Member postings for mgnbuk

If a used imperial long bed deluxe model with a lot of accessories might be of interest, I have been thinking of selling mine.

I can itemise all the bits if you are interested, but off the top of my head there is the milling column, milling vice, rack indexing unit, screwcutting gear set, compound slide. fixed steady, spindle & tailstock drill chucks, 3 & 4 jaw chucks + face plate.

It was bought used & there are some marks on the bed near the chuck where the original owner used a hacksaw to "part off" without using a bed protector, but otherwise it is OK - not mint, but quite useable. I got it as a 40th birthday present (I'm now 61 !) & have not used it much, particularly in the last several years hence thinking it needs to find a new home.

Nigel B.

Robert: Quite right to point out that a hobby grade machine will not meet industrial standards out of the box & will need additional interlocks / safeguards / rectifications before it could be released to my collegues. My only laser experience was with my previous employer, where I was provided with a Renishaw ML10 laser interferometer to setup & diagnose positioning & alignment issues with CNC machine tools- not really the same animal !

My first port of call for advice on operating equipment I am unfamiliar with is the relevant HSE Guidance, as it will be if this project gains momentum. Given the low initial cost of these units, adding a solenoid released guard interlock unit & a safety relay to operate it to lock out power to the laser tube (& possibly operating a solenoid operated steel shutter to the laser output port) at the same time as addressing the known earthing & power supply issues should not be too difficult - even doubling or tripling the initial cost would still be cost effective compared to a full blown industrial machine that would probably be overkill - always supposing that the Chinese machine is capable of doing the required job ! I would also need to invetsigate whether an air jet would be required & fume ventilation requirements.

Tim: I know that the particular item I would be working with can be laser engraved as our potential customer has provided a sample. Due to commercial confidentiality I can't give any more details, unfortunately. Graphite does burn but requires an external heat source to do so - put a piece into an oxy-propane flame & it can be seen to being slowly consumed, but take it out of the flame & it does not self-sustain. The dust is not explosive, unlike other dusts. We make graphite heating elements for vacuum furnaces that operate at 1500 C that can last for years - but an air or cooling water leak providing oxygen at that temperature & they disappear quite quickly (as does the graphite felt insulation). The sample I have seen showed black/brown smoke staining on the surface at the ends of the engraved numbers that did not easily rub off.

Duncan: The V2 guide vanes were graphite - there are some on display at the Peenemúnde museum. I guess that they didn't need to last too long in that application, rather like the rocket motor nozzles in current missiles - only a couple of seconds burn time & you will not be looking to re-use them..

David: You have incoming mail.

Thanks for the replies.

Nigel B.

Does anyone on here have one of the Chinese K40 laser cutter / engravers & would be interested in doing a test engraving for me ?

I may have to laser engrave a part number on a graphite component at work & would be interested to see if a 40W laser would be man enough for the job.

There are suggestions that the "40W" lasers are nearer 25 or 30W in reality, but as the sales pitch for (at least some versions of) these machines shows engraving marble they may do what we need without spending a large amount on a full-blown industrial machine.

I would also be interested to know more of real life experiences with these machines - capabilities, accuracy, reliability etc. - from a personl perspective as well as for the work application.

Nigel B.

Please put in a link.

The OP has a link to a video on the second line of the first post ?

Nigel B.

I recently had to sort out a non-running Stihl brushcutter at work. The problem appeared to be the carb, so a non-original "service kit" containg a complete new carb, spare priming bulb, fuel lines, fuel filter, air filters & spark plug was purchased from a UK Ebay seller for around £11 delivered. The carb was obviously not the same make as the Stihl branded, Chinese made, "Zama" original, but it fit & was straight forward to set up to get easy starting, a steady tickover & stumble-free transition to full throttle.

While this listing may not be the correct model of hedge trimmer & is for a direct-from-China seller, a kit of all the parts I think you are talking about isn't outrageously expensive. This link is for a pack of 4 conrods with bearings is £24 delivered.

Nigel B.

I’d start with a full 100KWH from home and plan 2 top-ups of 80KWH each total £65'ish or near enough 10p per mile.

That isn't much cheaper per mile than my Hyundai i30 diesel - at current £6 per Imperial gallon for diesel & the car's usual average of 55mpg, that is 10.9p per mile. I would have to do a lot of miles to save the difference in initial purchase price of a Tesla ! And I have a genuine 550 mile range per fill, regardless of the weather.

Maybe the proposed £18K hatchback Tesla with a estimated range of 250 miles will make electric cars more viable for normal drivers - £40+K for a Tesal Model 3 is just not do-able for me, I'm afraid.

Nigel B.

This Youtube video might offer a few hints on how to dismantle one of those.

I've only skipped through it, but brute force does not seem to be required.

Nigel B.

Can anyone tell me if there is a correct way to proceed

I don't know if the method I used on the 4 screw, 2 piece gib arrangement on my S7 is "correct" or not, but it seemed to work.

Slacken all the clamping screws (the ones you originally asked about), then tighten them just enough take up the slack without fully tightening them.

Slacken the locknuts on the adjusting grub screws & reset them as above.

I have a recollection that I disconnected the cross slide screw bracket to be able to slide the cross slide by hand to set the adjusting screws - easier to move the slide through it's full stroke & feel for slack or tight spots by hand rather than use the feed screw.

When you are getting close to a nice "feel", snug up the locknuts on the adjusting screws - feel for any changes in tightness & tweak the adjusting screws to suit. When the locknuts are quite firm & the slide is still moving freely, start to snug up the clamp screws & check for changes to tightness. When all screws & nuts are snug & the slide is still moving freely, fully tighten the clamp screws.

Screw the cross slide screw into the nut (minilmal thread showing) and refit the screw bracket to the cross slide in that position.

When you are getting close, only very small adjustments are required. You are aiming for a smooth sliding movement without binding or slackness & it takes a bit of tweaking here & there to achieve that. You will probably end up backing off the adjuster screw you started with slightly as the others are taken up. Oil up the slide before you start. Use the short end of the Allen key to apply the adjusting screw torque lightly by finger & thumb - you will not be applying much beyond the point that the screw stops moving. When you get to snugging up the locknuts, you will probably have to hold the adjusting screws with the Allen key while tightening the nut to stop the screw moving.

I just tighten the screws & locknuts by "feel" - they are only small screws, so don't need cranking down on hard. Just tight enough to stop them coming loose in operation. Diffiicult to describe "feel", as it is also to describe how much resistance to sliding motion on the slide is "just right". Sorry I can't be more precise than that.

Not something you will need to be doing that often, though. I don't think I have had to revisit mine since I went over the machine after I bought it over 20 years ago. It hasn't seen a huge amount of use since then - though that may change in a year or two - but I still don't expect to have to tweak the gibs on a regular basis.

HTH

Nigel B.

You can find the Myford ML7 operator manual as a pdf file online, which includes exploded parts lists. The standard ML7 cross slide on the parts list doesn't show anything like your screws, but also shows a slide that appears to have fewer t slots than yours (3 behind the top slide pivot hole). Does you machine have the optional accessory extended cross slide ? Do the screws just tap into the cross slide, or do they pass through into something else like a Super 7 block gib strip as Bill mentioned above ?

Nigel B.

Looking at "sold" listings on Ebay back to the beginning of July, £400 is probably on the low side.

The same model of Nutool made £700 at the beginning of this month, 2 off Warco Minors were £812 & £815, an Ajax equivalent £625. An Alpine version made £986 ! Cheapest were the Clarke version (£450), though one of those "dismantled for transport" only made £50 - a bit of a bargain for someone.

The larger RF30 models go for appreciably more - £1320 for one recently. Note that these were "sold" prices, not high "buy it now" listings that had dropped off with no buyers

Always a bit of a lottery with auctions, but the trend on Ebay for small milling machines of any description seems to be well North of £500.

Nigel B.

Pretty pointless getting all worked up over a 75 year old design, which used lubrication arrangements that would have been familiar to users of the time. That many thousands of users over the ensuing 75 years have managed to keep their machines in working order using these methods suggests that, while they may not be "cutting edge 2021", they do the job.

FWIW I use an oil can of this type in conjunction with a couple of short lengths of clear plastic fuel pipe on my S7. The pointed end of the spout fits into the ball of flush nipples and fills the oil cups & a short length of fuel pipe warmed in hot water to slip over the end of the spout fits nicely over the parallel head nipples with no leaks. The hydraulic type nipples on the QC gearbox require a larger bore piece of fuel pipe.

No need for expensive brand named oil guns to get oil in all the required places without making a mess, just a bit of lateral thinking ?

Nigel B.

“TD6 is a key part of the Army’s plan for electrification of the battlefield, which seeks to gain operational advantage through using novel solutions for power, performance and support while also reducing carbon emissions. The programme will provide evidence to support the benefits, both direct and indirect, that hybridisation of some or all of our vehicle fleet may bring to inform our roadmap towards a more capable and sustainable future.” Colonel Simon Ridgeway OBE – Assistant Head Plans, Ground Manoeuvre - Army HQ

Does reducing the military vehicle emissions on the way to blowing up the opposition's infrastucture count as being "environmentaly friendly" in the greater scheme of things ?

Nigel B.

Have you removed the quill anit-rotation dog point grub screw ?

IIRC this is on the LHS of the head casting, in line with the slot in the quill - it is a socket head grub screw locked with a nut. The groove in the quill that the dog point of the grub screw runs in doesn't break out at the top of the quill housing, so it won't drop out unless the grub screw is removed first..

Nigel B.

I have some 4 pin plugs and sockets connecting the steppers back to the control cabinet.

This isn't intended to be critical of you, Steve, as what you have done is what appears to be done often on DIY builds - but did you actually need a quickly detachable connection here ?

From a reliability perspective, every connection is a potential problem - your plug and socket introduces two soldered and one mechanical connection between motor and drive. Putting a gland in place of the chassis socket and routing the stepper motor wiring directly to the drive connector without any intermediate connections would have eradicated 3 potential trouble spots. This would obviously make removing the motor a bit more of an effort - but how often would you be doing that ?

On the drive systems used on industrial CNC machinery, it is not unusual for drive manufacturers to specify thet intermediate connections are to be reduced to a minimum, but preferably to connect the motor cable to motor at one end & drive at the other directlly. The fewer the breaks between the two the better & any joint that can be designed out can only be a good thing - particularly with soldered connections, which (in my experience) cause more problems than crimped.

In my previous employment (CNC retrofit & rebuild), warranty visits reduced when the drive manufacturers introduced pre-made & tested cable assemblies that were installed in one piece. Prior to that introduction, most issues when we made up cables ourselves (frequently broken at terminal strips for ease of wiring) had been caused at terminal blocks or soldered multipin connectors

Nigel B.

The "levelling" when used in relation to a lathe is a poor way of simply making sure that runs true whatever length of work is machined.

How did the machine tool industry get it so wrong for so long ? And as they continue to do so, they mustn't have a clue. I guess I'll be making work for myself when I use a level to check out the lathe I'm cuurently working on before it goes into production.

Questions: Are boats level, when at sea? If they needed to be precisely level to the planet Earth surface, how did the navy cope with all those Drummonds during the war?

I have a recollection that the lathes on ships are mounted on a "neutral axis" that is isolated from the usual twisting and other movement that ships exhibit while at sea. But the lathe would have been checked while it was being bult using a precision level. And as ships are built "out of the water" on supports in dry docks, it would not be difficult to check the lathe for twist with a level at the point of installation, before the ship was launched.

Nigel B.

RM are certainly having problems due to staff shortages. Talking with the postman at work yesterday (we share some interests, so have a quick chat most days), he said he was working 11 hour days to try and catch up as they had so many off - 10 absent on Thursday.

Also having issues with ParcelForce - checking the tracking on a "Next day" delivery of parts required to complete a repair, I found that the parcel had been "Out for Delivery" twice & "Returned to Depot" twice before it was finally delivered. Confirmed despatched last Friday, delivered 5.30pm Wednesday. If the drivers don't get all the packages delivered by the end of their shift, they just take them back to the depot.

Some of the RM & PF tracking (particularly for items supplied & tracked via Ebay) just doesn't get updated - most items I get at the moment are delivered while the tracking has not moved on from "Parcel collected".

Interesting times.

NigelB .

You might consider those ice-cooler machines from on Amazon

Two main issues with evaporative coolers - they don't work well when the ambient humidity is high & they increase the humidity if they are working. Do you want to raise the humidity in your workshop ?

Nigel B.

that the total cost of ownership of electric cars is already lower than the total cost of owning an IC vehicle.

Where do you get that information from, Dave ?

One of the car magazines (Car IIRC) ran a comparison test recently using an current IC car & the equivalent BEV from 3 manufacturers - in all cases the total cost of ownership of the electric version was higher than the IC version. Considerably higher in some cases.

This may change in future, but right now BEVs appear to be an indulgance - those who can afford them do so & then crow about their supposedly "green" credentials. For some they are a genuine alternative, but for many not so. The only electric car I have seen so far that I may actually consider buying (and could afford to do so) is the Citroen Ami - a very different solution to urban mobility than just trying to replicate the performace of an IC car. Very basic, limited performance (28mph max) and range (5.5KwH battery gives around 30-35 miles & recharges overnight form a 13A socket) ) but cheap (around £6K in France - not available here yet) and made to suit a licence-free category of vehicles in France that makes driving one available to 14 year olds after limited instruction. As my weekly shopping trip is around 20 miles, mostly in built-up areas, such a vehicle would work for me there.

As to the power of big oil, it's fading.

I don't think that is the case. There is more to our use of oil than just burning it for fuel. One of the ingredients of lithium batteries is needle coke - an oil refining by product. Needle coke & pitch are the primary ingredients of manufactured graphite - used in many areas of manufacturing that you are probably unaware of (I know I was before I stared working with the stuff), particularly in metals manufacture (arc furnace electrodes etc.). Carbon black (oil product) used for rubber manufacture. Plastics for pretty much anything (mainly oil product). Carbon fibre starts out a s PAN yarn - oil product. Graphite felt insulation (used in vacuum & semiconductor furnaces) starts out as rayon fibre mixed with phenolic resin (oil products).

The list goes on - we are heavily dependant on oil at some point for virtually everything we make or use today & I don't hear much about finding "green", oil-free alternatives to those. There is a much bigger issue than what we use for a transportation energy source that does not appear to have been addressed by the "sound bite" politicians.

Nigel B.

I would not be hitting the spindle of an FB2 (clone, by the look of it). Light duty parts & IIRC a "strange" bearing arrangement for the spindle and indeterminate parts situation - easy to damage something you may not be able to easily replace & when parts were available they were pricy.

If you got all the tools with the machine, there should be a thin sheet metal spanner to fit the flats on the end of the spindle nose - hold the spindle against rotation with the spanner & use a tommy bar in the support ring on the tool holder to jack the tool out of the spindle. It may well go with a bang, so have a piece of wood on the table to prevent damage when the tool is ejected. The drawbar should be axial restrained under the nut at the top of the spindle & this usually jacks the tools out. IIRC the original drawbar was M10 (actually an M10 socket head cap screw) - I can check when I get home if that helps.

Nigel B.

(who has a similar machine)

But the real issue is the particulates … but they weren’t trendy

Check out the latest Euro 6 emission levels for both petrol & diesel cars - the particulate levels are the same for both. And a major source of vehicle related particulates is not engine related - brake & tyre dust - EVs will also produce these. By all accounts, both sources are less than particluates from burning wood ineffieciently in wood burning stoves in built-up areas.

One of the things that came out of VW cheating situation was a more detailed examination of what actually comes out of tailpipes in "Real World Driving" rather than during "official" test regimes. One suprise was that many direct injection petrol engines were worse for particulate emissions than some earlier generation diesels, but they were not at that time tested for such. If you look at the current Euro 6 levels, you will see that particulate levels are set for both diesel & DI petrol engines now.

I had (for a while) a Euro 6d Ford Transit motorhome - a not particularly economical vehicle, but after 5600 miles (when I got rid of it) the exhaust tailpipe was clean to the point that when a white paper towel was wiped around the inside of the pipe it was barely discoloured.

Nigel B.