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form_change
05-29-2010, 05:49 PM
A guy has a Sajo mill advertised on eBay around here and when I looked at the pictures I saw it was a Universal (that is, able to swivel the table around). Unfortunately he's one of these seller who doesn't answer emails so I don't know anymore (although it looks to be a UF48 when I compare to pictures).
I had always thought that Universals did not come in small sizes. Does anyone know of others that have a small footprint (say less than 1m2 or 3ft x 3ft) suitable for a home workshop?

Michael

MickeyD
05-29-2010, 06:06 PM
Pratt & Whitney 3C ( http://www.lathes.co.uk/prattwhitneymiller/ ) and the Hardinge UM ( http://www.lathes.co.uk/cataract%20miller/index.html - scroll down to the bottom of the page). The P&W is a benchtop mill and the Hardinge takes about 3ft x 3ft of space.

uncle pete
05-29-2010, 06:50 PM
If? I remember correctly Evan has a small one that he thinks may be Swiss made. I was amazed at the depth of cut it would take. Probably easier to find a winning lotto ticket than another one of those tho.

Pete

gwilson
05-29-2010, 06:59 PM
I have a very nice Harrisson universal mill. It is a floor model. Probably not what you'd call a real small mill,but it's table is ABOUT 8" X 30"(this is a complete guess,as I seldom use it). It does cut like crazy,and is all geared. I think Harrisson made only 1 basic mill in different configurations of vertical,horiz. and universal. see Griffith's Engineering for nice pictures and info.

Unfortunately,the makers stopped making mills quite a while ago,and threw out all parts. That was stupid. So,if mine breaks a part I can't make,I'm stuck.

oldtiffie
05-29-2010, 07:25 PM
I'm curious as to why you'd want a universal (horizontal) mill unless you are doing some spiral/helical milling?

A swiveling table does complicate the "can't see/hidden" stuff under the table and the apron.

My guess is that it will be used as a normal (non-universal) mill with the table clamped at zero off-set - and which it will do very well.

If you are spiral milling and not doing by it CNC you are going to need a universal dividing head as well as some seriously complicated gear trains. The math is not easy either. This applies whether the spiral/helical/gears are cut with a normal gear cutter or hob as well.

If I buy a machine to replace my HF-45 square column mill (not likely - but!!) it will be this vertical/horizontal mill which has a swiveling table that I don't see me needing - but if I buy that mill, I have to put up with the swiveling table:
https://www.machineryhouse.com.au/images/37924.jpeg

https://www.machineryhouse.com.au/images/36943.jpeg

https://www.machineryhouse.com.au/Products?stockCode=M161D#

But I'd still need a universal dividing head:
https://www.machineryhouse.com.au/Products?stockCode=D003

oldtiffie
05-29-2010, 09:01 PM
A universal mill in all its glory!!

http://chestofbooks.com/crafts/mechanics/Mechanical-Processes/images/Fig-197-Universal-Milling-Machine.jpg
http://chestofbooks.com/crafts/mechanics/Mechanical-Processes/342-The-Universal-Milling-Machine.html

and:
http://www.lathes.co.uk/victoria/img9.gif

from:
http://www.lathes.co.uk/victoria/index.html

Evan
05-29-2010, 09:13 PM
This is the small universal I have. I only know that it was privately imported from Switzerland by a gentleman that moved to Canada from there about 25 years ago. It sat nearly unused since then until I bought it from the elderly and senile owner's son. I bought the entire lot of goods including his Swiss made instruments (5 micrometres, bore gauge, master precision level, three Interapid/Tesa dial gauges, height gauge), scraping tools, surface plate, camera gear, electronics instruments and parts as well as the mill for about 900 dollars several years back. I know the son of the owner and the price was contingent on me never parting out the tools but instead actually using them to make things. That made the old man very happy and that was his greatest hope in disposing of his shop. He couldn't talk much but he gave me a big smile and a thumbs up when I left with his equipment.

The mill has no trace of identifying marks but it is very likely Swiss made. The largest machine tool dealer in Switzerland, Luthy and Sons, has no idea who might have made it and claims to have never seen one the same. The mill has a variety of interesting features including the ability to install lever handles (included) to operate the axes instead of using the hand wheels. The table swivels and the horizontal head can be removed and attached to a (missing, but easy to make) adaptor that turns it into a vertical mill in about 60 seconds. The head also has a three in riser that gives it nearly a foot of headroom over the table. It is powered by a much later added 3 phase varispeed motor and transmission that will run it at the turn of a crank from about 30 rpm to around 1500 rpm depending on optional belt position on the step pulleys as well.

http://metalshopborealis.ca/pics3/smilla.jpg

coldformer
05-29-2010, 09:26 PM
Burke made a very nice one

Arthur.Marks
05-29-2010, 10:36 PM
Curiosity...
Was a "universal" largely intended for making tapered cutting tools?

I have seen various definitions for a "universal" in various publications of various vintage. I got the impression, though, the most often encountered use of the term was that a mill could do spiral work. Thus, there was an accessory gearbox designed to mesh with the table's leadscrew. Many of these also included a swiveling table.

Then I bought a manufacturer-labelled "universal" with no such spiral accessory ever made... though my table will swivel, but only to roughly five degrees. So basically enough to cut a Morse taper or other long spindle taper as well as tapered cutting tools. I might also mention that my "universal" is a horizontal by nature but with a well engineered vertical head I would hardly call an accessory. Which...

Leads me to the third usage I've seen for "universal": A mill with both horizontal and vertical spindle ability.

So does anyone know what it designated when the term was in standard use? Forgive me if I am wrong, but it seems to be an antiquated term today with little meaning and no true purpose associated with it.

And to link this back to the OP's question, I have a Schaublin 12 in my residential basement. It fits my home workshop needs beautifully.:)

AlleyCat
05-29-2010, 10:42 PM
I have a Burke #4 in my basement. It has a universal table and doesn't take up much room. Most of the parts I make are small and this little mill does an excellent job on stuff like that.

oldtiffie
05-29-2010, 11:07 PM
Arthur.

I will answer your query in RED interlaced within your post.


Curiosity...
Was a "universal" largely intended for making tapered cutting tools?

No. It would be easier to "cut tapers" with a tilting dividing head on any vertical or horizontal mill. The cutter would be at the top and would cut a series of triangular flats.

I have seen various definitions for a "universal" in various publications of various vintage. I got the impression, though, the most often encountered use of the term was that a mill could do spiral work. Thus, there was an accessory gearbox designed to mesh with the table's leadscrew. Many of these also included a swiveling table.

True. Just as I described in a previous post here.

Then I bought a manufacturer-labelled "universal" with no such spiral accessory ever made... though my table will swivel, but only to roughly five degrees. So basically enough to cut a Morse taper or other long spindle taper as well as tapered cutting tools.

Then you are limited to spirals with a helix angle of +/- 5 degrees.

I might also mention that my "universal" is a horizontal by nature but with a well engineered vertical head I would hardly call an accessory.

Which pretty well describes "Turret" mill or a horizontal mill with a vertical milling head attachment

Which...

Leads me to the third usage I've seen for "universal": A mill with both horizontal and vertical spindle ability.

See my previous answer - and which can include a BP mill with a horizontal spindle attachment.

So does anyone know what it designated when the term was in standard use? Forgive me if I am wrong, but it seems to be an antiquated term today with little meaning and no true purpose associated with it.

"Universal" as described is pretty well in universal use (sorry).

And to link this back to the OP's question, I have a Schaublin 12 in my residential basement. It fits my home workshop needs beautifully.:)

If any (Swiss-made) Schaublin mill, lathe or tools is/are in good condition you are very fortunate. I used them ina Tool Rooma long time ago. Thaey are a joy to use and are what others aspire to be.
http://www.google.com.au/#hl=en&q=schaublin+machines&revid=115818076&ei=ZscBTIjvIY2gkQWnvIDyDQ&sa=X&oi=revisions_inline&resnum=0&ct=broad-revision&cd=1&ved=0CEoQ1QIoAA&fp=1839eb0d6d01d192

Arthur.Marks
05-30-2010, 01:03 AM
I take it from the information given, then, oldtiffie, that a universal mill is basically the domain of worm gear cutting. Other necessary uses for the feature(s) of a true universal mill would be rare. Agreed?

Still... it seems to me like it would be the foremost (antiquated) method of producing twist drills, spiral mills, and the like.

Arthur.Marks
05-30-2010, 01:29 AM
I apologize for the thread-jack here. :(

"The universal milling machine was invented in 1862 by Joseph R. Brown... It is so constructed that the table may be swiveled to a considerable angle in a horizontal plane to permit the milling of spiral (twisted) grooves...
"The plain milling machine is a simplified version of the standard knee-type milling machine... It is very similar in appearance and construction to the universal milling machine, differing chiefly in that it lacks the swivel-table construction."ppg. 133-134
Machine Tool Operation, Part II, Burghardt and Axelrod (c)1954

Regardless, I agree with the earlier question directed to form_change, "Why a universal mill?" :confused:

oldtiffie
05-30-2010, 01:58 AM
I take it from the information given, then, oldtiffie, that a universal mill is basically the domain of worm gear cutting. Other necessary uses for the feature(s) of a true universal mill would be rare. Correct?

Still... it seems to me like it would be the foremost (antiquated) method of producing twist drills, spiral mills, and the like.

Arthur.

The off-set of the table will determine the limit of the helix angle of the grooves you are cutting.

5 degrees is about the limit for accuracy before serious consideration has to be given for "twisting" of a tooth form. In other words, if you were cutting a spiral gear the limit on the spiral gear would be five degrees so that you could use standard gear-cutters (store-bought).

Worm gear cutting is an entirely different matter as a universal is best for the job but it can be done on a non-universal mill by rotating the base of the dividing head the amount that the universal table would have been tilted/off-set.

When cutting a true form worm-wheel, a hobbing cutter mounted on the horizontal arbor is required - but - and here is the difference to the gearing set-ups mentioned previously (where the dividing head rotation was geared to and synchronised with the mill "X" lead-screw) in the case of milling/hobbing a worm-wheel the "X" and "Y" slides are locked/clamped and the universal dividing head spindle is geared to and synchronised with the mill spindle (and the arbor and the hobbing cutter which must be keyed to the arbor).

In most cases in a HSM shop a worm-wheel is best cut on a lathe with an "interrupted thread" cutter (like a gashed lead-screw or a tap) driven by the lahte head-stock spindle and the worm blank mounted on the lathe cross-slide and left to "free-wheel" and be "pulled around" as it is cut by the helical cutter. The action is not dissimilar to what you'd see on a domestic mincer.

Universal mills really do need a good universal dividing head as well as a very good gear train and mountings to get the "best" out of the "universal" capacity.

Check it out in "Machinery's Handbook".

Taps and "lead-screw" cutters and the like - and hobbing cutters - can be made with straight (zero helix angles) provided the helix angle of the cutter is not more than 5>10 degrees off-set from normal (90 degrees).

I suspect that as many "universal" mills as there are that are sold are to people who are impressed with "universal" over "plain" - and pay a premium for it. The down-side is that those of us that only want a plain mill have to take and pay for a "universal" feature that we neither want not need.

So, in short, for most cases the "universal" feature is neither here nor there and should/can be set to zero and forgotten about.

form_change
05-30-2010, 04:51 AM
The original question was not should I get a Universal but what small-ish Universals are there out there that might be of a suitable size for a HSM. The only Universal mills I have seen have been in an industrial context and were usually large machines used in a tool-room for special work. I wanted to know whether smaller machines were all that common or whether this machine was comparatively rare.

My interest in this particular machine was that it looked to be a similar size to the mill I have but a step up (powered feeds, heavier construction, (the swivel table), greater HP, slightly larger table). Even without the swivel table I would consider it, but as I do cut the occasional gear the swivel seems a bonus.

For those who would denigrate a machine with features they rarely use, I would firstly say that it's my preference as to what features I regard as important to have on my machines - my lathe has a taper turning device that I may use once a year, but I'm not getting rid of it just because I don't use it often.

By all means buy a new Chinese machine from the local machinery supermarket if you think that is the best option. I think I get much better value for money by fixing up and then using second hand machines but sometimes you don't get to choose what factory options are fitted.

The other point worth making is that just because it is not commonly used does not mean that it will not be used in the future. Buying a tool or machine after you need the functionality is pointless. Buying before it's needed makes much more sense. Is anyone here planning to remove the seat belts, air bags, spare wheel and jack from their cars as they don't use them?

Michael

lazlo
05-30-2010, 10:50 AM
For those who would denigrate a machine with features they rarely use, I would firstly say that it's my preference as to what features I regard as important to have on my machines - my lathe has a taper turning device that I may use once a year, but I'm not getting rid of it just because I don't use it often.

Michael, I think you're misunderstanding the feedback. Universal tables were made on horizontal mills for cutting helix's with a universal dividing head that was geared off the table feed. If you're not planning on cutting helices, there's no point to the swiveling table.

coldformer
05-30-2010, 11:27 AM
there's no point to the swiveling table.

i cut a 5 degree angle on a 3x3x10 in piece in the horz. mode on a burke number 4 it was much easier than trying to use the small vertical head so
the universal table does have some handy simple uses.

torker
05-30-2010, 01:49 PM
Well golldangit...
I've been doing it all wrong.
I've cut quite a few tapers on my Universal.
Was too easy...just hang it over the edge...swivel the table to the appropriate mark...mill the piece.Hmmm...
Guess that would have been easier on an angling/tilting dividing head...sheesh!
I cut gibs on it, a few knock out keys for MT's in the drill press...
About a hockey sock full of fabricating wedges...
I resurface and dress down tapers for a company for their quick attach buckets on their Gradalls....easy and quick on the Universal...
CRAPPPP....now I gotta mount that 200 pound dividing head and put a car jack under it to tilt the damm thing :D
Russ

Arthur.Marks
05-30-2010, 03:25 PM
I hope I didn't instigate an argument! I was trying to differentiate the term in order to better understand your question. As it turns out, after rereading all the literature I have on my machine, the SV12 (Schaublin 12 milling machine) is NOT claimed to be a universal. The manufacturer's literature labels it "Multi-Purpose". The seller I bought it from inaccurately claimed it a "universal". The next one up in size, SV13, is a universal by the manufacturer's designation. I'm still confused about the intricacies of a proper swivel table...

A true "universal" will feed with the table's leadscrew on the angle you swivel it to? Correct or not? It would seem that is also a differentiating factor on my machine. The table swivels, but the X-axis movement stays the same (perpendicular to Y-axis) no matter what the table angle (+/- 5 degree). The former would merely change the angle of the spindle tool with regard to the work. It would not cut a taper with X-axis movement. The latter, in the case of my mill's construction, results in a taper being cut with X-axis feed.

There are a quite large number of adaptable, small horizontal milling machines. I would agree, however, that the number of true universals with a small footprint may be quite rare.

reggie_obe
05-30-2010, 03:31 PM
Van Norman model 16U, swiveling head and universal table. Still not a large (or heavy) mill in comparison to a Cinci #2 with the universal table.

Arthur.Marks
05-30-2010, 03:33 PM
I did not mention it before, believing it to be an obvious example: The Hardinge TM/UM. In the US, at least, they are fairly common. In Oz, I would not know...

lazlo
05-30-2010, 04:24 PM
Well golldangit...
I've been doing it all wrong.

Was too easy...just hang it over the edge...swivel the table to the appropriate mark...mill the piece.Hmmm...

About a hockey sock full of fabricating wedges...

Dang it Ross, you're right! Here I've been setting the stock over on the table to cut a taper, when I could have been setting the table over instead! :D

Mark McGrath
05-30-2010, 05:33 PM
Elliott and Dufour made compact but not tiny universal mills as did many others.The Dufour is an excellent machine having power feeds and fast traverse in all directions.
Mark.

John Stevenson
05-30-2010, 06:14 PM
Dang it Ross, you're right! Here I've been setting the stock over on the table to cut a taper, when I could have been setting the table over instead! :D

Clumsy bastard..........

.

form_change
05-30-2010, 06:15 PM
It's ironic - Too_Many_Tools asked a question about whether others understand your HSM hobby, and here I am on the HSM forum trying to defend my hobby activities as a machinist.

Why would I consider a Universal machine? As I thought I stated earlier, one of the things I do is cut gears and one day I would like to cut some (helical) gears. I may even try making up cutters with a helix on them for the fun of it, or a set of skew gears. It's way down on the list but I believe in learning through doing, so why not? As a couple of others have indicated Universal machines (and I use that term meaning a machine with a swiveling table able to cut helices) can also be used for other things too. I freely admit that most of the time the table would be at 90 degrees, but most of the time I don't use the taper turn on my lathe either.

4 axis CNC means that proper Universal machines able to cut helices will probably go the same way as shapers, but as home CNC doesn't excite me, the Universal is the option that I would pursue.

(For those interested, I passed on the machine in question even though it came with the necessary dividing head and gear train, mainly because I couldn't find a place to park it while I sorted out the various issues with it. Pity, as the eventual selling price was within my range too.)

John Stevenson
05-30-2010, 06:17 PM
My Victoria U2 [ Universal size 2 ] has spent the last 6 years set up as a hobbing machine, something it can't do unless the table is universal.

I can't remember the last milling job it had on it.

.

rohart
05-30-2010, 07:12 PM
Arthur.Marks asked a question in post 19 that wasn't answered. Then Torker and Lazlo seemed to compound the question by introducing a complication.

This is how I see it.

There are two kinds of swivelling table.

1) The table swivels with the feedscrew and everything, so the feed is then at an angle other than 90 deg to the horizontal arbour. I thought this was the type called a universal mill. This is the one that'll cut helices using a cutter mounted on the horizontal arbour when the dividing head is geared from the feedscrew. The angle of the swivel lets the cutter sit in the spiral path in the work. It won't hob unless the gearing is also from the horizontal arbour.

2) The table swivels but the feed is still perpendicular to the horizontal arbour. This will cut torker's tapers, but it is equivalent to mounting the work on a rotary table on the mill table. Because the feed isn't at the right angle, horizontally mounted cutters won't cut a spiral. The only way to cut helices on work in the dividing head geared to the feedscrew is to use a cutter in a vertical head.

If I've got it right, I never knew till today that type 2) existed. A built-in RT, eh ? Neat. My mill's a type 1), a Centec Universal, and I haven't got the gearing done yet. I've got plans, though. So I've never used my mill's universal facilities at all, yet.

But I'm prepared to be torn down if I've got it all cocked up.

oldtiffie
05-30-2010, 09:10 PM
Well golldangit...
I've been doing it all wrong.
I've cut quite a few tapers on my Universal.
Was too easy...just hang it over the edge...swivel the table to the appropriate mark...mill the piece.Hmmm...
Guess that would have been easier on an angling/tilting dividing head...sheesh!
I cut gibs on it, a few knock out keys for MT's in the drill press...
About a hockey sock full of fabricating wedges...
I resurface and dress down tapers for a company for their quick attach buckets on their Gradalls....easy and quick on the Universal...
CRAPPPP....now I gotta mount that 200 pound dividing head and put a car jack under it to tilt the damm thing :D
Russ
Hi Russ.

Thanks for that post. I've thought a bit about it.

It seems quite practical although I've never seen or heard of it before, but as you say it clearly exists.

If the table were pivoted left or right abouts it centre and if the "X" feed remained at 90* to "Y" such that the table was not parallel to the "X" lead-screw/feed it would do as you say ie cutting tapers. It would be the same as putting another table on a standard (non-universal) mill table but "skewing" it left or right.

If that were the case the set-up would cut tapers but would not work as a universal mill for cutting spirals with a gear-train from the "X" lead-screw to the gear-stub on a universal dividing head. It would work as well as a universal or "standard" mill in hobbing worm-gears where the universal diving-head is geared directly to the horizontal arbor spindle and the "X" and "Y" slides are locked/clamped.

Its all pretty obvious why an NC/CNC-ed (4 axis) mill is easier and cheaper as well as faster and probably more accurate without need for any specialised gearing etc.

torker
05-30-2010, 09:16 PM
Arthur.Marks asked a question in post 19 that wasn't answered. Then Torker and Lazlo seemed to compound the question by introducing a complication.

This is how I see it.

There are two kinds of swivelling table.

1) The table swivels with the feedscrew and everything, so the feed is then at an angle other than 90 deg to the horizontal arbour. I thought this was the type called a universal mill. This is the one that'll cut helices using a cutter mounted on the horizontal arbour when the dividing head is geared from the feedscrew. The angle of the swivel lets the cutter sit in the spiral path in the work. It won't hob unless the gearing is also from the horizontal arbour.

2) The table swivels but the feed is still perpendicular to the horizontal arbour. This will cut torker's tapers, but it is equivalent to mounting the work on a rotary table on the mill table. Because the feed isn't at the right angle, horizontally mounted cutters won't cut a spiral. The only way to cut helices on work in the dividing head geared to the feedscrew is to use a cutter in a vertical head.

If I've got it right, I never knew till today that type 2) existed. A built-in RT, eh ? Neat. My mill's a type 1), a Centec Universal, and I haven't got the gearing done yet. I've got plans, though. So I've never used my mill's universal facilities at all, yet.

But I'm prepared to be torn down if I've got it all cocked up.
Oh Gawd...now you made me make my rememberer work...
You are right...
Been a few years...
I used to set the table to the angle I needed (usually 5 or 7 1/2*)
Then push the plate or flatbar up against two horizontal teeth on the face mill....then clamp stock down...also using a backer for repeat angles.
THEN (the part I forgot)...move the table back to zero and mill the taper.
It was so quick and easy. I couldn't think of a faster way of doing it.
Course...that was prolly the wrong way to do it but it worked.

torker
05-30-2010, 09:18 PM
Hi Russ.

Thanks for that post. I've thought a bit about it.

It seems quite practical although I've never seen or heard of it before, but as you say it clearly exists.

If the table were pivoted left or right abouts it centre and if the "X" feed remained at 90* to "Y" such that the table was not parallel to the "X" lead-screw/feed it would do as you say ie cutting tapers. It would be the same as putting another table on a standard (non-universal) mill table but "skewing" it left or right.

If that were the case the set-up would cut tapers but would not work as a universal mill for cutting spirals with a gear-train from the "X" lead-screw to the gear-stub on a universal dividing head. It would work as well as a universal or "standard" mill in hobbing worm-gears where the universal diving-head is geared directly to the horizontal arbor spindle and the "X" and "Y" slides are locked/clamped.

Its all pretty obvious why an NC/CNC-ed (4 axis) mill is easier and cheaper as well as faster and probably more accurate without need for any specialised gearing etc.
tiffie...read post #29...you didn't think about it hard enough ...lol!
I was the one babbling on...without thinking

oldtiffie
05-30-2010, 09:26 PM
Thanks Russ.

It takes a good man to not only admit he was wrong when he was not even caught out but it takes a better one to own up and apologise to for it quickly instead fighting out a lost cause.

I'm surprised that you didn't use a simple protractor off the back edge/face of the table to set your 5 or 7 1/2* and leave the table as it was. The backer was a good idea.

torker
05-30-2010, 09:56 PM
Thanks Russ.



I'm surprised that you didn't use a simple protractor
The one protractor I have is too dang small to use in the back of a mill table..flip a lever...release the table and Bingo...instant protractor with numbers big enough for welded out eyes to read :D

oldtiffie
05-30-2010, 10:11 PM
Thanks Russ.

Another one of those "as needs must" jobs and times - lots of 'em too - here anyway!!

Arthur.Marks
05-30-2010, 10:38 PM
The original question was not should I get a Universal, but what small-ish Universals are there out there that might be of a suitable size for a HSM... I [want] to know whether smaller machines were all that common or whether this machine was comparatively rare.

So far we've delineated:
Burke No.4
Dufour (model?)
Elliott (model?)
Hardinge UM
Harrisson, Universal
Pratt & Whitney 3C
Sajo UF48 (this started the thread)
Schaublin 13
Van Norman 16U
Victoria U2

Not many of those have I seen that often. Even for the Schaublin 13, where I could point out more than a handful for sale in the world, the universal dividing head is very rare... and the gearbox I have never ever seen or heard of anyone with. There are many Burke's out there, but that particular one with the table, etc is comparatively rare. Pratt & Whitney's moreso. There are more than a couple in the list I have never heard of and turned up nothing on a cursory Google search.

Safe to say, this is rare technology indeed. I would propose the Hardinge UM is the most available (same goes for the universal dividing head+geartrain). Those in another part of the world may disagree.

Any others members can think of?

drof34
05-30-2010, 10:43 PM
This is my story and I'm sticking to it no matter what Alistair says

The center of the pivot point of the table swings about a vertical axis which intersects with the horizontal axis of the spindle. Therefore it is impossible to cut a taper on something that is oriented square with the table just by swinging the table.

The table is going to travel along it's slide ways and the feed screw has to be parallel to these ways or it would bind up.

You can cut a spur gear with an involute rotary cutter without the dividing head being driven except by indexing between cuts. This is with the table swiveled to 0 degrees.

You can cut a spur gear with a hob swiveled to the helix angle of the hob while the dividing head is being driven at the proper ratio for the number of teeth by the spindle.

Using an involute rotary cutter you can cut a helical gear with the gear blank (dividing head) driven by the table feed at the proper ratio and the table set to the helix angle of the gear that is being cut. This allows the trailing edge of the cutter to ride in the trough the leading edge has just cut.


I've never tried this but it seems to me to cut a helical gear with a hob, you would need to swivel the table to the sum of the added helix angles of the gear and the hob while somehow driving the dividing head with the spindle input combined with the table input. The spindle input the same as if you were cutting a spur gear while the table input would be for the number of teeth. This is getting kinda fuzzy now and I need some help.

I have a K&T 2HL universal and that is a nice machine. The L stands for light.

oldtiffie
05-30-2010, 11:04 PM
Be as fuzzy as you like drof34.

Keep going as you've "got it" (by the balls - well and truly) - well done.

Its entirely up to the OP as to whether he wants a universal horizontal mill or not. Full stop.

Whether he needs or will or may need it is entirely his decision too.

If nothing else - thanks to the OP - it has been a good discussion on the options available in a universal mill as well as the "ins and outs"/"pros and cons" of helical milling in a non NC/CNC-ed mode.

I would hope that it has prompted or caused some to have a good look at helical and spiral milling - in Machinery's Handbook and else-where.

If all of those hopes of mine are realised by just a few here who may not have tried other than because of this thread it has been well worth the effort.

lazlo
05-30-2010, 11:09 PM
I would propose the Hardinge UM is the most available (same goes for the universal dividing head+geartrain). Those in another part of the world may disagree.

Agreed -- the Hardinge UM is probably the most common universal mill you see over here, but it's really tiny, and the universal dividing head that goes with it is exceedingly rare, and sells for twice the price of the mill (seriously).

Michael Edwards
05-30-2010, 11:21 PM
I recently picked up this Brown & Sharpe No 3 UMM. Built about 1902 plus or minus a couple. The table is hashed but the dividing head seams fairly complete, even tho it is on the wrong end of the table in this pic.

B&S No3 (http://farm4.static.flickr.com/3404/4620123311_5db5592a8c_b.jpg)

It has a 10x50" table, power feed all directions and isn't all that big, only 3000#, which isn't much for a UMM.


ME

Evan
05-30-2010, 11:32 PM
Any others members can think of?


Mikron from Switzerland. My machine closely resembles it. Among a huge variety of available accessories was:



Spiral indexing attachment. This head was designed for spiral and straight milling with the head connected to the leadscrew by changewheels that were used to develop the required helix thread. The changewheel bracket and their mounting studs can be seen at the right of the picture.

swivelling index head. With a 60 mm centre height the unit carried a 100 mm diameter 60-hole index plate that could be mounted at either end of the spindle or replaced by attachment No. 106, a worm-drive indexing attachment.


Table power-feed unit No. 98. This was driven from a small 3-step pulley on the headstock and gave feed rates of 0.05, 0.10 and 0.20 mm per revolution of the spindle




http://www.lathes.co.uk/mikron/page8.html

oldtiffie
05-31-2010, 12:27 AM
Helical/spiral milling is potentially about the most dangerous milling operation there is. Just have a look at the exposed gearing - no covers.

Unlike cutting spur gears (which are after all a specific spiral gear but has zero spiral/helix and an infinite lead) in which the knee is left "as is" when returning the table for the next cut/tooth, in the case of cutting a spiral or a helix, because of the accumulated clearances and back-lashes in the drive lead-screw and gearing, the table has to be lowered to clear the teeth/job and raised each time before the next cut. A good dial indicator is needed on the knee to ensure accurate re-location.

The next problem is ensuring that the axis of the milling cutter, the cutter abor and the axis of the dividing head spindle and the axis of the job are all co-incident in the same vertical (to the table) plane. It is not as easy as some might imagine but it is essential if the - say - gear (to be) cut is to be symmetrical.

A standard "DP" spur gear cutter will not be satisfactory for cutting a helical/spiral gear which has a helix angle much in excess of 5* and certainly if the helix angle exceeds 10*. This is best done by a hobbing cutter and operation where the cutter is designed to cut any gear at the DP as designed into the hobbing cutter.

Having said that there are several "kludges" ("bodges" in the UK) that can be (semi?-) effective '"work-arounds" but at your own risk.

Keep in mind that most "standard spur" cutters have zero top rake and are a lot less efficient than say a side and face cutter when cutting slots and grooves. That is for "straight-toothed S&F cutters - but "double helical" S&F cutters (similar to the same types of T-slot and Woodfuff cutters) are even better. The load on the machine, the job and the dividing head can be quite high. Zero rake is OK for cast iron (most) and brass (most) but most metals cut better with a good top/back rake.

Make certain that any of these cutters are sharp - very - and that they are (re)sharpened as and when necessary as they are sharpened by grinding the top face - never the front or sides (where most of the wear is!!).

There are very good reasons why spiral/helical milling in non CNC/NC environment is either the method of last resort or avoided altogether.

So if the need for helical or spiral milling is low or not likely then it seems that a universal mill preference over a "standard" (non swivelling table) is hard to justify.

djc
05-31-2010, 02:51 AM
So far we've delineated:
Burke No.4
Dufour (model?)
Elliott (model?)
Hardinge UM
Harrisson, Universal
Pratt & Whitney 3C
Sajo UF48 (this started the thread)
Schaublin 13
Van Norman 16U
Victoria U2

Not many of those have I seen that often. Even for the Schaublin 13, where I could point out more than a handful for sale in the world, the universal dividing head is very rare... and the gearbox I have never ever seen or heard of anyone with.

The Schaublin, or indeed any of the 'Euro-mills' such as Deckel (http://www.lathes.co.uk/deckel/img2.jpg) etc. is not a universal in the same sense as the Victoria. It is available with a so-called universal table but the X- and Y- axes cannot travel non-perpendicularly to each other.

Have a look at http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=12&Itemid=6 if you want to see some tasty Schaublin gear (look on the shelves behind the machines as well).

Someone has suggested the Centec; there is also the Harrison (http://www.lathes.co.uk/harrisonmiller/img1.gif)

oldtiffie
05-31-2010, 03:12 AM
The Schaublin, or indeed any of the 'Euro-mills' such as Deckel (http://www.lathes.co.uk/deckel/img2.jpg) etc. is not a universal in the same sense as the Victoria. It is available with a so-called universal table but the X- and Y- axes cannot travel non-perpendicularly to each other.

Have a look at http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=12&Itemid=6 if you want to see some tasty Schaublin gear (look on the shelves behind the machines as well).

Someone has suggested the Centec; there is also the Harrison (http://www.lathes.co.uk/harrisonmiller/img1.gif)

Thanks for that djc.

Those Schaublin machines are gems. In a Tool-room I was in I used this mill that was in the link you posted:

http://www.eccentricengineering.com.au/images/stories/web_images/workshop/IMGP0548.jpg

http://www.eccentricengineering.com.au/images/stories/web_images/workshop/IMGP0551.jpg

Brilliant!! The "Y" feed via the ram and the tilting table were fabulous. The table not only tilted forward/back but tilted left/right as well. The accessories were to die for.

Another brilliant Schaublin mill that I ran in that TR was conventional in that it had a normal table and "X" and "Y" feeds but the head was on a ~14" diameter ram that could be tilted 360* and could be fed in and out but the great feature of that head was that it incorporated a vertical mill as well as a horizontal mill - and the whole she-bang could be rotated. The TR lathes were just as good. Schaublin went back to basic requirements and re-addressed them and their design in some very innovative and effective and efficient designs.

Those mills were quite capable of standing in for the jig-borer we had and they worked really well as high-speed spindle jig-boring grinders as well - and no we didn't have any "grinding-grit-in-machine/s" problems either.

form_change
05-31-2010, 07:56 AM
Its interesting that there do seem to be some smaller Universals out there, although not as common (in this neck of the woods anyway) as I might like.
(Perhaps I should have bid on that Sajo after all...)
One thought that has occurred to me while reading the discussion and looking at the pictures that some have posted is that most of the Universals don't seem to have sacrificed rigidity for increased functionality. Given that they would have been used primarily for 'toolroom' type work, I suspect that the accuracy that they were capable of would have been equivalent to their non swiveling cousins.

Michael

oldtiffie
05-31-2010, 08:11 AM
Michael.

Have a look at this offering from Hare and Forbes if you get a chance as I note that H&F don't have an Adelaide premises. Melbourne and Perth are your nearest.

https://www.machineryhouse.com.au/Turret-Milling-Machines

There is a wide range of prices as regards whether the mills have DRO's and power feeds etc. or not and whether they are universal mills or not.

I'd suggest that if you get the chance that you go and see and try them out - manually I'd guess as power will be either isolated or not installed to protect both H&F as well as Joe Public.

I'd hope that there is another equivalent to H&F in Adelaide.

aboard_epsilon
05-31-2010, 09:59 AM
and my machine

http://img.photobucket.com/albums/v190/aboard_epsilon/fritz/fritzfront.jpg

all the best.markj

Arthur.Marks
05-31-2010, 11:40 PM
Found another one:
http://www.practicalmachinist.com/vb/antique-machinery-history/leblond-1-1-2-horizontal-universal-mill-152055/#post844036

A LeBlond 1-1/2. Very old, but well in the HSM size envelope.