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Paul Pless
12-24-2015, 12:44 PM
And need, okay. . . okay. . . not need to, but. . .

Want to machine a slot about one inch deep by one inch wide by six inches long in a piece of steel. Can this be done within the common repertoire of wood working machines. Accuracy to within 1/128" would be nice. . .

Canoeyawl
12-24-2015, 12:46 PM
"Band saw milling" if your saw will run slow enough.
100 feet per minute

Norman Bernstein
12-24-2015, 12:46 PM
And need, okay. . . okay. . . not need to, but. . .

Want to machine a slot about one inch deep by one inch wide by six inches long in a piece of steel. Can this be done within the common repertoire of wood working machines. Accuracy to within 1/128" would be nice. . .


The answer: no. Not unless you want to 1) ruin some tools, and 2) damage yourself, in the process.

I'm sure you can find someone with a mill to do the job for ya.... $20 ought to do it.

slug
12-24-2015, 12:57 PM
I just had some stainless milled. A half moon slot.

Two pieces. Unpolished. 60 dollars.

Best to take it to a metal shop.

An acurate drawing or a wood mock up saves expensive layout time.

seanz
12-24-2015, 12:58 PM
Can this be done within the common repertoire of wood working machines

No. You need a lathe, mill, shaper, flatbed grinder.....but Santa already knows that.

Norman Bernstein
12-24-2015, 12:59 PM
I see a really nasty gash, and a $500 emergency room visit, in Plessner's future.

Well, I HOPE not.

Dumah
12-24-2015, 01:08 PM
Very careful application of first a cape chisel followed by a very narrow square nose chisel, plus fine application of a jewellers file and 120 emery cloth to properly fit.

Dumah

Assuming Kat can pull you from the bathroom long enough |:(

Jimmy W
12-24-2015, 01:12 PM
Abrasive blades on table saw and a lot of time.

Canoeyawl
12-24-2015, 01:12 PM
Easy to do with a good band saw. You will need a fixture to work to an (adjustable) depth stop and slide the part back and forth the one inch, in infeed increments of about .010. The "set" on the blade is what makes this work. For that cut the less teeth with the most "rake" and "set" the better. Surprisingly, it can go fairly fast.

Simpler to do than to describe, essentially you are using each tooth of the saw as a tiny (metal) shaper cutter. Cut the slot vertically and just slide the part back and forth (1 inch) across the face of the blade between a pair of stops, infeeding a little with each pass. Do not exceed the cutting face of the tooth with the depth of cut. The "set" will determine the feed rate right to left. The fixture can be made with a good drill press vise working between some stops and a fence clamped to the table perpendicular to the blade. The vise will keep the part parallel to the face of the blade. Having a couple of set screws to control the infeed is nice. You could save some time by removing the bulk of the metal with a drill press, or just by sawing the edges and cutting in at 45 degrees to remove the bulk, leaving enough to clean-up the slot on all faces with the blade. A couple of licks with a mill bastard file and you will be hard pressed to know it wasn't done in a mill.

(I used to make custom lathe tool holders this way years ago, you will be surprised at the accuracy - .010 will be easy)

seanz
12-24-2015, 01:44 PM
Oh, there's always one...
:)


That's pretty accurate, I imagined that the blade might wander a little. But what's going to make it wander, iron fibers?

David G
12-24-2015, 01:48 PM
Not fully picturing the task. Is this an open-ended slot - as some have assumed - or a mortise? And how thick is the workpiece?

But those are probably moot questions. Even if it was just a hobby project... I'd be looking for a job-shop machinist to do the work.

seanz
12-24-2015, 01:52 PM
He did say 'in' and not 'through' but some drawings would be helpful. ;)

Jim Bow
12-24-2015, 01:52 PM
A file, and several weeks.

Peerie Maa
12-24-2015, 02:01 PM
He did say 'in' and not 'through' but some drawings would be helpful. ;)
Yep quoting a depth suggests a bottom rather than a though slot. The old way would be to drill as much out as possible and then finish with a cold chisel.

seanz
12-24-2015, 02:04 PM
A file, and several weeks.

Sorta whittlin, but with steel? I like it, sounds like a manly pass-time.

paulf
12-24-2015, 02:06 PM
Could you fabricate it from welded parts? Or does it need to be a solid piece?

Bottom plate, 2 side pieces, 2 end pieces.

If it needs to be solid even filing will be tough as it sounds like it,s a pocket.

End mills will leave a rounded edge at the corners. Sounds like a job for EDM.

paulf
12-24-2015, 02:17 PM
If you had a forge you could forge weld a 1"plate with a through slot to a bottom plate.

If arc welded plug welds with grove prep d edges then ground to outside plane.

Even with a milling machine a pocket, with square corners, is a pane in the a$$.

That's what foundry is all about.

paulf
12-24-2015, 02:28 PM
A video about it.

http://www.mmsonline.com/videos/video-hard-pocket-milling

Thanks for starting a brain worm!!

Boston
12-24-2015, 02:55 PM
Yeah, no, i'm playing in the machine shop today and I don't see how you are going to get within 1/100 without a decent mill. I have some sharp vertical mills. C&C. Even then I'd take it out in lifts and shy and then take a finish pass.

I'd never attempt that on a band saw, if I understand what you are after correctly

Chris Smith porter maine
12-24-2015, 04:09 PM
Take it to a shop with a slotter take them 10 minutes.

Paul Pless
12-24-2015, 04:10 PM
Take it to a shop with a slotter take them 10 minutes.what's a slotter?

Chris Smith porter maine
12-24-2015, 04:11 PM
https://www.youtube.com/watch?v=36davgmq2Kg

Slotting Machine

SMARTINSEN
12-24-2015, 04:34 PM
What are you making?

Nicholas Scheuer
12-24-2015, 04:41 PM
Nothing beats a Bridgeport for jobs like this in the home workshop. No, I don't have one. Yet.

The Bigfella
12-24-2015, 04:43 PM
Must've bought a Harley

oznabrag
12-24-2015, 04:44 PM
What are you making?

The Burning Question of the Day, no doubt about it!

Paul Pless
12-24-2015, 04:50 PM
What are you making?


The Burning Question of the Day, no doubt about it!

its a secret

James McMullen
12-24-2015, 04:51 PM
This is the kind of job that is super easy if you have the right tool, and vastly more time-consuming without it. How much of your precious free time do you want to invest in this? I think paying for a 1/2 hour of machining from your friendly neighborhood machine shop sounds like a fantastic bargain compared to the time it will cost you to do it the hard way.

oznabrag
12-24-2015, 04:52 PM
Not anymore, it's not!

Hey Kat!

He's making you that trebuchet you always wanted!

seanz
12-24-2015, 04:59 PM
Slotting Machine

How gauche.
:D


https://www.youtube.com/watch?v=UZ9BSnZsznc

paulf
12-24-2015, 05:00 PM
I've used a slotter before, if I'm not mistaken blind holes aren't their specialty.

I've used shapers to, they won't do blind holes ether.

seanz
12-24-2015, 05:06 PM
Paul (Pless), is this a slot (all the way across) or a pocket/recess?


Inquiring minds wish to know.
:)

Paul Pless
12-24-2015, 05:08 PM
Paul (Pless), is this a slot (all the way across) or a pocket/recess?


Inquiring minds wish to know.
:)

A slot all the way across open on each end

seanz
12-24-2015, 05:10 PM
That opens up the options a lot. Cheers. :)

paulf
12-24-2015, 05:11 PM
This is the kind of job that is super easy if you have the right tool, and vastly more time-consuming without it. How much of your precious free time do you want to invest in this? I think paying for a 1/2 hour of machining from your friendly neighborhood machine shop sounds like a fantastic bargain compared to the time it will cost you to do it the hard way.

Very true! However I'm thinking this is a job for EDM and set up will kill ya. If he was to make 1000 parts, it might get the cost down.

Paul, what are the structural requirements of this part, how big, can it be fabricated and not from a single blank?

Paul Pless
12-24-2015, 05:13 PM
i would prefer it be made of a single piece

paulf
12-24-2015, 05:14 PM
A slot all the way across open on each end

Much easier!! Milling machine and files or band saw.

Hell drill press and saw.

Paul Pless
12-24-2015, 05:20 PM
I have a decent drill press and an extra old table saw which I don't use for anything.

Jake's method sounds good, but don't want to get a bunch of metal filings in my bandsaw.

McMullen has probably offered the beat suggestion, but that's not in the true diy spirit.

Canoeyawl
12-24-2015, 05:39 PM
Let me try to explain this another way... :D

Use some Dykem and carefully layout the "slot" on all sides.

With the band saw set at 100 FPM using a 4 pitch hooked tooth blade, cut a slot not quite one inch deep. It is of no consequence how "tall" the part is.

Now, move the part over about 1/8" and cut another slot almost one inch deep (a stop is helpful if you want to maintain accuracy)
Repeat until you reach the desired width. You will now have a part that, from the top, resembles a comb.

After all the "kerfs" are cut get the excess stock out of there. How you do this is up to you, I would just saw in there at an angle and cut off the "teeth" of the "comb"

Now reset your depth stop and feed the work towards the blade while sliding the part from side to side just kissing the teeth to nick off what is left of the "comb" to finish the bottom of the slot. This may take a couple of settings of the depth stop. This is "milling" as opposed to "sawing"

The trickiest part of this entire operation is maintaining parallel depth to the blade. Make your depth stop tall enough to do this when the part is bottomed out top and bottom on the stop.

(For those of you that have run a shaper or slotter, imagine each saw tooth is a tiny shaper bit removing a small chip and that it does not back up out of the work)

edit to add; Merry Christmas All!
(Paul, you could send me the part, it sounds like about an hours work in the mill, and I am not closed for the holiday!)

Paul Pless
12-24-2015, 05:55 PM
Okay Jake, that makes more sense. I've seen the comb method done with smaller pieces of metal and then the teeth are broken off with a hammer and chisel.

Thank you for the kind offer to machine it for me, but this is something I'm just playing with for now.

Boston
12-24-2015, 06:05 PM
Um, yeah, no, you need a overhead or vertical mill with an end mill, if your looking for a 1" groove I'd use a 5/8 bit and take it in pieces. Switch to something more robust for the finishing pass. That "slotting machine" pictured is to small for the kind of tolerances you are after.

just take it to a machine shop, they'll have it done in about an hour assuming you bring them the stock and if you want it all surfaced or not.

This is the tool you need for that cut

https://upload.wikimedia.org/wikipedia/commons/2/28/Sharp_3_Axis_Vertical_Mill_Full_View.jpg

paulf
12-24-2015, 06:29 PM
Remind me not to get sucked into one of your"blind men describe an elephant" threads!!

They had no idea what an elephant is. They decided, "Even though we would not be able to see it, let us go and feel it anyway." All of them went where the elephant was. Everyone of them touched the elephant.
http://www.jainworld.com/literature/story25i1.gif







"Hey, the elephant is a pillar," said the first man who touched his leg.
"Oh, no! it is like a rope," said the second man who touched the tail.
"Oh, no! it is like a thick branch of a tree," said the third man who touched the trunkof the elephant.
"It is like a big hand fan" said the fourth man who touched the ear of the elephant.
"It is like a huge wall," said the fifth man who touched the belly of the elephant.
"It is like a solid pipe," Said the sixth man who touched the tusk of the elephant.
They began to argue about the elephant and everyone of them insisted that he was right. It looked like they were getting agitated. A wise man was passing by and he saw this. He stopped and asked them, "What is the matter?" They said, "We cannot agree to what the elephant is like." Each one of them told what he thought the elephant was like. The wise man calmly explained to them, "All of you are right. The reason every one of you is telling it differently because each one of you touched the different part of the elephant. So, actually the elephant has all those features what you all said."
"Oh!" everyone said. There was no more fight. They felt happy that they were all right.

Paul Pless
12-24-2015, 06:30 PM
I'm sorry Paul that I did a poor job describing what I was after at first. It was unintentional. . .

paulf
12-24-2015, 06:33 PM
I'm sorry Paul that I did a poor job describing what I was after at first. It was unintentional. . .

No Problem, I should have put a smiley, I actually love sorting out stuff like this!

You and Kat have a great Holiday!!

seanz
12-24-2015, 06:44 PM
It was unintentional. . .

Yeah, right... .

:)

The Bigfella
12-24-2015, 06:55 PM
So, is this groove called a trollph?

paulf
12-24-2015, 06:59 PM
So, is this groove called a trollph?


Oh man!!! I got trollph on my shoe!!!

Bigfella, you got a towel?

The Bigfella
12-24-2015, 07:00 PM
:D..

David G
12-24-2015, 07:17 PM
I'm sorry Paul that I did a poor job describing what I was after at first. It was unintentional. . .


Yeah, right... .

:)

Unintentional... right. He could have answered my #11, if he wanted it clear. He just wanted to see how far people could leap toward conclusions based in insufficient information. And... in grand Bilge Tradition... we did not disappoint him.

willmarsh3
12-24-2015, 09:02 PM
I'm thinking Dremel tool and (a lot of) thin grinding disks to cut 1/2 inch deep on both sides. Drill the corners out with a drill press and hacksaw. Then finish up with a file and check measurements frequently.

Could you cast this piece?

paulf
12-24-2015, 09:15 PM
Unintentional... right. He could have answered my #11, if he wanted it clear. He just wanted to see how far people could leap toward conclusions based in insufficient information. And... in grand Bilge Tradition... we did not disappoint him.

Yes master, I understand!!

The student said to the master:

You teach me to fight, yet you speak of peace? How do you reconcile the two??

The great master said:

It is better to be a warrior in a garden, than a gardener in a war, my student.

Paul Pless
12-24-2015, 09:34 PM
Unintentional... right. He could have answered my #11, if he wanted it clear. He just wanted to see how far people could leap toward conclusions based in insufficient information. And... in grand Bilge Tradition... we did not disappoint him.

But shouldn't this have been posted up on Tools/Materials/Techniques/Products?

Paul Pless
12-24-2015, 09:36 PM
Could you cast this piece?
Alas, just as I have no mill and no lathe, I also have no small steel foundry equipment either. . .

SMARTINSEN
12-24-2015, 09:58 PM
I'm thinking Dremel tool and (a lot of) thin grinding disks to cut 1/2 inch deep on both sides.




$15.00 for a cheap die grinder from horror freight set up on some kind of sled to guide it. Drill out most od the waste ahead of time and you could likely come up with something minimally acceptable. 1/128 is really quite a sloppy tolerance in the realm of machining steel.

Boston
12-24-2015, 10:25 PM
Uh, no, 1/128 is a whole lot like 1/100 which is within a thou. Your gong to need a reasonably descent tool.

I'm unclear as to the debate. No way a grinder is going to cut it. So to speak. You might as well just save yourself the headaches and bring it to a machine shop.

paulf
12-24-2015, 10:45 PM
Alas, just as I have no mill and no lathe, I also have no small steel foundry equipment either. . .

Master.... master!.... is he not a wimp if he has no tooling??

Canoeyawl
12-24-2015, 10:56 PM
Actually this little horizontal mill would be just the thing Paul!


http://www.wotol.com/images/thumbs/800x800/858722_1ae0e1e2ec5d672ef7bbfff335072d9e.jpg

(I have a small one, a bench model, I want to get rid of... Too heavy for UPS though ;))

paulf
12-24-2015, 11:00 PM
Actually this little horizontal mill would be just the thing Paul!


http://www.wotol.com/images/thumbs/800x800/858722_1ae0e1e2ec5d672ef7bbfff335072d9e.jpg

(I have a small one, a bench model, I want to get rid of... Too heavy for UPS though ;))

If this is a Cincinnati tool you are in the master club. I have a wimpy combo mill.

SMARTINSEN
12-24-2015, 11:09 PM
Uh, no, 1/128 is a whole lot like 1/100 which is within a thou.

Uh, no, 1/128" is a lot closer to 10 thou than it is to 1.

I would agree, however, that the machine shop route is the way to go.

Canoeyawl
12-24-2015, 11:35 PM
The one I want to get rid of is not a Cincinnati. (No name, but USA made, it may be the worlds smallest horizontal mill. With a table about 18" long and a single T-slot, its primary use has been cutting keyways and flats and it is really good at that. I had a nice little Shaper in the same class, maybe a 7" stroke, that went to a local gunsmith who wanted to make a rolling block action)

I have the Bridgeport overarm attachment for the occasional horizontal milling. Having stood in front of a big horizontal mill for weeks at a time, they have sort of lost their charm... (Not to mention the Cincinnati needs a crane just to get the tooling up on the table. The dividing head must weigh 300 lbs!)

Boston
12-25-2015, 04:15 AM
Uh, no, 1/128" is a lot closer to 10 thou than it is to 1.

I would agree, however, that the machine shop route is the way to go.

oops, I keep thinking that everything has a decimal in front of it.

PhaseLockedLoop
12-25-2015, 11:20 AM
There's a place in Ann Arbor near the airport called MakerSpace that has lots of tools, both woodworking and metalworking, and if you can show you're competent, you can use them. If not, they'll help you or train you. It's one of the Makerspaces inspired (I think) be Make Magazine. They've got 4 x 8' laser cutters for plywood and such. When I was there some time back, they had some sort of Bridgeport too.

David G
12-25-2015, 11:50 AM
But shouldn't this have been posted up on Tools/Materials/Techniques/Products?

I dunno... let me check with Scot. Oh, wait, he seems to have no clue either <G>

PhaseLockedLoop
12-25-2015, 03:38 PM
They've got a Bridgeport 2J vertical miller, a Clausing Colchester Model 800 5hp, a 4X8 Shopbot 3hp, and much else.