Sea Jay 500 Throatless Nibbler

[awemawson]

Having played around using the Bridgeport Slotting head as a nibbler, I had 'sort of' resolved to mount one of my hand held nibblers 'up side down' in a cabinet to hopefully make it more controllable. Most of my sheet work is 1.2 mm galvanised, but the job that had triggered this was actually 2 mm aluminium.

Casting around for something to mount it, I came across a rather rusty 'Sea Jay 500 Throatless Nibbler' on ebay. I thought that at least it would be a basis to build one round. Only specified up to 1.5 mm steel, but hey, we're mad modders aren't we. 

The price wasn't actually too bad at £210 but it looked a wreck and the seller wouldn't shift his price. Casting around for details of the unit I came across another one in a dealers at a much higher price (£360) but in a far more sanitary condition, so I told him if he'd match the price of the one on ebay I'd buy it. He did, and it arrived on a pallet yesterday 

[awemawson]

So straight to it, put power on and try it  Seems to work rather well 

The trouble with hand held nibblers is not only are they rather uncontrollable, they put loads of nasty sharp crescents of swarf all over the floor 

Not this one - it tidies up and put them safely into a drawer 

[awemawson]

Now nothing is perfect, and when you buy machine tools unseen you must expect to have to sort 'issues'. This is a very simple machine, but I did notice that the table was distorted, such that if you put a guide bar across it, the work would slip under it !!!

So time to start pulling it apart to flatten the table. Table  is 3 mm steel plate with C section bars welded to it front to back - the weakness being the slot cut in the table that takes a sliding pivot when cutting circles. It is bolted on to four substantial pillars of a rather complicated design

[drmico60]

Having played around using the Bridgeport Slotting head as a nibbler, I had 'sort of' resolved to mount one of my hand held nibblers 'up side down' in a cabinet to hopefully make it more controllable. Most of my sheet work is 1.2 mm galvanised, but the job that had triggered this was actually 2 mm aluminium.

I have mounted a hand held nibbler upside down in a table. This makes it much easier to cut straight lines and do more precision work. My portable drill mounted nibbler is probably not man enough for thick sheet but I find it very useful. More details are here:
http://mikesworkshop.weebly.com/a-nibbler-table.html
Mike

[awemawson]

So having removed the table and put it on the steel welding bench, expecting to have to apply violence, strangely the distortion had largely gone 

I presume that there are stresses applied by the mounting that are pulling it out of shape

[awemawson]

So I popped the table back on, and played about with the mounting pillars, but try as I might every adjustment results in the bend coming back - I'm coming to the conclusion that it's not so much the height of the pillars relative to each other, but perhaps one or more is not quite square so distorting the plate.

As a temporary fix I turned up a spacer ring to sit on top of the gear box and exactly fit the space to the underside of the table, so that the table cannot be forced low at that point, which is the most critical. It works but I need to skim a few thou off it as it's slightly generous.

[awemawson]

While I had the table off it would be rude not to dismantle further and see what's inside 

Simple - a one horsepower motor belt driven to a reciprocating gear box with mounting on top to hold the punch and die. Actually very nicely made solid engineering

[awemawson]

It would be perfectly feasible to make an alternative punch and die that would accommodate 2 mm aluminium. I have a 2.0 and a 3.2 mm Bosch nibbler, and I suspect that I'd base my new set up on the bigger Bosch one so that punches would be cheaply available. I have the facilities to grind them but it means custom dressing the wheel, and that gets expensive in wheels when they are 10" on my J&S cylindrical grinder !

It'll get used 'as is'' for the moment, but I will spend a bit more time trying to sort that distorted table, as what I've done as a work around is a bit of a bodge.

[dawesy]

Nice work Andrew.
Looks much safer than the big beasty nibbler

[awemawson]

Nice isn't it

Looking again at the punch design I realise that the reduced diameter that forms the step that does the cutting can perfectly easily be turned on the lathe before hardening and grinding of the diameter that slides in the die. No need for special forms dressed into the wheel

Making the replacement die might be a bit of a challenge, but that's what life's all about.

[Meldonmech]

 
   Handy bit of kit you bought there Andrew, pity about the table distorting, but I'm sure you will eventually sort it.

                                                               Cheers David