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Author Topic: Tangential Knife blade holder.  (Read 6677 times)

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Offline Tweakie.CNC

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Tangential Knife blade holder.
« on: July 13, 2012, 02:10:16 AM »
I needed a new blade holder for a tangential knife which would enable relatively quick and easy blade change and positional setups.

With just a couple of hours to spare, whilst another CNC job was running, this was the result (the only CNC operation was milling the flat).

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.

Offline Tweakie.CNC

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Re: Tangential Knife blade holder.
« Reply #1 on: July 13, 2012, 02:11:04 AM »
And just to add to the suspense a pic of the blade holder fitted to its Sonotrode.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Tangential Knife blade holder.
« Reply #2 on: July 21, 2012, 11:01:49 AM »
Tweakie, this is for cutting the vinyl for signs and such? Of course, I'm close to getting my machine to run so I want to start more projects. I was thinking about a knife and trying to mount a x-acto knife and holder on some kind of pivot to operate like this. Yours looks very heavy duty. Is it necessary for it to be this heavy?

Offline Tweakie.CNC

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Re: Tangential Knife blade holder.
« Reply #3 on: July 21, 2012, 11:34:52 AM »
Hi Jammerm,

For vinyl cutting you will only need the small, lightweight, Roland style drag knife (similar to the one I constructed here http://www.cooperman.talktalk.net/files/11.htm) The clones are now so cheap to buy complete from China that it is hardly worth constructing your own but at the time I made mine they were only available direct from Roland and very expensive. Tangential control is really not necessary with this type of drag knife as it self-steers into the direction of movement without any problems except perhaps that sharp corners have an 0.5mm radius but when it comes to the durability of vinyl signs the sharp corners will always lift first and a small radius here is actually an advantage.

The knife blade holder shown in the earlier post is intended to be used for cutting a particular gasket material that I cannot laser cut so I have resorted to tangential control of the knife direction and ultrasound to assist with the cutting. It does not need to be finished before early next year so I am taking my time and experimenting with different designs etc.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.
Re: Tangential Knife blade holder.
« Reply #4 on: July 23, 2012, 09:16:52 AM »
I see Tweakie, yours really looks heavy duty.

I just send some money off into cyberspace. :)

Offline Tweakie.CNC

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Re: Tangential Knife blade holder.
« Reply #5 on: July 28, 2012, 06:14:37 AM »
As it’s all part of the same project I thought perhaps these pics of the bearing housing may be of interest.

Stage 1 was to centre drill the 6 holes and (1mm undersize) profile the bore on the mill.
Stage 2 was turning the OD on a lathe.
Stage 3 was manually drilling and tapping the 6 holes and finishing the bore to a bearing fit.

Tweakie.
Success consists of going from failure to failure without loss of enthusiasm.  Winston Churchill.