Author Topic: Regarding long term clamping, and lathe chuck fitting ..  (Read 317 times)

Offline super7

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Regarding long term clamping, and lathe chuck fitting ..
« on: May 28, 2017, 07:11:56 AM »
Hello all, hoping you more experienced chaps can just answer a couple of questions.

The first is regarding leaving stuff clamped to the bed of the mill. The pic below is typical for me , it's an infinite vice kind of thing for the size of plates I work with - typically about 8" long. I have further strengthened the arrangement with some clamp bars, just to save it slipping when under load - i.e. With a workpiece in.
The gap in the middle is a nice space to clamp in my normal milling vice in.
The question is , is it ok to leave this setup as it is for extended periods? I don't go berserk when tightening down the fixtures to the bed.




The other question was regarding ' chucks in chucks'
I currently have a myford 7, but have just acquired a GH1330.
I realise a smaller chuck can be clamped inside a larger chuck, but I think I'm correct in saying this is only safe for turning between centres.
I had an idea to keep my 100mm 3jaw SC, 4jaw SC, and 4Jaw independent chucks for two reasons. Firstly to use them on a rotary table ( I would just buy a myford thread adaptor for the table ) and secondly to use them on the new bigger Warco.
My idea was to purchase a threaded backplate as below, and mount it int a recess cut into a standard D14 camclock backplate. I would simply then mount this assembly, and screw on whichever chuck I needed at the time. My warco only came with the standard 3J chuck.
Does this sound sensible, or do you have any other suggestions? I'm not building missile guidance systems, just fly tying vices and accessories, there's a pic of the myford backplate, and the sort of thing I make below.

Apologies for the waffle!




Offline Joules

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Re: Regarding long term clamping, and lathe chuck fitting ..
« Reply #1 on: May 28, 2017, 07:47:36 AM »
Very nice fly tying vice.  Something I have been meaning to make for ages.

As for clamping to the machine as long as you have no huge bending force (pivot) it's nothing to worry about, it's what the table was designed for.   Some machines have vices and jigs clamped too them for years.  Just keep the mating surfaces clean, though pretty much the worst you could inflict would be a dimple on the table, if a hard point was trapped.

I wouldn't recommend this...

http://madmodder.net/index.php/topic,12093.0.html
Just get doing and make swarf, you can decide what its going to be later.   :thumbup:

Offline super7

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Re: Regarding long term clamping, and lathe chuck fitting ..
« Reply #2 on: May 28, 2017, 08:07:58 AM »
Joules, thanks for the reply, yes I understand the point about the pivot, whenever I clamp it's always directly to the bed, so there no chance of breakout as such.

The vice was a bit of a labour of love for a charity, but enjoyable, raised 1250, so was pleased with that. You're a fly fisherman ?

Offline PekkaNF

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Re: Regarding long term clamping, and lathe chuck fitting ..
« Reply #3 on: May 28, 2017, 08:16:42 AM »
Pretty vice you have. More pictures? I buy mine, for whatever reason.

Normally with machine tools you can bend stuff fairly easy a little amount - is shows with indicattor. BUT. to cause a permanent deformation (non permanent one) is pretty big thing, like crash or hamfisted going grazy.

Only real occurences I know for a fact, were when someone welded a jig on milling table (idiot) and then some people who were pretty big on hammer when setting up pieces to mahine. This hammering was on obivious at the begining and took some years to develop. The milling machine tables went a little banana shape. These happened something like 30-40 years ago to pretty old machines.

So milling table is one thing...chuck is one thing. Scroll chucks are bit more sensitive than miller table. About chucks I don't hard evidence....I would assumet that quality chucks can pretty much take even load (not one jaw hanging loose and others taking up all the load or disc only at the tips) and with normal hand tightened with original chuck key (no cheater pipe).

Pekka

Offline ieezitin

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Re: Regarding long term clamping, and lathe chuck fitting ..
« Reply #4 on: May 28, 2017, 08:52:56 AM »
Super,

I have fixture plates bolted to my mill that rarely get taken off as i use fixtures more than vises I have had no problems. On the vise im curious to the spring looking thingy ...... can you explain what it is ?

Thanks  Anthony.
If you cant fix it, get another hobby.

Offline super7

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Re: Regarding long term clamping, and lathe chuck fitting ..
« Reply #5 on: May 28, 2017, 09:11:53 AM »
Anthony, the spring is just a short extension spring clipped onto itself around the arm that holds the jaws.

When you tie a fly, typically the materials that need to be wrapped up the hook last, need to be tied in first. For example, lots of aquatic insects have segmented bodies. In fly tying, this segmentation effect is done by wrapping a piece of fine diameter coloured wire up the body in open spiralling turns, this will create a colour contrast to the body underneath, and give you the segments.

When you tie this wire in, you have to keep it out if the way while you tie in other materials- to do this you just pop the wire into the coils of the spring to trapit, along with any other long materials you may be using.