Topic: Finally geting somewhere (Read 20354 times)

dave parker · « **Reply #50 on:** February 03, 2020, 09:35:07 am »

Thanks Tug Fanatic
It’s the wiring next before I put the top on
And I don’t know anything about wiring really so need to do some reading

DaveM · « **Reply #51 on:** February 03, 2020, 10:30:47 am »

Quote from: dave parker on February 03, 2020, 09:35:07 am

Thanks Tug Fanatic
It’s the wiring next before I put the top on
And I don’t know anything about wiring really so need to do some reading

This might help answer some of your questions http://www.modelboats.co.uk/news/article/but-i-don't-understand-electronics/18054
Also here's a diagram of what I think your installation might look like. You can remove the fuse to isolate the batteries for transport and storage
DaveM

dave parker · « **Reply #52 on:** February 03, 2020, 12:55:00 pm »

Thanks Dave M

Gardener · « **Reply #53 on:** February 03, 2020, 01:02:38 pm »

diagram with on off switch

Gardener · « **Reply #54 on:** February 03, 2020, 01:03:34 pm »

You will need to add fuse diagram does not show one ...

dave parker · « **Reply #55 on:** February 03, 2020, 01:11:49 pm »

Thanks gardener
Fuse as per Dave M

dave parker · « **Reply #56 on:** February 03, 2020, 01:12:57 pm »

Dave M
On your diagram is the switch on the speed controller the main on/off switch for the boat or do I need to add another??

DaveM · « **Reply #57 on:** February 03, 2020, 02:54:21 pm »

The diagram is complete as far as is necessary. If you really want to add another switch it should go in the positive line between the batteries and the fuse and be able to carry 15A. https://www.componentshop.co.uk/high-current-standard-toggle-switches.html
The small switch on the Viper merely switches on the power to the receiver.

DM

dave parker · « **Reply #58 on:** February 03, 2020, 02:57:50 pm »

Ok thankyou
I was if the opinion I should have a main on/off switch that controls all power to the boat, but obviously it’s only what I have found through examples???

dave parker · « **Reply #59 on:** February 03, 2020, 03:06:43 pm »

And can anyone recommend what specification I need for the wiring to and from battery etc???

Tug Fanatic · « **Reply #60 on:** February 03, 2020, 04:12:17 pm »

Quote from: dave parker on February 03, 2020, 03:06:43 pm

And can anyone recommend what specification I need for the wiring to and from battery etc???

This will be fine although you could probably get away with slightly less, eg 20awg, but for the difference in cost why bother?
https://www.componentshop.co.uk/18awg-silicone-cable-wire.html

Note that smaller awg number = thicker cable & more current carrying capacity. eg 20awg is rated for 11 amps whilst 18swg is 15amps and 16swg is 22amps.

Tips: Do colour code your wiring and do not use Tamiya type battery connectors. Personally I like Deans connectors.

Get some colour matched heatshrink as you will need it

Always remember when deciding which end of a connector to solder to what that you never have the exposed prongs live when the connector is not connected

dave parker · « **Reply #61 on:** February 03, 2020, 07:46:18 pm »

Thanks for all this help guys

dave parker · « **Reply #62 on:** February 03, 2020, 07:57:42 pm »

Tonight’s update is regarding my drive line.

Below are some pics of how I intend to install it but would like approval

Starting at prop end, there is the prop screwed on to the shaft nipping up to the nut, then the thrust washer.
This goes up against the bearing on the tube.

The other end has a thrust washer, then a locking collar which is fastened to a non threaded part of the shaft.

Then a little bit of thread before the nut which is nipped up to the coupling.

There is a small gap between the coupling and the motor.

Is this sounding right?

I want expecting to need a locking collar but as it turns out, due to the length of thread on each end and then location of the parts I do need one.

There will be a very small, less than 1mm movement from for and aft movement of the prop shaft.

Tug Fanatic · « **Reply #63 on:** February 04, 2020, 10:42:20 am »

Have a look at the attached crop of one of your photos.

The thrust washer on the propshaft end bearing does not look square with an equal gap all the way round. It might be an optical/ camera illusion but it should be square.

End play should be a lot less than 1mm. The idea is for the absolute minimum of end play that does not result in extra friction. If you have nearly 1mm play then you are putting nearly 1mm load onto a bearing somewhere else (probably the motor bearings) which is better avoided.

I suspect that you will be changing that 30mm 3 blade plastic prop pretty quickly but it is fine for shakedown runs.

dave parker · « **Reply #64 on:** February 04, 2020, 11:03:02 am »

Thanks tug fanatic

It’s an optical illusion on the picture
It is/will be square on the bearing, these parts were just rested in place for photos.
And yes will reduce the 1mm of play to pretty much no play at all

What is wrong with the propeller?

Tug Fanatic · « **Reply #65 on:** February 04, 2020, 11:42:30 am »

Quote from: dave parker on February 04, 2020, 11:03:02 am

...........................What is wrong with the propeller?

Absolutely nothing if it moves the boat well enough to satisfy you.

The standard Springer prop is a 40mm 3 blade brass prop which I have always thought was a bit too much for a standard low rpm 540 motor on 6v but it will do as a comparison.

Your prop is 30mm diameter and probably has a pitch of around 16mm. This gives a cylinder volume of 113 (volume of a cylinder = 3.14 x radius squared (15 x 15) x 16mm pitch) and shoves water out the back at around 0.4mph per 1000rpm.
https://www.cornwallmodelboats.co.uk/acatalog/Graupner-3-Bladed-Propeller-RH-30mm-M4-G2308_30.html#SID=334

The standard 40mm brass 3 blade has a pitch of around 41mm which has a cylinder volume of around 500 and moves water at 0.9mph per 1000rpm.
https://www.cornwallmodelboats.co.uk/acatalog/40mm-M4-Threaded-4-Blade-R-H-Brass-A-Type-Propeller-RAB147_13.html#SID=1220

You therefore have around a quarter of the water shifted per rpm of the prop and water moving at less than half the speed with the advantage of a much lower load on the motor. Whether this is enough is very much up to you and you won't know until you try it on the pond and see. If it isn't then the remedy is neither expensive nor difficult to achieve.

dave parker · « **Reply #66 on:** February 04, 2020, 11:48:10 am »

Wow ok thankyou

I am in no position to know these things yet so it’s food that you do!

Will have a review but as you say, easily changed

dave parker · « **Reply #67 on:** February 05, 2020, 10:42:38 am »

Is it usual to have to cut off the connectors on the end of a viper 15 speed controller in order to connect to sla batteries??

DaveM · « **Reply #68 on:** February 05, 2020, 11:11:59 am »

The alternative is to make up a battery connecting lead with the spade connectors at the battery end and a matching Tamiya type for the ESC-end. However Tamiya connectors aren't popular as they have been known to make poor contact and fail after a while. I favour the Deans or XT30 types from Component-Shop.
DaveM

dave parker · « **Reply #69 on:** February 05, 2020, 11:17:47 am »

Thanks Dave M

I thought that would be a good way of having a battery disconnect for removal, when not in use and transportation too

dave parker · « **Reply #70 on:** February 05, 2020, 11:43:53 am »

Do we think that using 14awg wire for power to match the 14awg on the speed co troller is a good idea rather than using 18awg??

Tug Fanatic · « **Reply #71 on:** February 05, 2020, 12:27:36 pm »

Quote from: dave parker on February 05, 2020, 11:43:53 am

Do we think that using 14awg wire for power to match the 14awg on the speed co troller is a good idea rather than using 18awg??

Going thicker never hurt.

You are using 4amp sealed lead acid batteries which will be very unhappy if asked to deliver more than say 8 amps even if you connect both in parallel. You are using an Esc that will do nasty things if you ask it to deliver more than 15 amps and you have a motor that has a stall current of 10 amps.

18awg silicon cable is rated for a continuous 16amps and 14awg for a continuous 32amps. 14awg will not hurt but it is unnecessary for any component that you are using.

PS How powerful is your soldering iron?

dave parker · « **Reply #72 on:** February 05, 2020, 12:33:43 pm »

Thanks again Tug Fanatic

A great source of facts n figures

I just felt uncomfortable going from 14awg wire on the equipment to 18 or 20 awg (thinner) wire without knowing it was ok to do so.....

Not much difference in price, and as you say, going thicker doesn’t hurt

Not “necessary” but no harm in doing

Tug Fanatic · « **Reply #73 on:** February 05, 2020, 12:46:13 pm »

The only disadvantage of going too thick on the wiring is that there is more metal to heat (wire & connector) for soldering which requires a more powerful soldering iron.

I am not sure if 18awg to 14awg will make any difference but bear it in mind. One of the most common mistakes people make when soldering is to try and use an iron that isn't powerful enough to get the heat in quickly enough.

dave parker · « **Reply #74 on:** February 06, 2020, 09:57:26 am »

Right, made some good progress last night

Now need look at how people do windows.

I have clear plastic to use for the actual windows, and have cut out openings. Jumped the fun a bit I think

I had the idea of in inner frame larger than the opening, in to which the plastic can be fitted but looking for ideas from you guys...

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Author Topic: Finally geting somewhere (Read 20354 times)