Manual metal scoring project

Here's the mechanism. You supply the cutting wheels:

I'm about to begin a simple project for cutting thin stock into strips.

I need to machine the following:

A) Disks that will be the diameter of slitting saws but thicker and without teeth but instead have relatively sharp edges for scoring.

B) Spacers about half the size of the above mentioned disks. (I'll grind them to the necessary thickness).

C) An "Arbor", actually a one foot rod with a long flat that the above disks, separated by the spacers, will fit on.

D) A three part table that will be comprised of two ends sitting at opposite ends and on top of the bed.(There will be an "cover" to hold the stock down to the bed).

E) Racks and gears for the bed ends and rod respectively.

The goal of this contraption is to allow me to score the metal stock so I can break off the strips. (It would be like using a rolling pin).\

I'm finishing up the exact dimensions and I'd appreciate some advice on the specific metals I should use for the parts.

Thanks.

Darren Harris Staten Island, New York. ========================================================================================

If you want to make everything from scratch, ok, but I think that the cutting wheels are going to be the heart of your process so I would go shopping for pipe cutters and find one with a cutting wheel the right size for your mechanism, then buy replacement wheels. That way someone else has already optimized the material and shape for you. Scoring and breaking is going to leave you with rough edges and probably slightly bent parts, so I think you should cut all the way through if possible.

----- Regards, Carl Ijames

It is always helpful if you explain what you are trying to accomplish. Yo u say thin stock, but how about what the stock is and how thick is it. If it is 1/16 to 1/8 aluminum, I would use a table saw. If copper I might stil l use a table saw, but with some thin plywood under the stock.

And how many strips do you want or need?

I am not sure how well it would work on wide stock to many thin strips. Th e disks are going to try to make the sheet wider. Not much of a problem for 4 or 5 strips, but 20 might be a problem if the strips need to be straight .

You might consider scoring on both sides of the stock, but only half as dee p.. You might also consider having the spacing of the scoring disk twice i s wide as you want. You would then run the stock thru once, and then flip the material over and score so you have it scored to the width you want. It would take less effort than trying to do all the scoring with one pass.

Dan

It is always helpful if you explain what you are trying to accomplish. You say thin stock, but how about what the stock is and how thick is it. If it is 1/16 to 1/8 aluminum, I would use a table saw. If copper I might still use a table saw, but with some thin plywood under the stock.

And how many strips do you want or need?

I am not sure how well it would work on wide stock to many thin strips. The disks are going to try to make the sheet wider. Not much of a problem for 4 or 5 strips, but 20 might be a problem if the strips need to be straight.

You might consider scoring on both sides of the stock, but only half as deep.. You might also consider having the spacing of the scoring disk twice is wide as you want. You would then run the stock thru once, and then flip the material over and score so you have it scored to the width you want. It would take less effort than trying to do all the scoring with one pass.

Dan =============================

Are you still trying to cut phosphor bronze contact springs?

It is hard to tell, but from your description, it sounds like you want to impress score lines rather than cut them. If this is the case, then you will run afoul of what I like to call the "conservation of volume." When you impress a line into metal, the metal is displaced to the sides. Your center strip will run true but the strips on either side will be wonky as they move outward because of this displacement.

Paul K. Dickman

I've already tried other ways of doing this including looking into ideas gi ven to me on this forum, and it has now come down to me designing a little jig in order to accurately and more efficiently cut these strips. So I deci ded to start this project.

I'm not familiar with a jeweler's grade rolling mill and don't know if it i s adequate of would fit standard stock sizes.

Thanks. I'll look into cutting wheels for pipe cutters to see if I can fit these into my design. I don't know if cutting all the way through is plausi ble, but slightly bent or even rough edges is not a problem. The dimensions only have to be close. (And I can file the edges if needed).

You say thin stock, but how about what the stock is and how thick is it. I f it is 1/16 to 1/8 aluminum, I would use a table saw. If copper I might st ill use a table saw, but with some thin plywood under the stock.

The disks are going to try to make the sheet wider. Not much of a problem f or 4 or 5 strips, but 20 might be a problem if the strips need to be straig ht.

eep.. You might also consider having the spacing of the scoring disk twice is wide as you want. You would then run the stock thru once, and then fli p the material over and score so you have it scored to the width you want. It would take less effort than trying to do all the scoring with one pass .

My attempts have been in line with scoring because scoring produces the min imum amount of waste. The stock is as thick as .042" thick and made of soft metal/alloys like copper/bronze. Of course the strips have to be straight and accurate to the eye. Attempting to score on both sides would present ac curacy problems. (These strips are less than 1/8" wide). Yes, I have several projects which involve phosphor-bronze contact springs.

I may just design this to cut one at a time, but as far as accuracy they wi ll be close enough.

Anyway, I?m thinking that the table parts should be mild steel. Th ere will be a slot in the table ends that will seat the main rod. (I? ?ll use shims to adjust the table height relative to the table ends).

Darren Harris Staten Island, New York.

Be aware that any error in width will cause a cumulative error in accuracy . Strips will come out curved , sometimes in odd ways . Saw this in slitting operations on plastic laminate (formica) used for edge banding and countertop edging . A long straight guide on the infeed helps a lot .

They will not build on one another so there is no cumulative error to worry about.

I'm looking at pipe cutter discs, but I see no sizes, so I'll have to swing by the hardware/BORG stores to get a better idea. I assume I would have no problem sharpening the edges.

Darren Harris Staten Island, New York.

Some of them actually have a flat edge to keep them from binding in soft metal (copper, mostly).. Look closely, or you may be in for a lot of sharpening.

If you have a lathe and tool post grinder, a tool and cutter grinder or a surface grinder with tool grinding attachments they should be no problem. Otherwise keeping them accurately straight and round while grinding freehand could be tricky.

--jsw

I'd look at circular knives before going to the trouble of regrinding pipe cutter wheels. Knives for common converting machines are cheap, for example:

A search for "circular knives" will turn up many sources.

I used those Dusenbery knives on a high speed cutter I built for a styrene tubing extrusion line. I think the wheels I purchased were D2 instead of 52100. But that equipment was making something like 50 cuts per minute, 3 shifts.

Thanks a lot.

This seems to be exactly what I need.

I just have to design a cutting jig around them.

Darren Harris Staten Island, New York.