I screwed up!

[Roger HeadParticipant @rogerhead16992]

Hi Geoff,

Both night owls I see. Not these days mate, 2am stints are a thing of the past. I'm on the other side of the world, hence my timestamp.

A couple of thoughts, not necessarily in any order, or connected.

1. I agree, the pinion shaft, in spite of being new, sounds like a good suspect, either as an alternative to, or as a possible addition to an off-centre gear bore. Plenty of measurements to be made there.

2. I don't understand how driving the pin (roll or taper?) completely home can alter the effect. Surely the gear is a neat fit on the pinion shaft, and shouldn't move/tilt or suffer any other untoward movement?

3. When you have the apron removed again, I would be making some very careful runout measurements of the pinion shaft inside the apron, with the gear removed.

4. In your second video you are troubleshooting with the apron bolted onto the carriage. So you cannot see what is happening to the gear mesh when turning the feedshaft. Furthermore, the pinion shaft motion is subject to the effects of its engagement with the rack. It may be instructive to remove the rack while the apron is mounted. You can then drive the feedshaft and observe/apply-loads-to the carriage handwheel.

Good luck.

Roger

 

Edited By Roger Head on 17/04/2016 14:00:26

[BazyleParticipant @bazyle]

If the holes for the roll pin were a product of the factory they are probably not 100% true to the shaft. Try 180 degree relative rotation of shaft and gear and try again.

[OuBallieParticipant @ouballie]

Roger/Bazyle,

Thanks for your thoughts.

I can only think that the hole through the gear boss is not square, and as you mention Bazyle. The gear to shaft is a neat fit.

Update.
Attacked the Apron boss that the spur gear revolves against with a file, and that lessened the binding somewhat.
The new DC motor had no problem getting everything working whilst the Apron was on the bench, BUT once fitted back onto the lathe and Carriage power selected, it grinds to a halt at the same spot the Handwheel reaches during each revolution.
Conclusion has to be that the Worm Gear Shaft has been bent just sufficiently to cause the binding.
Apron will now stay attached as I search for a more powerful DC motor as this WILL NOT beat me.
Digging heels in now!

I blocked off the access hole to the Carriage Handwheel shaft, at the rear of the Apron, to allow for more oil to be poured in, as Howard has done, and extended the overflow pipe.

Geoff – Spending time on the Austin Seven now, hence delay in responding.

[Howard LewisParticipant @howardlewis46836]

My! You are scientific!

I just turned a bit of nylon to size and, typically, bashed it in with the hammer!

Also you have cleaned up everything.

The rollpin hole in mine had been drilled freehand, so pin, gear and shaft only lined up in one orientation.

Of course, when making the new shaft, I driiled the hole square on, so refitting the pin needed a bit more impact force (aka Hammer blows). If you use official spares, the gear will probably act as a guide, so that the holes are more likely to line up.

Like the new plumbing to feed oil everywhere that its needed. Not too much, or it will go everywhere that its not needed, but nothing will go rusty.

Having overcome the problems (self made) with the worm housing, and the time spent retightening the capscrews, blind, everything works as it should, possibly a little sweeter.

If the capscrews on the wormhousing do need tightening, a 5mm Allen key needs to be shortened by about 6mm at the business end, and the long end extended some 60mm or more,.so that although you can not see what you're doing, fingers are not against the bed and tilting the key. Just take a large dose of patience before attempting to tighten the screws, in situ. (You really don't have much option, unless you have the sort of luck that wins you first prize in a multi roll over lottery

So, if anyone else has mangled their BH600 or a lookalike, even someone as nervous as I , with Geoff's advice, can fix it.

Howard

[Roger HeadParticipant @rogerhead16992]

Posted by OuBallie on 02/05/2016 12:22:18:

Roger/Bazyle,

… once fitted back onto the lathe and Carriage power selected, it grinds to a halt at the same spot the Handwheel reaches during each revolution.
Conclusion has to be that the Worm Gear Shaft has been bent just sufficiently to cause the binding.

Geoff, I'm not familiar with the apron handwheel gear train, but are you sure that it's a 1:1 correspondence between the worm gear shaft and the handwheel shaft? If not, then …

Apologies if I'm telling granny how to suck eggs!

Roger

[OuBallieParticipant @ouballie]

Howard,

I get it from my parents, both perfectionists. Thanks for the comment 

I drilled the replacement shaft using the drill press.

I just assumed (bad move) that the hole in the gear boss would have been all square, and had the same problem, although I did pass a drill trough the lot, but no improvement.

Life's too short to worry about that now.

Roger,

Good question and not sure as I never had a good look.

The drive is, however, via gears of different diameter so not 1:1

IF and only IF the Apron comes off again, for some reason, I will check.

Geoff – Perfect weather now to tackle the Austin 👏

Edited By OuBallie on 04/05/2016 14:23:29

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