Member postings for john fletcher 1

Many thank to all have responded to my request in particular Stephen who sent me all I need almost by return. Its good to know there are helpful people out there.

Hello Nick,I have a single phase motor ex Fobco Star and need a 3 phase. I've sent you a PM. John.

Has any one got a drawing of a Fobco Star drilling a machine. I have dismantled mine and found that the top bearing ( next to the pulley) is an angular type, which according to Tony@Lathes said it should be at the bottom. I would appreciate knowledgeable/help comments before reassembling the machine after a good clean up and painting. John/Ted

Before you go out and spend your money, remove the motor onto the bench. Scratch mark both end shield end, two across on the drive shaft end and one mark across on the no drive end. These marks are for easy reassembly, get them right and the motor will revolve freely, a flick on the shaft. Remove the through bolts and using a hide face mallet give the stator a sharp wrap. Carefully remove the rotor and store it carefully on the bench, don't let it roll off and bend the shaft. Have a good look at the centrifugal switch mechanism which is on of the motor shaft, the bob weights or what ever is used on your motor, should move freely and spring back after being moved by hand. Next check the switch contacts to see if they are clean and are not just blobs of weld, these are normally attached to the no drive end shield of a British made motor. The contacts can be cleaned up a bit by using a piece fine of wet and dry folded back to back. To test the windings you will need a multi meter on the OHMS range. There are two windings, start and run. The start will be thin wire compared to the start and will have a much higher resistance maybe 20 to 40 ohms. The run winding could be up to 10 ohms but more likely 4 or 5. Not all lathe motors have capacitors, especially if some one has changed a motor to one that was available at the time of need. Unfortunately there's not an easy way for the average person to check a capacitor other than to change it, like for like and it might not be the capacitor faulty after all. Electricians use their MEGGER to charge up a capacitor, then leave it for a few minute then discharge it by shorting out the terminals using a screw driver, if it give a loud crack they say it good, but how good. Do be carefully when re assembling the motor, its very easy to damage the windings, and look out for those marks on the stator. John

I've used a up/down car window motor for the past 12 or more years, I did know of the windscreen wiper motors problem. There was a good article in model engineer or model engineer workshop regard making your own speed controller using Thyristor and a few other bits, basically the same a 240 volt drill speed controller. I made a dog clutch to dis engage the motor for hand control, as required. I'm not sure about the wheel chair motors as they have a lot of grunt, maybe to much if things got a bit wrong and physically a bit big. I'm sure Neil will have the issue number. John

Normally neither Harrison or Myford lathes have motors fitted with brushes, so rule that idea out straight away. Both have induction motors. Some induction motors make a clicking sound as the slow down when you have just switched off,thats the centrifugal switch closing. Try unplugging the lathe completely from the electric supply and see if the sound is still there. Also tell use how the lathe is connected, such as a DEWHURST reversing switch. Ted

RS components have the correct bearings and are almost half the price of other suppliers. You don't need an account either, phone head office and arrange to collect from local branch or local branch might even have them on stock, I did.Ted

Hello Paul and other readers, as Neil has mentioned it was MEW issue 132 in which I described altering my SIP turbo Mig. I have looked on the site which you told me about Paul but the diagram is so faint as to hardly readable. By what little I can see the transformer and rectifiers are different and not sure about the micro switch feed either. Unless you have a lot of electrical experience I think leave well alone or try as Ray has done. I can send you a copy of 134 if you send me your email address via a PM. Ted/John

I wrote an article for MEW some years ago when I converter my previous Mig welder. The fumes are awful from the burnt flux so do it where the is a flow of air, some thing you can't do with gas. Send me a PM then if you have a circuit diagram I'll have a look to see if it is easily converted. I think its got to be a DIY job as an electrician charge would be more than the cost of another welder. Perhaps Neil can locate the actual issue number, I must have it some where.Ted

The same circuit board and modification will work on most ex washing motors. I have looked at other makes of washers and they are much the same. I can't exactly remember, but I put an extra resistor on the board limiting top speed, regardless of the speed potentiometer, a bit of safety feature. The motors are well balanced, and can get some revs on, but noisy at top speed. More importantly the aluminium heat sink on which the Triac is mounted is at MAINS VOLTAGE, user beware. That is why I put the board in a 12" X 8" X 4" plastic box which I already had.Ted

There was an article in MEW some years ago regarding altering the motor speed board from a front loader washing so that the motor and board could be used for other purposes in the home workshop. I have couple some where, I put the bits in plastic box and mounted the speed potentiometer on the front, the motor is very noisy and is designed to run in a horizontal position and has little protection from bits getting inside. So the idea never got used, however the motor bearing are good for other uses in the workshop. Better to get a 3 phase motor and inverter if you need motor speed control. Back

To Ian, these motors have a small Taco on the end of the shaft for feed back so that as the motor slows down more current is applied to the motor, maintaining the selected speed. So not quite the gutless straight series motor as was fitted to the twin tub.Ted

I suggest you contact HPC gears of Chesterfield their phone number was 01246 268080, but you will need to know the gear technical details.Ted

If you can access MEW issue 147 Feb 2009 its all there. I made both circuits one for my mill and the other for my Super 7. My inverters are very old no display, so the addition of a read out has been useful. If you send me a PM with your email address I'll email you a copy. Ted

Sounds good to me, I did the same several years ago using Dexion. Four vertical legs, six other pieces, 3 at the front and three at the back, horizontal. Then six smaller bits front to rear, all bolt together. On the top was a piece of thick kitchen work top. A shelf half way down, all was screwed to the wooden floor, making every thing rigid. At the evening class I made a sheet steel tray just like the Myford one, as they were tricky at the corners, I first made a news paper pattern. I think you have got it cracked.Ted

Before considering buying a scope I suggest you join Vintage Radio.Org its free. On Vintage Radio there are people who really understand and can explain electronics in every day terms and where you might pick up a scope for a lot less than £100 but do you really need a scope. An £8 Aldi multimeter is useful aid, also on ebay there is another useful piece of test gear, which for about £12 you can test resistors, capacitors, inductors and transistor quite accurately. As a starter project, how about making a workshop power supply. Almost all the components you will need can be obtained from an old washing machine speed board or an old audio amplifier or an old type TV. Get a soldering iron and solder sucker and start removing components and then identifying them. You will learn a lot that way especially when fault finding.Ted

We at the evening glass made are own tool holders and I'm sure they could be made at home in the workshop.. Not so difficult, to get the angles correct we milled out the "slot" where the lathe tool will eventually will be held, then drilled and tapped the 4 holes 2 BA. I bought from the auto jumble sale half of a broken VEE block which after a bit of machining became the clamping jig. The milled out slot was clamped to the jig by the 4 screws, now all angle were correct for milling the rest of the tool holders. Once that part was completed the centre part was milled away and with great care a tee slot cutter was used. Initially we had a couple of failure but soon got into production. We used free cutting mild steel, I'm sure bought one will be hardened and ground finish but these home produced ones have stood the test of time Ok. Ted

If you send me a PM with your address ,phone number and email address I will send you a copy. I and my friend made clutches and they work well.John

My old mate George ( now in the final resting place in the sky) had a similar problem in his garage workshop. He got some corrugated iron sheets and we made another roof inside if you see what I mean. Water came in and we arranged the sheet and some plastic spouting so that the drips had a away out and it worked. It would have been difficult for the two of us to work on the outside of the roof, in the end we didn't need to. Ted

Back again, initially forget about varying field current (weak fielding) that come after you have completely notched up if at all. Follow my instructions and get the thing running, then play if you feel like doing. In days gone by when DC drives were around Face plate starter were used. On stud one, a current was applied to the field (full 220 volts) then there was about 10 brass studs mounted on some thick black insulating material in a circular fashion. Behind each stud was a resistance wire, such that as the arm was moved across the studs resistance was lowered, until at last stud the armature itself was connected directly across the 220 volts. Then and only then, was weak fielding applied and it was electrically inter locked so that you couldn't attempt to start the motor on a weak field. Weak fielding give speeds above normal and not all motors were balanced well enough to weak field with safety. As some one has already said modern permanent motors are much better, and more efficient than the old dynamo, no field current. Unfortunately the resistors are wasting energy ( heat) and that is not you really want, its cheap, cheerful and energy wasteful. Also, if my memory serves me well, the size of the resistance wire (CSA) varies, thicker at the beginning. I don't think soldered connections will last long . Can you make good mechanical connections as an alternative? Ted

I'm not familiar with the article you make reference too. Was there a circuit diagram, if so could you send a copy here, then we might be able to sort you out.

Car dynamos were shunt wound generators, one side of the field and armature were connect to the frame. No doubt you have lifted those connections and made two new terminals. You will need four terminals in total, two small ones for the field and two larger ones for the armature The field winding should be separate and be connected straight across the battery, full 12 volts. The fire element should be in SERIES with the armature bit by bit via the studs, one end to positive the other to negative. As you notch up the resistance should get less and motor speeds up until eventually, the arm armature its self is straight across the battery full 12 volts, that will be maximum speed. There are better speed control circuits around using electronics, I think Neil the editor might be able to assist in that area, better than me.Let me know how you get on.Ted