Member postings for Martin of Wick

Speaking as somebody that worked in the industry man and boy, pre and post privatisation, all I can say is it amazing how defective memories are.

The industry was privatised because of the political heat involved with paying the bill for 75 years of public provision neglect to fix the following:

• reduce leakage from up to 45% of water into supply
• put in place sewage treatment where there was none (ie all around the coast)
• improve environmental standards and reduce overa bstraction
• deal with the utterly appallingly poor sub 3rd world drinking water standards
• end the problem of unacceptably low system pressures
• build capacity and modernise the systems

This has been largely completed, the fact that bad actors have been allowed to 'financially engineer' the companies and generally get away with continuing poor performance is down to poor regulation. This is not necessarily to blame regulators per say, although the economic regulator being the one that calls the shots generally has a very poor grasp of engineering practicalities. Secondly, Ofwat is really only the organ grinders monkey - you have to look further up the food chain to see who is shouting 'free enterprise' and 'open markets' and 'no bill rises' and 'light touch regulation' etc etc.

Re nationalisation is not the answer, as a taxpayer, I do not wish to pay for the debt racked up by private companies, let them sort it out. Secondly look at places where water supply is in public hands - mostly it is a disaster and neglect-fest because because there is always something more exiting to spend the money on - until the day the taps run dry or sewage back flows into your house of course!

Edited By Martin of Wick on 09/08/2023 12:58:09

So to answer your actual question, I am sure there would be a demand for the mechanical parts and drivers for anyone wanting to convert an M7 to CNC.

A good thread on github with a modified Grbl but requiring an Arduino Mega - Doubt if a UNO would have enough capacity for the extra control a lathe requires.

You can try to get a pukka UC100 USB to Parallel motion controller adapter if you want Mach 3 'big Button CNC' (for which you still have to pay a hefty licence fee). Find a reputable source of supply because it is said there are plenty substandard knockoffs about.

Or go down the Arduino UNO / CNC shield route wire up the drivers and PSU etc to it and use Grbl or any of the other free G code runners and run your machine off a laptop.

Much to my surprise, I managed to easily convert an old Chinese Mach 3 engraver/router with the arduino approach and I have no electronic knowledge whatsoever. Heaved all of the big boxes complete with parallel ports into a skip, never been so glad to see them go. Mind you, they were so old maybe they could have been flogged on line as 'vintage' post Turing computing equipment!

Edited By Martin of Wick on 08/08/2023 18:48:32

Andy,

thanks, wasn't aware of that site - very useful.

It looks as if what appears from outside to be a single socket may be two parallel collars, which is useful to know. As is how thin the casting walls are. Sooo glad I didn't start a-hammerin on it!

From measurements, it looks as if my version has an increased the length of lower collar, certainly downwards and probably upwards as well. A relief to know it was just a placement fit.

NF - Eeek! Thanks, you are quite right. The column fitted exactly between the two bars of the brace so my thought processes suddenly ceased at that point. It will be an expensive piece of plate too...

NW - The health aspects of 2K paints as sprayed have put me off in the past, it had never occurred to me that 2K might be brushed. Thanks, I shall investigate that option.

Thanks to all for the advice. I was hoping someone with similar Denford would chip in and confirm not screwed in or some sort of hidden fastening. I see no reason why it should be threaded and peering through the lock screw holes can see no evidence of threads or other means of attachment. Just an unnecessarily long collar with 8 or 9 inches of rusted metal column!

Unfortunately I do not have any access to welding gasses and totally take the point about heating to red heat, I just don't think it would be practical in my situation. The best I can manage is a 21/2 inch propane burner (as in picture). That isn't going to get 25Kg of cast iron to red heat, maybe 4-500c. I'm not sure if there would be sufficient gas flow for a larger burner, assuming such would be available.

The picture showing the press and base was not taken under pressure. The base would have been further to the right with the upper and lower lips of the collar top pressed against the red cross beam and the mandrel from the jack piece to the bottom of the column inside the base.

I will have another go when I fabricate an accurately sized custom steel mandrel. I am wary of heating while attempting to press as I thought CoEf expansion for steel is greater than iron. Perhaps in this circumstance it doesn't matter. May also try using a 20 tonne jack unit, which are available at the same size. If it destroys the frame, then I know I have done my best!

As a unit, the base + column is just a bloody awkward, heavy, difficult to manhandle piece of kit and dragging it in and out of the garage numerous times as a single item to abrade, pressure wash, undercoat, paint the base and then phos acid, neutralise, wet'n'dry and polish the column would be a total, 100%, 24 carat, PITA.

But in the end, as suggested, restoring as a unit will be the reality if second pressing fails to work. By comparison, the head (without the 6 pole motor) and table are pathetic, tinny, lightweight items at a mere 30Kg a-piece or there-abouts, with the motor and accessories adding only another 15 Kg.

Do any floor standing pillar drill owners have any info/advice on how to separate a drill column from its base, This example is a Denford Viceroy.

The column looks somewhat rusted in but has had some penetration oil applied over a few months. I am hoping that the column is not screwed in!

One slight problem is that the small hole in the base that allows sight of the column from the underneath is not centred over the column, therefore the press mandrel only bears on a crescent shaped portion of the column.

I will try again making up a better mandrel from steel parts being 2 3/4 diameter billet to get into the hole in the base.

If that fails, what options do I have?

I would like to restore column and base but the two parts together are about 45Kg and for me are too much to easily move.

Pic 1 shows the general arrangement

Column appears to be held in socket of about 10 inches depth. Please tell me that it is not likely to be threaded or tapered!

Pic 2 shows rear of base with the two securing flat ended grub screws removed.

Pic 3 shows 12 tonne press propped up on a tottering pile of bricks after first attempt to push out using turned hardwood billet.

Result - epic failure!

Well precisely, not so much for finer threads but a more compact gear train using less material and better matched to the size of lathe, as well as the facility for a more reasonable fine feed using 70-80 tooth gears.

However, for the enthusiast, the Norwegian engineer site provides a good explanation and mod for a banjo that allows double compound using DP16 but needs more 65s for a fine feed(which could be 3D printed).

'Course, the big PITA that makes using this lathe rather tedious is really the full nut. I have seen solutions, but none have appealed to me as being particularly reliable.

So on account of 'elf n safety' to avoid RSI, my EW doesn't get used as much as it should be!

Try this site for a various ideas on EW lathes and mods if you want for improved screw-cutting

http\\modelengineeringnorge.weebly.com

There is a screw-cutting table for EW on the site (I would post it here but it is too much of a bloody faff)

M.

(had a memory refresh!)

note this is for the original 16DP change gears (why 16  wtf? had they lost the smaller cutter?)

Edited By Martin of Wick on 17/07/2023 09:00:26

Edited By Martin of Wick on 17/07/2023 09:02:44

The quick answer is yes, there will be a relationship from which you can estimate the RPM.

But this will depend upon the type of VFD, (vectored or not), the various loaded parameters and likely only valid for no load or constant load conditions.

The other question is WTF do you need to know lathe RPM to any degree of accuracy?- it tells you nothing.

The approx speed is usually more than adequate if you don't want to fit a spindle counter.

This was achieved in my case by using a linear control pot and setting the min and max frequency of the VFD to give the desired min and max motor RPM in line with manual belt speeds at min and max pot positions (usually 1400 to 1500 for a 4 pole).

Then print out a 0 to 100 dial for your control pot, so the approx spindle speed can be determined by the dial percentage times the max speed at any particular belt setting, plus or minus say 10%. Therefor if your pot setting is 40% and the full speed would be 600 RPM at the given belt setting, then 40% of 600 would be about 240 +/- 20 or 30 RPM.

As a caution, I would not drive the motor for high load operations at any less than about 20% of full pot deflection. If you have a fancy vectored thrust unit, you may be able to go to lower frequencies without cooking your motor.

I would add, that my experience has been the lower the frequency, the larger the range of  speed variation under load. But then I am partial to the cheapest and nastiest VFDs money can buy, so your mileage may vary.

Edited By Martin of Wick on 17/03/2022 10:07:59

Edited By Martin of Wick on 17/03/2022 10:12:55

Was Gonna say check all carriage, x slide, top slide, tool post gibs and fastenings before blaming the spindle.....

If it is in its unmolested form it should be BSF - having 18 TPI, you can check with a rule.

Edited By Martin of Wick on 06/03/2022 18:47:56

1 With the belt de-coupled, does the spindle revolve freely when chuck spun by hand. If not, find out why before proceeding.

2 check for any obvious oil contamination and clean.

3 If you have, as I think, a link style belt, bear in mind the tension may often need to be much higher than for a normal A section V belt, and the cheaper the replica belt the higher the tension required, usually.

4 Replace dodgy belt with standard or segmented A section belt for little cost, or if you have to, get a genuine Fenner product replacement. You should then be good to go with 40 thou cuts (if you want to be brutal).

BTW a suitable basic 23 inch A section V belt should cost about a fiver plus delivery from any number of  bearing, drive, belt, motion  factors  on the net.

Edited By Martin of Wick on 06/03/2022 18:28:37

Without knowing exactly what scales you need, difficult to advise.

UK Vevor have a good deal on basic 5um glass scales for sino dro & clones at the moment. Ordered a 2 axis set on Sunday for WM16, delivered today! (usual disclaimers etc).

I generally start with this....

RPM = SFM x12 / d x 4 as a first estimate of starting point for lathe RPM ( in yards feet and inches).

So assuming turning a 2 inch billet of Al, something up to around 900 RPM would be OK based on 600 SFM, assuming the material is of a free cutting nature.

You can double that RPM with XXGT carbide type tools, but you have to bear in mind the size and power of the OPs lathe, 'cos you cant really go hoofing massive cuts on a Taig.

As an unhelpful aside, while you are carrying out detailed and complete measurements of bed wear, I suggest you check other components, ie, various lead-screws and their nuts, cross and top slide for rocking and lifting, all the various oilite bearings including countershaft etc. etc...

Only sayin cos if the bed is badly worn, then everything else is usually well shagged also. Then your small project suddenly becomes a bottomless money pit as well (wonder how I found out?).

Secondly, if you are considering a second hand bed, you gotta ask the question why is it for sale? I would suggest it is extremely unlikely that you will find one in an unworn condition.

Edited By Martin of Wick on 04/01/2022 10:14:50

An all to common problem, but don't assume the worst until you have carried out other checks and considered other mods. If you search the forum posts using terms such as myford, bed, regrind, worn etc, you may find something useful.

I had mine done at Slideway Services of Nuneaton in 2015 by an uber-grinding maestro (since changed hands so I don't know how receptive they will be to small works now). At that time it cost about £250 for lathe saddle (turcited for wide-guide) gibs and clamps on top of which was fuel for the 2 x 300 mile round trip to drop off and collect.

Expect regrinding to be someway north of £300 now even if you can find an outfit with sufficient equipment, expertise and interest to carry out the work now.

For the benefit of the OP, good advice at the beginning of the thread.

If not familiar with this class of device, almost any branded product from a reputable UK supplier will be suitable (several have been mentioned). You will have peace of mind, a guarantee of some sort and useful back up. one of the vendors supplies helpful quick set up diagrams if you go down the DIY route.

Avoid web sourced unbranded generic VFDs unless know what you are doing, content with the associated risks of inadequate documentation, zero back up, worthless guarantees and quality control issues. etc. Many (including myself) have managed to get useful service from these units but that has come (in my case) at the cost of a great deal of time and effort trying to understand and test the available control parameters etc.

Assuming you purchase from a UK supplier...

You will pay more (much more in some cases) for a full installation solution/package of motor pendant VFD all wired up, but it will save you time and may be a lower risk solution.

You do not need a complex VFD device with hundreds of weird and wonderful parameters that you are unlikely to use and that has a premium prices accordingly. A simpler unit will be perfectly adequate for a manual lathe drive, just check that the control functionality suits your requirements (ie do you need braking, ramp start, reverse, jogging, e-stop, reset etc). I assume that your lathe is not set up as a CNC device, in which case you may need additional control functions.

A vectored thrust device to give more low speed torque is desirable but you are likely to have to pay more than for a simpler device.

The VFD power rating should match the rating of the intended motor. A slightly higher rated VFD will be OK, but not a unit that is rated at less than the nominal motor power rating.

Ultimately I would ask do you really, really need a VFD? If the answer is because you want to use a 3 phase motor and benefit from the smooth and quiet power delivery and low voltage controls, then pass GO and expend £200 in blood and treasure.

If the answer is 'because I cant be arsed to change belt position every time I switch from turning to threading' then you might well be disappointed with the outcome.

Edited By Martin of Wick on 01/01/2022 12:15:45

Can't honestly remember what the gib looked like on my S7, I dont recall any threaded holes in it though.

Wear will occur on the sides of the shears, but also on the top and bottom. Don't tighten the saddle gib for this test, Set it sufficiently loose to all full and free saddle movement up and down the bed.

Then check to ensure the saddle clamp plates are in place and all bolts are all fully tightened (just in case, cos I am prone to finger tightening then forgetting to nip up fully!). When fully tightened, these should not significantly affect movement in the Y axix (or the X!)

Can you still move the saddle nice and easily up and down the full length of the bed -

Yes? great, now move the saddle so its LH side is at the location you measured the greatest lateral wear on the shears. Then seize the front of the saddle in both hands, one each side, fingers on the plates, thumbs on top of the saddle but also contacting the bed and attempt to lift and or rock the saddle vertically up and down to detect any looseness in this location. You are only concerned with detecting vertical movement in this test. If there is no vertical movement that you can detect you can try the same test with a DTI.

If there is still no, or virtually no movement up and down, then consider yourself more fortunate than most as there is insignificant wear to top and bottom of the shears.

Edited By Martin of Wick on 19/12/2021 20:21:53

Ordinary MS will be fine, gauge plate OK, no need to harden. Probably best to avoid the copper based alloys. I have even read of someone that claimed to have used some of the blue steel banding strip from large packing cases!

I had (still have) a 1947 ML7 that had much worse wear issues. In the end I had to admit defeat and used Slideway Services to regrind. I asked them also to grind out the saddle to allow a wide guide conversion using turcite. They did a superb job but the proprietor cautioned me that the turcite must be kept fully lubricated at all times to avoid rapid wear, that could in theory impact the angle of the saddle over time.

One thing you could usefully do is check play in Z axis of saddle at the unworn part of the bed and again in the wear zone. Set Y gib to give smooth play free movement over the bed. Set the saddle retainer strips to give you nil/minimum vertical play at the RH end of the bed (shimming/de shimming as required. Move saddle to wear zone and check vertical play again. If acceptable to you, then you are good to go. I could probably tolerate a thou or so movement.