Member postings for YouraT

So - spindle out, and the oiling felts are oval in section, 10mm x 15mm and have a thickness of ~25mm

The other felts were in the oiler ports where the oil goes in - maybe to act as something of a filter to swarf and other rubbish in use.

They look in good condition, so I'm just going to rinse them (white spirit?) and re-use, same with the very coarse stuff that was in the oiler ports, although I'm not sure that's actually needed at all.

Hi all.

Thanks for the info and the generous offers of some felt - I'll have the spindle out by the end of the week I hope, at which point I'll know what the wick dimensions are. From the x-section drawing my guess is that the length is something around 25 to 30mm, but I don't know the area at this point.

I'll also look at cleaning what's currently there - after all, unless it's damaged in some way, I'm pretty certain it's the original part from the factory.

Cheers,

Youra.

Thanks - I was unaware that Myford 7s used a wick - looking at it on the Myford website, I think it's too thin for my application, but I'll have the dimensions I need shortly when I get the spindle out.

Hi all.

I'm about to strip down my "large" Lorch headstock to track down a potential lubrication problem, and one of the things I'm girding my loins to potentially have to deal with it replacing the wicking oilers.

Theses are shown as the cross-hatches parts dipping into the oil reservoirs (1) in the drawing:

I've seen in other threads that felt is available from McMaster Carr in the US (expensive!) and from Hardy & Hanson in the UK, but I have no clue about what grade I should be asking for. H&H may be able to offer advice (I'll call them this coming week) but any pointers/experience would be appreciated.

It's a different approach from the more usual felt dripping oilers, in that the felt needs to wick the oil upwards, and I've not been able to find any specific guidance.

Also, my headstock differs slightly from the one in the drawing in that there are no oil sight glasses on mine, so I'm unsure how far to fill the oil reservoirs - is it enough to be sure that the bottom of the felt is covered, or should I be going up as far as I can without the oil leaking out simply because there is too much....?

Any pointers gratefully received !

Y.

John - thanks - I found the article in issue 159 which was indeed helpful !

Clive - wow - OK - *so* much more info Thanks !

Thanks again Rod - maybe the slightly larger set given the ER25 size I'm aiming for, but a useful pointer.

John - yes quite possible - I'll measure, and I have access elsewhere to a toolpost mounted grinding spindle should I need to make things better.....

Thank you both very much Rod and Dave - that's reassured me somewhat, I'll go ahead with my plans..

Rod - curious, what bearing arrangement did you use in your spindle? I have the "Spindles" book, but can't really decide which layout will be most suitable for wheel and pinion cutting....

Thanks again,

Youra.

Hi all.

I'm looking to make a milling spindle (mostly for clock making) and want the nose to be ER20 or ER25 for a number of reasons.

I've been thinking of starting with a commercially available ER collet chuck extender on a 20mm or 25mm shaft to simplify the collet holding end of things, but I'm not sure how hard the shafts are, and thus how difficult will be to modify them, and in particular to cut a thread at the end for pre-load nut reasons. Questions to the suppliers have not resulted in particularly illuminating replies.

Does anyone have experience in this area?

Thanks,

Youra.

Edited By YouraT on 16/02/2021 10:04:47

Oh - and I also forgot to say that I've removed the spring that was biasing the pinion upwards...

A few months along, and I thought I'd tidy this up in case anyone's still interested....

I decided on a weight counterbalance system, as I couldn't easily see how to get a gas strut into the space, and also wasn't too keen on the possibility that it suddenly fails. Springs were interesting, but again more challenging due to the space constraints.

I've adapted the existing quill guide block to carry a bar that's pulled up on each side by two 1mm stainless steel ropes that are tensioned by weights at the back of the machine.

The routing of the cables to the back is dealt with by a series of pulleys in a length of steel box section:

and finally there are ~8kgs of weights hanging on the end pulling on the cable. I printed a spacer bush to keep everything central and nicely symmetrical - much more material efficient than turning up something from the stock I had to hand:

(Some of the pictures were taken before the weights were attached, hence the cables are slack)

So far, it's doing really well - I'm confident that the cable strength is sufficient for the application - each cable only carries around 5kgs, and the manufacturers tell me that even with de-rating, each 1mm cable is comfortably rated at 25kgs. I've used the largest hardware (M5 mostly in pairs) that I could comfortably fit in, so in theory at least nothing is close to breaking.

Finished a week or so ago, I think it's doing the job I might add some more weight to make the upwards force a little more positive, but the backlash and lumpiness is largely gone!

Thanks Rob

1/6hp agrees with advice given elsewhere too - I have a slightly bigger motor to hand, and as long as it's not too heavy, I'll likely go with that.

Youra.

Hi all.

I've acquired after much searching a nicely built JM Wild overhead gear cutting drive system, but minus the motor and its pulleys.

I know the pulley diameters and the motor speed (1425rpm), but can anyone help with the as-designed motor rating?

I'm thinking that 1/2hp would be ample for my expected worst case load of pinion cutting, but any knowledge and advice would be appreciated!

Thanks,

Youra.

Hi.

So - following the advice, I've turned the OD true with a centre on the end, and found around 0.4mm of out-of-round was present where the steady was set, which is the lion's share of the 0.6mm taper I'm seeing on the bore, and will of course depend on exactly how that interacts with the steady fingers.

With just that, and some care taken around swarf build up, I've got to <0.2mm taper on the bore, which is good enough for this purpose (It's a model light-saber handle I'm making with my son......).

Next will be working out how to hold two indicators as suggested by Pete for better setting of the initial and steadied locations of the stock, but I think that will need to be for when I next need to do something like this again - perhaps a new handle design in a couple of weeks...

On other comments - yes, that's a rather thinner and flexible boring bar than I'd like to use, but is the only one that was both long enough and would actually fit in the largest drilled hole I'm currently tooled up for (25/32" ). For reasons that escape me, I do have a larger bar, but it needs a 1" starter hole...

Thanks everyone, and many good pieces of advice to get my on the road to nice parallel bores !

Youra.

Edited By YouraT on 14/04/2020 21:53:36

Thanks for the further input guys.

I'm returning the bar to the start by hand after moving it clear of the cut a little and then returning to the original position and putting further cut on for the next pass. The cut is done through the powered saddle - I do the last 2mm or so using the topslide as the Viceroy doesn't have a repeatable saddle travel clutch arrangement like the Boxford, just an 'anti catastrophe' dog clutch.

I'm going to:
- true up the outside of the bar stock
- adjust the steady with the tailstock in place
- check the parallelism of the stock once the steady is set
- pay extra attention to the swarf bird-nesting effect described - although I don't *think* that was happening

I've not seen any tendency to walk out of the chuck, but I'll keep more of an eye on that too.

Likely tomorrow now, but might manage to start something tonight.

Cheers,

Youra.

Thanks everyone

- a number of things to think about - I'll take a look at skimming the stock before setting up the steady (I have spare OD on the stock), and also at setting the steady up right up against the chuck initially, then moving it into position - both suggestions are eminently sensible.

'Not done it yet' - my terminology was perhaps a little vague - the boring bar stick out is only around 70mm - it's the aluminium bar stock that's ~150mm long.

Nick - I'm not sure I understand why cumulative spring might be the case here given the initial drilled hole (as large a drill as I have, but I'll give it a go.

Thanks all

Hi all.

Returning to a 'filed' project, I'm trying to bore a 60mm long hole in an aluminium bar using my lathe's power carriage feed, but I'm finding it's significantly tapered to the tune of around 0.6mm (in 25mm or so) over the 60mm length of the hole, with the end closest to the chuck being the smallest. The lathe is a Denford Viceroy 250, but I don't think that's particularly relevant for this question.

As the bar is around 150mm long, I've brought out my fixed steady to help keep things in place (see picture) but I wonder if my lack of experience in using it is causing the taper I'm seeing.

I've simply used the steady on the outside of the bar (which is perhaps not perfectly round....?) and gone from there - is there a technique/order of setup things up that I should be using in order to ensure everything is lined up properly to give me a non-tapered bore?

The boring bar is of course sticking out quite a long way, but I'm taking deliberately light cuts and in any case, the deflection forces on the bar should be the same at all points along the cut.

Thanks,

Youra.

Bill,

I wasn't too hopeful of a reply, but thank you for your suggestion, which does make sense.

The problem I have with etching is the dimensions of the features - I think they would be too small if done chemically to look as they did on older clocks, but I'll try a few options and see.

Thanks again,

Youra.

Hi.

Coming I realise *very* late to this thread, I'm reading Richard's description of the tool his friend made and I'm struggling with the phrase

>>
....machined the edges so that had the same angle as the knurl....
<<
as it's a straight knurl...

Richard - if you're reading this - would you possibly explain perhaps differently so I have a chance of understanding, or maybe sketch something....?

Here's hoping!

Thanks,

Youra.

Hi all.

So - I make the weight of the quill around 8kgs - my final question really is - should I "counterbalance" with as close to that as possible, or do I want to bias noticeably above that, at say 12kgs or more?

I'll work out the best way to apply that shortly - I'm in the middle of some stuff just now, and don't want to loose the mill for a period just yet....

Thanks,

Youra.

John,

Thanks for that - it does look a lot simpler to implement than the gas strut arrangement.

Something like one or two of these:
https://springcompany.com/products/constant-force-springs
would do perhaps... Perhaps I won't even need the extra shaft and SS shim in your setup..?

I'll take the machine apart again shortly to check the weight of the quill to work out what might fit - you don't perchance remember what the weight is (even approx...)?

Many thanks,

Youra.