Member postings for Ajohnw

The cross slide T slots are much more rigid than the ones on the boring table Ian. That is really intended for lathes that lack the ones on the slide. It locates in place of the compound slide using the same location method.

My lathe came with both. Maybe if some one buys the Boxford dividing head that makes sense. It didn't come with that.

The only thing I have used the cross slide T slots for so far is to hold a Myford style slotting attachments. Things like that are pretty easy to adapt. The castings just need boosting up with a plate - usually aluminium.

Seriously if you do want to do anything about the gears John Ward is likely to be the person to talk to. People are often surprised by his prices and he really does know his boxfords. With Boxford from my limited experiences of talking to them part numbers are fine but asking without them proved to be a waste of time. Might just be the person I spoke to.

I think a fixed steady is essential. The boxford travelling steady is really designed to use with a lantern type tool post but it is possible to manage with qctp and others. Without some thought there can be a lot of space between the steady supports and the tip of the tool. This is the worst problem on the lathe as far as I am concerned.

For any mechanical bits you need a mention on the group can be worth while but more people usually look on normal week days. Some one may have the spares you need - if any.

John

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Something across the chuck in between the jaws and pressure if the back gear is used to lock things but best left out or as I often do a good sharp whack with a mallet on the chuck key - if I can't budge it by hand, back gear out. Other than something between the chuck jaws both and maybe a sharp whack are bad practice. I believe some models do come with a spindle lock.

I usually manage with a sharp pull on the chuck key but am really good at snapping off the ones with the welded on ends. Fortunately I have a proper one.

John

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Edited By Ajohnw on 01/01/2016 18:07:27

If those are the bearing coves I think that they dropped the washers later and just left the grooves but the covers only just clear the spindle.

That is a typical repair on bust teeth. They can last so that may not be too much of problem but may well bust up more teeth if they break. The chobbled tooth looks like a case of partial engagement of the back gear. Again might be ok. It may be worth talking to John Ward of lathe parts about the problems. Boxford have kindly covered the prices of the bits with a parts diagram on my browser but increasingly more parts are marked obsolete. They do offer the washers at 58p a piece and lots of other bits.

**LINK**

He will also do you a T slotted cross slide if you want one. Other lathes too.

I think this is your headstock

**LINK**

John

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If you go onto the Boxford site they have a spares section complete with prices last time I looked. Downloading the parts list pdf off the Boxford group may help you navigate that. It's somewhere in the files section. It can help a lot with strip downs and rebuilds.

The other aspects really are just adjustments. Slides and bearings. There has been a lot of discussion on bearing adjustment at times. You can try the boxford method first but from what I can gather many find it leave them too loose so go their own way. I'm always reluctant to be very specific on that as what works for me might wreck some one else's lathe and my idea of what warm means is likely to differ to others. What people must do is to check what happens when the lathe is run at max speed. I initially check at around 500 rpm and to be honest don't use max speed much at all.

John

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Reading some of this thread makes me wonder if MS have started a new form of beta releases. I have run these when I used Windows in the past. They were given to selected people some time before the real releases came out. When the actual release was installed over these a message saying we can do better than that popped up. Little difference really and as always machine slowed down as more and more updates are installed. That aspect will get worse and worse as releases age.

The content of that link may encourage more people to switch to Mac or Linux so I really like that. God like companies that infringe people rights without them being fully aware of it should be stamped on. These days though especially with Mac there is so much wifi going back and forth it's hard to be certain what is going where.

Interesting extension of the commercial web though. I had a laugh yesterday. I wanted to check something I had already bought. No one would buy another and adds for it started appearing on several sites - suppose it helps the owners cover the cost of running the sites though. Increasingly I use one browser for looking for things and another for buying. Then there is one that retains nothing that I sometimes use for fun. It probably does keep something though even when everything is turned off.

MS have been at loggerheads with commercial users in the past. They take no notice. The users continue to use what ever release they are happy with rather than upgrading but later have no choice usually saying they are happy with the one after that. In real terms it's given them more time to prepare.

All in all MS have a fantastic business model. Good for them but us? I remember reading an estimate on how many hours their users waste planet wide some time ago.

John

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I would follow either Jason or Ian's suggestion Brian. Probably Jason's as I would use countersunk headed from underneath which would leave zero scope for adjustment.

One thing you should check on your drill - are the drills square to the table? Often they can be adjusted on one plain. Out of square can cause holes to wander about. An automatic centre punch helps or in in critical places a centre drill first - those can be pulled a little with care.

A small toolmakers square can be a useful thing to have about. They usually come with 3 blades. On straight, one angled at each end and a narrow one that can be used to measure. The blades are 100mm / 4" long.

The manic method on larger holes is to scribe a box with a height gauge and pull the drill central as the tip goes in. Done correctly the drill will break the scribed lines on all sides = positioned to better than 0.001".

John

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There are some older books about on engine "physics" in general. You might find some on the internet archive.

One I read some where or the other offered a mathematical proof that an external combustion engine of any type can't exceed 50% efficiency in a theoretical sense which probably means they don't even achieve that in practice. It also covered internal combustion engines of various types.

No doubt written by an academician who are unfortunately inclined to prove what they want to prove.

John

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Interesting I thought they all used the keyway in the lead screw for the feed apart from some of the very early ones which were rear drive. A,B or C and UD, under drive. I hadn't realised the C lacks it.

To be honest I never use the power cross feed on my ME10, it needs too much variation of feed rate and I'd rather do that by hand.

My rear bearing inner was extremely tight on the spindle. If you got your spindle out easily yours probably isn't tight. I have wondered if this is down to a bearing changes and fitting what people usually use rather than the separate outer and inner rear that can be bought at great cost. The fit seems to vary lathe to lathe.

The other thing I found when I bought and used the lathe was that the bearings needed adjusting but every time I did some heavy work they loosened again, especially opening up holes to 1" from 1/2" with a drill. All I can put it down to is the front cone not being fully home. Eventually they stayed adjusted. I did see something direct from Boxford years and years ago about making sure that the front inner was fully home against the shoulder too.

I use ArcEuro's high speed moly grease by the way on the head stock gears and the bearings. It doesn't need much on the gears just a smear. It stays there. Around 1ml or so evenly smeared on the bearings is likely to be about right. Too much isn't a good idea. Oil is the best thing to use on the change wheels as swarf is less inclined to stick to it - the lead screw too.

John

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This what a suitable spanner needs to look like

I would tell you the size but it's another thing I have yet to find again. You can check for fit at the change wheel end.

John

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There is a keyway along the lead screw that provides the feed not the lead screw thread that is for screw cutting.

One mine that has a gearbox min thread pitch is 224 and that give a feed rate of 0.0015" per rev. The ratio between the two will always be the same. There is usually a chart on the machines some where that shows both. Probably inside the change wheel cover. There may be photo's about on the web even off a SouthBend.

The feed is engaged with a black knob that sticks out of the saddle that screws in and out. It's actually a clutch arrangement so that the saddle can be run up to a rigid stop. It might even stop you wrecking the machine if you managed to engage both feed and screw cutting which is a no no - just one or the other.

I think Harold mentions the real reason for levelling the bed - if you haven't got a high precision level there isn't any point - other than suds trays overflowing of it's at a stupid angle.

You would do well to google for Know Your Lathe and also join the Yahoo Boxford group to obtain parts lists with breakdowns.

Sometimes the bearings need adjusting - first job if you are going to set the machine up. I do that by running the machine at around 500rpm for 20min and feeling the heat on the inside of the spindle under the rear bearing plus what it does when I turn.

The parts list shows Boxford's way of setting them on new machines but usually grease added over the years and wear prevents that from working and they need to be a bit tighter. Searching the yahoo group will bring up various views.

Boxfords are set up via turning once that area is ok - the 2 rings method with light cuts then staining the bed at the tails tock end to correct their sizes. Then the tailstock is set up. This is only intended to correct maybe a thou or error maybe a bit more. Any more from bed wear has to be put up with. The lathes are very precise as they come and this just finesses them. The method is detailed in know your lathe but I would use a bar well over 1" dia, also for checking taper and bearing tightness via plain turning. They also mention levelling the lathe but it really is a red herring. If a precision bubble is used it can be used to check for bed wear and twist - within limits but the myth persists. An ordinary spirit level is enough to make suds run out of the tray rather than leave puddles.

Oh do check that the head fixings are tight. These lathes are often moved by dismantling them and it's best to bend up a combination spanner to tighten or even check them. The ring end may need filing down a bit and don't go for a very long one as some of the spanner will foul on the gap between the bed rails.

John

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Edited By John W1 on 31/12/2015 15:58:35

Chip breakers are fine but when they cause bits to fly it's only a matter of time before one hits your face. The chips can cut and burn at the same time. Not a pleasant experience I have had it happen.

I also had a lathe that tended to cause all tools to behave like they had a chip breaker on them until it was adjusted and had the head stock bearings replaced - ML7 and no further adjustment on them.

The little bits also get all over the place and are hard to clean up. They cut into and stick to the soles of shoes and people who walk about in stocking feet at times had best watch out. Then there are pets.

Swarf - that's what swarf hooks are for, not hands and fingers.

In my view this one is a bit manic and OTT but

The other aspect is that the tip geometry / angle it's used at will always tend to send swarf in a direction that doesn't cause problems.

John

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A mini lathe isn't as powerful as a Harrison Andrew and EN3B is a pretty variable metal as this links suggests

**LINK**

The ability of a lathe to take very light cuts and give a good finish is mostly down to rigidity, lack of vibration and the state and type of head stock bearing arrangement.

Interesting tests though and it does pay to take cuts as deeply as possible to minimise wear and hit sizes bang on with decent sized cuts as most lathes have some play somewhere and the cut will remove that at some depth leaving a decent finish.

With a metal like that this OP might get better results finish wise with a good sharp hss tool with 15 degrees all round, side clearance and back rake. Maybe more rather than less. I've turned loads of the stuff but some is terrible. At smaller diameters the machines were incapable of reach the cutting speed you suggest.

John

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I should add to that post for a more exact description. When the dimmer blew up the lights dimmed to the point of nearly goin off so the 20kv must have dropped a lot. The fault then clears and it shoots back up to 20kv and a huge spike goes down our mains due to the capacitance of the transformers they use to supply us with 240v which is actually usually connected to 440v 3 phase somewhere.

If some one get the lights dim a bit like that or the computer doing odd things now and again especially if the lights flicker it might be worth installing a mains filter. There are plenty on ebay but wall mounted ones are generally far more robust.

We had the dimmers go several times so I bought a more expensive one. It lasted but then received a spike that was way way higher and longer duration than it aught have been.

John

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If they are using scr there should/maybe some snubbers across them - a resistor and capacitor in series. They can cause grief if they fail - usually the capacitors, that might even go bang. They are used because high speed voltage rises on scr's can turn them on when they should be off. Should / maybe - well with mains frequency electricity they shouldn't be needed - in theory anyway. IGBT's are I believe a lot better. I think those are usually used in inverters but I've never needed to go into one - yet.

With the sort of circuit describes a MOV, metal oxide varistor across the supply would be a good idea to kill any high voltage mains spikes. They are usually a bit like big disk capacitors. They are also fitted in extension leads intended for use with computers. People might think they don't get them. It's an odd effect. I can't remember actual voltages but say the local sub station gets 20kv and there is a sudden load change usually due to a fault some where. The voltage changes rapidly and the change goes through the transformer that is providing the 240v and hardly changes so can result in a several Kv spike. We used to get them from time to time round here when Leyland was in full swing. One literally blew part of the casing off a light dimmer off the wall. The dimmer was kaput and one of the components literally exploded. A mov.

John

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Edited By John W1 on 29/12/2015 19:32:02

If you are sure that the cutter is set correctly especially not bending to under centre when boring the best way of telling is that the finish wont be so good, You might see wear on any coating with a loupe when this happens. I'm assuming you can see chips etc.

The problem with boring and the tip going under centre is that clearance is reduced and the tool can rub rather than just cut. If it does that because it bends things get worse - deeper cut so more bend and deeper cut etc.

Can't help on gearing for power feed. The manual for the lathe or a similar one is probably your best bet.

It doesn't surprise me that the chips are that hot at 400 rpm with a bore of that size. Up to an inch or so they should be relatively cool. 2" probably rather hot.

John

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With circuits like speed controllers the parts most likely to let the smoke out are those that drive the motor, It's probably relatively easy to spot what these are and replace them via what ever manufacturers part number is on them.

Another problem that can occur with brushed motors after some time is accumulated brush dust. That just usually causes earth leakage trips to drop out. Even a simple mulitmeter can some times show lack of resistance between the coils and the chassis of the motor. I doubt if that is your problem though. It happens on unimats.

If electronics are well designed it's nearly always the bits that are connected to the outside world off the board that fail. On motor drivers it might be the parts that drive the motor driving parts that fail if some one has skimped. Big FET's for instance need a fair old whack to switch quickly. There may be clamp diodes on motor drive leads. Again if some one has skimped these can fail and that happening blows up the part doing the actual driving.

If there was a pop their may even be a hole in what ever went.

John

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There is another material worth mentioning. OSB. In a moment if madness I bought 2 8x4 sheets of it and made a pair of garage doors with it. Fitted to toolmaking standards. Still fine after more than 15 years but did it take a lot of paint. I'd picked up that it is moisture resistant so tried it more out of curiosity. Just 1/2 days work sawing it up including making braces from it to stiffen it up.

The only problem is that our "garage" is an extended old outhouse and the doors are out of site and even painted don't look that good so I have intended to replace them using ply with timber edging but out of site = out of mind. My wife doesn't see them often either. In fact she has never even mentioned them.

It is an interesting material. It can be used for structural beams. They just route out a groove in a strip of timber and glue it to the edges to stop the beam from bending side ways.

Yet another material that has been used for sheds, boats and all sorts of things is this

**LINK**

Might even make a good presentable cladding for OSB. (Oriented Strand Board) but other things could be used for that.

OSB has been available pre coated with something like car underseal for roofing but not for living accommodation at the time for some reason. I presume it would normally be covered with something. Maybe fibreglass shingles.

John

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Years ago when lead started disappearing from paint and wood rot was a problem some one phoned one of the timber preserver manufactures and they told him to use it and then coat with aluminium paint and then normal paint on top of that. No idea how well it worked as I changed job but ok for the couple of years I was there.

My father got sick to death of painting the house and eventually used Tekaloid. It did last a long time. Dulux weather shield lasts well round here if stripped right back and the watery primer preservative is used first followed by their primer and top coat. A builder told me that he did a wooden conservatory with it and all was still fine 20 odd years on. The primer preservative wasn't easily available a few years ago but does seem to be about in DIY stores again now. Some of our windows have sun on them all day - when it's out. 15 years and then a change of colour using a their top coat. Wish all of the wood underneath was so good. We don't like the colour though.

An old trick on black and white houses was to use lamp black for the black and then a varnish. Tidied up every now and again with fresh varnish. Something to remember if it's ever stripped off. I've left out black alone as I suspect it was done initially like that. We did have it over coated with weather shield about 5 years ago when the windows were repainted. I bought the paint myself - the contractors will use any old junk. No way will I go up a fully extended 3 section ladder. This lot did sand it before painting. A neighbour wasn't so lucky, no sanding, junk paint and the lot is peeling off.

John

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Thanks for mentioning SIP panels. The outside can be covered in a type of board and coated with a light weight polymer render. Now that might really make a self build "conservatory" a very easy job. The house is part rendered.

I reckon I have been in a truck stop that did amazing breakfasts that was based around a modified container.

Timber garages coated repeatedly with old engine oil used to be popular. My grand dad had one. It must have stood for 30 or 40 years. It might even still be there. I think but don't know that they diluted it a bit.

John

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The equatorial platform for the sct's is simple to use as well Neil.The one I have used on a 10 SCT is just 2 shaped aluminium plates that are hinged with the usual scale. I'd say around 1/2" thick and they are normally kept on the tripod. Meade had the bright idea of using a nut that contained a compass and level as a nut to fix it on with.

Polar alignment is different as there is no polar scope but it can be done in other ways. Meade did a finder with a polar reticule in it. The other way is to use star drift. For visual use I used to swing the whole lot about initially and then use the adjusters. It was more than good enough for planetary use and didn't take long. It's also possible to keep switching between 2 stars centring them with the adjusters. Getting it exact isn't quick with any type of portable mount.

The biggest pain with all of them is levelling the platform the head sits on especially on a tripod. I feel it would be fairly easy to make a levelling platform using 3 pairs of spherical rod ends with opposite hand threads. That way the tripod legs could be used for a coarse setting.

I still have a vixen pier. My impression is that these are more rigid than a similar weight tripod. Levelling is also easier on hard surfaces as they sit on screw jacks. Never done it but it would be easy to add some locations for the jack screws to sit on in the garden and also locate the head in the mount. That way once set up it could be simply plonked down and used.

Must admit I am not really interested in long exposure photography. I came across some one on cambridge in colour that uses a dslr and shorter exposures. He gets good results so I will be trying that. There are indications that a go to alt az mount might be track well enough if set up carefully. The exposure time that could be used was read on the web though - Always a dubious source of info.

My first bought scope was an 8" Celestron SCT. I've always regretting selling it as they are so easy to move around and use. A 10" isn't so much fun. I also have a now very elderly Meade 5" F9 APO. It's on a Meade GEQ that Astrophysics used to buy off Meade and rebadge and tweak. It's joy to use even with the tripod legs fully extended. Contrast wise it matches maybe beats an 8" sct but it's far more of a handful. It costed me all of circa £250 some time before apo's became really popular. I often wish I had bought a full set of Takahashi eyepieces then as well. Their prices rocketed not long after. I tried to get some discount on a full set off the dealer and he wouldn't offer me any so gave it a miss. A lot of the price hike was profit. I found a Mewlon for sale in France for a lot less than UK prices but the dealer wasn't allowed to sell it out of France. I'm more educated these days - wouldn't want one any way. Dall Kirkams have more problems than SCT and focal reducer correctors can be bought for those a well.

John

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Edited By John W1 on 29/12/2015 14:07:36

Edited By John W1 on 29/12/2015 14:08:17