Member postings for Ian P

John

Lathewise I have a Boxford so personally I don't have problems. my comment was just a general one. If I had to make a quantity of pulleys I might make a form tool though.

By coincidence, yesterday I put a 15mm wide 45 degree chamfer on an 200mm diameter chunk of aluminium using the same 'stroking' technique. After turning the OD and face I rotated the toolpost so the (tipped) cutter edge was at 45 degrees, a few moments work produced a smooth chatter free chamfer.

In the above example the edge of the TC tip was about 7mm wide and if fed directly into the job it would start to chatter at some point. By keeping the tip moving so that it is cutting on a gradually increasing radius the cut proceeds really smoothly.

Yes, the same chamfer could have been done with a small radius tip with the topslide set at an angle, or it could be done with a form tool. For speed my way is more efficient.

The problem with form tools is that they cut on several edges at the same time which on a light machines leads to chatter and other problems.

I have cut many pulleys and large chamfers using a tool with the angled cutting edge much shorter than the finished surface. In fact I usually do it without the topslide having to be set at an angle.

The technique is so 'stroke' the cutter manually using the saddle and cross slide so that it follows the surface that it is cutting. I find that the majority of material and the best finish is achieved when the cutter is traversed in the outward direction. As long as the cutter edge is at the correct angle the final result will be more than good enough for a belt groove.

Ian

Neil

I'm not talking of a delay (which makes SCAYT uttrely yoosless) but a total hang up lasting several minutes.

It has nothing to do with cloud computing which this website isn't anyway.

Ian

John

I have a feeling that whatever causes it to happen, its not platform related.

All I know is that it only ever happens on this website.

Ian

V8

Please dont feel you are causing any (even the slightest) distraction.

I think the majority of threads weave about a bit, few stay exactly on topic.

Ian

PS there was a 'J' at the end of one of your posts which I though might be your initial, but I see you have 'redacted' it now.

In the last few weeks I have noticed that whilst typing replies to posts, that my keyboard becomes unresponsive. The browser eventually tells me that the page has stopped responding and give me the option of quitting or waiting. It usually happens after I have been typing (and thinking what to say) for longer than 3 or 4 minutes.

Whilst the page is dead I can still use any other tab and even open another instance of the same thread I was replying to (and reply to that one!).

What I have found is that if I wait, (maybe 5 minutes) the page does come back to life as if it never happened.

Has anyone else seen this effect?

Ian

(Using XP, Chrome etc)

J (thats a better name/title)

I too suffer from occasional bouts of 'page not responding' but I will put it a new threa

Ian

Mr Veeeightengine(eer?)

Can you expand on the 'got locked out bit', if its what I think it is then I suspect you are not the only one experiencing lockups on this website.

Ian

I concur with the fact that the holders are fine, but the tips are basically useless.

The pity is that a newcomer might buy the Glanze set and be put off tipped tooling forever.

Ian

Mark

Useful reference diagrams. I am sure they will bring clarity to this confusing subject. You mention that you did not include 'bowed' because you had never seen a bowed bed, does that infer that you have seen all the others?

Ian

Gray

I'm not lacking in experience (of tramming/aligning) but the sheer inconsistency of the trial and error process becomes very challenging.

On my machine the other complication is that to correct a head 'nodding' error I have a 0.07 shim positioned at the lower third of the head rotating joint.

Because of the difficulty of getting the spindle vertical I doubt I would ever tilt the head to do a particular machining job, I would look to find an alternative way of milling at an angle.

Ian

Gray

I know what all the fuss is about! ! ! !

I know the theory, I know the practice, I know the principles, I know how to do it, I've got the equipment, and I've done it, The problem is not the fuss, its just how long it takes!

You hinted at one of the problems (things change when the bolts are tightened) but tapping with a mallet, the palm of your hand, a fist, or whatever is not a precise science and sods law dictates that the one point where the the two halves of the head are in alignment gets skipped over every time a small movement is made.

The whole process boils down to trial and error and to get the best result needs a lot of luck or a lot of time. The last time I went through the procedure I spent a full hour before I decided I could not get it any better. The worst thing is that I know that no matter how tight I make the two 'T' bolts the alignment might be disturbed if a cutter jammed or I took too heavy a cut.

Ian

Edited By Ian Phillips on 31/03/2013 15:24:55

Neil

I am not sure I would have described my post as constructive! but it certainly was not meant to offend. I am not in a position to criticise your skill an an author either as I have never written any articles (I am full of good intentions to write some but after realising how hard it is, keep putting it off). I do realise, more than I ever used to) that without people such as yourself our engineering magazines would just not be around.

As regards the bearing installation, angle iron is stiffer than a flat strip but only at the stiiffened edge. A large washer, even if it deformed under load would still apply the force concentrically. In general though, ballraces seem to be much more robust than we are led to believe and do tolerate loads that they are not supposed to.

Ian

Thanks Gray

I presume when you mentioned a 10mm needle race you meant a thrust race?

Ian

I have never had problems getting polyvee belts in the UK. I have not actually purchased belts from 'simplybearings.co.uk' but I have bought bearings and other parts and they gave an excellent service. (no connection etc)

In my opinion the article had too many similar photographs but a bit vague on some details.

I did notice, is that the method of installing bearings shown does risk potential damage to the new ballraces. Apart from the the fact that the peice of angle iron the writer used could bend, picture 41 just made me cringe as the inner race is unsupported so all the force neede to seat the shaft is being transmitted through the ballrace itself.

When installing bearings in shafts and housing its is important to apply pressure ONLY to the inner or outer race (whichever is the relevant press fit) so that at no time is any axial force applied to the balls or track surfaces.

A plate (washer) of substantial thickness that bears on the inner and outer race is also acceptable as its unlikely to dish more than the axial movement in the bearing.

Ian

Edited By Ian Phillips on 28/03/2013 12:05:11

Gray

My mill is a Mentor. It has the Mentor plate fixed to the base casting so that pretty well nails it!

Interesting you mention the Spanish manufactured bits. I would never have even suspected that it was not all in-house Emco. From a quality point of view I would rate the base and slides as being noticeably better than the column and head parts.

The only bad design feature of the base is the positioning of the Y axis locking screw/lever. When I bought my machine the Y axis gib was bent because a previous user had tightened the lock whilst the gib strip was in mid air. I have moved the lock to a position where the slide is always fully engaged. Incidentally the front most gib adjusting screw bears on the end the gib that is always in fresh air anyway (but as you say gib stiffness still makes it a valid adjustment.

Ian

Edited By Ian Phillips on 27/03/2013 20:18:43

I have found the one reason why it might not work.

Looking at David's (Woody) album photographs, it appears that his Myford does not have a tailstock!

Ian

In my limited experience I have found that moderators do often explain their actions.

By coincidence, only today I had a automated email from a classic car forum I subscribe to. The site owner has recently upgraded or changed the forum software and it seems that the subscribers will now get report of the moderators activity.

I must be naive though, I watched the video without noticing any commercial connotations!

Ian

I saw part of the video earlier today but then had to go out. I have just tried to find the thread and the whole thing seems to have disappeared, why?

Ian

Gray

I do not have a manual for my mill but I am now wondering whether my machine should have the push rods in the adjustment holes? Your mention of them, and the fact that the existing (M6 Allen grub) screws are quite long at 25mm make me think that it might be worth fitting them.

I presume the holes are tapped all the way through so the push rod would only be sitting on the thread crests but since no real movement takes place it should not pose a problem.

Ian