Here is a list of all the postings norm norton has made in our forums. Click on a thread name to jump to the thread.
|Thread: Lathe stand to suit an ML7|
It is really useful to have a cabinet with drawers and storage space underneath.
I use one from Axminster under my Myford like this: **LINK**
|Thread: Myford Super 7 metric change gears|
Printed gears is a good idea. Of course the 33 and 34 teeth tumbler items were made and sold by our friend John Stevenson, who is no longer with us.
If you have the gearbox fitted then you do not need a metric quadrant to be able to cut metric and BA threads.
There is a simple solution using swaps of the tumbler feed gear and this has been written about many times. This is what Brian's book describes. There is a link here to this forum **LINK** when the subject was raised a few years ago.
I can supply you with a complete table of all the tumbler gear swaps if you message me with your email.
Edited By norm norton on 14/01/2018 13:00:55
Edited By norm norton on 14/01/2018 13:03:14
|Thread: Static phase converter|
We have not answered your initial question about how a static converter works. Yes, the Machine Mart chap is right in that two phases are fed, one fully and one partially if I remember, and then the third gets energised as the motor spins. The converter box contains capacitance and inductance bits to generate this and there are setting knobs to make it run 'sweetly'. It means that the converter power rating ought to match the motor reasonably well and that the motor is under extra stress when starting up. A rotary converter already has the spinning motor and therefore its three phase delivery is there all the time and more 'clean'.
Edited By norm norton on 19/12/2017 17:05:07
Martin, as John says, if the motor can be reconfigured to 240v 3-phase then a VFD is definitely the way to go. It is probably 415v at the moment if it came from a 415v 3-phase workshop. There will be lots of threads about to help you take the cover off and work out if it can or can't be changed by swapping three wires - just Google search.
Only use a static converter if the motor cannot be changed and you don't want to replace it. They work but people don't like them for various reasons and they are not cheap. You will also need a reasonably large one, probably 3HP minimum.
|Thread: MEW260 Myford Cross Slide Nut|
....start the ball rolling.... Cheeky monkey, I thought the OP might have done that
But no one has responded to my original question on whether the sprung loaded cross slide is a reliable (accurate / safe) device when boring. Jeff suggests that a REALLY strong spring is needed when facing. If that is correct for boring then the whole concept is not viable.
This was an article I appreciated seeing, that showed a simple nut and spring used to virtually remove the backlash from a Myford Super 7 cross slide screw and handle. The extra, bronze, nut engaged in the Myford alloy nut with an Oldham (key and slot) coupling and a spring and tube ran over the feedscrew to apply pressure to the bronze nut. This pressure means that (all) free play is removed and only the play in the Oldham coupling can be felt at the handle.
I liked the idea and thought about it. But how firm should the spring pressure be? I then realised that when you rotate the handle anti-clockwise and withdraw the cross slide it is just the pressure of the spring that acts on the bronze nut and thread to move the slide.
Thus, if you applied pressure on a tool for an internal boring cut then one (initially) only had the pressure that the spring could apply. Is this a bad thing? How much pressure does a tool need to cut, and if this is applied by a spring might the tool 'bounce' as it applies a cut?
Clearly, the best idea is to have a split nut with some form of mechanical adjustment to remove the free play. But then this has to be adjusted for the non-worn portion of feedscrew.
I apologise to Mr Warren Jacobs, who wrote the article, if this appears critical as I do appreciate his contribution, and I agree that it must be an improvement. But what do others think of a spring loaded nut as opposed to a mechanically split nut, assuming it would even be possible to design one for a Myford cross slide?
|Thread: New chinese lathe or old Myford lathe|
You have to work out what you emotionally like - classic British technology or functional and perhaps cheaper modern?
Also, are you going to work in imperial or metric? as the hand wheels will be one or the other.
If you do go for a Myford or Boxford then do not buy a cheap, worn one. A full bed and slide regrind of my Myford made a big difference.
Go and see some old ones at somewhere like Home and Workshop or G and M Tools (both south of London).
|Thread: Soldering gun, not iron.|
I agree with those who say - Never Solder if the Copper Wire will be subject to vibration.
I once soldered some connections on a magneto ignition on a racing motorcycle - an earth wire broke next to the solder after two laps. Boyer made electronic ignitions for motorcycles in the 1980s and hundreds of units failed on Norton Commandos when the wires fractured where they left the PCB pickup. A old Marconi engineer told me that soldering wires was forbidden anywhere on the missiles they produced because of the massive vibration..
My interpretation of this behaviour is as follows: Stranded copper cable is in a semi-annealed (semi-hard) state as supplied. When you solder it a weak annealing is applied to the copper in contact with molten solder - this effect ceases some small distance (1mm ?) beyond the solder penetration. As the wire vibrates in use the movement is concentrated at the most flexible (annealed) point within 1mm of the solder penetration. This point rapidly work hardens and fractures.
If anyone has a better explanation I will be pleased to hear it, but the concept works for me.
|Thread: Four Facet Drill Sharpening and Grinding Wheel Dressing|
Thank you Harold! You have answered my question regarding four facet drill sharpening that seemed to fall on deaf ears in this recent post. http://www.model-engineer.co.uk/forums/postings.asp?th=125481
I then remembered that it was in your book Workshop Practice Series 38, which I have read and is on my shelf! Dooh, memory....
Your video is very helpful in showing the grinder use. I notice now that you have some useful drawings on your website regarding the finished drill angles that do not appear in the older book. I give the link here in case others wish to find it http://www.homews.co.uk/page360.html see sk.7 to 9.
Edited By norm norton on 15/03/2017 10:01:32
|Thread: New CBN wheels + Tormek drill sharpener|
I have a home-made tool grinding platform, with multiple angles, etc. that I use for lathe and other tooling. I am also nearly there with a milling tool holder to do the tips.
But I have never sorted out a jig for drill grinding and I tend to just buy in more Dormer A002 four facet drills, which are the best for all sorts of work. So this Tormek DBS-22 interests me as it produces the four facet finish. It costs £184 from Tyzak. Hmm, that is about 30-40 new drills of typical sizes. At my current wear-out/damage rate that is perhaps ten year's worth.
I was never keen to follow up on the many improvements on the 'sweep tool' for a conical grind that have been in many editions of ME/MEW. However, I cannot recall any magazine article describing the construction of an attachment to do exactly what the Tormek DBS-22 does. I seems straight forward to make and just needs the angles described for the facets. Did Harold Hall describe something? or has anyone seen it elsewhere?
I do agree about the CBN wheels though.
|Thread: Tramming the Sieg SX3|
Nigel B has hit on the problem that I faced when doing the same to a Sieg X3 (with fixed head).
There are two things to align: the column being perpendicular to the table in both planes, and the spindle being truly parallel with the column. Mine was out on the column by about 0.001" per 1" of vertical travel (ignore which plane for now to keep the discussion simple), and a similar amount on the spindle in both planes - 0.0009" and 0.0013" per 1".
The problem I found was that if I shimmed the column, using a pair of dial gauges rotating on the table, then the error in the spindle resulted in the column still being non-perpendicular.
I think that what I needed to do was 1) clamp a dial gauge on the spindle outer and clock the column ground ways in X and Y while raising and lowering the spindle (with a locked head to column). Then correct the head mountings so that the spindle was able to raise and lower with no change in clock readings - this seemed a tricky job. Then, 2) conventionally 'tram' the column to the table by shimming under the column, knowing that the rotating spindle was now parallel to the column.
If anyone disagrees, or can even understand what I am trying to say, I will be pleased to hear. I actually set the spindle true to the table by shimming the column, knowing that this left the column non-perpendicular. I simply stuck a label on the side of the machine telling me of the head lift X and Y error! It was only ever a problem if I was taking a zero point from the top of a job (e.g. gearbox casing), and wanting to bore precisely a hole 4" down inside which meant dropping the head on the column. I am now fortunate enough to have big second mill so I never went back to fix the Sieg properly.
" and ) smiley removal! Edited By norm norton on 15/02/2017 10:23:26
Edited By norm norton on 15/02/2017 10:24:28
|Thread: THE GLOSSARY!|
Just looked for your publication Neil, but is it only available as a Kindle and not in paper? If it is only Kindle I will get it anyway and put it on the Mac.
Being a self taught home engineer I never heard the language describing component parts as a trainee. Things like flange, pinion, detent, lug, journal are now obvious, but on first encounter you can struggle to work out what part someone is referring to. It needs a set of pictures labelling the areas being described. A few complex components could contain a lot of descriptors and help explain a lot.
Similarly, pictures of: a lathe, locomotive valve motion, a beam engine, etc., etc. could be fully labelled.
The Glossary idea has been started elsewhere, for example http://www.fluor.com/about_fluor/newsroom/pages/engineering_glossary.aspx#A
|Thread: Level Gauge Faulty|
OK I have taken it apart, partly out of curiosity, with little expectation of fixing it. The nature of the fault, being data jumping to a wrong value at certain levels, implied an electronic error rather than a physical malfunction.
So here is a picture of the component parts:-
On the left is the rear cover with a ring of magnets, that damp the copper pendulum, with a shaft that slides into the two bearings carried in the middle of the green, square pcb that is still attached to the display in the main body. The green pcb circle affixes to the pendulum shaft with the nut and washer and I guess carries a set of capacitive elements around its circumference. The final square pcb on the right carries a web of fine traces and a few components. I presume that this senses the capacitive changes. The odd thing was how this pcb connected to the main one with the display. There was a plastic/carbon rectangular section that was compressed between the two when assembled.
The good news is that having disturbed all these parts and reassembled them, it now works without error!! I can only guess that the plastic/carbon connector has changed its behaviour, as that was the only electronic item disturbed, but how it transmits its signal I cannot see.
Obviously the absolute zero level had been disturbed by taking the circular disk off and putting it on in a new, random location. But the device has a 'reset absolute level' sequence of button presses and this was successful. I put it on a metal block bolted to a vertical Rotary Table and slowly rotated it through a full 360 deg. The display seemed to smoothly follow the rotation with no jumping of displayed digits.
I shall now continue to use it, but perhaps keep an eye out for any repetition of the fault. Thank you to those who encouraged me to have a look inside.
Tried the battery - no different.
It seems like the encoder is dirty/malfunctioning, the way it jumps repeatably to wrong values at specific angles.
I like your write-up Les taking one apart. I might as well undo mine. But is it a rotating sealed encoder or will I be able to wash it? Or does it use capacitance across a gap, hence a cleanable gap?
Sorry MichaelG… the Clinometer is a bit big to use! These magnetic scales are very handy as you can clamp them to the job and then adjust stuff. I have a whole set of angle measuring protractor type scales, including fancy ones with a vernier, but often you cannot access the angle between the work and the reference surface.
Hmm.. I cannot see one on CPC Farnell. eBay has a non-Wixey identical model at £25 +p&p.
I purchased this level gauge back in 2012 and have used it several times. The other day I was trying to set 5 deg on a mill job and the display was jumping from 5.2 deg to 3.2 deg.
As a test, I slowly elevated it from zero and the reading would slowly increase, then suddenly jump to a different value for the next 0.2 deg, then revert to its correct value for a reasonable arc, and suddenly read in error again for 0.2 deg.
Obviously it is going in the bin. But what worries me is that it could have been like this for a long time - if I was using it at the OK values I would not have seen the jumping.
Are these units inherently unreliable? Do I pay £40 for a replacement or are there good ones from the many to be seen on eBay?
Edited By norm norton on 31/10/2016 14:37:18
|Thread: VFD drive for a pond pump?|
Thank you Martin, you have kindly confirmed my thoughts on conservation of energy - no fluid moving thus energy used only to heat the motor plus heating the churned, trapped fluid. I have just had my electric meter compulsorily replaced by one of those 'indoor readout sim card things' and it records right down to a single watt (W) being consumed. My lowest domestic consumption in the morning is 650W of which 250W is the two pond pumps (one waterfall and one filter circuit). The remaining 400W seems to be going into all the standby and computer devices. But I can now choke the flow on one pump and see what the change in power consumed is.
I like the dual pump and solenoid idea. But, perhaps I need motorised gate or ball valves to achieve that?
You are quite right about the danger of oxygen depletion at night, but I have never understood why some say MORE oxygen is needed at night. I have always suspected that the cases of fish death at night in hot weather are due to the pumps being turned OFF completely. I can't use basic CH pumps as my upper and lower ponds sit below the filter house and the lower one is below ground level, thus I need submersed pumps.
Thank you for all the replies, very helpful. I wanted to cut down the flow at night, thus a timeswitch and power control would be helpful, plus I might reduce the energy consumption.
Yes the 15year old Tetra pump is power wasteful and new Oase pumps at circa £200 are half the power use at 80w for 8,000 l/h. Perhaps the cost effective solution is to replace the pump, and perhaps put a gate valve that I have spare in the output line. But there would be no time automation.
I was very interested in the comment that putting a restriction on the pump will reduce energy consumption. Is this because as it works harder the back emf rises and thus its resistance?
I spent some time looking for web answers before I asked this question, and I have looked again this morning. You can buy fancy pumps with their own speed controllers (£600 plus) but there is no information on DIY speed control. There are stories from the USA about a triac fan speed controller sold for pond pumps that didn't always work.
You can get fan motor controllers, they are used in a lot of horticultural set ups. About £30, but no clue on how they work. The fans seem to have inductive motors so perhaps I should speak to a UK manufacturer that I have found regarding if they work for pond pumps.
There also appear to be no 250v single phase VFDs as boards or box devices down at the 1amp rate. You can get nice, assembled motor controllers from China but these are around £100 and 10amp. Again, I don't know enough to understand whether they would drive a 'shaded pole' motor (is that a specific type of inductive motor?).
Edited By norm norton on 12/08/2016 14:42:09
I want to control the flow from my pond waterfall pump. It is 175w and moves 7,000 l/h. It has an encased 250v winding of some sort that induces rotation in a 4" did iron rotor that has a number of inset copper segments.
Now, I don't understand electric motors in detail but I presume this one rotates at a set speed that is derived from the 50hz supply. I thus assume that the only method of speed control will be to adjust the frequency. If I did this and ran it at, say, 25hz, would it draw less current, which I am hoping it will, or the same as it maintains torque?
I have found pond pump speed controllers for sale but they seem to be triac type that effectively reduce the total current - I can't see that these are suitable for my induction pump.
I would appreciate any thoughts on the subject…..
|Thread: Cable size for Oxford welder|
I respect your care and attention Marcus, but the qualification on thickness of metal is not correct. I have a 150amp commonly supplied, basic MIG welder (Clarke) that runs through a 13amp domestic plug and fuse, and I can fully weld 6mm steel that is butted, vee groove. I have even joined items onto 10mm plate by working from both sides, although probably not a fully penetrating weld. Whether it really delivers 150amps is another matter, but it's called a '150 turbo' !!
Edited By norm norton on 26/07/2016 22:04:15
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