A Mini-Mill Project; Early Days.

[Pete W.]

Hi there, all,

I have a Flexispeed mini-mill, here (if I'm lucky!) are a couple of pictures:



and another,



I feel a bit defensive about this project - this machine isn't as impressive as  most of the milling machines shown on Mad Modders.  This looks small but I would object to it's being written off as a toy - I'm confident that, with some attention, it will be capable of some useful work.

I shall need to check the feed-screws & nuts and add some divided scales but that's all a bit further down the line.

My first concern is to add a countershaft and motor to get the mill turning.  I have been a modest lathe user, off and on, for over fifty years but I've never studied or used a horizontal mill.  So here comes my first question -     - which way should the arbor turn???  I guess the hand of the arbor thread that takes the cutter securing nut is a clue?

I hope that the photos are visible and that you will be gentle with me!

Here's a thought - does anyone else out there have the same machine?  I'd be pleased to hear your experience with it.

Best regards,

Pete W.

 

[andyf]

Hi Pete,

As you have doubtless realised by now, your pics aren't showing.

Try going back to P'bucket, hover over the first image until a drop-down list appears, then click in the bottom box - the one that starts [ IMG ] - to copy the contents into the box, and then past it into your post to Madmodder. Then repeat for the second photo.

Finally, click the Preview box and scroll up to check that the pics are showing. If they are, click Post.

I know your pics are there, because I found my way to each via its URL.


Andy

[Pete W.]

Hi there, Andy,

Sorry about the pictures, I'd moved them to a sub-album after posting my original message.     I could still see them here.

I've now renewed the links to the sub-album and my wife can see the pix on her computer - I hope that you can see them too.

Best regards,

Pete W.

[andyf]

That's fine, Pete. It looks a very serviceable bit of kit. I have never used a horizontal mill, so can help with the direction of rotation, other than to refer you to this animation http://www.technologystudent.com/equip1/hmill1.htm . But as you say, the thread on the retaining nut is probably the best guide. I suppose the cutter can be attached with either face outwards, so it can be orientated to suit the thread.

Andy

[Brass_Machine]

I feel a bit defensive about this project - this machine isn't as impressive as  most of the milling machines shown on Mad Modders.  This looks small but I would object to it's being written off as a toy - I'm confident that, with some attention, it will be capable of some useful work.
...

Hi Pete,

No need to feel defensive. I have an elcheapo, small import mill. The important thing is that you use it (or at least try)!

We look forward to seeing the work log.

Eric

[Pete W.]

Hi there, again, all,

Here's another picture to show you just how mini this mill is!



Best regards,

Pete W.

[Chuck in E. TN]

Pete, Here's some historical info on your mill. Not much help on the origional question, though.
http://www.lathes.co.uk/flexispeedmiller/
Chuck

[andyf]

I think it's cute. I'd love one as a companion to my 1.75" centre height Perris lathe*, so I could set up on the kitchen table for small jobs during the cold winter months.

I wonder if small cutters can be obtained easily?

Andy

* A Flexispeed lathe design inspired the Perris, which now appears with only detail changes as the fabulously expensive Cowells.

[Pete W.]

Hi there, Chuck and Andy,

Thank you for your replies.

Chuck, I did know about the information on Tony's site.  I thought I'd sent him some photos of mine but he doesn't seem to have used them.  Mine's much less rusty than the Mark I he's shown.  I wonder if the one on Tony's site has been refurbished since he posted those photos.

The Mark II is better, having its integral countershaft and motor housing, though it would make the machine a bit tall.  I plan to install mine, with a separate countershaft and motor, on a thick and stable wooden baseboard, waterproof ply if I can find some.  That way I can move it to one side when it's not in use.

I did buy a Myford countershaft, with 1/4 HP motor, probably from the ML2/ML4 era, but it's too big for the mill.  I recently tried to sell it on eBay but got no takers.  Maybe that was because I made it 'buyer collects' or maybe just because the market is flat just now.

Andy, I also have a Flexispeed lathe but that's not an imminent project as I have the ML7.

The size of cutter, of course, is determined by the gap between the arbor and the over-arm - I'll go and measure that tomorrow.  The arbor diameter is smaller that it is on 'grown-up' mills so some custom adaptors will probably be necessary, spacers too.  I guess that spacers need to have parallel end faces so that the cutter doesn't wobble!

One of my other interests is microscopy and there is an occasional need to make small parts when renovating.  A mill this size is a natch for slotting screw-heads.  Folks may also have seen my post asking where all the vernier height gauge scribers and clamps go?  I've recently bought a scriber for my height gauge but because it's a Mitutoyo (1/2" high shank) I'm going to need to make a custom scriber clamp to fit it to the Rabone Chesterman height gauge (0.600" high stub).  I think this mill will help with that job, too.

Best regards,

Pete W.

[Rob.Wilson]

Hi Pete

Interesting mill ,just the job for making small fiddly parts   


Rob

[Stilldrillin]

Hi Pete.
That's a dinky little thing! Cute, even! 

I guess the arbor is held into the spindle by a morse taper. Able to be replaced by a taper shank drill?

That will indicate to you the Forward direction, (anticlock). Though an ability to run either way would be a bonus. 

David D

[BiggerHammer]

Very nice. I think you will be surprised at what you will be able to accomplish on that mill given time and patience (personally I tend to be short on one or the other). I have been able to surprise myself with a Ryobi bench-top drill press and an el-cheapo Harbor Freight cross-slide vice. Can't wait to see what you do with it. If you have video capability I would definitely like to see it in operation. Thanks for sharing the pics, I had never seen a small horizontal mill like that one before.

[Pete W.]

Hi there, again, guys,

Thank you for your posts.

I have another question, sort of aimed at Rob:    

Am I correct in assuming that the X axis is parallel to the long dimension of the table and the Y axis is parallel to the short dimension of the table, or is it vice versa?

And that the Z axis is the table rise & fall?

Best regards,

Pete W.

[Stilldrillin]

You've got it right, Pete! 

X = left and right......
Y = in and out.......
Z = up and down.....

David D

[Pete W.]

Hi there, David D,

Thank you for your post.

Now that you have confirmed the terminology, here is a summary description of the mill:

Table size, 10_13/16" by 3_3/8" with two longitudinal Tee-slots (I'll measure those next time),

Table travel,  X-axis 7_3/8" with 118 handwheel turns, i.e. 16 tpi or 0.0625"/rev,
                     Y-axis, 2¼" with 41 handwheel turns, i.e. 18 tpi or 0.0548"/rev !!
                     Z-axis, 4" with 31 handwheel turns, i.e. 7¾ tpi or 0.129"/rev !!
(I find those last two screw pitches a bit odd - I'll check them)

The arbor diameter is ½", the over-arm diameter is 15/16" and the maximum cutter diameter is 3¾" (guess who just bought two 4" side & face cutters!)  The cutter securing nut has a right-hand thread.

The arbor runs in split bronze or brass bearings in the slit cast iron frame with pinch bolts - I'll shim the gaps to prevent over-tightening when I get to machine up-&-running.

I'm particularly disappointed by the Y-axis screw pitch (assuming I didn't make a measurement boo-boo) as for the sort of work I anticipate doing on this machine, that's the axis I'll need to set most precisely.  The X-axis travel will usually be from clear, into the cut and through to clear the other side.  I forgot to note the hand of the feed-screws.

I haven't yet investigated whether the arbor is one with the spindle or whether it's fitted with a Morse taper.

Best regards,

Pete W.

[andyf]

Pete,
As Chuck's earlier link shows, the spindle should have a 2MT socket for the arbor, the Y axis (forward and back)  feedscrew should be 3/8" BSF (20tpi), the X (crosswise, or X-wise, left to right) 16tpi square form, and the Z 8tpi square form.

It's always struck me as odd that many imperial leadscrews and feedscrews have fractional pitches like 1/8" / 0.125" (and 1/16" in your case) when 10 (or 20) tpi would be much more convenient if you want to move in thousandths. That said, your machine doesn't seem to boast any dials....

Andy

[Rob.Wilson]

Hi Pete

I see Mr drillin answered your question , the way i remember which  is which is .

Across the front of you is X and away from you is Y .


Very mixed bag of leadscrew pitches you have there , i take it there is no dials fitted to the machine .

If your wanting to add a  canny bit of accuracy to the machine for machining small instrument parts , you could go with fitting a long travel DTI to each axis , no backlass to worry about , easy to zero ,no need to make dials . 

http://www.arceurotrade.co.uk/Catalogue/Measurement/Dial-Gauges

I have microscopy question for you ,,,,,,,,,,,,,well need to take photos first.

Rob

[Pete W.]

Hi there, Rob,

I have microscopy question for you ,,,,,,,,,,,,,well need to take photos first.

Rob

Well, is my bluff about to be called?    

I'll do my best to answer, I look forward to receiving your question.  It's a bit      Do you want to address it here or via PM?

Best regards,

Pete W.

[Rob.Wilson]

Hi Pete   

I will PM you , just after a bit info .


Cheers Rob

[philf]

Hi there, Rob,

I have microscopy question for you ,,,,,,,,,,,,,well need to take photos first.

Rob

Well, is my bluff about to be called?    

I'll do my best to answer, I look forward to receiving your question.  It's a bit      Do you want to address it here or via PM?

Pete,

I too have an interest in microscopy and I guess there may well be others so I would like to see the odd post relating to microscopes. I always use a stereo microscope with my watchmaker's lathe - it makes life so much easier.

Phil.

[Pete W.]

Hi there, Phil,

I just found Rob's photos in a new post in 'The Water Cooler'.  There are several replies.

Best regards,

Pete W.

[Pete W.]

Hi there, all,

I expect you had all thought this project had died!  Well, it's moving slowly but it is moving.

I'm intending to visit a motor rewinding firm tomorrow, not about a rewind but in the hope that they can supply me with a resilient mounting kit for the motor that came with the mini-mill.

I dug the motor out of its temporary stowage ready to take with me tomorrow and noticed something on the rating plate that seems rather odd.

Most of the rating plate data is normal, 'type GP/1906, Volts 230/250, PH 1, c/s 50, HP 50W, A 1.1, BS 170 Cont. AOM, Class E'.

However, the entry for frequency states 'RPM 1275'.  How's that for odd-ball?

For induction motors running on a 50 Hz supply, I'm used to about 2850 RPM for two-pole (usually woodworking machines), 1425 RPM for four-pole machines (like my ML7 lathe, and rarely about 950 RPM for six-pole machines.

Squinting through the ventilation slots of this motor, I can't see any signs of a centrifugal switch so I'm wondering if it's a shaded pole motor designed to operate with a larger then usual slip speed?

I do have a Smiths tacho so I'll have a go at measuring the off-load RPM, maybe whoever stamped the data on the rating plate made a mistake.

Having thought about it for a while, maybe 50 W is a bit low-powered even for a mill the size of the Flexispeed - I think I have a 1/4 HP motor somewhere.

I'm still intrigued by the 1275 RPM though!

[vtsteam]

Pete, I love that mill!

Did you ever fit it with a DTI or DRO?

If not, I wonder if it would be helpful to make up a handwheel dial graduated in thousandths or other convenient division, even though they won't come out evenly in a proper decade. Often you need to bump in a certain number of thousandths, and you could still do that by the dial.

[NeoTech]

Just curious but isnt that thing supposed to have the power distributed from the roof through a belt or something?  =)

[Pete W.]

Gentlemen, thank you for your replies.

Vtsteam,

First of all,

One of the early replies to my post regarding feed-screw pitches referred me to lathes.co.uk and pointed out that my measurements were incorrect.   The odd-ball feed-screw is the X-axis, 16 tpi.  The Y-axis is 20 tpi and the Z-axis is 8 tpi.

In answer to your question, I don't intend to fit either DTI or DRO to this machine - watch this space!!  (Here's a clue for the Z-axis - think ML7!)

Neotech,

The smallest of the three drive pulleys is smaller than the part of the casting that supports the over-arm so I think drive from above would not be ideal.  The Mark II Flexispeed mill was driven from a motor enclosed in a box beneath the mill and also had a form of back-gear.  However, mine is a Mark I.  I intend to drive it via a counter-shaft parallel with the mill axis and off to one side.  The counter-shaft will be arranged to permit simultaneous adjustment of both primary and secondary drive belts, rather like the arrangement on the Myford ML7 lathe.

As regards the motor, since my post earlier this evening, I've decided not to use the 50 W 1275 RPM motor.  A 1/8 HP or 1/6 HP would be ideal but I don't have either so it'll have to be a 1/4 HP.  That's getting inconveniently and inelegantly large!