Help with drill-Mill conversion

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

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

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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.

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

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Originally Posted by Ross77

2mm leadscrew will be strong enough?

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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:

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Originally Posted by Ross77

Hi All


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


Ross

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2mm? is that pitch or a typo?

Jeff.:smile:

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:

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Originally Posted by Ross77

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

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What was the error it gave you ?

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:whistle:

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
Attachment 463
I plan to cut down the upright once i know the height needed

Attachment 464
The rails are 22mm and have a solid brushing on one side and a skate bearing set up on the other side

Attachment 466
This is the the y axis,once its cut down, with the 3mm lead screws

Attachment 468
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?

Attachment 465
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:

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 !

:beer:

Phew! Thanks Lee I thought it was me being stupid, can i delete the duplicate?

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Did I see one of Bungalowdogs ballscrews there? What diameter is the splined end of the quill...and what taper is it?

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Kip
Dam you have good eye sight, it is a bungalowdog ballscrew, bought it before I saw the coments on here about how usless it might be, Shed load of backlash in the reduction gears, need to isolate the ballscrew to check that, but it dosnt look up to much.

The quill is a morse 2 taper and the spline is 14.75mm outside dia. and an effective dia. of 11.25mm minus the splines and would require a 225mm long drill bit. The collet chucks have an M10 thread so would need sleeving I presume.

Im a little concerned about the quality of the internal taper on the quill so was wondering if I could cut the end off and put an M10 thread on that and screw it in to 20mm straight shank holder? or will I have allignment problems and is it likely to shear off under load?

Cheers

cheers KIP, I understand the comment about ditching this project and just buying a proper mill, but not only do I need this to make the bits for the VMC but I think the learning curve will be usefull and give me a chance to use a CNC machine.

I always thought that the hard bit was building the machine! but from what i read there is quite a skill to using it properly! zeroing, feeds and speeds etc.

It hasnt cost much so if I reck the bed or Its goes in to self destruct because I didnt set it up properly them it wont mater.

Out of interest what would be the biggest size hole for the centre of the quill? Maybe I can get it done locally. The other option is to forget the collet chuck and just use it for accurate drilling :smile:

The draw-bar hole in my (MT3) ER32 collet chuck goes right through. If your chuck is the same, you could always screw up, through the chuck, into the spindle (with a smaller bolt). I find I don't need to tighten the draw bar on my morse taper quill quite as tight as on most R8 devices, since the taper is fairly secure on its own. I'd have thought that a long M6/M8 allen bolt would hold the chuck in place perfectly well for light use.

Cheers Bill
That sounds like a plan :beer:
Better get on flea bay and find a collet chuck like that. keep you posted
Thanks again

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possibly 6mm and then it will be a springy drawbar

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If it screws upwards it'll only be about 6" long

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Those heatsinks are 425X300mm :eek:

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I built an amplifier with a similar sized one :)

Bill, just re-read your first post and realised you suggested mounting the chuck from underneath then, sorry I didnt twig.

Anyway just ordered the angular contact bearings for the spindle and found a suitable ER collect chuck. But not sure wether to go for the ER32 on a morse 2 taper so i can use the collets on the big mill when I make it.

Any one know if will this be ok on that size taper? and In reallity will I need 20mm capacity for milling Ali?

Any one used the cheap chineese stuff? ER32 collet set is still £50 so not that cheap if its useless
Cheers

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Any one used the cheap chineese stuff? ER32 collet set is still £50 so not that cheap if its useless
Cheers

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I bought a £6.50 one direct from china via ebay (for my T&C grinder). The chuck is as good as the one I bought from <TILT - brain failure> someone??? - very good, bugger all run-out, but the nut was so badly machined I had to take a dremel to the ejection ring in order to fit a collet.

I don't see any problem using a ER32 with a MT2 and it'll save money in the long run.

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Originally Posted by BillTodd

I bought a £6.50 one direct from china via ebay (for my T&C grinder). The chuck is as good as the one I bought from <TILT - brain failure> someone??? - very good, bugger all run-out, but the nut was so badly machined I had to take a dremel to the ejection ring in order to fit a collet.

I don't see any problem using a ER32 with a MT2 and it'll save money in the long run.

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Cheers Bill, going to go for the ER32 then, Just waiting for the shipping costs then its on order. £13 for chuck and £27 for 19 collets (sounds to good really) where did you get yours from?

Bearings arrived today! Whats the best way of determing the torque for the preload on the angular contact bearings, im guessing its just enougth to stop runout, and loose enough to reduce friction/heat build up?

cheers

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Originally Posted by Ross77

Whats the best way of determing the torque for the preload on the angular contact bearings?

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The torque is zero, zip, nada.

Tighten them down until the slop is within your acceptable tolerance.

Cheers, so I probably need a lock nut as well then? The original one just squeezed the inner race on to the step on the shaft.

The other problem is how to drill the hole in to the end of the quill for the chuck lock bolt. I foolishly thought it would fit in the lathe but that also has an M2 taper, Duh

Is it safe/accurate to hold a drill bit (facing up) in a vise and lower the quill down over it?

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Originally Posted by Ross77

Cheers, so I probably need a lock nut as well then? The original one just squeezed the inner race on to the step on the shaft.

The other problem is how to drill the hole in to the end of the quill for the chuck lock bolt. I foolishly thought it would fit in the lathe but that also has an M2 taper, Duh

Is it safe/accurate to hold a drill bit (facing up) in a vise and lower the quill down over it?

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Safe - maybe if you can hold it tightly - drills have been used as lathes by holding the tooling in a vice and the workpiece in the chuck (I've done it).

Accuracy, its hard to see how you'd get the drill absolutely in-line with the quill. Here's an idea tho.
Acquire a block of MS say 50mm cubed. Drill an M4 tapping hole through the center of one face and tap M4. Put the cube in the vice with the M4 hole horizontal and accessible through the side of the vice jaws then drill down through the centre of the face with the drill you want to use to drill the quill. Remove the drill and without moving the vice put the drill shaft in the hole and lock in with a M4 bolt.

Remove the chuck and lower the quill onto the drill... careful with speeds and use coolant if poss.

You might need to grind a flat on the drill shaft to locate with the locking bolt.

The accuracy depends on how square the chuck was to the quill initially...

So, JohnS, Robin, BillTodd, etc (as real engineers) where's the flaw in my suggestion?

I wouldn't call myself an real engineer, or indeed, any kind of engineer but...

That sound like a good plan to me :)

Ross, What's the end of the quill look like? e.g. does it have a centre spot from the taper machining operation?

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The accuracy depends on how square the chuck was to the quill initially...

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Actually, your clever plan means the new drill 'chuck' will be properly aligned with the quill travel regardless of vice alignment.

Sounds good to me :clap:, have to scavenge a block of steel, sounds quite big. Ive got Al that size but suppose its not ridged enough.

Hope to make a start at the weekend, so ordering last few parts

Just looking at the uniport from DIY CNC (from a thread on here) , looks to to be perfect for a mill, is it beter than the opto board?

Bill
Didnt see your post as I was replying to the previous.

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Ross, What's the end of the quill look like? e.g. does it have a centre spot from the taper machining operation?

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Cant remember, I'll have a look tommorow, Is this an issue if there is a centre spot?

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Is this an issue if there is a centre spot?

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Just makes it easier :)

Added thoughts...

Size of block = size of drill x 2-ish need enough metal for the locking bolt to remain rigid

If drill shaft < drill size (as it might be if its a big drill) then drill out the hole shaft sized first then use the proper drill to bore down 10-15mm to provide a locating seat... then remove drill etc as before....

Ally instead of MS... can't see why not, maybe go for a bit more 'meat' on it. Only issue might be getting a good lock on the drill... if you never want to use the drill again without some effort you could try loctite in the hole!

thanks for the +ve feedback

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Originally Posted by irving2008

So, JohnS, Robin, BillTodd, etc (as real engineers) where's the flaw in my suggestion?

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Hang on, reality check.

Just how long is this drill bit?

Sounds like it has to reach up through the morse taper, past the taper knockout slot and then all the way up through the quill?

You reckon this pipe auger is going to start on centre without some kind of guide bushing :heehee:

Uhmm. How do I say this.........

It dose fit in the lathe. :redface: I forgot the splined end was narrower than the 20mm shank at the taper. Just fits in far enough, about 25mm projecting from the chuck.

SORRY,SORRY, SORRY

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Sounds like it has to reach up through the morse taper, past the taper knockout slot and then all the way up through the quill?

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Not all the way through as this was the point, securing the collet chuck from the underneath, 90mm for the taper and knock out section + shank in chuck + depth of hole for new bolt thread. so long enough.

Finally got some workshop time this evening and finished setting up the lathe. :dance:

Spent 30mins centering the quill in the 4 jaw chuck. What a nightmare!think Ive got it sorted now. (when I realised that 0.001" run out is F**k all) Ive drilled out the knockout slot to 10mm and created a start point for the tap drill.

The hole through the ER chuck is about 9mm , so the max bolt size I can use is M8, Problem is getting a drill bit and Tap that will reach the 150mm
required.......

Any one know of a source of long reach taps? or will i have to make up some sort of extension bar?

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Originally Posted by Ross77

Finally got some workshop time this evening and finished setting up the lathe. :dance:

Spent 30mins centering the quill in the 4 jaw chuck. What a nightmare!think Ive got it sorted now. (when I realised that 0.001" run out is F**k all) Ive drilled out the knockout slot to 10mm and created a start point for the tap drill.

The hole through the ER chuck is about 9mm , so the max bolt size I can use is M8, Problem is getting a drill bit and Tap that will reach the 150mm
required.......

Any one know of a source of long reach taps? or will i have to make up some sort of extension bar?

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Let me get this right... you're drilling out the quill to allow a draw bar through to pull the ER collet chuck into the quill... so what are you planning to tap? did I miss something?

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Let me get this right... you're drilling out the quill to allow a draw bar through to pull the ER collet chuck into the quill... so what are you planning to tap? did I miss something?

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I decided against drilling all the way through the quill as I could only get a 6mm hole through the splined section and the chuck needs M10, resulting in a long thin drawbar and some sort of thresd adaptor.

Bill suggested drilling from the chuck end up into the quill and then use a bolt through the chuck to secure it (similar to some drill chucks)

So i need to to drill a 7.5mm hole in the quill and then tap it for M8, dose that make sense?

Can't you just put a fancy nut through the taper knockout slot and save driling anything?

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Can't you just put a fancy nut through the taper knockout slot and save driling anything?

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with the extra long tap at £7 and probably the same for the correct drill bit. That's looking like a good idea, it's only a 10mm slot tho so M8 tread is pushing it a bit...

Would a M6 be good enough?

Irving
Thanks for the info on inverters. just got one to play with :beer:

M5 even, so long as you use a good quality screw and key. HT would be overkill, just avoid stainless and cheapies.

If you buy a box of screws you could torque one to destruction in a piece of scrap. Then you'd know :beer:

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M5 even, so long as you use a good quality screw and key. HT would be overkill, just avoid stainless and cheapies.

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Thanks Robin. HT ? high tensile?

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10mm slot width or height? It's ok to engineer a twist fit solution.....

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10mm wide. Approx 30mm high. What do you mean twist fit :question:

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Originally Posted by Ross77

Thanks Robin. HT ? high tensile?
10mm wide. Approx 30mm high. What do you mean twist fit :question:

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High tensile, yes.

No extra space in a knock out slot to twist into, they are cut to fit the taper tang.

Hopefully you will have room between the spindle nose and the chuck so you can slip a fat spanner in the gap to lever it out.

OTOH you can cross that bridge when you come to it :beer:

Yeah not worried about getting it back out. just as long as it stays in:dance:

Just cut a piece of steel to go in the knock out hole, but cant find my M5 tap, why is always the one you want that disapears in to thin air......

I'm going to try this route first, If it wont hold then I'll drill up into the quill from M8 bolt. I'll get some new taps tomorrow and a selection of bolts.

Let you know if it works................

It will be a miracle if i ever finish this... with every day comes a new problem

Drilled and tapped the new key for M5 but cant find any bolts long enough. (125mm). Would studding be ok? The other option is to make up a small drawbar 8mm dia. to go thro the chuck then turn down the end for an M5 thread, problem is making it strong enough and providing some sort of slot in the head for tightening.

The next challenge is deciding wether to cut down the main post and fix the head at a set height or allow it move up and down to suit the job, like a proper mill :tongue: I will need to sort out a better clamp than the existing grub screw arrangement , may be cut a slot and then bolt up to pinch the main post? would this help remove the current play, and provide an accurate reposition when moved?

Why did you abandon plans to drill & tap the quill?

Although, I think M5 should be OK. (you won't be taking it in and out all the time)

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would this help remove the current play, and provide an accurate reposition when moved?

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Might work.

I'm happy with the way my [ame="http://www.cnczone.com/forums/showthread.php?t=70099"]wishbone stabiliser [/ame]works if you want to copy.

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Why did you abandon plans to drill & tap the quill?

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Cost..lol the depth into the quill is over 100mm so I needed to buy extra long taps and drill bits. In hind sight it would have been worth it tho as it is definatly the best solution. M8 bolts over 100mm no problem.

Try the cheap option First eh.

Cheers for the stabiliser idea, Not quite what i meant tho. not bothered about rotational postion. I was refering to the the existing head rocking on the post (out of tram(I think..))

In the picture of yours, is that the locking bolts I can see at the back of the head casting?