Bike computer as chain counter?
- Thread starter Norman_E
- Start date
VicS
Well-Known Member
Simple.
Mount a cycle wheel on the boat ( without tyre and tube)
Fit the sensors to the wheel and suitable mounting bracket
Run the chain over the wheel rim.
It'll measure the chain let out in kilometres
theoldsalt
Well-Known Member
This doesn't answer your question but I don't bother with a counter.
My electric windlass lowers the anchor at roughly constant speed. I have measured how much chain goes out per second. So it's easy to work out how many seconds (counted in my head) for the length of chain required.
Simples !
My electric windlass lowers the anchor at roughly constant speed. I have measured how much chain goes out per second. So it's easy to work out how many seconds (counted in my head) for the length of chain required.
Simples !
lenseman
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I have lowered 15 mph of chain?
All I have to do now is to work out what the heck it all means before I go aground?
vyv_cox
Well-Known Member
There have been threads on this topic previously. The main problem is that the device cannot count backwards. If you could cycle in reverse the computer would show exactly the same speed as if it was forwards. There may be a clever way of switching it so that it does what you want but there must be simpler ways. Tie wraps work for me.
noelex
Well-Known Member
I have seen it done. Most of the modern windlasses have a magnet on the gypsy or a recess where one can be fitted.
The bike computer will read distance. One problem is the very small wheel on the gypsy and a Km reading on the compmuter is outside the range of adjustment of the bike computer so you. end up doing some simple maths to convert the result and the resolution is not ideal.
The bike computer will read distance. One problem is the very small wheel on the gypsy and a Km reading on the compmuter is outside the range of adjustment of the bike computer so you. end up doing some simple maths to convert the result and the resolution is not ideal.
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temptress
Well-Known Member
Interesting - might take a look at these.
[70521]
Well-Known Member
Why do you need to make things so complicated? Don't you mark your chain every few meters?
noelex
Well-Known Member
The main advantage of chain counter is when there is no one up forward to see the marks.
When Med mooring for example the helmsmen can release more chain while reversing without any fear that the chain will run out. Leaving a crew member free to tend lines or fend off.
To take advantage of this the chain counter and windlass controls need to visible/usable from the helm.
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[70521]
Well-Known Member
Must be a much bigger boat than mine
nigelmercier
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On a recent trip this would have caused an argument, with the helmsman insisting that x metres of chain was enough, and the man on the windlass (me) beleiving him to be wrong. I just lied, and told him in the morning
I dare say that the device in question could be used to give an arbitrary number related to the number of revolutions of the windlass, but a number of magnets and a look-up table would probably be needed; just try it and see what you get.
[Later] Assume a bike wheel moves up to 2m per revolution, it is going to take 500 revs to make 1km. This would equate to about 160m of chain. So the first thing to check is the distance resolution of the device: how many digits after the decimal point does it display.
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AntarcticPilot
Well-Known Member
Don't people usually range chain on deck before anchoring? I'd never trust chain to run cleanly from my anchor locker, as other things are stored there. But even if other stuff wasn't stored there, the chain could easily get tangled in a locker and not run cleanly.
Then again, I don't have an electric anchor winch.
Then again, I don't have an electric anchor winch.
lw395
Well-Known Member
Both my boats had only a little chain, so marking the rope in 10m increments was good enough.
noelex
Well-Known Member
The bike computers are adjustable for different wheel diameters, but the ones I have seen need some slight mental arithmetic to convert the reading, but a table is not needed.
noelex
Well-Known Member
I have not seen anyone do this or a few years appart from a stern anchor. Nothing wrong with it, but generally unnecessary with modern boats.
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BlueChip
Well-Known Member
Doesn't marking every few metres make it complicated?
We mark every 10m with cable ties. 1 tie for each 10m so 1, 2 3, or 4 ties for 10, 20, 30 or 40m of chain - couldnt be simpler.
elton
Well-Known Member
rogerthebodger
Well-Known Member
Or modify the software in one of the YAPP projects.
AntarcticPilot
Well-Known Member
I guess it's personal preferences. If I lowered directly from the chain locker, I'd be worried that the chain would kink and jam somewhere, and that despite my having marked the chain, I might misread my markers (yes, it is clear enough, cable ties with 5m and 10m intervals marked). Ranging chain on deck ensures a) That I have the right amount of chain ready, b) That it will definitely run freely without jamming and c) that the end of the chain is firmly secured to a cleat. The last because although I am quite sure my manual winch is securely mounted, I'd still worry about it taking a sudden jolt loading.
I also made a conscious decision NOT to install an electric winch, for several reasons - mainly because the nature of the chain locker precludes mounting a winch over the top of it, but also because of a dislike of having to either install a battery and charging cables in the bow OR massive cables from the battery bank at the stern
