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Member postings for mgnbuk

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: ER25 or MT2 Collets
18/03/2019 09:22:48

I use MT2 collets for holding milling cutters in my FB2 clone. I prefer them for the reduced overhang from the spinlde nose that puts the cutter closer to the spindle bearings. Not had any problems with cutters slipping or pulling out, though as the FB2 clone has a captive drawbar I can pull the collets in tight and easily release them without having to pound on the drawbar.

The ability of ER collets to grip different sizes within each collets range isn't much of an advantage with milling cutters, as most are supplied with shanks to a standard size i.e 1 - 6 mm cutters all come with a 6mm shank.

Nigel B

Thread: Soba rotary table
14/03/2019 14:11:36

Here's the kind of thing I was looking at: LINK

That looks like an industrial reduction gearbox with a short spindle added. Only 20:1 reduction & no clamping facility. As is typically the case the stepper motors are defined by frame size & current, not rated torque, but by the motor fame sizes output torque isn't going to be great. "This Old Tony" did a welding positioner based on a similar gearbox.

Output torque will be higher than the other item, though - 4:1 reduction with a 52 Ncm motor ! Maybe fine for engraving small plastic or wooden parts (as shown in the "application" photo), but not much more ?

My 6" Vertex RT came from a Harrogate show (Chronos IIRC) at least 15 years ago. Can't say I have noticed anything untoward about, but it hasn't seen much use. I have had mixed experiences with Soba tooling (more bad than good), to the point that I avoid the brand now.

Nigel B

Thread: Wazer
14/03/2019 09:01:39

I'm not sure I would want that technology in the garage. From their manual in the safety section regarding actions to be taken in the event of injury :

Injuries caused by high pressure waterjets can be serious. In the event of any waterjet injury the Waterjet Technology Association recommends:

  • Seek medical attention immediately. Do NOT delay!

  • Inform the doctor of the injury.

  • Tell the physician what type of waterjet project was being performed at the time of the accident and the

    source of the water and the materials involved.

  • Inform the physician of the following information:

    • This patient may be suffering from a waterjet injury.

    • Evaluation and management should parallel that of a gunshot injury.

    • The external manifestations of the injury cannot be used to predict the extent of internal damage.

    • Initial management should include stabilization and a thorough neurovascular examination.

    • X-Rays can be used to assess subcutaneous air and foreign bodies distant from the site of injury.

    • Injuries to the extremities can involve extensive nerve, muscle, vessel damage, as well as cause a distal

      compartment syndrome.

    • Injuries to the torso can involve internal organ damage. Surgical consultation should be obtained.

    • Aggressive irrigation and debridement is recommended.

    • Surgical decompression and exploration may also be necessary.

    • Angiographic studies are recommended pre-operatively if arterial injury is suspected.

    • Bandages with a hygroscopic solution (MgSo4) and hyperbaric oxygen treatment have been used as

      adjunctive therapy to decrease pain, edema, and subcutaneous emphysema.

    • Unusual infections with uncommon organisms in immunocompotent patients have been seen; the

      source of the water is important in deciding on initial, empiric antibiotic treatment, and broad-spectrum

      intravenous antibiotics should be administered.

    • Cultures should be obtained.

  • For your convenience, we have also included a wallet sized laminated medical alert card in the pouch of this printed User Manual. This card contains the above injury treatment information per the Waterjet Technology Association’s recommendation. We recommend users of the machine carry this card. Additional copies of this card can be attained by contacting WAZER Customer Support.

  • Bacteria can build up in the standing water of the Tank. Any injuries or cuts, even minor ones, should be treated with caution. If you have open wounds avoid contact with the water or wear gloves that do not expose you to the Tank water.

This doesn't go as far as a former customer of mine who operated such a machine suggested - he stated that in the event of a cut the affected area had to be amputated two joints back from the site of the injury as a matter of course. His operators also carried a card for information of medical practioners in the event of an accident.

I would rather pay a specialist to produce parts than mess with one of these. I note that they don't give an indication of the cost of rebuilding the high pressure pump, the most expensive ongoing cost outside consumables like nozzles & abrasive IIRC.

Nigel B

Thread: AutoCAD substitute
05/03/2019 08:32:17

Another Draftsight user here. I used Autocad LT at my last employment & find I can use Draftsight in the same way & with the same commands & mouse clicks as Autocad. There is a requirement to re-validate your details annually to use it, but this is quick & easy to do if you are on-line.

I recently downloaded DesignSpark Mechanical 3D software from RS Components to have a tentative stab at 3D CAD, but have yet to find time to have a go. This is also free, though you need to set up a DesignSpark account to validate it. My PC doesn't meet the specs for Fusion 360 (32 bit OS), but DesignSpark Mechanical runs fine.

Nigel B

Thread: Warco Rotary Table - What Grease?
01/03/2019 16:03:04

Has anyone come across this and can they say what sort of oil to use?

I refilled a 24" "Bessboro" RT at work with 68 viscosity slideway oil after the ,machine operator found out the hard way that a horizontal, oil filled, RT wasn't designed to be bolted to an angle plate and retain its oil. The stuff that leaked out was pretty non descript & I have been unable to find out any information about Bessboro RTs to determine the original recommendation, but the slideway oil has proven to be fine. In an 8" RT in all probability anything medium viscosity & oily would also be fine !

Nigel B

Thread: Quality issues with a SIEG SX2.7 mini mill
21/02/2019 09:26:53

have the original makers "M" mark cast into them

I was told that the "M" mark signified that the casting was Meehanite, not a maker's mark.

XYZ import (or have imported - they have been doing so for a while) Bridgeport type machines from at least two different makers - when looking for a manual on their website to order spares for our XYZ KRV2000 there were two makers of turret mills to choose from. The KRV is made by "King Rich" IIRC. Decent machine, but a bit big for my garage.

Nigel B

19/02/2019 19:44:51

I was using a tool that produces a similar pattern finish to that shown in the OP today - a "soft" backing pad with fine abrasive disc on an angle grinder. The Biax power scraper (the machine tool fitters I used to work with refered to these as "diggers" ) produces a very different pattern, as Jason's picture shows.

I would be interested to have more details of the "scraper" that Sieg use, as I have not come across anything other than the Biax type in the UK. Given the price of Biax machines, something that does a similar job more economically would be of interest, though I suspect that I already have it.

Nigel B

Edited to banish the unwanted "smiley"

Edited By mgnbuk on 19/02/2019 19:46:19

Thread: Aircraft General Discussion
19/02/2019 19:35:08

I work around 5 miles from RAF Linton on Ouse & contrived to have "something to do" outside at the appointed hour - saw & heard nothing ! An item on the local TV news this evening covered the 3 aircraft flypast at Linton, so I know they were there - just didn't approach or depart from my direction, unfortunately.

19/02/2019 12:22:33

RAF Tornado Farewall tour


Rather late notification, but to mark the retirement from service of the Tornado a country wide flypast is taking place from today until Thursday. At the bottom of the link above are provisional timings.

Nigel B

Thread: Boxford machinery auction
14/02/2019 09:56:59


Following on from an earlier posting about Boxford's premises having a For Sale sign before Christmas, details of a sale of machine tools popped in to my Inbox this morning.

Can't think that they will be making a lot when those machines have gone, but note the reason as "rationalisation of the business" so not dead yet ?

Nigel B

Thread: Y axis problem
14/02/2019 08:02:06

Nearly but not quite - see annotations above

"T type of cutter - cutter number, used for toolchangers, it doesn't say anything about the type of cutter, simply where to find it" Depends on the system - some use the T number to call the tool offsets as well, so also applicable to machines without an ATC

% end program - more an end of file marker, somewhat obsolete now that programs are normally stored in memory rather than loaded on the fly from tape Still used on Fanuc

H home position - tool length offset, ie, relative length of each tool, and where to find it in the tool table Not on all systems, as above.

Nigel B

Thread: Stepper motor and surface finish
12/02/2019 19:52:53

Many Matchmakers with Posidata stepper motor controls in industry back in the '70s, along with Bridgeports with (IIRC) the "Boss" stepper motor control. Acton & Beaver used the Posidata system as well. These used 1/2 step drivers so pretty coarse by modern standards, yet I saw those machines making aircraft & turbine parts and used in goverment research departments.

I took ptenty of those systems off & replaced them with Heidenhain controls & DC servo drive sytems (SEM motors & Indramat amplifiers) in the mid-'80s to mid '90s in a previous employment.. I don't recall anyone commenting on improved surface finish after the conversions, which were usually done to gain reliability and improve useability. Going closed loop with a measuring system & not having to deal with lost steps was also an advantage.

Doing such retrofits died the death when the smaller capacity machines that usually had the stepper motor controls got cheaper new (like Bridgeport Interacts & Spanish/Taiwanese imports) & the cost of the conversions rose over time, so it no longer made financial sense to retrofit an old machine.

Nigel B

10/02/2019 10:43:35

When the wiring was removed, a crimp fell off too

Not really suprising since none of the remaining connectors are properly crimped. Looks like they were bodged on with a pair of those awful pressed steel abominations sold as "crimping tools" - such "tools" get an otherwise reliable termination system a bad name.

Nigel B (Boxford 8" shaper owner)

Thread: Boyes of York, good value
08/02/2019 13:44:13

Not all Boyes stores carry all items, though. The original store in Scarborough & the Skipton store are far larger than my local store in Brighouse, for example. Brighouse doesn't carry as comprehensive a range of hobby lines as Skipton - no Vallejo Model Air paints in Brighouse, just Model Color for example. So if you want something specific, it may be worth phoning the store you intend to visit to ensure that they carry the item - though I apprecaite that could be difficult if you don't know what the full product range is !

Nigel B

Thread: Tinhat warrior trademark.
01/02/2019 16:59:24

I prefer the TS250s to the ETZs (250 or 251) - less peaky power delivery & more economical, but the disadvantages of 6v electrics and drum brakes. I had one of the last DDR-era produced ETZ251s, (in a fetching shade of beige) rescued from my brother-in-law, who had bought it new but then lost interest & left it festering in a damp garage. Build quality had rather gone down hill by the end of the DDR, though. Didn't keep it long, though did do a round trip to the Ace Cafe for the first "Red October" East European bike day on it - near 400 miles in the day & a long way to go for an expensive, indifferent burger !

My late friend Mark Dicker was Classics Officer for the MZ Riders Club & he reckoned that the ETZs would disappear before the earlier bikes due to frame corrosion - the area of the frame that the footrest bar bolts to rots off. The frame is used as part of the inlet air system & heavier dust accumulates at the bottom of the frame - this gets & stays damp, causing the frame to corrode from inside. The TSs used a similar intake system, but the tubular frames were heavier gauge than the sheet steel box section on the ETZs, so they last better + the tube is blanked off with an easily removed plastic plug that enables the dust to be cleaned out. The ETZs have (IIRC - it has been a while) a welded on closure with a small, easily blocked, drain hole. May be worth checking this area on your tidy bike ?

I have 6 in various states of assembly & function - 3 off TS250/1, and ES250/2, an ES150/1 and an ETS250 G5 ISDT Replica , of which only the oldest TS250/1 (which I have owned for 29 years) is running. So many projects - so little time !

Nigel B

Thread: Parting off tool - straight or angled.
01/02/2019 13:31:28

I use a small diamond ball cutter in a Dremel to put a dimple in the top face, just behind the cutting edge. This mimics the form of a parting insert & distorts the swarf, which comes off narrower than the groove, so no jammimg.

Nigel B

Thread: Tinhat warrior trademark.
01/02/2019 13:19:16

Come a long way since I first threw a leg over a BSA Bantam two-stroker.

BSA Bantams are mirror image MZs - with the quality engineered out !

The second most produced motorcycle engine of all time, the DKW RT125. Given as war reparations to BSA (who didn't really want it !) & Harley Davidson & widely copied by many others (including the first Yamahas). The DKW factory was dismantled lock, stock & barrel & taken to the USSR as part of reparations, where the RT125s designer - Hermann Weber - died in a Russian labour camp after the war.

Nigel B

Thread: Parting off tool - straight or angled.
01/02/2019 13:12:47

Why should the rear tool post give a better result then the standard tool post ?

When the parting too is inverted in the rear tool post, if it digs in it can "escape" into fresh air, whereas a front mounted tool will get dragged into (and under) the workpiece and probably break was the reason I recall being given.

Isn't the idea with the angled holder to give easier sharpening of the tool blank ? The top rake is provided by the tool holder, so only the front face of the tool blank requires grinding. On a "flat" holder, top rake as to be ground in, which can lead to more wastage on the tool blank when regrinding is required.

Nigel B

Thread: Tinhat warrior trademark.
01/02/2019 13:06:48

1 per cent oil mix in a two-stroke bottom end and cylinder? That sounds pretty radical. Is it possible with synthetic oils?

MZ had engines reliably running at 100:1 on synthetic oils before they suffered from German reunification. They were looking for ways to reduce emissions as regulations tightened, but didn't formally adopt the leaner pre-mix as it was felt that accurately administering the smaller quantities of oil was likely to be problematic in the real world. The adoption of Mikuni dosing pumps on export bikes reduced emissions compared to premix bikes - the effective ratio on the pumps was around 32:1 at full throttle, but leaned off to around 70:1 a low speeds/ throttle openings, compared to 50:1 on premix versions. My wife always hangs back if she is following me on a premix MZ after prolonged town running, as the over-lubrication puddles in the crankcase & clears (smokily - for a couple of hundred yards) when accelerating when the restrictions clear. No visible smoke at higher speeds with modern oils, though.

Nigel B (two stroke fan since 1976)

Thread: Vfd
29/01/2019 18:13:59

2 little round things like a lolly on 2sticks

Could be NTC inrush current limiters - these are a highish resistance cold & heat up when the current to the rectifier & capacitors flows (at a reduced level, due to the resistance). As they heat up, the resistance reduces towards zero. Their purpose is to "softly" charge up the capacitors on start-up & some types look as you describe.

I have had a couple (in small power supplies) that have gone pop & failed open circuit, so no current flows. There should be a part number on the side of the device - hopefully still readable if it is burnt - that should allow identification & replacement. A search for NTC inrush current limiters will get hits to Franell, Mouser, Digikey etc.


Nigel B

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