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A simple problem

Pmat

Plastic
Joined
Mar 16, 2014
Location
Maine USA
I have a very small scale fabrication problem. I make and sell clam hoes. Many are made from 1 inch wide by 1/8 inch thick 1080 steel. I use a plasma cutter to cut the tines, the cross cuts are a snap, but cutting perfect points quickly and easily is more challenging. I've made several different gigs but still am not satisfied. Would consider any solution to this simple but frustrating problem.

Thanks,
Paul
 

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Depends on your definition of "perfect". If it was me, I'd have those teeth laser cut, then finish the edges of the blank on a belt sander with 50, then 120 grit abrasives. Bend (looks like there's a radius). Heat treat (1080 steel, right?), temper, finish sand to your level of shiny. Shouldn't need a jig to follow the laser cut angles on the belt sander.

I've had various kinds of high carbon (1095, 52100), low alloy steel laser cut. In 1/8" material, that profile shouldn't cost more than $3.00-$4.00 per part, in quantities under 100. I just sent in a PO on some 11 and 12 gauge mild steel parts, WAY more complicated, for under $3/EA. in quantities of 20.

Not worth my time or the plasma consumables/electricity to try and compete with a laser cutter on something like that.
 
What plasma to you have? For a do-it-yourself template its hard to beat a hypertherm drag tip.
 
are you saying there are vendors that could offer the 1080 steel precut to my specs? That would be great if the cost factor wasn't prohibitive. I don't know of any suppliers like that.
 
are you saying there are vendors that could offer the 1080 steel precut to my specs? That would be great if the cost factor wasn't prohibitive. I don't know of any suppliers like that.

Yeah, as long as you can generate a .dxf file or something equivalent. I usually supply any high carbon alloys - just not something most places will have on the shelf.
 
I have a inexpensive plasma without a drag tip. The problem I've had with templates is hard to explain. They should work but often the points are uneven and require too much grinding. I've made V shaped templates and pull the torch towards me, and I've tried single sided templates for each side. It's not that they don't work, they just don't work well, and it takes more time than I think it should. Before the plasma cutter, I just used a tine as a template and cut off each side with an abrasive wheel. Too much mess, but simple. The offset is what makes the plasma template a bit of a problem to get a sharp point. I'll try a drag tip and see if I can get better results....
 
I have a very small scale fabrication problem. I make and sell clam hoes. Many are made from 1 inch wide by 1/8 inch thick 1080 steel. I use a plasma cutter to cut the tines, the cross cuts are a snap, but cutting perfect points quickly and easily is more challenging. I've made several different gigs but still am not satisfied. Would consider any solution to this simple but frustrating problem.

Thanks,
Paul

If you are cutting it with a "V" template you are likely overheating the tip of the tine. Try cutting across all the way with a 45 flip and complete the point with another 45 cut. As other suggested a simple plate shear may give you cleaner cuts.

dee
;-D
 
Have you priced getting them laser cut in some quantity? Laser is often surprisingly inexpensive as the big shops get material in quantity.
 
Do they have to be a sharp point? something like a 1/8" radius or less will solve a lot of your problems and look far better.

Cutting from strip a simple hand shear will make short work of them, when we do bits like that we normally cut the whole coil to length, then a simple jig chop off each of the 45 degrees, it goes really fast, several hundred strips a hour cut and pointed with out breaking into a sweat is easily doable.

I would not laser that part and your then going to have to heat treat them, far easier to buy heat treated coil stock and just cut them out. To the best of my knowledge no one offers flattened preheat treated sheet steels suitable for laser cutting like they do the slit coil spring steel stocks.
 
Would such a plate shear handle high carbon (1080) steel? All the ads give specs for mild steel....

I really like the idea of a shear if it would work. Just don't want to spend the money and find out it's not the answer...

I've also looked at some smallish ironworker type machines.
 
They don't have to be a sharp point and even if they start out sharp they wear down pretty quickly. I start out with 1075/1080 hr steel then cut out, weld, heat,bend, heat treat then temper. There is nothing precise about the points other than they should look symmetric to start out. You would be surprised at how much abuse these implements take. I dug clams for a living in the 1970's and 1980's. I'm retired now and have spent the last few years attempting to build a better hoe... for fun and retirement amusement and a little extra income. I have not found any suitable heat treated coil stock. Can you point me in the right direction?
 
I have that bench shear, primarily for aluminum. I made about 200 cuts one day on .100" 3003 aluminum, and my shoulder was wrecked for the next week. I'm 6'3" and it's still a long reach to grab the end of the handle. Now I have a foot strap rigged to the handle, awkward, but it saves my shoulder. You will need to make some kind of a hold down to cut the bevels on the end. Depending on the volume of parts you wish to make, you may find this shear to be almost adequate at best.
 
Thanks to everyone that offered suggestions, I think I've resolved the problem for now. Since my scale of production is so small, it seems I'm better off simply refining my plasma technique which I did today using a one sided template, to cut one side of the point, flip it over and cut the other side... made 25 tines today and they came out good and didn't take too long.
 
Mount your plasma torch to a pantograph/pattern torch.

Make a simple template of the tine end. Feed stock to a stop and reset torch after each cut.

I see this being low cost and giving a good, consistent cut for what you're doing.


You can buy what's called blue clock steel which is in the hard condition. You can form it and it's real tough stuff. I priced out making a product from it and the issue for me was it only comes in slit strips. IIRC around 36"X8" were the biggest pieces I could get without a mill run. The price was pretty cheap when buying a few tons at a time though. I was looking for 48X96 sheets for laser cutting which were not available.

Another thought-

Can you use mild steel tines that are a bit thicker then have them carburized to harder then hell? You'll have zilch for material cost and carburizing is very cheap. It turns out a lot of stuff you think is spring steel or 8620 or something fancy is just plain old crummy mild steel that is carburized.
 
Because these are hand implements, weight is a big factor. Going thicker, I suspect would add too much weight. Clam hoes are often made from garden spade forks, these are thicker but narrower. For softer mud, wide tines are needed which is where the 1 inch wide by 1/8 inch thick 1080 steel comes in. It needs to be tough but not brittle as the tines can easily snap off when fetched up on a rock. Folks around here have been making wide tine hoes since the 1980s, my goal has been to improve the idea with proper heat treatment and tempering.

I would love to see a picture or sketch of the pantograph torch holder/setup. It sounds like a great idea. Thanks, Paul
 
Clam hoe tine cutting rig

I believe I've solved my problem and had some fun in the process. Not an original idea but made a duplicator plasma rig from a drafting machine. Not counting my plasma cutter, about $100 in the project. Also doesn't include my downdraft welding barrel made from a discarded 55 gallon drum and a discarded blower from a jenn air kitchen range. FullSizeRender 3.jpgIMG_2229.jpgIMG_2230.jpgIMG_2231.jpg
 








 
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