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: Milling Machine Identification|
I looked to buy one of these when they were first introduced, as it was the only small milling machine that looked vaguely affordable at the time for me. IIRC they started out around the £700-800 mark & also IIRC that included the 3 speed table feed gearbox that is not present on the machine pictured.
Ultimately I didn't get one. I had reservations about the limited speed selection (4 speeds via belt change), the high lowest speed (400 rpm IIRC) & the lack of quill graduations. But the biggest "downer" when I had a close look at one was the method of raising the head on the column. The head mounting telescopes on the fixed column and is only clamped with a very basic split in the head casting closed up with a bolt. When the head is elevated, there is very little of the head casting engaged on the column & the clamp action on the one I inspected was poor - at the kind of head postions you would be using most of the time with a vice + tooling fitted, I couldn't see how it would have much rigidity. Add in the generally poor fit & finish of the example I inspected (fastners & clamps loose in threads, backlash in the feed screws & quill arrangement & the sloppy column fit) & I decided that however low the purchase price it was not the machine for me.
With inflation, if it all looked reasonable & included the vice & chuck shown then £500 might have been reasonable - but not much more IMO.
Keep looking - something better will show up eventually.
|Thread: Unusual Project|
And who says the wings are too small...
Fit a big enough engine & wings are not so important ?
I wonder if the designers used the torque recation to aid in following the course. The Reno Air Racing Association motto sums up pylon racing quite succinctly : Fly fast, fly low - turn left !
|Thread: Is there any tips for sawing aluminium|
How many TPI on your hacksaw blade ? 12" blades are available in various tooth counts from 10 to 32 TPI.
For a 50mm section soft material bar you would want a coarse pitch blade (10 TPI) & I would be lubricating it with WD40 or similar.
I would not try a cut-off wheel on aluminium unless the wheel was specifically rated to such use - aluminium clogs abrasive wheels, which can have unpleasant consequences.
|Thread: Looking for foundry in Bolton area|
Huddersfield isn't that far from Bolton - if that is close enough then there is H Downs Foundry on Leed Road link
The contact I had there was Nigel Downs, but it is many years since I used them for my last employment. Nigel Downs was about my age (I'm 60 now) so he probably won't have retired yet - the company is still there.
Some years ago there was a TV recreation of how the original iron bridge at Ironbridge was erected - Downs Foundry did the scale castings for the project, with Nigel Downs being actively engaged & they cast the parts as they would have been done originally.
|Thread: Welder buy|
Avoid inexpensive "hobby" machines.
In pre-Google research days I bought a SIP Migmate 130. Occasionally - on those days when the stars & moon aligned & the was a U in the month - it would lay down a nice, smooth weld. But that was the exception, not the norm & the last time I used it I spent more time trying to get the wire to feed smoothly (including fitting a new liner & tip) than the job took.
Now with the benefit of Google I find that such issues with the Sip Migmate 130 are well documented. Looking at the options, a new reasonable quality machine is more than I want to spend on equipment I don't use regularly, but a thread on the Mig welding forum form someone who tried to sort the many issues with this machine (also known as a Cosmo) lead me to check out the cost of better quality bits on Ebay.
So for around the cost of a Lidl gassless Mig welder I have a 3 metre Eurotorch, Eurotorch chassis socket, a couple of Dinse power connectors, a replacement wire feed unit, gas solenoid valve, power supply & variable speed drive. Plus 4 metres of 25mm cable & a heavy duty earth clamp. Still to source a power contactor & a couple of relays. All that will remain of the Sip components will be the chassis, transformer & associated switches and the rectifier. This should remove many of the problem areas, plus add gassless capability (allow reversal of polarity) & a non-live torch. Probably find that the transformer isn't up to much then !
Worthwhile searching out the Mig welding forum for more information & to ask about any particular machine that takes your fancy.
Depending on your usage the "rent free" gass suppliers may not be the cheapest option. BOC do a hobby user, low rental rate scheme for a "Y" sized (IIRC) Argoshield Lite cylinder that is much cheaper for refills than the "rent free" suppliers. A similar deal is also available for Argon for Tig use.
|Thread: How to test dc motor or board?|
I tested that the motor of a Chester mini lathe I bought without a control board from one of their open days using a 12v car battery - it ran smoothly. As my lathe had no board fitted, the motor leads were directly accessible without any disconnection required.
IIRC the OE motors are 180v DC, so the motor should run at 1/15th maximum speed @ 12V, as speed is proportional to voltage applied for a PM DC motor.
It struck me as strange the way it was handled - no communication at all, just "bidding suspended" and then all trace of the sale disappeared. Not that I was getting anywhere with my bids, though !
I guess the auctioneer has some get-out buried deep in the "Ts & Cs".
The signage had already disappeared from the site at the time the sale began - I'll keep an eye out to see what it ressurects as, as I pass the place most weeks on my way to Lidl.
|Thread: Is a hand scraper pulled or pushed?|
I see the 'three plate' test often quoted but it's not very relevant in these days of good quality affordable granite plates.
Used to be part of the apprentice training school tasks for trainee machine tool fitters at Asquiths in the '60s.
3 finish planed castings to be scraped together to a prescribed standard. If the instructor though the trainee was trying it on with a heavy application of blue to make them look good, he scraped a deep gouge across all three & sent them back for another go. This was recounted to me by one of the victims, who also said they went home with bleeding hands in the early days. They used scrapers they had forged themselves in the training school, which were then cyanide hardened in the work's heat treatment facility.
After the training task had been successfully completed, the plates were sent back to the machine shop to be finish planed for the next set of victims.
Scratches to hold oil are made with a short handled scraper applied more gently to an already flat surface, and usually pulled to mark a regular pattern of crescents.
That might have been how Duplex did it, Dave, but it wasn't how my former collegues "frosted". They just used the same scraper, but manipulated it differently (still pushing, though) to put a pronounced "curl" on the surface - some refered to "frosting" as "curling". To get an even pattern, lines were chalked onto the surface which were used to align the row of curls. When the first set of lines were completed, another set of lines were chalked on at right angles to the first & the process repeated.
Mostly, though, "frosting" was accomplished with a Biax power tool. This was not the same as the Biax power scraper (my collegues refered to the two types as "The Digger" and "The Froster" & when pushed firmly across a surface produced regular half-moon shaped cuts. The same method of chalking lines then chasing those lines was used. Using this tool took quite a lot of brute force & it was not easy to get a regular pattern - varying the rate the tool was pushed over the job varied the size of the half moons. I saw one of these Biax frosters mounted on a planer at Landis Lund grinders to get a really nice, even pattern. I was not strong enough to use one !
As I said initially, I have not seen pull scraping used in the UK . Scraping was only prevalent because surfaces could not be machined accurately enough at the time. My former employer didn't like having to employ skilled fitters because he reckoned that they were only needed because the machinists couldn't do the job he was paying them to do accurately enough.
Now scraping is a bit of a "lost art" because it isn't needed as much - castings can be machined to tighter tolerances & better surface finishes than in the days of planers, so what was once "fitting" is now "assembly".
It does seem, though, that some are treating it some sort of high art form, rather than the widely practiced rather mundane necessity it once was.
|Thread: Emco FB2 Quirks and Additions|
Finally I do believe Emco supplied a Badged version of the FB2 to AJAX, I think these were Blue, but I have not seen one in the flesh.
I'm pretty certain that the Ajax machines were Taiwanese. My current machine is a composite - an Ajax base & table assembly (which has sloping sides to the base & was supplied painted a light hammer finish grey) and a column/head assembly that came from Denford's stores & was fitted with the casting that was intended to be mounted at the rear of a lathe bed - this was painted Denford's house turquoise colour, but I think that it had been re-painted. The lathe bed attachment casting has been cluttering up my garage ever since & is available FOC to anyone who wants to collect it !
Ajax used to be a customer of my last employer. I went to the Bredbury site quite often over a number of years & knew the technical people there well. On one occasion I was over to measure up a lathe to see if we could come up with an add-on automatic component loading / unloading solution for an enquiry they had received & my visit coincided with a general culling of obsolete parts from the stores. I recognised the base / table assembly that was positioned near the skip & mentioned it to my host, who promptly offered to load it into my car rather than the skip - it would have been rude to have refused ! Ajax had stopped selling the machines at that point & it was thought that the head/column had probably been supplied as a warranty replacement at some point.
I bought the ex-Denford head & column from Mercer's in Cleckheaton, who had bought several direct from Denfords when they were having a stores clearout. Again. I think this was Taiwanese. My first FB2 clone was supplied new to the first owner by Mercer's, who had imported several from Taiwan - these were painted a brightish hammered green & also had the sloping sided base casting. The original owner had stripped the Tufnol drive gear on a couple of occasions & bought the replacement parts (at great expense !) from Ajax until a friend of his(who worked in the toolroom at David Brown Gears locally) made up a couple of bronze replacements - I kept (and still have) the "spare" one when I sold that machine.
I seem to think that Warco offered two different clones - the early one (which had the Myford nose) was Taiwanese & the later one (called the ZX16 IIRC) was Chinese. The fit & finish on the Chinese version was not as good as the Taiwanese one.
Chester's Champion mill (which Warco also sold as the ZX15 IIRC) used what appeared to be a copy of the FB2 base assembly with a poorly designed 4 speed belt drive head & nasty column arrangement. This had a copy of the Emco 3 speed feed gearbox, though, one of which I bought at a Chester open day with a damaged motor cover & which fitted on to my Ajax table without any problems, other than the feedrates shown on the plate are for a 60Hz motor, not 50Hz.
Axminster also offered this style of machine for a while. I seem to think that theirs were Taiwanese as well & were finished in their "house" colours (turquoise /white).
Last time I looked (a couple of years ago) there was still a Taiwanse MTB offering this model - shame nobody brings it in, as they are good little machines.
Probably way more information than anybody wanted .....
|Thread: Is a hand scraper pulled or pushed?|
I think it largely depends where in the world you come from.
My former machine tool fitter colleagues based in Halifax (UK) all used the push method. I have seen videos of German / Swiss fitters using a different type of scraper designed to be pulled. I have not seen this technique used in the UK. My collegues were trained at the likes of Asquiths, Butlers, Churchill Redman, Stirks & Crawford Swift (when Halifax was awash with machine tool builders), though on a visit to Bridgeports in Leicester their fitters used the same technique. The patterns left by the two techniques are different - pushing while "rolling" the scraper gives a longer, curved mark, while German / Swiss machines show short, straight strokes.
Scrapers need to be sharp to do anything. I am by no means a scraping expert, but I "test" scrapers for sharpness by lightly scraping against my thumb nail (what remains of it - nibbler !). A sharp scraper takes a light shaving with no effort - a blunt one just skates off the surface. My former colleagues had a bench oil stone along side them when using a steel bladed scraper & regularly rubbed the flat side against the stone to maintain the edge. Carbide insert scrapers were usually hand ground on the face on a fine green grit wheel, though by rights they should be diamond lapped to a fine finish for best results. Power scraper (Biax) carbide inserts were taken to the Biax agent (who was conveniently local) for diamond lapping. The end face is ground with a slight curve across the width to a negative cutting angle from both sides to give two cutting edges.
Carbide scrapers were prefered for cast iron & steel scrapers (usually old flat files re-purposed) were prefered for steel. Three square (triangular) or curved blades were used for bore scraping - something done rarely for us, as we got very few plain bearings requiring scraping in.
I have a couple of different length commercial (probably Chinese) steel scrapers & find that they don't hold an edge long. I use the longest I can get in on the job in hand - more leverage with a long blade. I use a small three-square for deburring & have a 12" or so long holder + file handle I made up to hold a carbide blade. I have only seen Sandvik carbide scraper blades & they also used to make handles/holders for them in a variety of widths. Mine is about 25/30mm wide from memory. They are also expensive - £25 / £30 each for the inserts some 20 years ago.
You don't take much material off with a scraper - my colleagues used to reckon on 3 scrapes across a surface to take off a thousands of an inch. I am limp-wristed, scrat about & am probably nearer 5 scapes to the thou !
|Thread: Triumph motorcycle auction|
The machines appear to be slow three axis ones, which are well past their prime.
The machines are from a good quality manufacturer, but I am suprised that Triumph still operated them as some look to be of a vintage that suggests they were bought when they initially started up. Most machining operations don't require any more than 3 / 4 axis operation & they will not be "slow" even at that age.
I doubt that you would find machines of that age in a Japanese factory - my understanding of Japanese manufacturing is that they replace machine tools very regularly (every 2 years or less) to ensure that they are accurate, reliable & keep up with the latest technology. There is a least one UK machine tool dealer who imports these ex-Japanese factory machines & sells them here as "nearly new".
There would be little sense in exporting such old machinery to Thailand. Better to buy new machinery to expand operations out there as required.
I think the company is in good shape with no signs of trouble .
Not what is being reported or speculated here from what I can see.
Lots of them in my circle and never heard of any problems
Lucky ? Starter sprag clutch problems on the early ones, with a design that required a full engine strip to change. The German magazine Motorrad has a Speed Triple on long term test at the moment that has dropped a valve - twice. Mutterings of widespread gearbox shift mechanism problems on the liquid cooled twins that are not being addressed with a recall. Triumph seem to have just as many issues as other makers.
Triumph trade on their "Britishness", but in reality they are just another "globalised" company. Some customers will not be bothered where the product is made, but others will not be happy to support them now they have shed UK jobs. Manufacturing in Thailand does not seem to have been driven by being able to offer the products at a lower price - even entry-level Triumphs are not what you would call cheap here.
|Thread: Facing bar ends parallel on the lathe.|
It turned out about 0.03mm out of parallel across 100mm. Not good!
But not too bad for a 3 jaw either ? Close enough to sort with a scraper if you are in a position to measure the error.
Could you not put the component between centres, face one end, reverse the part & face the other ? Should be pretty close to parallel done that way. May need a hole drilling & tapping in a non-working area to take a drive peg. I have a cylinder square at work that appears to have been machined that way, complete with an off-centre tapped hole at each end.
|Thread: Training school auction|
An independant industrial training school near me has ceased trading & is auctioning off everything.
Lots include 19 Colchester Student 2500 lathes (extra chucks & faceplates as separate lots) and a dozen or so small Asian Turret mills, Haas Toolroom mills & lathe and some Boxford CNC training lathes. Also lots of measuring equipment + garage & sheet metal stuff + computers. The premises they used are only a mile or so from J25 M62.
Always sad to see auctions for companies closing, but the closure of the largest engineering training establishment in the area can not be good long term for engineering apprenticeships locally.
|Thread: solenoid circuit|
Not sure a solenoid is ideal for this application. Solenoids pull a magnet into a coil with a snap action which takes a fair amount of current, meaning a big battery.
OP says he wants to trip a sear in the trigger, so short movement & low pressure required. No need for large solenoid & big battery. There are already "electronic triggers" on production rifles (Daystate) that use small rechargeable batteries that apparently require very infrequent charging, which does not suggest a high current solution.
Unless the air-rifle must fire as soon as the solenoid operates
That would be the general idea. When I get the sight picture "just so", I want the pellet on it's way straight away with just the application of a slight further pressure on the trigger, not for the gun to fire sometime arbitrary time later.
Is jerking a trigger bad for accuracy?
Triggers are generally "squeezed", and definately not jerked. Well not if you want to hit what you thought you were aiming at ! "Nice" triggers are often "two stage", in that there is a small movement up to a noticable increase in resistance, then just an increase in pressure from that point releases the mechanism. All very controlled & predictable. I don't think that a solenoid would replicate a two stage trigger, though from what I have read the Daystate trigger is supposed to work well. Reading about Daystates is as far as my wallet will allow, though.
|Thread: cutting upholstery foam|
Do you have an upholstery foam supplier in your area ?
They use band knives to cut the foam from the large blocks it is cast in. I had some replacement cushion foam cores made for a motorhome & the band knife the supplier used made very easy work of cutting parallel slices from a block that required a fork lift truck to place it on the machine. Taking thin slivers off large pieces of foam was easy on the machine. Far easier than struggling to do it yourself. & doing a worse job.
|Thread: New Lathe - poor suface finish on my results|
I think when I readjusted my hand position for the next bit of the turn, I was getting little lines as the tool was paused for a while. I'm sure I could develop some two-handed technique so it doesn't stop while I adjust hand position
Do try using two hands on the handwheel - you can continue the feed when one hand gets to the limit with the other, which allows you to re-position the first hand to take over when the second runs out of travel. Do this with all the feed handles - takes a bit of practice, but becomes second nature after a while.
Does get a bit tedious facing a faceplate when you don't have power cross feed, though.
|Thread: DRO installation - a salutary lesson|
New restrictions tonight in Kirklees means I shall have more time for the man cave
You are affected by the antics of the residents of Ravensthorpe & Dewsbury as well then Bob. No wonder there are calls from Huddersfield residents that those areas are are separtely administered as "North Kirklees". No coincidence whatsoever that the lockdown was announced just before the start of Eid.
Can't help with capacitive scales - not much experience. But maybe the screws were bottoming before the read head was fully secured, allowing it to float slightly & shortening the screws fully secured it ?
|Thread: Can anyone identify what this is and how it works?|
I can't see which photo you are referring to....
Click on the picture montage on the page I linked to. This opens a string of pictures - the "object" is visible on the LHS of the 8th picture down.
|Thread: Quality small metric spanners|
Otherwise they're not magic and don't tighten and undo ordinary nuts and bolts any better than ordinary spanners.
"Nice" spanners do have another disadvantage - they have a bad habit of "walking".
When I was mobile & worked in many different places, decent spanners disappeared from my tool case regularly. I bought an inexpensive set of metric combination spanners (6 - 24mm) from an autojumble. The machining of the bits that mattered was good, as was the material used, but they looked rough - coarse forgings not well fettled, but they "did the job". Never had one of those walk ! Not particularly pleasant in the hand, though I wasn't using them all day every day .
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