What's in a vertical head?

[neksmerj]

Greg, making a vertical head would be a terrific project.

For the uninitiated like me, what's inside?

I'm guessing, but firstly you are going to need a housing. I assume a horizontal input shaft will enter the housing via bearings, and will terminate with a bevel gear.

Another bevel gear will transfer the torque to a vertical shaft having at it's end, some form of taper to accept an arbor. Is the transfer ratio 1:1?

This impression is greatly simplified, am I close?

Ken

[Pete F]

That's how the Hercus vertical head works Ken, extremely basic. However the gear ratio is 1:1.5 as I recall, anyway there's a speed increase over the horizontal. The increased speed would be beneficial for the typically smaller cutters used in the vertical head as opposed to the horizontal.

Pete

[Anorak Bob]

I could have posted some cross sectional drawings of various heads, but the question was asked of Greg. They are all pretty simple. The differences will be in the accuracy of their execution.

BT

[Anorak Bob]

I had better clarify "simple". I'm only talking about a basic, bolt on head as fitted to say the Hercus or my Schaublin. Things increase in complexity when a drilling quill is introduced and become vastly more complicated when we get into the realm of Bridgeport type heads.

BT

[Anorak Bob]

This may be of interest to Greg and other viewers. Malcolm Wild is an English clockmaker and maker of tools for clock and watchmaking, who addressed the need for a vertical head with a precision drilling quill to fit the little Aciera mill favoured by members of his profession. He designed and produced a small number of these (expensive) heads.

http://www.j-m-w.co.uk/HJ%20Published%20ArticleNEW.pdf

A different scale to GQ's mate's headless Perrin but it might have some features worth replicating.

BT

[Greg Q]

I just lost a lengthy and pithy reply.:doh:

I like the head Bob linked. I also like Ken's Arboga quill design: it has a regular drill press handle that we all know and love, but it also has a micro-adjust worm feed. It's exactly what we should all have.

And yes, a vertical head is exactly as stated: a horizontal shaft, some bevel gears and a quill. Nice bearing$ too. (or bushings in the case of the early units). Attached is a photo from the Deckel FP-1 spare parts manual of the conventional vertical head. There is also a belt-driven head which is the general scheme of what we'll end up with.

[Greg Q]

Here's the Deckel FVV belt-driven high speed head for your amusement. Something like this, scaled up, with the Perrin mounting is where I think we're going.

[Scott]

As an ex-steel-sales-guy and to take this a little further (and this is purely out of interest), what grade of steel would you be looking to use? Mild steel, hardened or even something like stainless?

[Greg Q]

No clues in the clues closet, sorry. I'd guess 4140 or similar. Something that would harden up to (again, guessing, 55 RC or so). Grinding to final dimension after HT. But I really don't want to have to start from scratch, but modify an existing unit somehow.

Greg

[Scott]

I think you'd be right with 4140 however, from memory (deep, dark recesses) welding 4140 is dodgy. The heat alters properties? Not that any components for this application would require welding.

Thanks for the answer though Greg, the question was purely out of interest.

[Anorak Bob]

Attached are a couple of photos lifted from Tony's site that show the simple fine feed mechanism on a Dore Westbury mill.

[Greg Q]

That's simple but effective. I like it.

Just thinking about this, I think the way to go might be to fashion a head that fits over the two horizontal support arms on the arbor support. That way change-over would be less fraught with peril, and we'd gain a huge amount of headroom under the spindle.

It appears however that we have some scraping to do first, so that will occupy a long time rigging up a bench, doing a survey and then trying not to make it worse. There's also decisions to be made regarding the missing x-axis feedscrew, attach points, end brackets etc.. This machine is hell-for-stout though, so any effort will have rewards.

GQ

[.RC.]

Spiral gears would be best if you can find some.. plain bevel gears will be noisy...

A quill would be hard to make... The quill housing needs to be honed and the quill ground to fit.... With bridgeports and the like I believe the quills are not interchangable with different machines..

It would be do-able but would require much care..

[Greg Q]

Spiral gears would be best if you can find some.. plain bevel gears will be noisy...

A quill would be hard to make... The quill housing needs to be honed and the quill ground to fit.... With bridgeports and the like I believe the quills are not interchangable with different machines..

It would be do-able but would require much care..

That's all true, and that's why I am daunted by the prospect of doing this, at least economically, both in time and money. And since we lack an elegant way of getting a horizontal power input, we're going to go with a motor/belt combination. I don't want to contemplate bevel gears-its beyond my nascent engineering skill set.

Greg

[neksmerj]

Arrrrah me hardy, what's wrong wiff ya?

If we put our collective heads together, we'll come up with an elegant design that will not only mill steel and aircraft parts, but will double as a coffee grinder and meat mincer.

Just givus a yell, you know the score.

Kennearth

[Anorak Bob]

Greg,

Attached are scans of exploded drawings of two heads made for the F4. Also included is a diagram of a far simpler adjustable tailstock than my Hercus version. The quality of the images is poor. I may be able to find the original files I downloaded at home, if you are interested. They include exploded drawings for the accessories made for the F4 and F5.

BT

[Greg Q]

Thanks Robert...they look like they'll be very useful.

[Anorak Bob]

Before I found my 13, I toyed with the idea of building a self powered head with a quill for the little Hercus. I had a few discussions with Steve Durden at Hercus about machining an accurate rack in the quill. His suggestion was to buy an existing rack and pinion and insert the rack into a milled recess in the quill. Makes a lot of sense if you are not in a position to cut the rack yourself. Trick is finding a rack and pinion that will provide the correct gearing when combined with a worm and wheel, to suit your chosen micrometer feed dial calibrations. Having a separate rack would also allow for adjustment to ensure correct tooth engagement.

Something to think about.

[Dave J]

Hi Bob,
This guy made a rack in a quill back in 2006. He used hardened chrome hydraulic shaft so it should be a lot easier in cast iron. With you expertise with cast, it should be no problem. He used a fly cutter but a rack gear could be used in something softer.

CNCzone.com-The Largest Machinist Community on the net! - View Single Post - Hafco Metal Master HM-52 CNC Conversion (http://www.cnczone.com/forums/219151-post38.html)

Dave

[Anorak Bob]

Here is a link to the Aciera manual and parts drawings. A lot of desirable accessories. That they are all newer box look parts would aid in their replication. Might clash with the more voluptuous shape of our older machines though.

http://home.online.no/~ewaness/aciera_f4_manual.pdf

[Anorak Bob]

Hi Bob,
This guy made a rack in a quill back in 2006. He used hardened chrome hydraulic shaft so it should be a lot easier in cast iron. With you expertise with cast, it should be no problem. He used a fly cutter but a rack gear could be used in something softer.

CNCzone.com-The Largest Machinist Community on the net! - View Single Post - Hafco Metal Master HM-52 CNC Conversion (http://www.cnczone.com/forums/219151-post38.html)

Dave

Nice welding and his lathe must have some grunt to cope with a drill bit of that girth.

Dave, when I bought the Schaublin I was given a crate containing a variety of accessories, one of which was a high speed drilling head (6000rpm max.). The desire to make my own version for the Hercus suddenly disappeared.

Bob.

[Dave J]

The drilling and milling where done at his work.
I know your not going to make one, but it just goes to show it is possible.

Dave

[Anorak Bob]

Dave, I wonder how he indexed the rack teeth. You DRO boys just dial it up on a screen I suppose.

[Dave J]

I am not sure if he had a DRO, but I would use "holes in a strait line" where you dial in the number of holes and the distance, and the DRO divides it up and tells you each step by having to zero it on the spot.
You should think about a DRO while the dollar is up. They can be installed with 4 x M4 socket screws for each scale so it doesn't mess up the machine in a big way. Sometimes a bracket can be made from existing holes to save drilling any others. Once you have used one, you will never go back.

Dave

[Pete F]

Good idea Dave, especially on the Hercus Bob. You reeeeaaalllyy want to have a DRO on that little puppy* :2tsup:

Pete

*This encouragement may or may not be any attempt to get Bob to fit a flawless DRO installation to his Hercus so that I may shamelessly precisely copy the whole setup for my own Hercus :D

[Dave J]

LOL, good con Pete

Dave