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Stent T&C Grinder questions

Hi,

Has anyone here aver built (or otherwise know anything about) the Stent Tool and Cutter Grinder ? I've seen some pictures of these and I wondered if it might make a suitable candidate for conversion into a cnc cam/crankshaft grinder ?

My idea was to fit a cnc indexing head along with cnc x and y table motion and so move the shaft past the head while rotating it in the indexer at the same time as shifting it nearer and further from the wheel according to the required cam profile. I'd need to fit a feedscrew instead of / as well as the rack and wheel. Any comments most gratefully received...

If anyone here knows anything about the Stent I'd be grateful if they'd answer a few qestions for me :

  1. Can the spindle be rotated so as to point parallel to the table long axis as well as perpendicular to it ?

  1. What are the dimensions of the table ?

  2. What are the maximum table X and Y travels ?

  1. What capacity constraints would you need in terms of a lathe and mill in order to make this machine without too many horrible issues arising ?

Many thanks,

Reply to
Boo
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Has no-one here ever built a Stent then ? I'm a bit surprised 'cos it's been featured in MEW (alledgedly) and is supposed to feature in an article in the next edition of this journal.

Of course if you just missed my first post then please feel free to answer this time ;-)

Mucho gratio amigos !

Reply to
Boo

In message , Boo writes

Don't know much about the Stent. Though some years I did get the info from the casting suppliers.

But for your application I would try to find a 2nd hand Clarkson. That's exactly what I use for the same purpose. My MK2 Clarkson cost me 75 quid. I know thats a steal but I was lucky ;-)

Personally I'd not go the CNC route. You would have to have absolutely NO backlash and very fine interpolation to get a successful cam. I CNC Mill my 4x master cams, but manually finish grind the cams on the clarkson with a simple motorised attachment. Takes a few minutes each when set up.

I rough grind before heat treatment on a different machine.

Using 4x or even bigger masters reduces the Mills interpolation errors by the same amount.

Reply to
Wayne Weedon

Well congrats on that but somehow I doubt I will be that lucky :-) I can't afford a new one that's for sure...

Actually, I don't think backlash will be a problem because the cutting forces will always be in the same direction, all that's required is a spring or something to hold the table against one side of the thread. Ballscrews would be an alternative but pricey... Interpolation should be easy enough - modern stappers have up to 256 microsteps per step and

200 steps per revolution.

I'd be interested to see some pix if there are any available ?

Be possible to do this with 4:1 gearing though, and easier than making masters ?

Thanks for the response, I'm still trying to find out the table travel for the Stent, if anyone has dropped in and happens to know it ?

Thanks,

Reply to
Boo

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