OT(?): Could somebody make a metal shaft for me? (for payment of course)

[R]

Post an "OT" request on Uk.Rec.Motorcycles and await "WUN" to appear......

[Mathew J. Newton]

Hi Geoff,

The 'flapper' has a D-channel all the way through it and whilst you could just poke the shaft in by only a small amount this would work fine when free-running. However, when food starts getting caught between the rubber flapper blades and the container walls the torque required to turn it increases significantly. At this point the plastic centre of the flapper really needs a good grip on the shaft hence the more that's in there the less the likelihood of something rounding off at this interface.

Mathew

[Mathew J. Newton]

I use it to interface the motor to the network. Basically, being a managed switch you can disable/enable each switch port individually. With some loopback adapters (shorted Ethernet plugs for want of a better description) plugged into the ports you can thus switch the LEDs on/off.

I have piggybacked some connections to the LEDs to drive some transistors which in turn activate relays to drive the motor forward/backwards as required. The switch PSU also provides the power for the motor.

Of course the novelty of manually telnetting to the switch to do this soon wears off and so I have a shell script on my server which automates the process.

Mathew

[NT]

I'm not seeing the point. Cats dont overeat, so dry food can simply be left for them, set out in several small pots to avoid spoilage. I'm not saying this sort of approach is at all a good way to look after cats, but if youre going to do it at least this removes the risk of feeder failure from the loop.

What mechanism are you using for water?

NT

[Roger Mills]

I had in mind using a horizontal drill stand. Even better if you can find a bearing which will fit over the other end end of the shaft to support it while you 'machine' it. [You might find a bearing on a router bit which would do the job].

I would have thought that it would be much easier to bore out the coupling than to turn a 8mm shaft down to 6mm concentrically without a proper lathe (whereas going from 8mm down to 7.6mm - if you really have to - is less of a problem).

[soup]

technical college tutor/techy teacher at the local high school).

I would imagine a 'weak link' would be required rather than stalling the motor,and possibly setting fire to the place, the weak link would 'give' so it was fairly easy to replace perhaps the coupler with the two grub screws could be made to be easily (relatively) broken so you could just replace that rather than the shaft, the motor or one of the rubber vanes.

[Mathew J. Newton]

I'm afraid it's probably the child in me - have always liked making things, particularly anything with an engineering element.

Watering cans in the garden, the puddle that collects on the tarpaulin on my ladders, etc etc. They won't drink anything else - and that includes tapwater in a bowl! ;-)

Mathew

[Mathew J. Newton]

That's a good idea. I might pop down for a chat.

It's really quite sad that these skills/capabilities aren't in abundance. I'm just as guilty though given I work with computers all day.

I will almost certainly be monitoring (or rather controlling) each feed so would be able to stop/reverse the motor should it stall. It has a stall torque of 25kg-cm though so hopefully it won't come to that.

Mathew

[Mathew J. Newton]

Thanks for the pointer Nige - a couple of guys over there have offered to assist.

Thank you everyone for your thoughts and suggestions. Whilst computers may have killed off in droves the numbers with the necessary skills/ equipment to do this sort of work the Internet does at least help with finding the few that are left! ;-)

Cheers,

Mathew

[geoff]

In message , R writes

Ah yes - Nigel has cats ...

[Jules]

Hmm, try telling that to our two male cats. I think they were probably shire horses in former lives :-)

Although I kind of like that approach - something that essentially introduces a full pot and takes away the previous pot (whether the contents are completely consumed or not) at set intervals. It can still fail in interesting ways, but eliminates the need to check that the food dish is empty before pouring a known quantity in (or the need to detect food level and only add enough so that the dish is 'full')

cheers

Jules

[geoff]

Actually, the obvious way of doing this doesn't require any moving parts.

All that's required is an upturned plastic bottle, maybe with an enlarged spout placed at the correct height above the bowl, removing food allows more food to drop down

Anything else (refreshing food, paddles, and other moving parts) is just playing around for the sake of it

KISS ... as they say

[Lobster]

Yeah, where on earth do you get that that from?! See

And ours...

[Mathew Newton]

In theory, yes.

I bought one to try it out though and it didn't work - the shape of the food was such that it wouldn't always fall down properly - the cats ended up effectively digging it out and attacking the whole thing in frustration. I might as well have put a big pile of food down for all it was worth!

Mathew

[NT]

4:57:53 -0800, NT wrote:

The problem with that proposed mechanism is spoilage. As cats eat they leave saliva behind, and spoilage results. Serving fresh food on top of spoiled food isn't workable or in any sense safe.

Several small pots, each with a book on top of it, normally results in each potful being eaten before the next one is 'opened'

All moving parts do is introduce significant risk.

NT

[geoff]

Larger hole required, then

That's what I do ...

[Mathew Newton]

In case anyone is interested in how this turned out I'm happy to report it went well - better than expected in fact!

[Ash]

Excellent! Our last cat would have had one look at the thing and eaten it along with the biscuits ... he was a hungry nosed fat cat who would have breakfast with us and then nip down the street and have breakfast with at least two other neighbours before returning for more food and giving that "I'm hungry Feed Me" look. He even got too big/fat for the cat flap and took to sticking his head through the cat flap and meowing (screeching) until we opened the door for him.

Ash

[Stuart Noble]

Am I just easily impressed, or is that bloody brilliant?

[Jules]

a) That's rather good.

b) I'm really impressed with the write-up. Homebrewing stuff is one thing, but conveying what you've done to others is just as hard, I think...

Now you need an internet-enabled self-cleaning litter-box ;)