Thread: What can I do about the noises in my head?

I must admit to taking a rather simplified approach here Bob.
- all the others are hardened and look fine; the one that is not and is looking pretty beaten up. Therefore hardened is probably the way to go. (And I'm herding 4 horses here from memory)

With the amount of use the mill gets 1020 may well be fine but like lots of things we book taught types do, we try to do the best job we can even if it would seem like overkill to a trade qualified person (but then the trade doesn't use mills like this any more as they aren't driven by a computer - and I regularly get to tell the fitters at work how to use "antiquated" equipment like the things we have in our sheds because it's not taught in trade school. Previous place I worked I even had to prepare some test samples at home in the shed as it was too difficult to arrange access for me to the workshop at work or find someone qualified who could do what I needed to have done)

Michael

Explanatory note
I should point out I'm not intentionally trying to upset any tradies we have here. I have met some tradesmen who are excellent practitioners and very cluey - some of them have given me valuable pointers on what I am doing wrong or inspired me to try harder. However, I am concerned that a lot of the newly qualified machinists I see (and newly qualified engineers too for that matter) have never been exposed to much of the basics. To hear that some of these guys have never seen a gear cut makes me wonder where we are headed. They also seem to be lacking something I attribute to the "old school" tradesmen I've worked with and that is the ability to figure things. I once had 4 fitters tell me a lathe compound was stuffed and we should dump the lathe. It took around 5 minutes to work out the leadscrew was bent. It was removed and straightened and suddenly it was a wonderful lathe again. Why couldn't they work that out?

Originally Posted by Michael G

Why couldn't they work that out?

No passion.

I got some more done today - mainly packing bearings with grease and installing them. I'm really glad I have a little hydraulic press (10 ton). It has been a great help for this job.
I had two lots of advice from "professionals" on this job. One opinion was to put thin bearing grease in the bearings and then "see how it goes" using grease on the gears. Not terribly inspiring! The other from Shell (which I am following) was to use a stifffish grease to pack the vertical bearings and rely on the labyrinth seals to keep it there. Part B was then to run the gears in an oil bath.
On the horizontal shafts I am running sealed deep groove bearings on the lower shaft and oil lubed angular contacts on the top shaft.

We lost power here from just past 6am today until a little past 3:15pm. (that's nothing say the non-city members, but we are only about 4 km from the CBD. Lots of shops down too. A worry) Big winds took down a power pole I'm told. Having no power made me realise how much my hobbies depend on electricity. It came back on too late for today's efforts but tomorrow I was going to use the Nexus method for sorting out pre-load on the main bearing (tacho to show the speed, tighten until the spindle speed starts dropping then back off just enough to get back to no-load speed). The top bearing (item 4) has me looking for answers though.
Sajo V head (Large).jpg
It is a cylindrical roller so it can float up and down. The real thing that needs adjustment is the bevel gear vertical position. The method currently under consideration is to tighten until it just feels right. The gear (and bearing) slide on the shaft but not smoothly, so I'm not sure how reliable that is going to be. One other method may be to tighten it up so it is hard, back off a fraction of a turn, run it for a while and then just nip up. Thoughts?

Michael

Originally Posted by Bryan

No passion.

I agree. I don't think it's their knowledge letting them down, more their attitude. Problem solving is one the the many things that I love about this hobby. Every new problem solved is another new experience and lesson learned that can then be used next time.

Simon

Originally Posted by Michael G

I once had 4 fitters tell me a lathe compound was stuffed and we should dump the lathe. It took around 5 minutes to work out the leadscrew was bent. It was removed and straightened and suddenly it was a wonderful lathe again. Why couldn't they work that out?

One or more of them wanted to buy it - cheap. You ruined the plan.

PDW

After replacing the bearings and packing everything with grease I started up the mill last weekend and the grease and oil were being flung all over the place within minutes. It appears the grease originally used was much stiffer - doesn't really help me though when cleaning the grease up. Spoke to Gardner bearings about it and they said basically look at the sealing. Trying to find a seal to graft into a 45+ year old mill without doing drastic things is tricky but I stumbled on these though -
P1020002 (Medium).JPG
They are referred to as a V seal, made by SKF and are a nitrile seal - they stay in place on the shaft with a stretch fit. Looking at the drawing of the head I was able to machine out a slight recess in part of the existing labyrinth seal and put one in. It is purely co-incidence but once the machining was done it fits with less than a mm clearance to the bearing cage.

v seal.jpg
Installed it looks like this (the red stuff is rubber grease)

P1020004 (Medium).JPG

I've had the head running for (off and on) probably close to 1/2 an hour and no puddles of grease or oil yet. The grinding noise seems to have gone too so I'm happy there. I tried using the nexus method for setting the preload but I need to look at that again as the head is hotter than I think it should be. I suspect that I've over tightened the taper roller and will need to do some fiddling to get the outer race to move down a little.

Michael

Hi Michael,
Thats the seal drawn in in pink just below the tapered roller i take it? Hope fully it will stay not leaking. I used Mlle today for the first time in a week or so and there was oil all over my vice, she has sprung a leak from somewhere.....

I am glad the noises are gone too, how is it at high speeds? At 1500rpm i am a bit concerned about some of the noises i hear in Mlle's head.

Cheers,
Ew

Yes, that's it. My main concern at the moment is temperature. The seal is rated to 100 degrees, so I need to get the bearing adjustment right. The mill goes up to 1800rpm but today I just did 900rpm to bed things in. Once I have the adjustment right then I'll take things up a bit.

Michael

I'm still not sure about the adjustment on the main bearing. At low speed (say 200 to 300 rpm) I can rest my hand on the head next to the bearing and it will just feel slightly warm. If I go up to say 900 or more (top speed is 1800rpm) it gets hot enough that I can rest my hand there for a while but it starts to get uncomfortable. ( I should put a thermocouple on I guess and get something more exact than that)
I'm not sure whether the heating is due to the grease being churned about or the bearing preload being too high. I slackened it right off and then brought it up until I had just eliminated any spindle play but???
Anyone care to tell me how hot their vertical heads get when running?

Michael

Hi Michael,
Mine gets just nicely warm at all speeds. Maybe 30-40deg? Certainly not uncomfortable to touch. And thats at all speeds. When i pre-loaded the bearings again i just took up the slack plus a little and kept an eye on the temp. So far i have not touched it. Remember mine runs in an oil bath, about 1L of ISO32. That would help to move the heat around a bit and not just have it build up near the bearings.

Ew