Member postings for William Ayerst

Hi all,

Another boring operation and more frustration. I worked out that my 8mm shank cutters have the cutting edge 280 thou above the bottom surface, so needing a shim of 33 thou to bring it up to the expected 5/16" - but it still bottomed out.

JasonB, where can I find those bars with the holes for inserting HSS tooling, please? I'm trying to avoid carbide inserts, really.

Where can I find out the height of the cutting face above the bottom surface, for boring tools?

I figured it out - the knurled wheel is threaded onto the cylindrical arbor inside and it was rusted solid on my X-axis dial. I used some loctite to bond the whole assembly to a mandrel and then was able to break it free after soaking in WD40. After reassembly I put the wrong spacer on the wrong dial - which meant no matter how much the wheel was unscrewed it never locked tight. After swapping them back over, both are working as expected.

There is an additional washer between the knurled ring and the handle on the Y-axis to make up for it being a smaller casting - are you missing that, Dave?

One thing I am struggling with, is the resettable dial on the X-axis. It shares a design with the Y-axis - the outermost ring is a locking nut - twisted one way it pushes against the handwheel and the dial, locking it in place. Twisted one way it pulls inward, allowing the dial to spin freely.

This works fine on the Y-axis, but on the X-axis, the outermost ring just spins in place, so I can't lock the dial and am unable to move the table a set amount, as the dial will drift out of sync with the handwheel.

I wonder if the thread has been stripped, as the ring is halfway pushed out, not enough width to lock the dial, but a gap between it and an adjacent spacer. If I nip up the handle fully with an additional washer it can locks the ring, but the rest of the assembly still rotates.

Is there something obvious I'm missing? I've compared both sets of dials and they seem identical.

Clearly, spare parts are a no-go for this mill, so if possible I'd like to repair rather than replace with something else. In the meantime, I was thinking of using some brass shim to make the dial rigid and not resettable.

Edited By William Ayerst on 30/07/2021 13:15:41

I have one for the horizontal, but not the vertical. For now I'm using a bit of threaded rod and I'll look to turn up a captive drawbar at my earliest convenience.

Righto - good to know - when I said 'take it gentle', I meant with removing the tools with a (brass faced) mallet via the threaded rod drawbar, as opposed to just twisting a self-ejecting one. I'll look into some wedges - like a pry bar?

Thank you for the tips re: tanged vs threaded arbors. If I could find a compatible JT6 taper MT2 arbor with a 3/8" drawbar thread I would. I'll keep an eye out for one, but good to know I can do without.

Yep, I forgot of course the flats are there for tightening. Time for me to get a 1" spanner!

I tightened the horizontal arbor down and had another go and all was well - up until the point that the cap on the end of the arbor brushed against the inside of the arm support, and being reverse threaded proceeded to unscrew itself, which was quite a bum-clenching moment. I think there's meant to be a bearing that would fit in the arm support to gap it properly, I'll have to look through my bag of bits.

Is there a commonly available equivalent to 'Shell Vitrea 41' oil and 'Alvania 3' grease? There's a good amount of lubrication already but I don't want to do too much while risking it.

It seems there's a drawbar for the horizontal arbor, but just some threaded rod for the vertical, so I'm using that for now but will keep it gentle until I can fabricate a proper one.

On a related now I'll need to do some drilling soon, and would love to do it on the mill. I'm a bit confused though. I can find almost no drill chuck arbors with drawbars at all, let alone the specific one I required - (JT6 to MT2 with a 3/8" thread).

Am I over-thinking it that I will need a drawbar for the drill chuck? So many are sold as tanged and I find it hard to believe that all of those are used on a lathe only?

That said I have found one 2MT drill chuck arbor with a 3/8" drawbar thread and that's a B18 taper. It seems only import tools use this and I'd prefer to avoid that if possible - but the drawbar and drill chuck would set me back only about £25.

I have a control box hanging off with a fwd/reverse toggle so that's OK!

I inadvertently left the fixing bolts for the vert head slightly slack while milling, it caught slightly and must have unstuck some hardened oil or something, as the head now moves OK.

I meant to say that the top of the riser block has a dovetail on the full length, so I would have expected it to move somewhere - but it doesn't budge in either direction when the angled bolts are slackened.

Thank you both, I wondered if I was going mad on that one!

For tightening (both the horizontal arbor and the clarkson chuck), is there an obvious way to lock the spindle(s) other than putting it into low gear and hoping?

Good evening gents,

Courtesy of Steve at Landylift (stellar service and will have no objections to using him again) I have taken delivery of my first ever milling machine, a Centec 2B.

It came with a horizontal arm and arbor support, a fabricated riser block and Mk. III quill head, as well as a 3" Abwood vice, two dozen horizontal milling cutters of various kinds and a couple of T-nuts.

It's fitted with a VFD and separate control box for run/jog, reversing direction and start/stop.

I have tried a little milling using the vertical head, a fairly high speed and a four toothed endmill and it was an absolute success.

I can't seem to move the vertical head ontop of the riser block even with the nuts slackened off, it seems to be held fast. Before I do anything stupid, is there a common cause for this?

I decided I wanted to also try horizontal milling, so I slid the riser block forward to act as a support arm (having to disconnect the vertical head belt since I couldn't slide the vertical head backwards to keep it in line). I fitted the arbor, with a cutter and the arbor support and noticed - there are keyways on the spacers, keyways on the cutters, but no key or keyway on the arbor. Once I hit any resistance in the cutting process, the cutter stopped while the arbor kept spinning. Am I missing something??

What is the purpose of the nut on the front of the vertical head? It seems to just spin in place on my one.

Thanks for the advice re: collet chucks, I have a Clarkson Autolock collect chuck and a series of imperial collets, and imperial cutters from Tracy Tools. Annoyingly, some of them only seem to thread partway on to the collets, not sure if I can do anything about that?

Anyway, thank you all for the help and advice - I'm having a blast already!

Wow, what a veritable gold-mine of information.

I had not even a vague idea that I could use thicker boring bars with the cutting edge set down from the top of the tool. My toolpost is a four-way with 1/2" slots - so that might be a good immediate solution.

Checking my carbide boring bars and I can see that although they are 8mm, the cutting surface is set down by a few mm as well - which would explain why they are bottoming out on the bore when an equivalent 8mm high speed bit (with the cutting nose at the top) works OK.

JasonB - my toolpost does not have any provision for a round bar - will I need to fabricate my own or do the ones you've pictured also have flats? (RDG?). I'm thinking back to our conversation about parting tools.

Dear all, good morning.

I've been casting my mind back to boring my steam engine cylinder and standard and I feel like I must be going mad.

While I was doing it I must have bought about four boring bars in HSS and brazed carbide in 8mm or 5/16" (i.e. to fit my toolpost and centre height) and the only time I've had success was when I ground away most of the support under the cutting face on a HSS tool, and along the length of the shaft to allow it into the hole without rubbing on either the bottom of the tool (or underside of the carbide tip). This meant that it was very bendy and required many spring passes - still ending up with a very small taper in the bore.

The standard and cylinder were both drilled 1/2" before boring, one ending at 5/8 and one at 3/4.

Is it as simple as a 5/16" boring bar needs to start with a 5/8" hole? Is there some kind of formula or reference chart I'm just missing?

Many thanks,

Hi Howard,

Both the grooving tool and parting blade have side clearance. The grooving tool in the boat is about bang on centre height with all the bolts nipped up now - thank you for the tips though, I'll file those away for future use!

Thanks,

Hi all,

Some more experimentation including fixing the rake on the front parting off blade:

It parted off without much fuss at all - so maybe it's as simple as that? I do see some other holders for 8mm blades but it looks very similar to what I've now got above? i.e. ebay 265202611958 or 373410105832 - is it worth getting one of that design intead or am I going to be alright?

Rod, the tool I've got is shown as a grooving tool on the etched markings, but is the same as those sold as parting off tools (from square tool steel) I can see anywhere - am I missing something? i.e. ebay 402994146273

Edited By William Ayerst on 23/07/2021 14:24:51

I re-set the grooving tool with the packing piece between the boat and the tool, instead of ontop of the tool - and it was almost bang-on centre. It is still flexing a bit - for example if I part out halfway then I can see the tool generate a little swarf on re-insertion.

I have a parting blade tool and holder (the kind that is inserted into a normal toolpost, rather than integrated into the toolpost) but the tip of the blade is way over the centre height, so I've had to grind down the top of the tool so it's got a chance in hell of cutting. In this view, it looks like I've inadvertently got some positive rake...

It looks like I need to fabricate myself a dedicated 'blade'-type rear toolpost holder like Alan or John? I can't seem to find anywhere to buy one!

Rod, this is a REAR toolpost, so the cutting edge is facing downwards. I guess the angle achieved to reach the centre line is increasing the rake, though?

The tool boat is a Myford one (the new Myford, not original) and the tool is 8mm - if the tool is placed on the boat and the boat is flat/horizontal, then it's well below the centre-line of the lathe. Maybe that's what the extra packing piece (currently ontop of the tool) is for?

Edited By William Ayerst on 21/07/2021 17:00:51

Dear all,

I'm using a rear toolpost parting tool and it's generally very pleasing to use - but one thing I've noticed is that occasionally I will part off some work and notice that one of the faces is very slightly convex.

To me, this indicates that the tool is crooked in the toolpost, or the toolpost itself is crooked. Now, I'm using a toolpost which has a very positive key onto the t-slots of my cross slide, so I think it's less likely to be that, and more likely to be the way the tool is held.

The toolpost has a boat shaped cutout on the bottom, onto which sits a boat with grooves ontop. The tool sits on the boat, and then there's another plate which sits (seems to sit?) between that and the adjustment screws.

However I seem to secure the HSS tool, when clamping down it always seems to twist - either away from perpendicular, or rotating around its axis.

Clearly, I am doing something wrong here!

Bit of a stupid question - but does anyone have the height from the floor to the underside of the swarf tray? I'm just trying to work out if a short rack shelf will fit underneath one side....

I had the same book as Bob Blackshaw (Building Simple Model Steam Engines) and built Elizabeth, the first standalone horizontal engine. I built it entirely on a myford 3-½" lathe as my first attempt and I think it ran quite well!
https://www.youtube.com/watch?v=R8pSfY9nZNA

Oh I'm overwhelmed - thank you all for the help. My mill is now en route via Landylift so I'm all on tenter hooks.

JasonB/Martin - thank you for the tip on using 5/8" shanks for other things - what a good idea!