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Posted 04 May 2007 - 11:56 AM
There have been quite a few posts on hand cutting lips, maybe this is of some help!!
Here’s a device for cutting round “Lips” (20mm or about 7/8”). I have been using it for years to cut Aluminum, “Lexan”, Brass etc,- steel may be a bit too hard, although I would love to have a go at 20 gauge S/S with it. As you can see from the drawing, the lip size is determined by the hole and punch size. I scrounged a truck shock absorber shaft which happened to be this size and also would be hard enough to be able to grind the face nice and sharp. If ground/filed at a slight angle the punch will cut much easier. I am sure mild machine steel bar would do the job, so pick a lip size and go looking for a bar to suit your requirements.
The hole below the cutting slot is slightly bigger to allow the lip to pass through the punch after it is cut. The snugger the punch fit in the bore, the better the cut will be, with less finishing required. I grind a curved face on the punch and when the metal lips are punched out the shape is also imprinted on the finished lip.
The finished lip will not be a full circle, but will have a small flat on one side, I use a paper punch to nip a ¼” hole here, which gives it a bit of grip when it is inserted in the lip slot.
To punch out a lot of lips, the punch can be fitted to a press. I have used something I made out of a few bits of flat bar and square tube, but you could use something like a cork or capping press for beer/wine bottles and you can probably knock out 100-200 lips an hour. If you can’t find a press, just give the punch a sharp whack with a hammer and out they Plaster of Paris. These lips can be seen in my avatar pic and as you can see they are aluminium, some have been a bit abused; they are probably about 15-20 years old.
For me hand cutting lips is one of the most tedious, time consuming tasks in lure making, so I hope someone gets some ideas from this. I will try and get some pictures tomorrow, so you all can get a better idea of what’s going on. Pete
Posted 04 May 2007 - 07:58 PM
Here's two more pics, hope this helps someone .Pete
Posted 05 May 2007 - 12:47 AM
Just went out to the shed and took a couple of close up's of the slot etc which includes the lower half of the punch "barrell".
As I hope you can see the punch passes past the slot which is where the cut is made. When the punch is raised and the sheet is placed fully into the slot. The punch is then driven down against the sheet, which in turn is forced against the lower edge of the slot (same diameter as punch here), this force causes the sheet to sheer off (in this case a circle). You would be suprised how easy it cuts sheet Brass, Aluminum, Lexan which are all about 5mm thick (not sure in " s). As I am sure you know, this is nothing new, it's just a die punch but instead of complicated shapes for lips I have made it round as it is easy to source and no huge cost in having a die made, I have been down that road with a die I had made for hook hangers. I think she divorced me around then!!
As I think I said in the previous post, if you shape the end of the punch the lips (not Lexan) will be bent to this shape also, it's up to your imagionation I suppose.
Hope this helps, if not, keep asking. See 2 x pics Pete
Posted 05 May 2007 - 12:59 AM
Sorry Longballs, did not load again- see how it goes later, does not like the pics for some reason . Pete
Posted 05 May 2007 - 04:56 AM
I will have another go- 2 x pics and 1 drawing. Cross fingers.Pete
Posted 05 May 2007 - 05:16 PM
The ingenuity on this site amazes me. I no more build that contraption than fly to the moon!! lol. Cool idea, good for you.
Posted 16 May 2007 - 10:09 PM
That thing rocks.
I'm with Riverman. I'd either hurt myself or catch something on fire if I ever tried to fabricate something like that.
Got any pictures of the lips? Are they done after you punch them out on that device or are there a few more steps before the lips are done?
Posted 17 May 2007 - 09:56 AM
I think that the lips he cuts are SS or light ga. aluminum. I don't know how that would work with lexan without cracking it. I have been trying to get a die that you could press into lexan but have had no luck with it. I hate cutting dive bills and I'm not as accurate as I need to be. A punch tool would be perfect, expecially if it was user friendly enough to allow for different designs. Lets keep this thread working so we can figure out something. I'm in.
Posted 18 May 2007 - 12:31 AM
Hi again "Longball"-If you look at Pic 1020178, that's how they come out-except for the small hole , which is punched later with a paper punch (for ring binders), I need to do this so the brass hook hanger frame can pass through the lip (see new pics). The lips in the picture are Aluminum @.5mm (about 1/50th inch in your measurements) and as you can see from the die I have ground a few angles and a centre mark to get curve and a reference point for when gluing the lips into the lure. I have used brass as well, with same result and just yesterday cut a couple of Polycarbonate ones @ 1mm (about 1/25") , no problem, except you will not get the curves etc, just comes out a flat disc. I have been using this for about 15 years on and off, the press has only been added in the last couple of years as I needed to cut them in the hundreds and I got sick of holding everything and trying to whack the punch with a hammer, sometimes missing. You and your mate, one feeding a 6' strip of Al or Poly in and one punching can make something like 100/ hr, if you paint the lips, just sand the strip before punching them and they are ready to go.
I think this may cut "stainless steel" but would maybe need a longer lever, as you would know, staino is hard and "work hardens" as you cut it, also you need to have quality hard steel in punch and die, that's why I originally went for the truck shock absorber shaft, it's chromed and nice and hard. If you want to make just a few, don't worry about the press part, just make the punch/die part put it in a vice, use a hammer and watch your knuckles. Pete
Posted 19 May 2007 - 01:16 PM
Nice accurate work Pete. I like the last pics. If you say it will cut poly I will build one and test the tolerances. Have you only cut the disc shaped one? I need a couple different styles to punch that can't be fabricated from a round drive pin. Thanks for the info.
Posted 21 May 2007 - 01:30 AM
Longball- no I have only cut discs. If you want to square parts of it off, maybe you could cut a larger disc and square it up (or whatever) with a small gillotine or a large pair of sidecutters work well. I have all ways assumed Polycarbonate and Lexan were the same material, you said in a previous post you had problems with it cracking, have never seen that happen- maybe it's not polycarbonate (Laxan) after all. They say polycarbonate does not crack?? although recently I saw a sheet that had been hit by hail stones in a storm here and it was full of 1/2" holes, no real cracking though ! !pete