Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is required
to be smaller the main shaft - I could not find a shaft coupling any
bigger than 6mm (the motor shaft is also 6mm). The rather strange
(specific) dimensions of the main shaft (which is fully inserted into the
flapper body) is, I believe, a result of it being US-made and hence of
imperial measurements.

Happy to provide further info and clarification if required. Indeed I am
all ears to alternative ideas too and/or suggestions as to who/where
might be able to make this shaft for me.

Regards,

Mathew

Mathew J. Newton formulated the question :
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

I could do that for you, providing you supplied the mild steel and
could file the flats on each end.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

Mathew J. Newton wrote:

am in the middle of project building a network-enabled cat feeder.

Fantastic! Now there are 4 words I never thought I'd see in the same
sentence...

Can't help I'm afraid; but isn't there a website out there somewhere
where you can enter in requests for jobs like this, and people bid a
price to do it? Don't recall any details but maybe someone else will?

David

On Nov 11, 8:56 pm, Harry Bloomfield
wrote:

I could do that for you, providing you supplied the mild steel and
could file the flats on each end.

Hi Harry,

To clarify, the shaft is D-shaped all the way along hence manual
filing could be problematic...? This is why I thought a milling
machine might be required...

(I can't believe I didn't mention it being D-shaped given it is such a
fundamental point! Sorry about that...)

Mathew

Mathew Newton pretended :
On Nov 11, 8:56 pm, Harry Bloomfield
wrote:

I could do that for you, providing you supplied the mild steel and
could file the flats on each end.

Hi Harry,

To clarify, the shaft is D-shaped all the way along hence manual
filing could be problematic...? This is why I thought a milling
machine might be required...

(I can't believe I didn't mention it being D-shaped given it is such a
fundamental point! Sorry about that...)

Mathew

I don't have such, but I thought the D shape was just to enable it to
be firmly fixed at each end.

--
Regards,
Harry (M1BYT) (L)
http://www.ukradioamateur.co.uk

On Nov 11, 9:05 pm, Harry Bloomfield
wrote:

I don't have such, but I thought the D shape was just to enable it to
be firmly fixed at each end.

Unfortunately the design of the flapper is such that the shaft needs
fully inserting - it thus needs to be flat across the whole length. I
have modified the drawing to hopefully remove the ambiguity.

Thank you anyway for the initial offer.

Mathew

On Nov 11, 8:57 pm, Lobster wrote:
Mathew J. Newton wrote:
am in the middle of project building a network-enabled cat feeder.

Fantastic! Now there are 4 words I never thought I'd see in the same
sentence...

The result of requirements creep unfortunately!

Whilst it started out as a simple timer-controlled dispenser it soon
became a bit more 'interactive'. It now has streaming video and a web-
based interface...!

If I can get it up-and-running (the software is now written, and the
electronics built) I'll be publishing details of the end result on a
website so finger's crossed I can get this shaft sorted.

Mathew

On 11 Nov, 20:59, Mathew Newton wrote:
On Nov 11, 8:56 pm, Harry Bloomfield

wrote:
I could do that for you, providing you supplied the mild steel and
could file the flats on each end.

Hi Harry,

To clarify, the shaft is D-shaped all the way along hence manual
filing could be problematic...? This is why I thought a milling
machine might be required...

(I can't believe I didn't mention it being D-shaped given it is such a
fundamental point! Sorry about that...)

Mathew

angle grinder?

JimK

Mathew J. Newton wrote:
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

If you don't get any joy on that basis, there's always these guys:

http://www.emachineshop.com/

I believe they'll post to the UK and presumably the cost of sending such
a small part will be minimal.

I also have a work colleague who is thinking of retiring and then
earning some "pocket money" with jobs like this, but I'm not sure he'd
necessarily appreciate me touting for business on his behalf just yet :-)

Pete

Mathew J. Newton wrote:
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is required
to be smaller the main shaft - I could not find a shaft coupling any
bigger than 6mm (the motor shaft is also 6mm). The rather strange
(specific) dimensions of the main shaft (which is fully inserted into the
flapper body) is, I believe, a result of it being US-made and hence of
imperial measurements.

Happy to provide further info and clarification if required. Indeed I am
all ears to alternative ideas too and/or suggestions as to who/where
might be able to make this shaft for me.

Regards,

Mathew
Go and find a robot wars supplier site.

Everything you need is probably there already.

http://www.technobots.co.uk/acatalog/

is a good read!

On Wed, 11 Nov 2009 22:07:35 +0000, John Rumm wrote:

I take it the smaller end is coaxial with the main shaft - therefore
there is a step in the flat section at that point?

There is. Basically, the shaft rotates on a central line as if there
weren't any flats.

Mathew

On Wed, 11 Nov 2009 21:49:47 +0000, Pete Verdon wrote:

If you don't get any joy on that basis, there's always these guys:

http://www.emachineshop.com/

I'll certainly check them out, not least given you get an instant price
if you design it with their free software! Looking though at their
samples prices it might still be a little steep though.

I also have a work colleague who is thinking of retiring and then
earning some "pocket money" with jobs like this, but I'm not sure he'd
necessarily appreciate me touting for business on his behalf just yet
:-)

I'd be happy to be his first customer... And would of course put a link
to his site (if he's going to have one) on my cat feeder pages! ;-)

Mathew

On Wed, 11 Nov 2009 22:00:57 +0000, The Natural Philosopher wrote:

http://www.technobots.co.uk/acatalog/

is a good read!

Yeah I've been all over that site - I was really starting to think
robotics would be a great hobby to get into...

Unfortunately I didn't manage to find any suitable shafts... Basic round
shafts (of not quite the right size!) and similar raw materials but
nothing really close enough to what I'm after.

All good pointers and ideas guys though - I really do appreciate them.

Mathew

In an earlier contribution to this discussion,
Mathew J. Newton wrote:

Hi all,

I am hoping some kind and able soul out there with a lathe and/or
milling machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands
I am in the middle of project building a network-enabled cat feeder.
The current design is based around a cereal dispenser driven by a
high-torque/ low-revs motor, the latter being controlled by a
modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have
managed to separate the shaft from the knob and connected everything
up I am concerned that over time the high torque required when food
gets caught in the flapper will cause the connection to the brass
coupling to fail. This is based on the fact that the plastic shaft is
rather soft and is not held all that firmly by the grub screw in the
coupling. I have considered inserting a metal shim of some sort but I
really can't see it lasting.

Hence, I am wanting to replace the plastic shaft with something made
out of metal. Unfortunately whilst my apprenticeship days taught me
the skills to do this I do not have access to the necessary machines
to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is
required to be smaller the main shaft - I could not find a shaft
coupling any bigger than 6mm (the motor shaft is also 6mm). The
rather strange (specific) dimensions of the main shaft (which is
fully inserted into the flapper body) is, I believe, a result of it
being US-made and hence of imperial measurements.

Happy to provide further info and clarification if required. Indeed I
am all ears to alternative ideas too and/or suggestions as to
who/where might be able to make this shaft for me.

Regards,

Mathew


Does it really need to be as accurate as your specification, if it only
rotates slowly? Does anything have to slide along the D-shaped shaft in
operation, or only in assembly. If the latter, can't you:
* Start with a length of 8mm mild steel rod
* Rotate it in a drill chuck, and use a file and emery cloth to reduce it to
7.6mm
* File the flat all the way along
* Bore out one end of the coupling - thus avoiding having to reduce the end
of the shaft to 6mm?
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

On Wed, 11 Nov 2009 23:13:37 +0000, Roger Mills wrote:

Does it really need to be as accurate as your specification, if it only
rotates slowly?

Probably not. The measurements were just those obtained from the existing
shaft. I didn't want to round anything off in case it resulted in it
either not fitting, or being too loose for good grip (there is no grub
screw arrangement in the flapper end - it just sits inside a D-shaped
channel through its centre).

Does anything have to slide along the D-shaped shaft in
operation, or only in assembly. If the latter, can't you: * Start with a
length of 8mm mild steel rod * Rotate it in a drill chuck, and use a
file and emery cloth to reduce it to 7.6mm

Hmmm... interesting. Do you think that would work? I haven't got a pillar
drill - or were you just talking about a suitably-clamped standard drill?

* File the flat all the way along
* Bore out one end of the coupling - thus avoiding having to reduce the
end of the shaft to 6mm?

I hadn't considered boring out the coupling either! I suppose though if I
can form the rest of the shaft with my 'homemade lathe' as per your
method above then I can just go a bit further with the small end..?

Mathew

"Mathew Newton" wrote in message ...
On Nov 11, 8:57 pm, Lobster wrote:
Mathew J. Newton wrote:
am in the middle of project building a network-enabled cat feeder.

Fantastic! Now there are 4 words I never thought I'd see in the same
sentence...

The result of requirements creep unfortunately!

Whilst it started out as a simple timer-controlled dispenser it soon
became a bit more 'interactive'. It now has streaming video and a web-
based interface...!

If I can get it up-and-running (the software is now written, and the
electronics built) I'll be publishing details of the end result on a
website so finger's crossed I can get this shaft sorted.

I'm intrested in the modified Cisco switch. Why is that needed?


--
Graham.

%Profound_observation%

In message
,
Mathew Newton writes
On Nov 11, 8:56 pm, Harry Bloomfield
wrote:

I could do that for you, providing you supplied the mild steel and
could file the flats on each end.

Hi Harry,

To clarify, the shaft is D-shaped all the way along hence manual
filing could be problematic...? This is why I thought a milling
machine might be required...

(I can't believe I didn't mention it being D-shaped given it is such a
fundamental point! Sorry about that...)

But why ?

Surely the flat is only required at each end

--
geoff

In message , Mathew J.
Newton writes
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

It depends how urgent it is - I could prolly turn it down from a piece
of 3/8" SS, but I'm not sure when I might have time to do it


--
geoff

In message , Mathew J.
Newton writesHi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

Ask in uk.rec.models.engineering lot's of very capable people there
who could do this.

--
Nige Danton

"Mathew J. Newton" wrote in message
...
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is required
to be smaller the main shaft - I could not find a shaft coupling any
bigger than 6mm (the motor shaft is also 6mm). The rather strange
(specific) dimensions of the main shaft (which is fully inserted into the
flapper body) is, I believe, a result of it being US-made and hence of
imperial measurements.

Happy to provide further info and clarification if required. Indeed I am
all ears to alternative ideas too and/or suggestions as to who/where
might be able to make this shaft for me.

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

On Thu, 12 Nov 2009 00:04:04 +0000, geoff wrote:

To clarify, the shaft is D-shaped all the way along hence manual filing
could be problematic...?

But why ?

Surely the flat is only required at each end

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

On Wed, 11 Nov 2009 23:58:58 +0000, Graham. wrote:

I'm intrested in the modified Cisco switch. Why is that needed?

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

On Nov 11, 8:45*pm, "Mathew J. Newton" wrote:
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so..

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is required
to be smaller the main shaft - I could not find a shaft coupling any
bigger than 6mm (the motor shaft is also 6mm). The rather strange
(specific) dimensions of the main shaft (which is fully inserted into the
flapper body) is, I believe, a result of it being US-made and hence of
imperial measurements.

Happy to provide further info and clarification if required. Indeed I am
all ears to alternative ideas too and/or suggestions as to who/where
might be able to make this shaft for me.

Regards,

Mathew


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

In an earlier contribution to this discussion,
Mathew J. Newton wrote:

On Wed, 11 Nov 2009 23:13:37 +0000, Roger Mills wrote:

Does anything have to slide along the D-shaped shaft in
operation, or only in assembly. If the latter, can't you: * Start
with a length of 8mm mild steel rod * Rotate it in a drill chuck,
and use a file and emery cloth to reduce it to 7.6mm

Hmmm... interesting. Do you think that would work? I haven't got a
pillar drill - or were you just talking about a suitably-clamped
standard drill?

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].

* Bore out one end of the coupling - thus avoiding having to reduce
the end of the shaft to 6mm?

I hadn't considered boring out the coupling either! I suppose though
if I can form the rest of the shaft with my 'homemade lathe' as per
your method above then I can just go a bit further with the small
end..?

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).
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Mathew J. Newton wrote:

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....
The following diagram shows roughly what I am doing from a mechanical
perspective:
http://www.newtonnet.co.uk/permanent/feederdiagram.png


Can't help you with the machining (perhaps a quiet word with a local
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.

On Thu, 12 Nov 2009 04:57:53 -0800, NT wrote:

I'm not seeing the point.

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

What mechanism are you using for water?

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

On Thu, 12 Nov 2009 14:02:03 +0000, soup wrote:

Can't help you with the machining (perhaps a quiet word with a local
technical college tutor/techy teacher at the local high school).

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 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.

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

On Wed, 11 Nov 2009 21:05:26 -0800, Nige Danton wrote:

Ask in uk.rec.models.engineering lot's of very capable people there who
could do this.

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

In message , R
writes

"Mathew J. Newton" wrote in message
m...
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabled cat feeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

The following diagram shows roughly what I am doing from a mechanical
perspective:

http://www.newtonnet.co.uk/permanent/feederdiagram.png

The cereal dispenser contains a rubber flapper mechanism which
accommodates a plastic shaft connected to a knob. Whilst I have managed
to separate the shaft from the knob and connected everything up I am
concerned that over time the high torque required when food gets caught
in the flapper will cause the connection to the brass coupling to fail.
This is based on the fact that the plastic shaft is rather soft and is
not held all that firmly by the grub screw in the coupling. I have
considered inserting a metal shim of some sort but I really can't see it
lasting.

Hence, I am wanting to replace the plastic shaft with something made out
of metal. Unfortunately whilst my apprenticeship days taught me the
skills to do this I do not have access to the necessary machines to do so.

Would anybody be able to help me out here? That kind person would be
suitably compensated as required. I have made a drawing showing the
necessary dimensions (using Word - my teachers would not have been
impressed!):

http://www.newtonnet.co.uk/permanent/shaftdrawing.png

As you can see, the coupling to the motor (right-hand side) is required
to be smaller the main shaft - I could not find a shaft coupling any
bigger than 6mm (the motor shaft is also 6mm). The rather strange
(specific) dimensions of the main shaft (which is fully inserted into the
flapper body) is, I believe, a result of it being US-made and hence of
imperial measurements.

Happy to provide further info and clarification if required. Indeed I am
all ears to alternative ideas too and/or suggestions as to who/where
might be able to make this shaft for me.

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

Ah yes - Nigel has cats ...


--
geoff

On Thu, 12 Nov 2009 04:57:53 -0800, NT wrote:
I'm not seeing the point. Cats dont overeat

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

set out in several small pots to avoid spoilage.

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

In message . com, Jules
writes
On Thu, 12 Nov 2009 04:57:53 -0800, NT wrote:
I'm not seeing the point. Cats dont overeat

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

set out in several small pots to avoid spoilage.

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')

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


--
geoff

Jules wrote:
On Thu, 12 Nov 2009 04:57:53 -0800, NT wrote:
I'm not seeing the point. Cats dont overeat

Yeah, where on earth do you get that that from?! See
http://images.google.co.uk/images?hl=en&source=hp&q=fat+cat&gbv=2&aq=f&oq=

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

And ours...

On Nov 12, 11:27 pm, geoff wrote:

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

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

On Nov 12, 11:27*pm, geoff wrote:
In message . com, Jules
writesOn Thu, 12 Nov 2009 04:57:53 -0800, NT wrote:
I'm not seeing the point. Cats dont overeat

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

set out in several small pots to avoid spoilage.

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')

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

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

In message
,
Mathew Newton writes
On Nov 12, 11:27 pm, geoff wrote:

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

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

Larger hole required, then

- 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!

That's what I do ...


--
geoff

On 11 Nov, 20:45, "Mathew J. Newton" wrote:
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabledcatfeeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

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

http://www.newtonnet.co.uk/catfeeder

Mathew

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

http://www.newtonnet.co.uk/catfeeder

Mathew

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

Mathew Newton wrote:
On 11 Nov, 20:45, "Mathew J. Newton" wrote:
Hi all,

I am hoping some kind and able soul out there with a lathe and/or milling
machine might be able to help me out here....

At the risk of sounding like I've got too much spare time on my hands I
am in the middle of project building a network-enabledcatfeeder. The
current design is based around a cereal dispenser driven by a high-torque/
low-revs motor, the latter being controlled by a modified Cisco switch.

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

http://www.newtonnet.co.uk/catfeeder

Mathew

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

On Mon, 23 Nov 2009 04:30:19 -0800, Mathew Newton wrote:
In case anyone is interested in how this turned out I'm happy to
report it went well - better than expected in fact!

http://www.newtonnet.co.uk/catfeeder

OK,

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

On Nov 23, 1:49 pm, Jules
wrote:

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

The neighbour often sits in his garden using his laptop if that
counts...? ;-)

Mathew