Kennet Tool and Cutter grinder

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Fergus OMore:
Hi Nick- still computer problems :loco:

OK- and now to the pulleys!

Here I strongly disagree with the plans :hammer:
The plans say 5. 3/16th and 2. 5/8th for the pulleys which is fine for the small wheels supplied by Model Engineering Services for both the Quorn and the Kennet but there will be times when your machine should have a larger wheel to rough grind. In consequence,
you should think in terms of a double pulley at both the grinder and the motor.

If you think about it carefully, your lathe has variable speeds. Your Kennet is only different in that your lathe moves metal with a tool whereas your Kennet uses grit. All that you have to ensure is that you don't exceed the recommended( safe) speeds for the abrasive wheels.

Sounds pretty heady stuff? Well, I did say that you are moving into an aspect of model engineering where you leave most people are either unable or unwilling to make their own cutting tools. Well, I hinted at it.

Cheers

N

MadNick:
Thanks Norman,

Anything I can do to help or is it still under 'the curse'? lol

So those are two pulley sizes recommended for use with two types of grinding wheel on the 1/4HP motor, is that right?

Nick.

Fergus OMore:
I'm assuming that you want to go no faster than 7000rpm for a small wheel so if you had a 2880 rpm motor- which you haven't, you would use the 2 to 1 pulleys( per drawings and my earlier post) to give something like a safe 4000 revs. However, you want roughly double the motor pulley diameter for the dreaded 1440 one. however, I assume that if you want a bigger wheel the present pulleys would be OK.

If you think about it, a cheap but not too nasty 6" Double ended grinder ( full of Eastern promise) will drive a 6" wheel at each end at 2880 rpm.

So, if you recall my earlier reservations, I would have gone out and got one- until something better materialised.

:Doh: If you had one, you could rough grind at one end-- and drive the Kennet from the other. : :bang: :bang: :bang:

I might not be the World's best computer freak( said he waving his wooden leg aloft) but I 've done this tool and cutter malarkey before :hammer:

Goes back to his wheelchair and incontinence pads :clap:

Norm

MadNick:
Hello,

Well its been a busy afternoon.

I started off by farting around with a newly purchased Clarke DE grinder to do away with the pulleys and spindle and go direct against the cup wheel that I purchased. Mid morning I nipped round to a mates who told me he had found a sweet little Emerson motor - 1450RPM and 1/10 HP -

Well that started off some frenzied calculations on safe wheel speed and what I could manage with my limited pulley choice. After further farting around I found a pulley which came from my old MK2 Golf. I quickly made up a boss for it to go on the Emerson -

My calculations tell me with the drive speed of 1450RPM and diameter of 82mm will achieve a driven speed of 4100RPM on a diameter of 29mm. The grinding wheels have a safe speed of 4500RPMs. Hopefully this will be enough to get me started, just enough so I can make the tool profile I need to make a slightly larger driver diameter.

Loosely assembled -

Next will be to fit the Emerson to the base and wire in some electrics.

Nick

Fergus OMore:
Hi Nick,

You are almost in a position to -- See The Wheels Go Around.

Leave altering pulleys - and get some tools that will make life easier.

That- in case you've forgotten- is where you came in.

Cheers

N

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