Here is a list of all the postings Geoff Causon has made in our forums. Click on a thread name to jump to the thread.
|Thread: Noisy Lathe Gearbox|
Nigel, the gasket may be wrong. It's hand made & much wider than the lip on the lid. Strange, I bought the lathe new & have not replaced the gasket. A proper factory one would be die cut. I can't see clearly enough through my perspex lid to check if the modified one drains, but it can't hurt.
Like you, I suspect the sight glass is too low. The absence of any clever oil management features on the underside of the lid suggests the design /testing process was short. Also, the drain plug is too high, I had to make a vacuum sucker to drain the last half. It's all starting to add up.
Dave, The new oil level is 18mm above the middle of the sight glass, & the lowest shaft is about 15mm below the sight glass. That's well below the new level, but I'm not at all worried about leaks. Every drop of oil I put on the ways & cross slide ends up swimming with the swarf. I wouldn't notice a weep from the gearbox.
I made a clear acrylic lid (as suggested by Nigel B) & filled it a bit more to get those gears lubed.
The groove around the housing is sealed by the gasket, so is not draining onto the main bearings.
It's hard to get a decent photo, but the spindle gear & it's driver are misaligned by about 3mm. The spindle gear shows damage, but it's not as bad as it looks in the photo. I just wonder what the mating gear looks like.
I investigated spare parts, the big one is listed but not the small one. I'm not brave enough yet to ask prices, no use just replacing one anyway.
Edited By Geoff Causon on 10/02/2020 05:26:43
Thanks for all the advice. It's a typical Chinese lathe, 38mm spindle bore with huge taper roller bearings. No back gear, 6 speed gearbox & 2 speed pulleys. Overall, I am very happy with value for money & don't regret my purchase.
I hadn't considered EP oil attacking bronze bushes. The only bronze would be in the selector pivot bushes. (although they may just run in the cast iron casing)
I will investigate a 90 weight manual trans oil, which I don't think has the EP additives. The noise reduction is so good I would sacrifice any pivot bushes.
Russ B, Thanks for your diagnostic offer. Chances of being close enough are slim, but here goes. I'm in Drysdale, Victoria, Australia. That's about 100 km south of Melbourne. And yes, it's still smokey.
I have periodically changed the oil & carefully filled it to halfway up the little window.
In desperation, I over-filled it with EP90 car diff oil & it now sounds "not too bad" ( Very scientific)
It got warm after approx. 1 hours intermittent use, so heat may not be a problem. (car diffs get very hot).
I filled it so the gear that drives the main spindle gear was just picking up oil. It is the highest pickup gear in the box.
Is there a problem with too much oil?
|Thread: Black Oxide coating|
If you want to add a black finish to your homemade steel masterpiece, heat it to dull red & dunk it in old sump oil.
Do this outside with the part on a longish wire, as it will flare & smoke.
Obviously won't work with heat sensitive parts, but you will be amazed how professional it looks.
|Thread: Setting lathe top slide angle accurately.|
Thanks everyone for your help. I have decided to make some "wedges" for the commonly used angles (like 29 1/2 deg) that don't need extreme precision & use Joe Piezinski's method for more accurate jobs. His method doesn't need a long travel DTI & I have a DRO on the cross slide. He also has a good video on milling angles on wedges. A good result all round, thanks again.
Does anyone have a clever idea to set the lathe topslide to a precise angle. My top slide swivels 360 deg & the crude plastic dial goes +/-50deg. Anything other than that I use my protractor but this means eyeballing the ruler to the edge of the cross slide. There must be a better way.
|Thread: Weybridge/Brooklands Exhibition|
I have booked a trip to the Weybridge exhibition in September.
Can you recommend any side visits after the weekend?
Would prefer Engineering/model related but tourist OK.
|Thread: Travelling Steady.|
The 1st thing I will do is thread a scrap part & perhaps I can contribute a bit more intelligently. As you can tell from my posts I have never used a travelling steady.
If I use the old 4way toolpost it moves the tool about 20mm closer to the fingers so that will help.
I am reluctant to just make a spacer for the steady, as every mm of spacer means a mm less length of leadscrew & I want it as long as possible.( The spacer would be a minimum 29mm)
Keith's idea of turning the toolpost 90deg & using the clamp screws to longitudinally adjust the position of a "special" toolholder sounds like a simple solution. I already have a 16mm square holder that allows me to use short pieces of 1/4" HHS. Bit like a boring bar & is close to what is req'd.
Re: Inclining the Top Slide.
One advantage is it clears the top slide from the tailstock without having to excessively extend the tool from the toolholder. Quite important with small thread diameters.
Embarassingly, I was so focused on the LH part I missed what you all saw. With the compound angled to the left I can only make LH threads but I also need RH parts.
I guess I am back where I started.
The problem seems to be the large offset toward the tailstock on the steady casting, as all the pictures I see of steadies show approximately "straight" castings.
I can use the existing steady for the LH parts, & will need to make a "straighter" body for the RH parts.
Obviously, summarising the collective wisdom above, the new steady also needs to let the fingers lead the tool if turning parallel. It almost needs to be adjustable .
Thanks everyone for your help.
Thanks for your help. Photos' attached will explain better.
I tried swinging the compound to the left as Steve suggested & the tool lines up perfectly at 30 deg & is 6mm ahead of the fingers at 15 deg.
I have never cut a thread backwards before but it should work ok. In fact, it means I can run the tool off the part at the tailstock end. This will be good for my heart rate as disengaging the half nuts before crashing into the shoulder at the headstock end is always exciting.
I guess if I want to use the steady for parallel turning I can swing the compound to line up the tool. It would not be possible to have the fingers lead the tool, but I doubt I would ever need that.
Re: 29.5 deg;
We both mean the same thing. My 29.5 deg is after swinging the compound 90 deg, then back 29.5. ( or now an extra 29.5)
Hope someone can help.
I have "upgraded" to an asian lathe which came with fixed & travelling steadies. My next project needs leadscrews, which obviously require the travelling steady. My problem is, how do I line up the cutting tool with the fingers?
Harold Halls excellent article simply says "use the compound slide".
When I rotate the compound to the 29.5 deg angle this is not an option. Even worse, I have replaced the 4way toolpost with a quickchange one, This results in the steady fingers being about 50mm behind the tool.
I am about to make a new steady, have I missed something?
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