Here is a list of all the postings mgnbuk has made in our forums. Click on a thread name to jump to the thread.
|Thread: The diesel controversy|
Once done you can drive at 70mph on the motorway, instead of 60.
Vans can drive at 70 mph on motorways anyway, so no change there ?
|Thread: Engineers blue alternatives|
Or Cromwell Industrial Supplies if there is one near you
|Thread: Truing up chucks|
Of course there must be many exceptions, but to me the need for a fitter either indicates small-run production or a firm vulnerable to competition.
I would put many machine tool builders in the "small run" category. Machine tools are not consumer durables like printers in terms of volumes produced & the market is too small to justify the substantial investment required to produce say, a mini lathe or mill in a robotised factory. If Joe Public bought a new mini lathe at Currys every couple of years like they do printers, things may be different !
My former employer was of the opinion that fitters should be unnecessary if the machine shop did their job properly - but also complained about the cost of having parts precision machined. I understand that some volume builders ( Haas springs to mind) do machine to tolerances that require the machines to be "assembled" to the required accuracies from a kit or parts, rather than being "fitted". They do this by using linear guides that bolt-on, rather than require precision fitting like plain bearing machines - which is fine if a linear guide machine does what you want. If it doesn't, then it's back to a "hand fitted" plain bearing machine. They have also invested very heavily in the plant to produce the parts to the required standards.
Michael, fabrications where you suggest would probably cost more than a casting. The 7 series lathes were designed to be mass produced & (initially) sold at a competitive price. I guess that as their volumes declined, they started to believe the hype about the "higher quality than an import" & adjusted the pricing accordingly, rather than investing in more modern methods to produce the same (or better) quality product cheaper. An affordable British lathe - rough edges or not - is not likely anytime soon, I think. Though if you know why it isn't rocket science to do so, please demonstrate how !
I presume what lathe manufacturers did (or maybe still do) was to temporarily fix the tailstock and head stock body together and bore/ machine all the mating surfaces at the same time. so that everything lines up on the bed.
You presume incorrectly, Michael.
Parts are made indvidually to tolerances & then "adjusted" on assembly to the required accuracy - that is what machine tool fitters are for !
|Thread: Aircraft General Discussion|
3/4 scale ?
1:1 scale - the real thing.
|Thread: Doncaster show|
I Agree regarding comments about Doncaster being better than Harrogate.
Maybe better than Harrogate as you remember it from the last ME Show, but not now after it has been redeveloped. I was there last weekend for the Northern Shooting Show & can see why the cost of hiring the venue has increased - the replacement for the rather dingy hall that used to house the model boat pond & most club stands is bright, airy & about 4 times the size it used to be. And there is another cafe at the far end of the new hall as well as the "between the halls" original, as well as extensive outdoor catering on a piazza that I don't recall being there before. Still no easier to get in though - 2 mile que at 8.15 for a show that opened the doors at 8.30.
After seeing the exhibitor list for Doncaster, I chose the NSS instead this year - maybe reconsider next year, depending on who (trade-wise) can be enticed to attend.
|Thread: The diesel controversy|
the emission test passed no problems
The MoT test for diesels is a visible smoke test, not "emissions" such as Nitrogen Dioxide. I am pretty sure I have seen something about proper emissions tests being developed for MoTs, as the current test is acknowledged as being inadequate. As well as being illegal, tampering with emissions control equipment is downright antisocial IMO.
The "problem" of older diesels will work it's way out in reasonably short order due to attrition. Euro 4 limits came in in Jan 2005 & Euro 5 in Sept 2009 - I pass a vehicle breakers on my way home & most cars there are post 2000 (many post 2004), so it won't be long before many of the Euro 4 cars are getting recycled naturally. The costs of basic repairs are such that even a relatively minor failure in a 10+ year old car makes it unviable to repair - even if you can get the parts. I have shifted 2 out of my last 3 cars because of actual or potential repair costs, the last being a 5 1/2 year old Toyota Avensis with 85000 showing that was eating money. It had 1 front wheel bearing under the 5 year warranty (just within & done with bad grace), another front bearing failed 3 months later & Toyota wanted £500 to replace it (Independant did it for £275). A rear bearing was noisy 2 months later + the CVT gearbox ws getting noisy & Toyota didn't supply parts, only a brand new gearbox for £4500 ! I got £4500 in P/X for another car instead - pointless pumping money into an older car.
The bigger problem with older diesels would appear to be busses, taxis & large commercial vehicles, which have a much longer operating life than cars and light commercials. Legislation to mandate retrofitting of emission control equipment or re-engining with compliant equipment of these vehicles would appear to me to be a more sensible option if faster air quality improvement results are required than car scrappage schemes would provide.
|Thread: warco lathes.|
Various Colchester Student 1800s, Chipmaster, Triumph 2000 + Harrison M300s at this auction, ending this week **LINK**
|Thread: Alternative to PC based Cnc controllers|
I thought that I could mount it inside the machine main casting / body to keep the noise down
Not a good plan to put an air cooled compressor in a small enclosed space, or to introduce a heat source within the carcass of a machine tool.
Power drawbars, and presumably the gear selectors, tend to be transitory. They don't need continuous air flow at pressure to work. Provided there's enough capacity to operate once it comes down to how often you're going to be tool or speed range changing. Probably not that frequently.
Indeed. But oil-free compressors don't take kindly to this application - been there & killed a Wolf unit with a 25 l receiver in a very short period doing just this. Killed two of them, actually - the first one was replaced when it died, as it was presumed faulty. I was working part time for the company at this point & the first one came & went while I wasn't there. I read the booklet that came with the second unit & found it had a 15 minutes in an hour duty cycle. Unfortunately this enlightenmant came just as the second unit turned it's toes up. OIl-free compressors are OK for very light use, infequently, or they die young.
found that the mythical "suitcase compressor" was finally in stock at Lidl as of yesterday. Clouds and silver linings etc. So now I have a means of operating the power drawbar and gear selection solenoids. The CNC gods smiled on me again.
Not with that compressor they havn't. Have you read the specs ? - 1.5 minutes operation, then 8.5 minutes rest to cool down ! No receiver. "Hearing protection required" This maybe OK for the occasional tyre top up, or football inflation, but it won't run a machine tool & survive very long.
The vee twin compressors on a 50 litre receiver that Aldi did recently would be more like it - you would still be deaf when it ran, but at least the receiver would keep the machine operating between deafening bursts to top it up. And, being a wet sump compressor, it is continuously rated. Unfortunately it also cost £100 more !
Retrofit looking good.
|Thread: Bronze, Phosphor Bronze, Cast Iron or Graphite for LTD Stirling bearing|
The graphite we machine is man made from, as I understand it, a mixture of coke and pitch. The coke is ground to specific grain sizes according to the grade of graphite required. Other compounds may also be added, like iron filings or sulphur to vary the properties. The resultant thick paste is either extruded or isostatically pressed into blanks, then baked to form a carbon block. The carbon blocks are stacked, covered in deep layer of coke, then heated to very high temperture by passing an electric current through the stack - this converts the carbon to graphite. Improperly graphitised blocks have a higher resistance & are harder to machine & I understand that the graphitisation process is "one chance" process - if it is not done properly first time around it can't be re-visited..
The properties of the blocks vary depending on the mix & how it is processed - some are soft enough to be able to take chunks out with a teaspoon, while others are almost like ceramic & can only be worked with diamond tools - with many variations in between. My understanding is that these man made graphites are different to the natural deposits that are used for graphite lubricating powders - but my understanding may be flawed. When we are asked to supply graphite powders, these come from different suppliers & are physically different to the talc-fine dust that comes out of our dust extractors from machining extruded & isostatic blocks.
I work for a specialist graphite machining company. so see the stuff (in various grades - and there are many, with widely differing properties) being machine daily. Most grades are easy enough to machine with normal metalworking tools - HSS, carbide inserts etc. For short run special profiles, form tools made from silver steel & gauge plate used unhardened also work. It is abrasive to the tools - a bit like cast iron. It is also very dirty, but (according to HSE investigations conducted at my employer's previous company), poses no particular health hazards and, in particular, poses no explosion risk as airborn dust as it requires the continous application of heat to cause it to burn. Motor brushes are mainly carbon IIRC, not graphite (we don't make motor brushes).
If you PM me the dimensions of the billet you require, I will see if I can get you a suitable piece of fine grained Isostatic graphite from the oddments bin. My employer is usually OK with this & only requires that photos or videoes of the finished item / machine are sent so he has the option of using them for publicity purposes. This grade machines to a good finish & parts can be made to close tolerances (we hold sizes to better than 0.01mm) - it is a bit dirty, mind !
|Thread: Is it ok the hold a small lathe chuck in a larger one|
You could put the whole of a Super Adept in an 8" 4 jaw
To turn it into something useful ?
|Thread: Boxford BUD restore|
I would be inclined to remove the spindle to clean out any old, hardened, grease from the bearings, check the gearing for damage (missing teeth from locking the spindle with the back gear to remove a stuck chuck are common), then re-grease and reset the bearing pre-load. The mid-60s CUD I inherited from my father had grease in the bearings, nipples & drillings that was the consistency of candle wax & took quite a bit of shifting. There is also a good chance that the back gear shaft will have been greased rather than oiled at some point, so that would also benefit from a good clean out & correct re-lube. Same goes for the saddle - anything with an oil nipple could well have been (incorrectly) greased.
Colour ? Your choice, but lighter colours make for a lighter workshop & something really "off the wall" could have an adverse effect on future resale value.
Good luck in your endeavours,
|Thread: Is it ok the hold a small lathe chuck in a larger one|
The turners at work regularly hold a small 4 jaw in the normal, larger, 3 jaw as it is easier than swapping chucks.
|Thread: Source for pneumatic fittings?|
Haha, sky hook, tartan paint...
Bucket of sparks for the grinder, a gallon of 10 thou backlash oil ("we havn't got any 10 thou in stock - go back & see if 2 gallons of 5 thou oil will do " etc. etc.
|Thread: Air compressers|
only to be told that this was not an Ingorsoll Rand model
That looks very similar to a Clarke branded compressor we had at my last employment - might be worth a look on the Machine Mart site to see if there is currently one like that offered. MM do supply parts, but at a price and in their own good time !
|Thread: repainting powder coated metal ?|
My local powder coaters bake old coated parts to make the remaining coating brittle before shot blasting the remains off.
If you can remove the loose bits mechanically & scuff-up the secure remaining coating, a two-pack etch primer should give a sound base to refinish. International Paints used to do a two pack etch primer for outboard motor bottom units that was particularly tenacious on aluminium castings (I used it brushed on to motorcycle alloy wheels to good effect), but it isn't cheap.
|Thread: New pound coin|
I think the hidden security feature will be inside, something like a hollow section to alter the weight or balance.
Or it's electromagnetic "signature" - vending machine coin sorters have an inductive coil system to check this, along with the weight & size of the coin.
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.