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Clamping method

Clamping method

Postby mikeusnret » Tue Apr 13, 2010 3:39 pm

One method of clamping I had seen in the past was that a person had used thier 1/4" bit and drilled a grid of holes into the spoil board at 2" spacing. The next row was 2" up but offset by 1" using this simple code:

XO Y2 Y4 Y6 etc
X2 Y1 Y3 Y5 etc
X4 Y2 Y4 Y6 and so on for the length of thier table.

Then all they did was use 1/4" shelf brackets that you find in book cases etc to hold thier stock in place. on the 1 side and end, if using square stock, you could butt that up against the brackets then on the other side and end, you could slide wedges inplace between the stock and pins to snug things up.

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Clamping method

Postby Awesomeness » Wed Apr 14, 2010 5:27 am

If you don’t have time to do it right, when will you have time to do it over?
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Clamping method

Postby homebear » Fri Apr 16, 2010 3:31 pm

Nice find Guido! Have you used these yet? I'm looking at the solidworks model right now and considering buying four or so. They seem really perfect, I just hope that plunger travel is sufficient. Also, .938 is some weird spacing for those screw holes.

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Clamping method

Postby mikecnc » Sat Apr 17, 2010 2:52 am

After looking at the options I installed 123 t-nuts under my blueChick table. I drilled seven rows and spaced the holes 2" apart and offset every second row by 1". This works really well for the blueChick and I'm using the low-profile cabinet screws to hold down stock. I've cut a few parts so far and there is no way they will move in any direction.

One of the big advantages for me with this method is that I can place holes on the centre line of a part and machine, then flip the part 180 deg and do the other side. At least that's what I'm hoping for in theory, I haven't tried it yet.

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Re: Clamping method

Postby Awesomeness » Tue Apr 27, 2010 6:04 pm

homebear wrote:Nice find Guido! Have you used these yet? I'm looking at the solidworks model right now and considering buying four or so. They seem really perfect, I just hope that plunger travel is sufficient. Also, .938 is some weird spacing for those screw holes.


I have some on order. They should be here in the next couple of days.
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Re: Clamping method

Postby voltsandbolts » Tue Apr 27, 2010 11:21 pm

In the past I have just drilled a grid of clearance holes for 1/4-20 in the MDF base, flipped the sheet over and countersunk the hols just big enough to hold a 1/4-20 nut, pressed one in each hole and added a dab of epoxy to keep it in place. Cheap and effective. And it only cosst about $5 :D
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Re: Clamping method

Postby PHoodDaniel » Tue Apr 27, 2010 11:38 pm

That is also a great idea. Nuts are very cheap and there will always be a pulling force towards the table. I wonder if there would be a better (non-brittle) glue that would work better.
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Re: Clamping method

Postby Awesomeness » Wed Apr 28, 2010 12:08 am

I haven't had much problem with epoxy being brittle. Even at sub-zero temperatures it has served me well.

But I'm biased... I LOVE epoxy, and use it whenever possible. I probably go through a gallon of the stuff a year, haha.
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Re: Clamping method

Postby philipw » Wed Apr 28, 2010 1:01 am

I'm surprised you haven't had a problem with epoxy being brittle as it's a known drawback. I've recently started using Gorilla Epoxy because it overcomes this problem. They call it "impact tough" and it definitely is.
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Re: Clamping method

Postby PHoodDaniel » Wed Apr 28, 2010 1:32 am

Well then... That's the perfect combination... gorilla epoxy and cheap nuts.

I just cam across a great clamping method that one of my customers did. Check it out here: http://sites.google.com/a/hthmaengineering.org/2nd-semester-senior-projects/home/land---cnc-router---kaory-jeremy/5-final-product-phase

The MAE students developed a table surface and t-style clamping simply by overlapping boards. Simple and quick.
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