Vertical Milling Heads – Are there any published designs?

[JellyParticipant @jelly]

Recently acquired a Harrison Milling Machine which was otherwise destined for the scrapheap, but is in fact in almost as new condition but for surface rust and a missing Lo-Vo light.

I got a great deal, but (unsuprisingly enough) no vertical head, and my understanding is that the Harrison vertical heads are now rare as hens teeth and command a price which is an order of magnitude more than what I paid for the machine.

So I'm going to have to make one, however before sitting down with the CIMT Machine Tool Design Handbook and reinventing the wheel vertical head attachment, I figured it would be worth looking for any published designs i could intellectually cannibalise adapt.

I have built machine spindles (last one was a 30,000 rpm ER11 spindle for a Taylor-Hobson pantograph) and gearboxes in the past, so not scared of taking on a complex and technically demanding project, but the less mechanical design and prototyping I have to do the better.

I have a detailed sectional drawing of a Huron/Elgamill style all-angle head (see below for the uninitiated), which I aesthetically and functionally think is awesome, but probably won't replicate because the complexity (and specifically cost/time involved in obtaining/producing the non-standard bevel gears) would be wasted on a non-ram type machine.

My ideal design would have a body consisting of 1 or 2 weldments made from plate and standard dimensions of tube or bored bar, ideally with a wall thickness of no more than 15mm, (I can access welding equipment which will cope with sections upto about 40mm, but it would mean getting an appropriate bottle of gas, spool of wire, liners and tips to set the machine up for really heavy welding).

[JellyParticipant @jelly]

[old martParticipant @oldmart]

An ambitious project, especially if you intend to include the quill feature which is very useful to have. Occasionally, heads of various sizes come onto the market and it would be easier to overhaul and adapt an existing one for your mill.

[DC31kParticipant @dc31k]

If you do not already have it, the manual for the mill is here:

Machinery manuals

It has a drawing and parts list for the standard (non-quill) 30 taper vertical head.

It is also worth perusing the manuals available from here:

https://passion-usinages.forumgratuit.org/f29-fraiseuses-mills

Aciera, Deckel and Schaublin ones would be good to look at as they all have similar style vertical heads to the Harrison.

With all the cross sectional drawings, you can print them out and then enlarge/reduce on a copier until a known dimension (e.g. a bearing OD) is 1:1 scale and then proceed from there.

Overseas eBay sellers are listing 'BT30 vertical power head' which is effectively a 30-taper spindle and bearings with a casting around it. Apply pulley to top and belt up a motor and it is a good approximation of a vertical head. Some investigation needed into how the drawbar would work.

I would be tempted to look at the horizontal conversion heads for turret mills (that clamp around the quill and turn the drive though 90 degrees). The right angle drive is made for you; the spindle taper is made for you. You just have to repackage and mate to the Harrison mounting scheme.

There appears to be a 40-taper Adcock & Shipley one for sale here (very cheap): https://www.tphmachinetools.co.uk/products/3101-used-adcock-shipley

If you are to fabricate one, I would buy 6-8 inches of 9" diameter cast iron bar (e.g. M-Machine metals) and carve it from that.

[BazParticipant @baz89810]

Now that Huron is a proper mill, what a beautiful machine.

[JasonBModerator @jasonb]

I would think one of the BT/INT 30 spindles that the guys making the larger home brew CNC machines use would be worth considering with suitable motor and a welded mount.

[Anonymous]

Posted by Baz on 12/09/2022 15:50:30:

Now that Huron is a proper mill, what a beautiful machine

+1, makes my A&S 2E look weedy.

Andrew

[VicParticipant @vic]

Posted by Baz on 12/09/2022 15:50:30:

Now that Huron is a proper mill, what a beautiful machine.

I was thinking the same thing. Some folks lust after the old Bridgeports but I’d far sooner have something like that Huron.

[BazyleParticipant @bazyle]

Look for a lathe headstock with ball bearings (so post ww2) that is fully enclosed for rigidity and as it won't provide a quill feed if you need that a saddle & cross slide from a larger lathe which will need some brutal machining to reduce to just the slide. Though I would suggest it would be better, at least initially, not to ape a mill drill and forgo the quill action.

The early small Bridgeport head was often grafted onto the horizontal support for a A&S 1ES.

[John PParticipant @johnp77052]

Seeing the Harrison that is described in "lathes UK" the vertical heads
don't seem have a specification that would be of much use these days.

It would be a simple job to make a bolt on head similar to
this seen here that i made for my Dore Westbury cnc conversion.
Entirely fabricated from steel and cast iron and 2 simple castings,the 4 main
parts are the mounting plate in steel bolted on to the the main body of
cast iron , the quill assembly is eventually loctited into the main body
The 3 bearing spindle has the taper for the er collet bored in directly
and uses a Myford 7 nose thread so all Myford accessories fit.
The aluminium castings made from 1 pattern hold the motor on top
and through 8 toothed belt pulleys and the inverter the head has a speed
range from 100 rpm to 10,000 rpm . I don't have any drawings, something like this
you can draw up on the back of an envelope ,i did ,its just a matter of working
out what you need.

There may be a more recent published design for a bolt on vertical milling head in
MEW but i cant find it ,there was one published in MEW 34 for a Tom senior
that used parts of a Dore Westbury milling machine .

John

[not done it yetParticipant @notdoneityet]

Which model do you have? Vertical by design or the horizontal which could have had a vertical head fitted?

[Clive FosterParticipant @clivefoster55965]

Assuming a fixed spindle without quill is acceptable the tricky bit will be replicating the vertically stepped up drive system without spending silly money on gears.

Lots to be said for Jasons suggestion of an import BT30 spindle. Independent, offset, motor drive Bridgeport style seems a potentially good way to go. Look to be plenty of breeds of offer direct from China in the £150 to £200 range. Some with pulleys for a motor drive, albeit single speed but a VFD probably allows sufficient speed range in practice. Hafta watch the shipping costs because there is huge variation for "same" thing. Like £30 to £130!

There is even one with and offset mounted 3/4 hp motor included so its mostly done for you. £300 looks good then £150 shipping takes the shine off.

If you do go for an independent motor drive system its worth spending quality engineering time figuring out a vertical feed set up. The standard knee feed is very limiting in vertical mode. Some of the Victoria verticals have the head on normal dovetail ways set vertically with a screw driven feed. I felt it worked pretty well on the one I briefly drove. Are the X form extrusions strong enough?

Clive

[JellyParticipant @jelly]

Posted by not done it yet on 12/09/2022 19:34:18:

Which model do you have? Vertical by design or the horizontal which could have had a vertical head fitted?

Horizontal, though with the higher speed range (63-1500RPM)

[JellyParticipant @jelly]

Posted by Clive Foster on 12/09/2022 20:37:40:

Assuming a fixed spindle without quill is acceptable the tricky bit will be replicating the vertically stepped up drive system without spending silly money on gears.

Lots to be said for Jasons suggestion of an import BT30 spindle. Independent, offset, motor drive Bridgeport style seems a potentially good way to go. Look to be plenty of breeds of offer direct from China in the £150 to £200 range. Some with pulleys for a motor drive, albeit single speed but a VFD probably allows sufficient speed range in practice. Hafta watch the shipping costs because there is huge variation for "same" thing. Like £30 to £130!

There is even one with and offset mounted 3/4 hp motor included so its mostly done for you. £300 looks good then £150 shipping takes the shine off.

If you do go for an independent motor drive system its worth spending quality engineering time figuring out a vertical feed set up. The standard knee feed is very limiting in vertical mode. Some of the Victoria verticals have the head on normal dovetail ways set vertically with a screw driven feed. I felt it worked pretty well on the one I briefly drove. Are the X form extrusions strong enough?

Clive

I was figuring on using a belt drive (Z-Section or A-Section) with the belts permanently installed in the head, and drive to the head coming from the input shaft meshing with the drive dogs on the horizontal spindle (as per the Huron design above) rather than using a driving pinion on a ISO30 taper meshing with a gear in the head (as per Cincinnati practice).

That eliminates the need for gears to produce the vertical displacement, simplifies the design and manufacturing (if not assembly) of the head and gives me a lot more flexibility in gearing, and even the option to have more than one ratio available.

I have discussed the external head option with a friend of mine who has one of those spindles (his is a BT40 driven by a 4kW motor) and is very happy with the performance…

It's definitely a serious consideration, because of the comparative ease of execution, although somewhat clunkier to install and harder to store when not on the mill even with a small motor (and ideally I'd like to maintain the Harrison's 2kW power output so I can use my big face-mills on the vertical head, which would mean an even bigger heavier motor).

With respect to the z-axis travel of 11" on the Harrison, except for drilling (which honestly I would just do on the drill press instead) it doesn't seem as limiting as the 6.5" Y-axis travel.

I'm not sure what the X-form extrusions you're referring to are, as in using aluminium extrusion as a material or something within the casting of the machine?

[JellyParticipant @jelly]

Posted by John P on 12/09/2022 19:21:05:

Seeing the Harrison that is described in "lathes UK" the vertical heads
don't seem have a specification that would be of much use these days.

It would be a simple job to make a bolt on head similar to
this seen here that i made for my Dore Westbury cnc conversion.
Entirely fabricated from steel and cast iron and 2 simple castings,the 4 main
parts are the mounting plate in steel bolted on to the the main body of
cast iron , the quill assembly is eventually loctited into the main body
The 3 bearing spindle has the taper for the er collet bored in directly
and uses a Myford 7 nose thread so all Myford accessories fit.
The aluminium castings made from 1 pattern hold the motor on top
and through 8 toothed belt pulleys and the inverter the head has a speed
range from 100 rpm to 10,000 rpm . I don't have any drawings, something like this
you can draw up on the back of an envelope ,i did ,its just a matter of working
out what you need.

I agree that the Harrison's 1:1 ratio and 22-1000 or 63-1500 speed range isn't particularly well suited to vertical milling with modern cutters, when a 10mm carbide endmill will happily run at 4000 rpm in EN1/EN3 and 2000rpm in 709M40T, which is a big part of why building rather than buying makes sense…

"Why pay over the odds for an attachment which would ultimately be unsuitable for a good proportion of my existing tooling anyway?"

The assembly you're showing for the spindle of your vertical head mirrors the way I planned to assemble the spindle if I make one myself.

However as with my comments to Clive there's a consideration as to how hard translating horizontal to vertical rotation would be and how that compares to the inconvenience of storing/lifting a much heavier assembly with a motor mounted on it; the approach you've taken is definitely simpler to execute from a manufacturing perspective than having mitre gears and a power-take off from the main spindle.

[JellyParticipant @jelly]

Posted by Vic on 12/09/2022 16:49:57:

Posted by Baz on 12/09/2022 15:50:30:

Now that Huron is a proper mill, what a beautiful machine.

I was thinking the same thing. Some folks lust after the old Bridgeports but I’d far sooner have something like that Huron.

Whilst it benefits from amazing brand recognition, the Bridgeport isn't even the best Bridgeport Clone…

TOS's FNK25(A) and Shizuoka's VHR(/G) both blow it out of the water on features, rigidity and performance whilst being cheaper new (and probably cheaper now due to not being "the" brand).

.

It's a long-term ambition of mine to own a Huron (and by extension have a workshop big enough for that to be sensible), they are far and away the best designed and most ergonomic to operate of all the ram-type "Euro-Mill" machines (including the Deckels and Schaublins) a lot of effort clearly went into making them easy to operate no matter what possible use case you had for one…

It's just unfortunate that they only made them in a size range from "That's really quite a big mill isn't it?" to "Ah, so you'll be wanting to machine the column casting of a Bridgeport now will you?"

[JellyParticipant @jelly]

Posted by DC31k on 12/09/2022 15:20:32:

There appears to be a 40-taper Adcock & Shipley one for sale here (very cheap): https://www.tphmachinetools.co.uk/products/3101-used-adcock-shipley

If you are to fabricate one, I would buy 6-8 inches of 9" diameter cast iron bar (e.g. M-Machine metals) and carve it from that.

It's a shame that's a 40 taper, as it would otherwise be a good starting point.

Why do you suggest the carving from CI approach?

From an efficiency standpoint it would mean buying nearly £300 of material to then spend a lot of time and electricity machining the bulk of it away again.

I can conceptually see the benefit of CI over steel for damping (and to a lesser extent rigidity) but given its not easily (sanely even) welded, it results in a lot of waste for making a complex and hollow shape.

[DC31kParticipant @dc31k]

It's a shame that's a 40 taper, as it would otherwise be a good starting point.

Why do you suggest the carving from CI approach?

It is possible to buy 40-taper to 30-taper reducing sleeves if that helps.

With a welded item, I would think it would need to be stress-relieved after initial fabrication and possibly again after rough machining. The last thing you want is to finish bore it and then find it moves about. A lot of it is the facilities and materials to which you have access.

[John HinkleyParticipant @johnhinkley26699]

What size are the workpieces that you intend machining? Would you not be better off (both time-wise and financially) holding the work at 90° to the existing horizontal spindle? Or am I being too simplistic?

John

[not done it yetParticipant @notdoneityet]

Posted by Jelly on 12/09/2022 23:01:32:

Posted by not done it yet on 12/09/2022 19:34:18:

Which model do you have? Vertical by design or the horizontal which could have had a vertical head fitted?

Horizontal, though with the higher speed range (63-1500RPM)

In that case, you might be able to relatively easily fit a Centec vertical head? Likely with a motor above, but whatever happens to fit. It would only need a dovetail adaptor-plate/riser block to fit the head.

There may be other, similar fitting, heads from other machines which could be used? While expensive, they are more available than a genuine Harrison head.

[JellyParticipant @jelly]

Posted by DC31k on 13/09/2022 07:44:19:

It's a shame that's a 40 taper, as it would otherwise be a good starting point.

Why do you suggest the carving from CI approach?

It is possible to buy 40-taper to 30-taper reducing sleeves if that helps.

With a welded item, I would think it would need to be stress-relieved after initial fabrication and possibly again after rough machining. The last thing you want is to finish bore it and then find it moves about. A lot of it is the facilities and materials to which you have access.

I would definitely be stress relieving any weldments:

The initial post-welding cycle could be done by heating to an even light yellow oxide colouration (or using a few marks with a 200C Tempilstik Crayon) with the oxy-propane rosebud then wrapping the whole thing in a welding blanket till it's cool; I could probably do this by baking the parts at Gas Mark 8 for a few hours also

After rough machining I'd want a full stress reliving cycle of something like 6hrs ramp to 600C, min 1 hr soak, 4 hours ramp to 200C, still air cool; the "how" element depends on the size of the final assemblies really:

• If the parts end up less than 200 x 250 x 450 mm I can do this "in house" (actually at a friend's workshop, with the PLC controlled heat treatment oven I built for his knife making workshop).
• If the parts end up bigger than that, or I have very slim machining allowances on any of the parts due to initial stock sizes, then I can send them out for controlled atmosphere normalising, (one of the benefits of living in Sheffield is the ready supply of every conceivable type of subcontract manufacturing service still).

[JellyParticipant @jelly]

Posted by John Hinkley on 13/09/2022 07:52:02:

What size are the workpieces that you intend machining? Would you not be better off (both time-wise and financially) holding the work at 90° to the existing horizontal spindle? Or am I being too simplistic?

John

It's pretty likely that I'll want to use the full envelope of the machine…

There's plenty of parts where using it as you describe would actually be better than using a vertical head (although would require fabricating a really rigid angle plate for any vice held work) because it gives a 15" X & 11" Y envelope, at the expense of only 6.5" Z travel and reduced "daylight" between the part and the spindle.

But equally there's work where the increased "daylight" of a vertical head (on the basis that I offset the head upward vertically, probably more than the original design so that the bottom of my normal collet chucks would end up level with the top of the horizontal spindle) would be more important, specifically I own quite a lot of insertable milling tooling which has comparatively long shanks, which I'd like to be able to use on this mill, but also don't want to go cutting down to make it fit.

In any case my plan is to (as far as possible) use the approach you're suggesting to make the parts of the vertical head which require milling, as a bit of a challenge.

[JellyParticipant @jelly]

Posted by not done it yet on 13/09/2022 08:50:51:

Posted by Jelly on 12/09/2022 23:01:32:

Posted by not done it yet on 12/09/2022 19:34:18:

Which model do you have? Vertical by design or the horizontal which could have had a vertical head fitted?

Horizontal, though with the higher speed range (63-1500RPM)

In that case, you might be able to relatively easily fit a Centec vertical head? Likely with a motor above, but whatever happens to fit. It would only need a dovetail adaptor-plate/riser block to fit the head.

There may be other, similar fitting, heads from other machines which could be used? While expensive, they are more available than a genuine Harrison head.

That's another option, although at that point the price (at least from a search today) is such that it would probably be as well buying a second hand Bridgeport Head, and fabricating a mount for it which fits onto the overarm dovetails.

Both approaches also result in using a lot more storage space (something which is at a bit of a premium for me), and being even heavier/more ungainly to lift into position (I have been rather more cautious about lifting after I gave myself Sciatica in my mid 20's by thinking I was some kind of superman, thankfully it was fully cured by a course of muscle relaxants and physiotherapy on that occasion, but if I was to allow a "next time" I may not be so lucky).

[not done it yetParticipant @notdoneityet]

Posted by Jelly on 13/09/2022 10:09:34:>

…

That's another option, although at that point the price (at least from a search today) is such that it would probably be as well buying a second hand Bridgeport Head, and fabricating a mount for it which fits onto the overarm dovetails.

Both approaches also result in using a lot more storage space (something which is at a bit of a premium for me), and being even heavier/more ungainly to lift into position (I have been rather more cautious about lifting after I gave myself Sciatica in my mid 20's by thinking I was some kind of superman, thankfully it was fully cured by a course of muscle relaxants and physiotherapy on that occasion, but if I was to allow a "next time" I may not be so lucky).

Fitment of a long riser block (as per quite a few Centecs – I have one on my 2B) could mean that the vertical head would not necessarily need to be dismounted for horizontal work. with my Centec I have to remove the drive belt, but not so if the drive comes from an extra motor

You clearly have several options, and the 2B is my only experience with a combination vertical/horizontal. I am confident, from your posts, that you will find a good way forward.

[JellyParticipant @jelly]

Posted by not done it yet on 13/09/2022 10:28:05:

Posted by Jelly on 13/09/2022 10:09:34:>

…

That's another option, although at that point the price (at least from a search today) is such that it would probably be as well buying a second hand Bridgeport Head, and fabricating a mount for it which fits onto the overarm dovetails.

Both approaches also result in using a lot more storage space (something which is at a bit of a premium for me), and being even heavier/more ungainly to lift into position (I have been rather more cautious about lifting after I gave myself Sciatica in my mid 20's by thinking I was some kind of superman, thankfully it was fully cured by a course of muscle relaxants and physiotherapy on that occasion, but if I was to allow a "next time" I may not be so lucky).

Fitment of a long riser block (as per quite a few Centecs – I have one on my 2B) could mean that the vertical head would not necessarily need to be dismounted for horizontal work. with my Centec I have to remove the drive belt, but not so if the drive comes from an extra motor

You clearly have several options, and the 2B is my only experience with a combination vertical/horizontal. I am confident, from your posts, that you will find a good way forward.

I was struggling to picture how the riser block would allow me to use it in horizontal mode, but a quick search revealed this:

(Future readers with the same problem I have, click the image to link to the original build thread for that design).

Which makes everything make sense, seen as it's clearly intended to function as the overarm as well as raising the vertical head up… Very nifty indeed!

[Author]

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