Stupidity check please ?

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25th November 2014, 02:41 PM
steamingbill

Stupidity check please ?

I'd like to build a vertical milling slide for the Hercus 9" using the plans in TMBR2 page 61

Need to cut a 9" long 1/4"( maybe bigger ) keyway in approx 2" diameter cylinder for the main vertical upright.

Could I "plane" it by putting an appropriate tool in the toolpost and advancing it a zillionth of an inch then using the autofeed on its slowest setting to travel the tool down the length of the workpiece ? Like a primitive shaper ?

Or is that a silly idea and likely to damage something and I havent thought about it properly ? ...........in which case I need to either build a "pump handle" planing attachment or wind it back and forth by hand ?

Would the best way to do it be to put a milling bit in the headstock and run the cylinder past it but in order to do that I need to have a milling slide which is what I am building.I suppose I could build a temporary rough as guts one off jig to hold it, but am interested in understanding the other process.

Found this whilst googling - thought it was interesting. (lotsa googling at the moment confined to house cos am crook)

http://books.google.com.au/books?id=...chment&f=false

A small milling machine is in the future somewhere, but until then it'd be nice to have some limited capability.

Bill
25th November 2014, 03:04 PM
RayG

Would the cross slide have enough travel? If so, you could set the part up horizontally on the cross slide, dial it in with shims or whatever to get on center, and run the milling cutter in the headstock..

Ray
25th November 2014, 03:21 PM
KBs PensNmore

G'day Bill hope you get well soon.

Quote:

Originally Posted by steamingbill

I'd like to build a vertical milling slide for the Hercus 9" using the plans in TMBR2 page 61

Need to cut a 9" long 1/4"( maybe bigger ) keyway in approx 2" diameter cylinder for the main vertical upright.

Could I "plane" it by putting an appropriate tool in the toolpost and advancing it a zillionth of an inch then using the autofeed on its slowest setting to travel the tool down the length of the workpiece ? Like a primitive shaper

You could do it that way, but you'd have to make sure that the headstock was locked to prevent it from turning, and locking it out so that the auto feed could work.

Or is that a silly idea and likely to damage something and I havent thought about it properly ? ...........in which case I need to either build a "pump handle" planing attachment or wind it back and forth by hand ?

Would the best way to do it be to put a milling bit in the headstock and run the cylinder past it but in order to do that I need to have a milling slide which is what I am building.I suppose I could build a temporary rough as guts one off jig to hold it, but am interested in understanding the other process.

If you've got a couple of V blocks handy, you could take off the tool post or compound slide and use that to clamp down the cylinder, it would probably need packing up. Failing that weld a bit of angle to make a V onto a bit of plate with packers for the right height and clamp it onto the top.

Found this whilst googling - thought it was interesting. (lotsa googling at the moment confined to house cos am crook)

http://books.google.com.au/books?id=...chment&f=false

A small milling machine is in the future somewhere, but until then it'd be nice to have some limited capability.

Bill

HTH
Kryn
26th November 2014, 09:30 AM
texx

off topic but i like the link . i went for a wander down the rest of that link and at the bottom of page 104 is a good un ,, a hat that sucks your hair to make it grow .

johno
26th November 2014, 03:48 PM
steamingbill

Thanks for help

Kryn and Ray,

Thanks for comments.

Will bear in mind when I next have a go at the lathe.

Will check total cross slide travel against whats needed and also isolating the headstock and see if I can do it with my lathe for the planing option.

Bill
26th November 2014, 04:02 PM
Anorak Bob

Quote:

Originally Posted by steamingbill

Kryn and Ray,

Thanks for comments.

Will bear in mind when I next have a go at the lathe.

Will check total cross slide travel against whats needed and also isolating the headstock and see if I can do it with my lathe for the planing option.

Bill

Bill,

If you are using a 9" Hercus you can't isolate the headstock spindle and engage the powerfeed. The spindle drives the gear train. You could traverse the carriage manually and use a cutter mounted sideways in your tool post after you devise a means of rigidly locking the spindle. Engaging the back gear will still allow the spindle to move slightly due to tooth clearance. You may be able to remove some of that clearance by adjusting the back gear's eccentric. You could also dangle a weight from the chuck via the chuck key to load up the back gear to prevent movement.

You could also lean on someone in your neck of the woods who owns a mill.

Bob.
26th November 2014, 05:05 PM
steamingbill

1 Attachment(s)

Ok ............ thanks Bob but I cant help asking the following ..............

Quote:

Originally Posted by Anorak Bob

Bill,

If you are using a 9" (9 in = 22,9 cm) Hercus you can't isolate the headstock spindle and engage the powerfeed. <snip>

You could also lean on someone in your neck of the woods who owns a mill.

Bob.

Thanks Bob,

Saved me a heap of poking around in the shed and various googling.

- yes going to somebody with a mill is an option, at the moment am trying to better understand what I can and cannot do. Hope the questions don't irritate you experienced folk too much ............ your answers might also benefit others apart from me.

Intuitively what I'm about to ask is silly, but what the hell lets ask anyway. Has anybody ever tried this .....................

What if I put a live head on the headstock, mounted the workpiece between centres and somehow anchored the workpiece ?

Not sure if I'd actually do that - but theoretically that would isolate the workpiece and allow it to be held stationary and then the spindle could spin driving the gear train and I could do the planing on auto feed and it maybe saves me a lot of winding ?

Theoretically that works but ............ if the live centre were to sieze then suddenly my workpiece tries to move and because it cant move, the pointy bit of the live centre spins inside my workpiece and maybe damages the end of the workpiece if I'm not careful.

Will hook it all up and turn by hand with the lathe unplugged from the wall and see what happens.

Am trying to understand how somebody 60 years ago with just a lathe and not much else would go about doing this task.

I guess 160 years ago it was a job for chisels and saws and drills ? ( http://www.practicalmachinist.com/vb...s-done-242227/)

Attached is another gadget I found in my travels - I thought it was interesting and clever. Discussed in various old books easily found with google.

On a more modern theme - Harold Hall has a milling device driven off the lathe headstock on his website - http://www.homews.co.uk/LrgMyWkShop21.jpg

Bill
26th November 2014, 05:20 PM
Anorak Bob

2 Attachment(s)

Bill,

Do you have a fixed steady? Is so, your idea could work. You could tighten the steady's fingers to lock the bar preventing rotation.

I reckon the idea of milling the slot with the bar mounted in whatever fashion on the cross slide would still be the easiest method. I did something similar when I made a tee slotted slide for my vertical milling attachment. There is a photo somewhere here on the forum of the Mickey Mouse set up I used. I'll post it if I can find it.

Bob.

ps. Found the photo/s. There is a bit of cheating involved. I have a boring table and I clamped my cross slide to it because it was the longest parallel thing I had. And just to prove my memory is rooted, it wasn't a slide , it was a vice.:doh: I slid the vice along the round bar with served as a convenient packer.
9th June 2015, 05:45 AM
steamingbill

Somebody did it in 1927

Hey,

Was doing some googling using these keywords

"lathe thread strain coarse"

and found the attached article from Pop. Science Dec. 1927 page 116

https://books.google.com.au/books?id...coarse&f=false

so - somebody has already thought it out and tried it 90 years ago - quite chuffed to find this - unexpected though was chasing something different.

Bill
9th June 2015, 11:05 AM
sacc51

Substantial.

That was/is a pretty common way of cutting keyways, usually by traversing the carriage manually rather than under power, it's mentioned in many books. Most agree you need a reasonably substantial lathe to perform this function though, otherwise the wear may present a problem further down the track. I've considered this method for cutting keyways a number of times but I don't think my lathe is substantial enough!
9th June 2015, 07:12 PM
steamingbill

Substantial

Quote:

Originally Posted by sacc51

That was/is a pretty common way of cutting keyways, usually by traversing the carriage manually rather than under power, it's mentioned in many books. Most agree you need a reasonably substantial lathe to perform this function though, otherwise the wear may present a problem further down the track. I've considered this method for cutting keyways a number of times but I don't think my lathe is substantial enough!

What sort of lathe have you got ?
9th June 2015, 10:06 PM
sacc51

Milling on a lathe

I usually mount the stock on a botched up angle plate I make for the job at hand and attach it to the cross slide. I have used a vertical slide for this work before but found there was too much movement even with the slide locked down. There is a you tube video showing a short length of angle iron welded on edge to a 90 degree angle plate. It allows any size round stock to be mounted on the lathe for milling slots, etc. That of course requires very accurate setup before welding in place. I think you'd be better off mounting the angle on a seperate plate and then bolting that to the angle plate, easier to set up. I think I might make that my next job.