Author Topic: A better PCB guillotine  (Read 14394 times)

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Offline akisTopic starter

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A better PCB guillotine
« on: June 15, 2015, 10:30:28 am »
Has anyone in the UK got metal working equipment?

After I paid an arm and a leg to buy a PCB guillotine,  (http://www.megauk.com/shears.php model DM9001), it is not actually all that good and it is very simple to make, if one had the metal working tools, actually it would be much easy to make one that is better in a number of ways.

It seems Mega UK are the only manufacturers of PCB guillotines, and they charge ridiculous amounts for what is a few pieces of metal, badly put together to form a PCB guillotine.

If you live in the UK and have access to metal working machines and tools please let me know.
 

Offline sleemanj

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Re: A better PCB guillotine
« Reply #1 on: June 15, 2015, 11:39:59 am »
For doing a handful of boards,a couple of rulers, a chunk of wood, a few screws, and a hook knife (aka laminate cutting knife)

Slide the board in to the stop which you've set, pull the knife a couple times to score, flip board, score other side, snap.


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Offline KJDS

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Re: A better PCB guillotine
« Reply #2 on: June 15, 2015, 12:30:38 pm »
I used to score them either side with a Stanley knife and then slam them in the desk drawer to get an even break.


Offline KJDS

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Re: A better PCB guillotine
« Reply #3 on: June 15, 2015, 02:13:22 pm »
I'm a little annoyed with myself for failing to mention an axe. If you want more precision, rest the axe on the cut line and hit it with a hammer. :)

Offline PaulAm

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Re: A better PCB guillotine
« Reply #4 on: June 15, 2015, 02:24:35 pm »
I use a metal shear.  I've also used an old guillotine type paper cutter with good results.
 

Offline djQUAN

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Re: A better PCB guillotine
« Reply #5 on: June 15, 2015, 02:46:33 pm »
I made my own micro table saw for cutting PCBs using a dremel and a diamond cutting disc.

http://www.quan-diy.com/projects/dremel/tablesaw.htm

I ordered 2" diameter carbide tipped blades from Proxxon to make a bigger version than my previous one.... still waiting for the blades :)
 

Offline Mark

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Re: A better PCB guillotine
« Reply #6 on: June 15, 2015, 04:06:52 pm »
I have the smaller of the two Mega guillotines, and many times I wish I'd bought the larger one!  I had to buy a proxxon mini table saw last week to cut some larger boards.  The proxxon cuts well, but there is a slight allignment issue between the sliding guide and the blade which causes friction between the blade and the PCB on longer cuts, I will probably end up adjusting the sliding bar guide to match the blade. 

For more intricate work including cut-outs etc I have a Proxxon DS 230/E Fretsaw.  It's fine for short cuts of a few inches but the blades get blunt very quickly and it's hard to keep a straight line on long cuts, hence the Proxxon KS 230 Saw purchase. 
 

Online Fungus

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Re: A better PCB guillotine
« Reply #7 on: June 15, 2015, 04:40:40 pm »
Scoring is definitely the way to go. The other option is to get a mini table saw.
Saws produce nasty fibreglass dust.

Power saws produce nasty fibreglass dust and distribute it around the room.

 

Offline atferrari

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Re: A better PCB guillotine
« Reply #8 on: June 15, 2015, 04:59:52 pm »
For doing a handful of boards,a couple of rulers, a chunk of wood, a few screws, and a hook knife (aka laminate cutting knife)

Slide the board in to the stop which you've set, pull the knife a couple times to score, flip board, score other side, snap.



There is a video by W2EAW where he shows exactly that method amongst other alternatives.
Agustín Tomás
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Offline edavid

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Re: A better PCB guillotine
« Reply #9 on: June 15, 2015, 05:02:20 pm »
Scoring is definitely the way to go. The other option is to get a mini table saw.
Saws produce nasty fibreglass dust.

Power saws produce nasty fibreglass dust and distribute it around the room.

A wet cut tile saw helps with that.
 

Offline akisTopic starter

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Re: A better PCB guillotine
« Reply #10 on: June 15, 2015, 06:05:21 pm »
Thanks for all the suggestions.

For what it's worth, I have used a tile saw, it is like a table saw but has a special saw blade without teeth, it cuts nicely and effortlessly, like hot knife through butter, and it has a tub of water underneath where the blade dips into and traps almost all the powder.

However, after having used it for many years, I can say it does not compare to the guillotine at all! The guillotine does not require water and you do not get water splashing everywhere and wet boards when trying to do a cut. The cuts are cleaner with the guillotine, there is less frayed material and copper strands sticking out after a cut. The guillotine cuts in one clean cut, the tile saw requires more effort and guidance.

The tile saw is the best there is in speed and no dust - after the guillotine.

In my opinion once you have used a proper guillotine you do not really want to go back.

My idea is trying to improve on the guillotine by making a better, stronger, longer, more powerful guillotine than the one made and sold exclusively by Mega.

The blades are straight and very easy to make. The base is a flat piece of metal again nothing extra special here. Unlike paper guillotines it is a bypass blade and it is not sharp, so you do not need special tools to sharpen razoe edge blades.

It is quite straightforward to do for someone that has metal working tools.
 

Online Fungus

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Re: A better PCB guillotine
« Reply #11 on: June 15, 2015, 06:18:52 pm »
It is quite straightforward to do for someone that has metal working tools.
A motorized one would be cool. Motorized, with a pedal.

(Ka-chop!)
 

Offline German_EE

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Re: A better PCB guillotine
« Reply #12 on: June 15, 2015, 07:43:48 pm »
Head along to your local printers and ask them to telephone you just before they replace the blade on their paper guillotine. It's a blade about 5cm wide (or bigger) and driven by hydraulics so it will cut through a 75mm stack of paper like a hot knife through butter. Cutting PCB material will however take the edge off the blade which is why you use their machine just before a blade swap.

Note: It's a very dangerous piece of kit which is why you tell the operator what you want and they cut it for you.
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Offline KJDS

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Re: A better PCB guillotine
« Reply #13 on: June 15, 2015, 07:51:06 pm »

Offline G0HZU

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Re: A better PCB guillotine
« Reply #14 on: June 15, 2015, 11:28:29 pm »
Quote
It seems Mega UK are the only manufacturers of PCB guillotines, and they charge ridiculous amounts for what is a few pieces of metal, badly put together to form a PCB guillotine.

If you live in the UK and have access to metal working machines and tools please let me know.

I'm in the UK and at work we upgraded to a new PCB guillotine a few years ago after having used the previous one for about 20yrs. The old one still worked but it became notably noisier when cutting FR4 boards and needed a decent tug on the handle to get a clean cut.

I don't know what make the new one is (but I can try and find out) but it really is a delight to use. I'm not exaggerating when I say it is effortless when cutting some of our more exotic Rogers PCB laminates. It's almost like cutting cheese slices! I haven't tried it with FR4 but I would expect it to be fairly effortless.

However, I don't think it was cheap to buy and it is visibly better engineered than the cheapo lightweight MEGA units.

Note:
I can't be certain but I think it could be this one here:
http://uk.farnell.com/fortex/gu045701/shear-guillotine-pcb/dp/483930

Ours is quite big and is very heavy. I thought it was much more expensive than the £650 Farnell price so ours might be a heavy duty version. But it looks very similar!
« Last Edit: June 15, 2015, 11:38:51 pm by G0HZU »
 

Offline jwm_

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Re: A better PCB guillotine
« Reply #15 on: June 16, 2015, 01:25:09 am »
I have actually just used these in a pinch when working with thin boards.

http://www.amazon.com/gp/product/B000FK3WOG

I am not sure I'd recommend it though.

Offline orion242

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Re: A better PCB guillotine
« Reply #16 on: June 16, 2015, 02:07:09 am »
I got a 8" plate shear.  Cuts right thru with minimal effort, no dust, water, or noise.

https://www.grizzly.com/outlet/Plate-Shear-8-/T23100

looks like the 8" is discontinued.  Here is the 6"

https://www.grizzly.com/products/Plate-Shear-6-/H0732

« Last Edit: June 16, 2015, 02:10:05 am by orion242 »
 

Offline VK5RC

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Re: A better PCB guillotine
« Reply #17 on: June 16, 2015, 02:27:17 am »
I have used the combination machine listed in the last link above,  good for metal work as well,  folding etc
EDit typo
« Last Edit: June 16, 2015, 11:14:59 am by VK5RC »
Whoah! Watch where that landed we might need it later.
 

Offline SeanB

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Re: A better PCB guillotine
« Reply #18 on: June 16, 2015, 05:25:16 am »
Head along to your local printers and ask them to telephone you just before they replace the blade on their paper guillotine. It's a blade about 5cm wide (or bigger) and driven by hydraulics so it will cut through a 75mm stack of paper like a hot knife through butter. Cutting PCB material will however take the edge off the blade which is why you use their machine just before a blade swap.

Note: It's a very dangerous piece of kit which is why you tell the operator what you want and they cut it for you.

That is why they always have a 2 hand safety circuit, where you place the work, then press an arm switch then have to press 2 switches placed physically far apart on the machine within 0.2 seconds of each other, before it will operate. Bigger ones have an added optical detector system across the front as well, so that you cannot put your hand there while the blade is coming down.

I will add that those blades will typically be resharpened quite a few times in use, as paper and board does blunt them quite fast. Still have a few in my office, which got to the lower sharpening limit. Still sharp enough to shave with, but too blunt for the neat cut you want. You will have around 1cm of blade that can be taken off before you reach the lower wear limit, so you can have quite a few nicks removed from things like staples and such before replacing the expensive steel bar. They make lousy knives though, way too thick in the body, and too brittle for any other use without a good backing.

The blade stop is typically a square nylon block, so that you can get 8 stop surfaces out of it before you throw it away, as the blade typically is set to stop 0.1mm into the nylon. Around 200 cycles and there is a chewed edge, so printers will always use a lower cardboard backing to get that last few pages as neat as the top.
 

Offline akisTopic starter

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Re: A better PCB guillotine
« Reply #19 on: June 20, 2015, 07:07:49 pm »
I bought on ebay an A3 paper guillotine able to cut trough like an inch of paper. It has a long blade that lands on a piece of sacrificial plastic. The blade is extremely sharp.

I then used it, foolishly to cut a few PCBs. That almost destroyed the blade. I removed the blade and gave it to a professional sharpener. However on re-assembling the guillotine, it does not cut as well as it used to, the blade does not land perfectly horizontally as it had used to. I cannot see any obvious adjustments to tweak the angle of the cut...
 


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