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View Full Version : How to hold-down for flycutting?



Swami
11-24-2004, 03:17 PM
I wish I had a better way of doing this.

I need to have around 6" of 1" barstock flycut. There isn't enough room on my table to clamp it on both ends, allow clearance so the flycutter doesn't hit the clamps, and to cut the desired 6"

So, I centered it in a vice. That was very difficult to level with the table, and since the ends were unsupported I got a nasty chatter.

Maybe just a typical c-clamp at each end of the table? Anything that would allow me more room.

I could put a couple countersunk holes through the material and bolt it right to the table, but thats more setup work than I wanted....

Any help appreciated.
Thanks,
Swami

JFettig
11-24-2004, 03:44 PM
It might take 2 vices to hold it so it doesnt chatter. How big of a vice are you using to hold the peice when you try a single vice?

If you havent aligned 2 vices, use a indicator to set them up perfectly parallel to eachother.

Jon

marx911
11-24-2004, 04:25 PM
you could clamp in your vice ...then clamp one end... cut most the cut swap ends with your clamp making sure to support from the bottom side at the same height as your vice bottom so you don't bend the part with your clamps... or use a couple matched "V" blocks to support the entire part then move your clamps to allow for cutting.... just a thought

Mark

Swami
11-24-2004, 04:55 PM
I think its a 2" vice. This is a little Sherline Mill. Its about $65 to get a "matching" vice. It wouldn't be the first problem I've had that would be remedied by a matching vice....

thanks guys.

Oh, what is a V-block?

Thanks,
Swami

DAB_Design
11-24-2004, 05:25 PM
What about toe clamps?

marx911
11-24-2004, 07:38 PM
Oh, what is a V-block?

Thanks,
Swami
here are pictures of "v-blocks" just the first one I found on a search

http://www.cartertools.com/vblock.html

Mark

vladdy
11-24-2004, 07:40 PM
I assume you don't have excess on the bar to mill or grind a recessed flat on the ends for hold down clamps, and with only a 2" vise it will chatter some with two inches basically 'unsupported'..
What _might_ help would be a support on each end, either just a piece of bar stock underneath, or better yet, a small support bolted to the main table with a slot cut into it to give some sideways support for the bar itself. With 1' bar a bit of pressure on the bar when you clamp in the center vise should help cut down the chatter..
If the vise and table are reasonably acurate you can cut one half at a time and just swap ends..
A bit of flat plate hand sanding would clean it up ok at the finish for the appearance of a 'one pass' machined surface

enjoy..

HuFlungDung
11-24-2004, 09:19 PM
Swami,
You could make a "subplate" for your table. This would simply be a larger piece of good quality plate which would have more space to drill holes around the edges for clamps. You could use some toe-clamps to hold the part down.

If you check with some of the tooling suppliers, you can purchase rectangular bars of W1 or O1 annealed tool steel, all finish ground, in various common dimensions. You could use a piece of this for your subplate, or indeed, just buy a piece to create your part from. It is not too bad to work with, using HSS tools to drill and tap it.