Thread: Slotting Head As Filer?

I have a small project where I would like to cut a 12 x 12mm square hole through a 22mm thick piece of 4E cast iron. My initial plan was to grind a 1/4" square piece of HSS into the shape of a slotting tool and use it in the pretend slotting head I made years ago for my little Hercus mill. Without the presence of coolant the HSS has turned numerous shades of purple and I have worn away a lot of my cup wheel so I have pretty much abandoned the slotting idea.

The current idea is to use a cut down file in the slotting head. I will need to make some sort of keyed backing piece for the file to avoid the possibility of bending the file with the toolpost's clamping screw. The file pictured, an English Stubbs in good nick, won't be the donor for modification. Die filers usually have their files clamped top and bottom but I'm thinking that if I used a file about 3/8" square I might have enough rigidity.

Has anyone tried something like this?

Filer (Large).jpg Filer 1 (Large).jpg

BT

Hi Bob,

Yes that idea will work fine. I would arrange a roller, under the table, use a ball race wrapped in masking tape, or a hard rubber faced one behind to support the file.

I made a similar arrangement using a drill stand and a chisel to cut some timber joints with square faces.

Last time I had to do a square hole in some steel (might have been 19mm square?) I drilled it out I think with something like 3mm holes in the corner of the square and then just under the full diameter in the centre. Doing it that way, it did not take long at all just to dress the sides with a square file.
Especially for a piece of CI, you may be doing more work on your set up than you need to.
(PS - it was the 36 handle...)

Michael

The roller makes sense John. My concern is the amount of Z I have, the ever present issue with both mills!

Hi Guys,

Whilst Michael is right, it wouldn't take a lot to do it by hand with a file, once you have removed the bulk of material ! There would be more fun setting up the slotter.

Bob, you only need about twice the material thickness of file movement.


What you really need is one of these:

14-08-2018-009.JPG

How do you keep all your machinery looking so nice and new, damned annoying that. Bet you'd like a filing machine, I know I would. I wonder if I could convert a reciprocating saw???

Probably not much help, but at least it's on topic!

https://www.youtube.com/watch?v=6lxJ...&frags=pl%2Cwn

On,

The trick is to not use something. I made that slotting head back in 2009 and I'm still trying to find a use for it. The rest of the stuff is just careful photography. As to wanting a filing machine, well if the slotter does the job I won't be looking any further.

Bob.

Sitting smugly here in Adelaide with my locally made Steelfast filing machine at the ready.

Originally Posted by Anorak Bob

I have a small project where I would like to cut a 12 x 12mm square hole through a 22mm thick piece of 4E cast iron. My initial plan was to grind a 1/4" square piece of HSS into the shape of a slotting tool and use it in the pretend slotting head I made years ago for my little Hercus mill. Without the presence of coolant the HSS has turned numerous shades of purple and I have worn away a lot of my cup wheel so I have pretty much abandoned the slotting idea.

If you're burning up the HSS either it's a really crap grade or you've got the stroke speed way high.

I've done a lot of CI, steel and aluminium on my slotter and steel needs to run really slowly IME. CI isn't bad at all.

PDW

Originally Posted by PDW

If you're burning up the HSS either it's a really crap grade or you've got the stroke speed way high.

I've done a lot of CI, steel and aluminium on my slotter and steel needs to run really slowly IME. CI isn't bad at all.

PDW

Me, crap grade? Come on Peter!!! It was a bit of Seco WKE45. The problem was impatience.

The slotting head in low gear runs at about 100 strokes per minute at 50Hz, 60 at 40Hz. I don't know how much slower it would go before it runs out of puff.

With the slotting, what depth of cut were you using, did you cut on more than one facet of the tool simuntainiously? I find with my filing machine I need to avoid cutting on two faces of square files.

Originally Posted by Anorak Bob

Me, crap grade? Come on Peter!!! It was a bit of Seco WKE45. The problem was impatience.

The slotting head in low gear runs at about 100 strokes per minute at 50Hz, 60 at 40Hz. I don't know how much slower it would go before it runs out of puff.

Yeah good question - I've got mine geared down running through a 90 rpm planetary g/box to dual A section belts with maybe 3:1 further reduction. It does stall on a too aggressive DOC - well the belts slip.

I've successfully nibbled out a 20mm internal keyway in A36 steel, 120mm deep, but it was painfully slow. Right on the limits of that slotter I'd say. If I ever have to do another it's going on the planer (assuming I have it running again when I need it).

PDW

I marked the cast iron bar out on both sides so I had the ability to check if the filing was square to the face of the bar.

DSC_9890 (Large) (Large).jpg DSC_9891 (Large).jpg DSC_9893 (Large).jpg

I drilled a 15/32" clearance hole and commenced filing with a brand new Nicholson square bastard file but found that the corner radius of the file was larger that I needed. I then used a second hand four dollar Stubbs second cut square file that while worn, cut in an easily controllable manner.

The problem I had with my initial set up using the angle plate was that I could not remove the cast iron bar without removing the file. With the file cut in half with a Dremel and the angle plate replaced with the mill's vice, checking for size became easier. The file cut square front and back because it was held square on the ram's tool mount. Sideways it cut a slight taper either through deflection or sloppy mounting of the file, either way it was easily remedied with a touch of hand filing.

DSC_9905 (Large).jpg DSC_9906 (Large).jpg DSC_9909 (Large).jpg DSC_9912 (Large).jpg IMG_20180831_142946298 (Large).jpg

I have never used a die filer so I am unable to draw comparisons but using the mill allowed me to utilise the table's micrometer feeds. I was able to work up to the scribed lines and corners with a reasonable degree of accuracy. A bit more accurate than hand filing in my bench vice. The stroke speed was not an issue.

Bob.

Nice one Bob, Just shows, there is more than one way to skin a rabbit.