Member postings for Alan Wood 4

I have a digital subscription and this works well on my desktop under Win7. When I try to read back copies on my Android tablet I get a black/blank screen suggesting the viewer does not work.

Anyone else had / solved this ?

Alant

Thanks Clive, your comments appreciated and all understood.

The problem might have been eased if the shaft was not so close to the 5/8" and even better if it was clean instead of having the thread witness marks.

Think I need to think this through before splashing out GBP200.

Some pictures of the protruding shaft

Kind regards

Alan

Quite taken by the article by David Shrimpton in 242/243 and wondering if it can be duplicated on my VMB. Having stripped the right hand winding wheel there is nowhere near as much shaft to work with (1.75" and the diameter is approx 0.59" so a tad under the 0.625" that David reduced his shaft to.

Can anyone give me any more dimensions on the main drive gear and overall completed dimension of the drive unit ? MSC are currently offering a similar drive unit at GBP200 + VAT.

Kind regards

Alan

OK, thanks guys.

Alan

Getting on for 9" which seems silly for just chisels etc.

The approach angle to the wheel is adjustable.

The grinding wheel sits in a bath so its well thought out.

Alan

Any idea what this is ?

The 'bed' moves across on a mechanical drive.

It looks to be a chisel or jack plane blade sharpener but not sure

Nice job Ian.

Certainly cheaper than the Sherline table.

Do you get any backlash ?

Alan

Thanks to everyone for the useful discussion.

Hopefully it will help others with the same issues.

Kind regards

Alan

Hi Phil

Been dwelling on this bit.

Initially I did the end collar up by hand but perhaps because the new bearings were so tight on the shaft I did not realise that the various components were gapping on the shaft. By making and using the tool I have 'shuffled' everything along the shaft but perhaps now overdone it ?

Having gravitated to the point where it has now come to rest, I can hand tighten and loosen but it does not align with the mark on the shaft. This is my slight worry.

Everything else seems fine.

Alan

Hi Ady

I have tried the dynamic technique and think it has merit. It makes me feel a bit more comfortable.

But ... seeing your later post with the image of the instructions, the scribed line on my shaft is a long way adrift on the collar split, like 180 degrees. I saw this line and assumed it was to tell me where the keyway was on the shaft.

My good feeling now dissipating ....

Alan

Thanks both of you for this.

Cabeng - OK on pre-loading, the mists begin to clear. I am a retired radio engineer with metalworking tendancies so can help you on intermodulation and blocking should you ever need to know ..... .I'm located near Newbury and I have copies of the handbook.

Ady - I think I get what you are saying and like the concept. I don't have a collet set for the spindle as yet, only a 3 jaw but the same should work. Will have a play and let you know. The S7 is 2001 vintage and very clean. Got it from Myford Lathes in Wiltshire. I also got a VMB and a BCA from him.

Alan

Hi Cabeng

Thanks for the useful comment. I am new to the hobby so I am trying to absorb and understand as much as possible.

I don't think this was the issue as it had been going on for a while with the old bearings with no heavy oiling. I had tried various adjustments with the new bearings before I went back to first principles in understanding what I now believe is going on. I guess had I understood the process a bit better I would have played more with the settings with the old ones still in place. It might have saved me a few quid and reduced my down time.

I still don't fully understand the 'loading' expression.

If, as I have now, all the components on the sleeve are held in place tightly by the end bush then all the adjustment of the sleeve taper position in the bronze front bearing is down to moving (in effect) the outer rings of the bearings within the casting using the castellated nuts. This is putting a sideways pressure on the outer ring of the bearing nearest the chuck (right hand one). The left hand one is then being tightened up against the right hand one with the split circumference washer between them to support it. As the sleeve is adjusted out of the bronze front bearing, the pressure on the outer ring of the right hand bearing reduces as it is not having to 'pull so hard'.

The Myford handbook implies the loading comes from the end sleeve adjustment but I guess this might assume the bearings have not been swapped and are still in place from the prior assembly ?

Still a lot to learn but it still sounds lovely this morning and I can get on with cutting metal again without twitching every time I had heard the graunching noise.

Further comments appreciated.

Alan

My Super 7 Large Bore began to make 'crunching/ grinding' noises from the headstock area. These were random and did not seem based on loading.

After some investigation with a 'stick to the ear' I figured that the angular bearings might need attention.

Taking the bull by the horns I stripped the shaft assembly down. This is straightforward.

Chuck off.

Remove the grub screw that is under the spindle and stick a large darning needle into the hole to spear the wick.

Undo the set screw in the main gear wheel.

Drop the tension on the drive belt.

Take off the thread protecting end bush.

Loosen the set screw in the end collar and take the collar off.

Protect the end of the shaft with a block of wood and tap the shaft free.

Gently pull the shaft out of the bronze front bearing while catching everything that slides off it in the process (including the two Woodruff keys before they drop down into the works).

Undo and remove the two castellated bearing retainers in the casting with a C spanner.

Push the bearings out.

Doddle, 10 minute job.

The front bronze bearing was clean with no scratches visible - relief.

The rear bearings didn't seem that bad but there was lots of crud in them and if I spun them stuck on my fingers they did rattle a bit. Sifting through the debris in the bowl after cleaning didn't reveal any solid foreign bodies.

The original bearings were NSK type 7007A which didn't seem to exist anymore. A call to Myford got me two new bearings by IBC with the same 7007 code. Given I had it all in bits I also ordered a new wick to oil the front bronze sleeve bearing. These tend to harden over time so worth doing.

So I now had all the bits to rebuild it.

First problem was the new wick was oversize for the feed hole against the shaft. Some shaving with a scalpel trimmed it to size.

A call to Myford told me that the new bearings had to go in with the thinest side of the outer ring, outer most - i.e, the front one with this side to be facing the chuck and the rear one facing away from the chuck. This meant for the bearings I had in front of me, the inscription sides on the bearings were facing each other. Sandwiched between them is the spacer washer. This has to go in with the gap in it, at 12 o'clock where the oil can feed down into it from the oil nipple on the bearing housing.

Now have you ever tried to make sense of the re-building as described in the Myford official manual ?

I was apprehensive to say the least as it made no sense. The new bearings were very tight on the shaft which worried me but I did what I thought was right per the manual and after oiling up well, switched on. (Don't forget to put the drive belt back on the shaft ...)

Not a good sound ensued. Probably worse than it was before. Really crunchy. Expletives.

Switched off and had a brew (or two). Scrap paper and pencil time. It took a while to dawn that there are two things going on.

The first thing is that all the elements on the shaft up to the 'spindle thrust shoulder' (5 in Fig 34) have to be squeezed together by the end rotating collar (4). To say you can do this with hand tightening is not practical. You need a spanner with two prongs on it to match the holes in the end collar. You can buy these from Myford but needs must and I made a crude one to do the job. Before you begin to tighten this up, loosen off the two castellated nuts sandwiching the bearings so the bearings are free to pick their own position inside the casting shell.

Once all the components are tight on the shaft you can now adjust the right hand side castellated nut to pull the front cone into the bronze bearing bush. Tighten this until the cone sticks and then back off by the specified 15 degrees so the cone is then free to move again. I fiddled with this a few times to make sure it wasn't binding in any way. Tighten up the left hand castellated bush to lock the bearings in place.

Switched on and what a difference, almost sewing machine quiet.

Given the experience I would now think that the old bearings were probably OK and had not been set up properly by the previous owner.

OK, you might say this is all obvious but I could not find anything on the Net to explain this is in simple terms and maybe I have still not fully understood but it is a different machine now.

Or have I made a fundamental mistake that someone is about to tell me about ?

Alan

Thanks John, no problem.

Clockmaking intrigues me, hence my need to get the resources in place. I have also followed Bill's idea and made a conversion block to put the Sherline headstock assembly on the Myford vertical slide for gear cutting. I am hoping to see him at the National Convention in Chattanooga in June.

Harrison's stuff is astonishing. I have a couple of ship's chronometers which I rashly bought after having been blown away by the internals.

I looked at your CNC site and there is some nice stuff. In my working life we designed and manufactured radio communication equipment and I dumped a Bridgeport CNC lathe with Haidenheim controller on the metalshop and told them to learn how to use it to mill our enclosures. They had never seen or used one before .... didn't get a Christmas card that year. Within a few months we were producing stuff and later added a second Hardinge with Fanuc. Product was designed initially on Alibre CAD and later Solid Edge. We used SprutCam as the interpreter driver to program the machines. Those guys ended up producing some really complex stuff and in big numbers.

Anyway thanks again.

Alan

Hi

This was my first post and I think I should apologise for not making myself clear.

The idea for using the Sherline Table came from William Smith and featured in his various documentation. Bill is a very elderly and learned gentleman for whom I have the greatest of respect and reverence. There was no intention to infer directly or indirectly that the idea was mine.

The project and the subsequent post was an attempt to bring his concept to a wider audience and offer a practical example of how it could be implemented to engineers who had the vision to see its merits but perhaps lacked the small print of how to do it.

Again I apologise for not making this sufficiently clear

Kind regards

Alan

Being a fan of the clock maker William Smith, I was interested in his use of the Sherline CNC table for indexing the Myford lathe.

While Bill shows its use there is little constructional detail of how to actually do this in his videos and books and this would have been no value anyway for me as I have a large bore S7.

I had purchased a S7LB hand crank and used this as a starting point for dimensions for the mandrel sleeve to fit into the rear of the headstock. The sleeve has a 7 degree taper grip on one end and the interface to the Sherline uses a standard 18mm collar from Bearing Boys bolted to the Sherline table.

In order to get the collar exactly centered I made a stepped bush to fit the table centre hole and with an OD of 18mm to snuggly fit the bearing collar. This was centre drilled 6mm and held in place while I drilled and tapped the collar onto the table.

The retaining shaft is a 6mm rod tapped and Loctite into the taper expander cone. The cone has a piano wire cross pin to stop rotation in the mating sleeve. Quad lateral slots are cut in the sleeve to match.

The shaft pulls the cone into the sleeve, expands the sleeve which in turn grips inside the head stock. This also pulls the sleeve into the Sherline table collar. There is a grub screw on the collar for added grip if needed.

The image below shows the parts involved.

The upper item is the sleeve.

The centre line shows the retaining shaft with taper cone and knob.

The three lower items are just for reference being the Sherline centre boss as supplied, my centering boss and an example collar.

The assembly is fixed with a simple aluminum bracket to the side of the S7 tool tray to stop rotation. This is the last thing fastened in place once the sleeve and table are mounted so there is no stress on the table.

I have done numerous checks on the repeatability of the indexing and find it excellent.

The Sherline is a wonderful piece of kit allowing any division by degrees or steps up to 999. It also has programming for multiple process steps.

If this is of interest to anyone I can do a more detailed write up with drawings and pictures.

Alan

Hi Ray

I have only just signed up to the site and saw your post and ignore this if too late etc.

I have a VMB which was originally single phase and I swapped the motor out for a 3 phase motor so I could use the Tesla controller system from a single phase supply. This works a treat giving me variable speed.

I now have a single phase motor surplus to requirements.

I have also fitted DRO to the VMB using simple vernier scales cabled off to a large readout.

I can let you have more details on these aspects if you want. I like the VMB but the Z axis certainly keeps your arms fit winding it up and down. Think I need a plan to motorise this in the future.

Kind regards

Alan