looked all over for the originals without success.
I am learning a lot as I go and wonder, looking back, if I have made a mistake. I bought the 3648 1450kv motor, yes, the beast. Just cannot help myself!!😁 Now that I understsnd these motors a lot more, I realise that it is an outrunner. Do you think I need water cooling and if yes, how is this done when the main outer can is rotating.😊🤔
Thanks.