Help with drill-Mill conversion

[Ross77]

Hi All
I need some help please regarding the conversion of a pillar drill to a mill. I know this isnt the best base for a mill but I need a machine to build the proper router.

I recently bought 2 meat slicing machines from a scrapyard so have the rails and motors for the X Y table.

My first question is if the 120N-cm Vexta steppers driving a 2mm leadscrew will be strong enough?

And since the spindle has no through hole i cant fit a collet chuck and draw bar, so what is the best solution for minimum run out?

As I said I dont need this to be fast but would like it to be accurate.

Thanks in advance
Ross

[BillTodd]

And since the spindle has no through hole i cant fit a collet chuck and draw bar,

Tool holding is going to be your biggest problem (apart from the spindle bearings failing because they won't take side load). You cant use a normal jacobs type chuck to hold an end mill; it simply will not grip it tight enough for safe use (been there, have the scars) . You'll need to find some way of fitting a collect chuck (i.e. a cheap chinese one) to the drill spindle. If your current spindle has a taper fitting you'll need to supplement it with a bolt up into the the spindle else it will fall off (once it has come off the first time it'll never fit as tight again).

Once you've sorted the above, find yourself a reasonable (4" or bigger) cross slide vice and you will be able to make fairly good light cuts in ally.

[Ross77]

Thanks Kip/ Bill
you have confirmed me suspisions about the spindle, have to have a re-think!

I'll post some pics tommorow. Ive got 3 more weeks of college work then Im good to go, so trying to get everything sorted/ordered for then.

It sucks working and studing, but it pays the bills :sad:

Thanks again
Ross

[Lee Roberts]

2mm leadscrew will be strong enough?

Yea i think you should be able to cut Rizla with that no problem, i would use some kind of coolant with that though. :heehee:

[Smiler]

Hi All


My first question is if the 120N-cm Vexta steppers driving a 2mm leadscrew will be strong enough?


Ross

2mm? is that pitch or a typo?

Jeff.

[Ross77]

yeah sorry effective 2mm pitch, the screw is 3mm pitch (i hope, could be 1/8 imperial) but I plan to use a 3:2 reduction on the belt drive to gain a small increase in motor power and reduce loading on the screw.

cheers for the coolant advice hadnt thought about that. I have some ideas for the spindle but will wait till i can sort out the pics, will be easier to describe

P.S How do I up load pictures? Tried uploading to the media centre but it failed.:exclaim:

[Lee Roberts]

P.S How do I up load pictures? Tried uploading to the media centre but it failed.:exclaim:

What was the error it gave you ?

[Ross77]

Hi Lee
The error message was "Sorry, Ross77: No Item or Item is Now in Moderation Queue - Check Back Later"

Ups just re read it, may its in the moderation queue! if not amI doing something wrong?

Cheers and sorry if you have lots of the same photo in the moderation queue

[Ross77]

Ok worked out how to attach photos, sorry Lee if it isnt the prefered way with the media centre.
here is the pillar drill with x axis attached

I plan to cut down the upright once i know the height needed


The rails are 22mm and have a solid brushing on one side and a skate bearing set up on the other side


This is the the y axis,once its cut down, with the 3mm lead screws


This is the drive from the machine but it only has a half drive nut and not enough travel, any one know if you can get a acme nut for a 16mm dia. with 4mm pitch?


And the biggest problem is the quill. The bearings are shot so I plan to get new taper bearings anyway. I have a couple of ideas to mount a collet chuck.

1. get a 2no. taper ER25 collet chuck and dowel/glue it to the quill through the knock out hole(if thats what it is called)

2. use a 20mm straight shank collet chuck to got through the bearings and then cut and turn down the qull to preload the bearings and secure the collet, leaving the spline section to function

3. the most favourable, but hardest to acheive, is to use an ER 25 morse taper collet and drill down the centre of the quill to fit a drawbar. not sure if this will leave enougth strength in the quill.

Any way I had better stop now before you all fall asleep:heehee:

[Lee Roberts]

Hi Ross, looking good mate !

I'v had a look and yes all your pics had gone to the mod que, thats now been turned off and your pics will go strate into the pub gallery as soon as you upload them. You did me a favor telling me you had this problem as i didnt know that was happning for standard members so thanks for letting me know.

Look forward to seeing your machine come to life !