Advice on cutting and tumbling small shaft key

[Pysiek]

As of now we are cutting 1/8" x 1/8" x 1/2" long shaft keys from tool steel stock on our small band saw. Then we sand all edges on belt sander by hand and it takes crazy amount of time to do it. I have purchased a benchtop metal cut off saw and vibratory tumbler. For media I bought ceramic angle cut rocks 1/4" size. Right now when I cut the key stock on the cut off saw it leaves a significant burr that has to be sand down by hand then I can place the parts in the tumbler. Is there a way cut the stock so the blade won't leave the burr on that one side? (it's the bottom edge of material). Also what will be the best additive to the rocks instead of water and soap?

 

[Overland]

Key from tool steel stock ?
Normal key stock is quite soft to prevent damage to shaft and hubs.

 

[Pysiek]

Key from tool steel stock ?
Normal key stock is quite soft to prevent damage to shaft and hubs.

Don't ask me why. But this is what the engineers want. It's crazy to me too but I can't argue with engineers

 

[EmGo]

Might be easier to get less burr with a chop saw. Cold saw for sure but that costs money.

 

[FredC]

I did not see whether the tool steel is hardened or not. Hard tool steel would require an abrasive cutoff or wire EDM. if it is annealed tool steel a thin carbide cutoff saw would be appropriate.
The 3/4 to full hard 304 being cut in this video is done with a .014 inch thick carbide saw.

On this tubing we deburred the hole lightly with small 60 degree bits because the tumbling stones would not reach them. Tumbling does a fine job on the OD. We have an out building where we tumble these and use kerosine instead of water based tumbling compounds. Kerosene cuts many times faster than water based compounds. We reuse the kerosene by letting it settle and pouring off the top,

 

[L Vanice]

You will get minimal burr on 1/8" square annealed O1 steel by using a thin fine tooth solid carbide saw blade. Tumbling should eliminate a tiny burr along with rounding the edges.

It is up you and your managers to decide what your equipment and budget can do to get the results wanted at acceptable cost. Making a fixture for an existing machine might cost less than buying a new machine, as in that previous video.

Larry

 

[Pysiek]

You will get minimal burr on 1/8" square annealed O1 steel by using a thin fine tooth solid carbide saw blade. Tumbling should eliminate a tiny burr along with rounding the edges.

It is up you and your managers to decide what your equipment and budget can do to get the results wanted at acceptable cost. Making a fixture for an existing machine might cost less than buying a new machine, as in that previous video.

Larry

That's what we cut it from. 01 precision ground tool steel. I did not expect solid carbide blade to cut thru it. I will take a look if I can find any that will fit our chop saw

 

[L Vanice]

That's what we cut it from. 01 precision ground tool steel. I did not expect solid carbide blade to cut thru it. I will take a look if I can find any that will fit our chop saw

How big is your chop saw blade? I would not consider using one in the 12 or 14 inch or larger diameter range to cut 1/8" stock.

For keeping the cost of the thin fine tooth solid carbide blade down to a reasonable level, I would look at a diameter of 2 to 4 inches. Such blades can be run in a milling machine or lathe and a fixture with integral lever feed adapted to the machine. There are some miniature chop saws out there, but they may be cheap Chinese things that would not be suitable for an expensive and fragile blade and long life. There are some very high quality and expensive small chop saws that use diamond blades with oil coolant. They are meant for met labs and are very slow to use, so obviously not suited to your job.

Larry

 

[Nmbmxer]

I'd try making a zero clearance fence/insert, if the burr can't fold down it will get cut off. Can be as simple as a shim under the keystock. Also make sure the cutoff part is secured, the very bottom will get cut thru first due to wear on the blade, if the good part is the offcut then it won't get the burr cut off. If it is clamped in place your more likely to have minimal burr.

 

[FredC]

That's what we cut it from. 01 precision ground tool steel. I did not expect solid carbide blade to cut thru it. I will take a look if I can find any that will fit our chop saw

What Larry said on the chop saw. I just looked at the blade we are using. it is 2 inch OD with 190 teeth .012 thick. They are fragile. One could do these with the blade in a precision arbor on a lathe and holding the part in a small vice on the cross slide. A Bridgeport mill with a right angle spindle adaptor could work.
I am sure Larry recognizes the mill in our set up as a Hardinge universal mill with the x feed screw replaced with a cable drive. Smooth feed is necessary to not break the blade in our case.
This could be done on a small horizontal mill or even a turret lathe with a lever cross feed. Lots of ways to skin this cat with low cost surplus machines. Again, I would not try it with any sort of chop saw.

Right now, I am almost caught up if you wanted to send us a couple feet of your material, we could do a trial run, and see if we are barking up the right tree.

 

[Strostkovy]

I've seen similar parts that were very clearly cut and chamfered by a dual spindle lathe.

 

[EmGo]

I've seen similar parts that were very clearly cut and chamfered by a dual spindle lathe.

That's not a bad idea either, little Hardinge type turret lathe (the hand one with the lever turret, fast and light) with a 5C square collet and a skinny partoff tool.

 

[Pysiek]

I don't think my boss will like to change it to get it cut on lathe since all our machines are VERY busy making parts that we need. He rather place someone on that band saw for two days and then another day on belt sander to finish 200 pieces. Our chop saw is 6". It's the cheap version from Harbor Freight. I made a steel plate and attached it to the saw table. Then cut a slot in it with the saw blade so there will be as less clearance as possible. The cutoff piece is not secured. I was thinking to add push/pull toggle clamp to the set up. Also I would like to say not all the cutoffs get the burr. So I assume probably it depends on how hard we push the blade down might cause it?
To tumble the pieces I bought 1/4" angle cut ceramic triangles. The problems is now that I tried water+soap solution and the parts get some kind of brown stains on them. I assume it's rust. Is there a solution I could use instead of water? FredC mentioned kerosene. Will it work better? I would like to avoid switching between stones and plastic triangles to remove the rust.
Let me tell you this. Buying a machine that will cost us couple thousands of dollars to cut those pieces is not an option. Boss will rather cut on saw blade and sand by hand.

 

[Pysiek]

 

[FredC]

Kerosene does cut a lot faster, think about 3 times faster. There are safety considerations, depends on how well guidelines are followed. We do it all the time, but when we use kerosene it is in an out building away from the shop and no one here smokes. Back when I was in a shop that had a centerless grinder it used a kerosene like fluid and not a water soluble. Even honing a knife is faster with a light oil and not water.

Your commercial water-soluble tumbling fluids should have rust inhibitors. Plain soap not so much.

Odd that your machines are all busy but there you have people that have nothing to do, so wasting time deburing is OK. My situation is opposite, lots of machines and no people to run them.

The offer is still open to do a few samples. The jaws in the vice are for 1/8 inch and larger. I would just have to move the stop to get 1/2 inch long.

One of the tricks to get a real clean cut off is to clamp both sides when making the cut. These jaws have a slot through them, so the stock and the piece being parted off are firmly held during the cutting.

Your saw may be running too fast to discolor your parts like that. That may dull your blade and contribute to extra burs.

 

[WizardOfBoz]

It seems to me that holding the little keys makes deburring difficult. Would gang cutting and using a sander reduce the workload? Cut the stock in half and deburr ends on a belt sander, together. Then cut two pieces in half and deburr all four cut ends on the belt sander. Easier to do than individual deburring. Repeat until you have n/2 pieces (when you need n, or when you can get n parts out of one length of stock). The length is desired length + 2 + allowance for deburring. Cut in half and then you only have to deburr half of the ends individually.
Also, is the cutting causing hardening? For reasons above, soft keys are often used. Too messy to use coolant I suppose?

 

[BT Fabrication]

chopsaws always do that.... need bandsaw etc then just a bench belt sander. literally takes seconds to clean up.

 

[EmGo]

You're in Illinois ... should have a shop with a cold saw nearby. 1/8" stock is cheap enough, just have them cut up 5.000 pieces, that should keep you for a while ?

Sometimes it's easier and cheaper to have someone else do it.

 

[DDoug]

I don't think my boss will like to change it to get it cut on lathe since all our machines are VERY busy making parts that we need. He rather place someone on that band saw for two days and then another day on belt sander to finish 200 pieces. Our chop saw is 6". It's the cheap version from Harbor Freight. I made a steel plate and attached it to the saw table. Then cut a slot in it with the saw blade so there will be as less clearance as possible. The cutoff piece is not secured. I was thinking to add push/pull toggle clamp to the set up. Also I would like to say not all the cutoffs get the burr. So I assume probably it depends on how hard we push the blade down might cause it?
To tumble the pieces I bought 1/4" angle cut ceramic triangles. The problems is now that I tried water+soap solution and the parts get some kind of brown stains on them. I assume it's rust. Is there a solution I could use instead of water? FredC mentioned kerosene. Will it work better? I would like to avoid switching between stones and plastic triangles to remove the rust.
Let me tell you this. Buying a machine that will cost us couple thousands of dollars to cut those pieces is not an option. Boss will rather cut on saw blade and sand by hand.

Send it out to a swiss shop, it will be run un-attended.
Local swiss shop does a very similar job.

 

[Mtndew]

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Cut more than 1 at a time. Stack 'em up and cut as many as you can with one sawcut.
Belt sander for deburring, just push the end face into the sander removing the heavy burr, the tumbler should be able to remove the rest.