View Full Version : homebrew BP slotting head (pix)

04-14-2005, 12:02 PM
hey folks, here it is. haven't posted pictures in a while so i'm pasting all three links from photobucket.

can't say i've tried cutting any keyseats with it yet, but it sure sounds pretty when it runs. kinda like an old train just coasting along through a sunny mountain pass with a crackling river and birds chirping.

its 100 strokes/min, with about 120mm stroke (i figure about 80mm of it is useful cutting action).

have to snug up the mount, and get it nice and square... oh, and learn to shape good tools for it. i tired an HSS blank in some plastic and it did a fine job. i can't wait to sink it into some steel.

<img src="http://img.photobucket.com/albums/0903/knucklehead/slottinghead.jpg" alt="Image hosted by Photobucket.com">


04-14-2005, 12:55 PM

Looks good! Any chance you could explain and/or post a pic or two of the mechanism that moves the tool back and forth?

The only way I've seen it (never used a shaper before) is where the tool gets its motion from the dovetail sliding back and forth. But I guess the shaping attachment for a BP wouldn't work that way.

Let us know how it works in steel.


G.A. Ewen
04-14-2005, 02:02 PM
Wow!!! that is one nice looking piece of equipment. Well done!!!

04-14-2005, 02:23 PM
thanks. i'll feel alot better once its got a big pile of chips around it.

the thing is pretty straightforward, really. works like a car engine in reverse. motor/gearbox turn a big wheel (you can just sort of see it in the picture).. theres a 'tie rod' on the edge of the disk.. and its connected to the 'ram'

the ram is sandwiched in between four pieces of bearing bronze. i put set screws on all four sides so i can adjust the bronze pads as they wear. there are oil holes and grooves cut in the bronze so i can keep this thing slipping along.

thrust bearings keep everything together at the top. the side plate you see in the picture is the backbone and everything bolts/welds to that. all important inside surfaces were machined at one time. the other plate is basically a cover, with some standoffs holding it in place.

i wish i'd put in some way to cycle this by hand, without power.

99% of the work it'll see is internal keyseat and maybe a spline or two. no real "shaping" .. dovetails would've been too complicated (ie time consuming) for me.

i'll post another pick when its painted/shaping.


<img src="http://img.photobucket.com/albums/0903/knucklehead/slotter.bmp" alt="Image hosted by Photobucket.com">

04-14-2005, 02:51 PM
To cycle it by hand use a 3/8's air ratchet and whatever type of bit or socket you need to hook up to the outside of axle on that gear box. How about some details?

What size is that motor?
How about the box ratio?
Have you figured out what kind of forces you are seeing at the cutting edge?

Great job, please post more pics when you start making some chips.

James Kilroy

04-14-2005, 02:52 PM
Good job. I'm diggin' it!

John Stevenson
04-14-2005, 03:23 PM
<font face="Verdana, Arial" size="2">Originally posted by jkilroy:
To cycle it by hand use a 3/8's air ratchet and whatever type of bit or socket you need to hook up to the outside of axle on that gear box.

You can't.
It's a worm driven gearbox and can't be run backwards.

04-14-2005, 03:51 PM
OK, I'm a dumbass. I was thinking it was a shaping head. I was wondering "how the heck does he get it do move forward and backward with any kind of mechanical advantage", but I see now it moves up and down, hence a slotting head. Pardon my ignorance.

You gonna do some broaching-type work with that?


04-14-2005, 09:02 PM
Well you are right about that, if it is a worm drive box then he would need to find a way to get a clutch into the driveline. Otherwise I don't think hand operation is going to be usable.