Member postings for john fletcher 1

When I worked for BR we fitted dimmers to florescent lights in signal boxes, bascically, they kept the tube end cap heaters on and lowered the voltage via a transformer.I'm sure there is now a non repairable digital gadget full of 16 leg chips which dims lights much better. Regarding pole changing motors it might be easy to design them, but try sorting out the switching arangement when some thing goes faulty. I've recently been sorting a two speed motor on a Smart & Brown lathe with several inter locks. Fortunately a reader on this ME site sent me a copy of the maual, but the circuitdiagram left a bit to be desired.Please to say all is now working.Thank you Richard. John

Insulate as Thor says and then get a dehumidifier, they don't use a lot of electrical energy as they cycle on and off as necessary. Look out at sale rooms for cheap buys or buy new.I can recommend them, I've had one for the past 20 years pre owned. Alternatively get some bags of selica gel and dangle them around, they will change colour as they absorbe the moisture, but they will need drying out as and when necessary.Ted

Well I think fit an inverter. Reconnect the motor in Delta, not a long job, some motors have the details of what to do in the terminal box lid. Regarding 800 rpm I don't understand, as one of the many benefits of fitting an inverter is being able to vary the lathe speed. Again its easy to make a remote control box, the details can be obtained on the net and as the voltages are low, cheap components are available.If you decide to make your own speed control the variable resistor needs to be a LINEAR type, not a volume control, they may look the same but are different inside I'm not familiar with setting all the parameter, but some one on this site will already have the same inverter as you intend to buy and I'm sure they would help you out. Best to obtain some 3 core mains screened cable from the motor to inverter (Sy) using the screen and earth one end. I use multi core screened lead ex computer for my control wiring. When using an inverter you can have forward, reverse, speed control,and jog. Ted

Well I think fit an inverter. Reconnect the motor in Delta, not a long job, some motors have the details of what to do in the terminal box lid. Regarding 800 rpm I don't understand, as one of the many benefits of fitting an inverter is being able to vary the lathe speed. Again its easy to make a remote control box, the details can be obtained on the net and as the voltages are low, cheap components are available.If you decide to make your own speed control the variable resistor needs to be a LINEAR type, not a volume control, they may look the same but are different inside I'm not familiar with setting all the parameter, but some one on this site will already have the same inverter as you intend to buy and I'm sure they would help you out. Best to obtain some 3 core mains screened cable from the motor to inverter (Sy) using the screen and earth one end. I use multi core screened lead ex computer for my control wiring. When using an inverter you can have forward, reverse, speed control,and jog. Ted

Can any one explain how the brake works/operates on a Smart & Brown type L lathe.I have a copy of the manual supplied when new.Brake details are very vague to say the least and the brake wiring appears to be correct. Ted

Your diagram is correct. Test using a multimeter, the start winding which is short time rated will have a higher resistance than the run winding. The capacitor together with the cetrifugal switch are both connected in series with the start winding and should be connected to 2&6. I can't remember which terminal on the terminal strip which wires goes to the switch but they are usually solder to the copper or brass strip of metal.So if you connect your terminal Z to one lead of the capacitor, the other capacitor lead to one side of the centrifugal switch then the second terminal of the switcg to your terminal T you have it. Whilst its best if you use the correct terminals it doesn't really matter providing the two destictive separate are connected in effect in parallel across the mains. Choclate block connectors are OK. DONT forget the most important wire the EARTH, good clean contact is needed.Now those dewhirst switches are not really rated for ON/OFF the contact easily burn, some times there are unused terminal at the bottom of the switch which if necessay you can with care change. Its best if you get a proper motor starter fitted with green and red buttons, have it wired so that you use it for ON/OFF and the dewhirst for direction only. So select direction then press the green button. Also a proper starter give No volt protection,if the mains goes off the lathe stops and won't come on again until you press the green button, you might be making some adjustment when the mains comes on again very Doggy. One other thing the manufactures didn't always use the same or should we say correct colour cable,so that can cause a bit of confusion when sorting the windings. Best use a multi meter then you can't go wrong. Ted

If you can make a workshop of Kingspan reject material. This is plastic coated profiled sheet steel with insulation 75 or 100mm between the two layers, the inside is white so not only is it very cosy but very light as well. In my area we can buy rejects very cheaply,so look in agricultural dealers magazines for possible suppliers in your area, farmers use it for their buildings. Its not difficult to handle either, with a bit of planning two people can make a workshop in two weekends and it obtainable in various colours. But as others have said a concrete floor is a must, one never know what you might obtain in the future. A length of 4mm steel wired armour cable down the garden for a electric power supply and you are set for many happy years.Ted

hello there, I've 3 inverters all pre owned. I've made my own remote control boxes and all three have their screened power lines (Sy cable i think) to the motor separate from the control wires. The screen is earthed at one end only to avoid current loops.The supply from the mains in each case is via a large double pole (10 amp) relay in which is wired the large RED stop stop button. To run the inverter I press the green start button, the relay energises. To power the motor I have a latching on/off switch togerther with a reversing switch, a potentiometer for speed control and a small switch for jog, handy when setting up. For the control circuit I've used ex computer screened lead. Once switched on I don't need to switch the inverters on and off, I leave them running until its time to pack up for the day, just use the motor local control as and when type of thing.I hope that might be useful.Ted

Regarding running an ex washing machine seies wound motor as a shunt wound motor Jim ???? who other name I can't remember wrote a small book published by model engineering and he gave details of what he found when doing just that. As you say the field resistance is low, I ran a modified one as a seperately excited shunt wound generator several years ago, I think I energised the field from a 12 volt battery. I was just sort of playing around and didn't keep details, but it did work OK. The motors are well made, have very good balance, but rely on speed to obtain the power, they have a nice pair of bearings, very useful for other for other projects. I modified a Hoover pcb to give speed control, just got it working then some did an article in MEW on the very same thing. Motors on the latest machines with digital control are much the same, they are also fitted with a tacho for feed back.If you are interested in power electronic,there some very good components on early type printed circuit boards ready for removal,not so on the digital ones,shame. Ted

50 years ago I worked for BR repairing and maintaining diesel electric locos, on some the auxillary generator was belt driven, a matched set of six. On break downs or failure we got them going by fitting link belts, we counted the links or often remembered from previous experience to attempt to load each the belt the same (one sixth of total load) Once we had the job on the moved we did remove a link or two and we did mark them with a bit of chalk. It was an expensive and time consuming to replace endless belts even on the depot. Its not such a big job to change an endless belt on a Myford lathe if one follows the instruction in the book. Most motor factors and agricultural dealer stock an equivalent belt for half the cost which the Model Engineer dealers ask. Whilst you are at the agricultural dealer ask about the cost of Esso Noto or the equivalent and you might get another pleasant surprise.Ted

Why not do as we do here in Scarborough form a group and hire the College workshops together with a member of staff , its not cheap but we think it is worth the money. We have access to larger lathes,large milling machines, grinders and some welding equipment.We have been doing this for the past 7 or 8 years and this year have a waiting list.We have an open evening every year as a means of recruiting new group members, usually one two decide to drop out,not this year. I collect the money and have a contract with the management. We meet for 20 evenings,10 before Christmas and 10 after Christmas. We don't get any help from the College regarding publicty,we are stand alone group.Ted

Several of us made our own QC tool holders at the "College" evening class.We each obtain a length of steel, milled away the centre part will eventually become the part which will be clamped again the tool post. Next milled away either side with a "TEE" slot cutter copying a Myford bought one. Then cut the length up into individual pieces, then the tool slot was cut.Next all the blocks were drill and tapped in 4 places 2BA and 4 X 2BA allen screws were screwed in

I had a broken cast iron VEE block, it was slightly modified to become a triangle jig. This was then clamped to the milling machine table, such that each tool holders could be clamped to it at a 45 degree angle, using the previously milled slots, one at a time, using the four allen screws. Now the 4 angle faces could be milled.We each made about 8 in two hours, once we got set up. We used mild steel and up to date all have been Ok with no problem and that was four years ago. Incidently we organise our own evening class, we hire the College workshops.Ted

Evening all. I have a home made "Growler" which is used primarily to carry out a rudimentary test on car/motor bike armature, but also to de-magentise tools cutters etc. I obtained a large transformer 240 volts in 55 volts out, about 4" X 4" X 5", much smaller will do. I remove the 55 volt secondary winding, taped up the primary as best I could and milled a VEE completely cutting through the lamination so that an amature would sit in the VEE. Most garages around in the 1920/1960 had a Growler made by Cryton or some other maker. The tape was to prevent swarf and coolant getting into the primary winding, once the machining was completed the tape was removed. To de magentise any tools etc, I switch on the mains to the primary, pass the object through the air gap, switch off job done. As some one else suggested use an instant heat soldering iron. Don't get involved with overheating and a lot of theory you are using the thing for a minute or so. Ted

Scarborough & District Model Engineering Group,

The group is based at Yorkshire Coast College they are having an open evening 2nd.July 6.30 -

9.0. The venue is the Mechanical engineering Workshop, where there will be a display of articles

made by members.

All welcome young,old,novice or expert.

I have BTH/AEI circuit diagram.If your motor has not got a capacitor fitted, then as some one says its a split phase motor.That being the case, the run winding will be connected to terminals A1 & A2, the short time rated start winding will also be connected to A1 & A2. If you want to make the motor reversable then that is possible, however it will mean a complete motor dismantle. Using a scriber or some other sharp instrument scribe across both motor end shields, two marks on the non drive end one on the drive end, righr across, these are alignment aids for re assembly. This motor is elderly so proceded with care, remove the 4 through bolts, and using a mallet give the stator a sharp tap on both ends, it should fall apart.When removing the rotor be very careful not to scratch the windings, DONT lay the stator on its windings, a sure way to ruin a good motor. Inside of the non drive end is the centrifugal switch, to which one end of the start winding is attached, the other end of the winding is connected to A1. Using a big iron unsolder the two wire. The start winding is the thinner of the two and has a much higher resistance than the run winding. Once dis connected the start winding should be connected to terminals T1 & T2 via the switch. To give the motor a much better starting torque a proper AC electrolytic capacitor of around 60 or so micro farads can be safely fitted. To reverse the motor is is necessary to reverse either the start winding or run winding one not both.So a double pole double throw change over switch preferably with centre off and a proper motor starter with non volt release.If you need any more help then contact me. By the way the formula regard cap value is correct for 60Hz 2650, different for us on 50, 3200 near enough if anyone is interested.Ted

Here in Scarborough 15 members hire the "Tec" College workshops,together with a member of staff, this years the cost was £1880. 10 evenings before Christmas and 10 after. Perhaps you could do the same.We have been running like this for 6 or 7 years, I collect the money and pay the college.

We are having our annual open evening 2nd July, where there will be a display of what we have been working on this year.Ted

My Austin A30 van had the same window problem. Where I worked we had some wonderful two part adhesive now known as Araldite, which had very good insulation properties and which we used when repairing traction motors. I thought I'd give it a try on the window catches, they never came off again. We also had another two part material, which the fitters used to mix up and squirt into very hot cracked exhaust manifolds as a temporary repair, brilliant stuff. I wonder what the research chemists are developing today, ready for use in the future. Ted

Many thanks to all who have replied to my request for help,good to know that folk like you are still around. I have copied the circuit diagrams,so will be studying them. Well regarding the transformer I was told that it tested out OK and that the motor had been loosely connected ( direct to the transformer) and that tested OK. So it leave only the pcb which I recieved and it tested OK, could be a duff micro switch. I will get over and see my friend next week very busy this week, Harrogate show amonst otherthings. I have a couple of multimeters, I am quite well equipt with test gear. Many thank once again I will let you know the outcome.Ted

My friend has a Chester milling machine fitted with power cross feed which has a fault.Over the phone he says it blows the fuse,he says the transformer is OK 240 in 110 out, he also says the motor runs.I got the pcb and checked out the thyristor (its not easy to get access to unsolder it and test it) its OK.Any ideas or help would be appreciated before visiting.Ted

Contact me:

• Email: Send Email
• City: Scarborough
• Name: john fletcher 1
• Tel: 01723 362537

4" box section is a bit over the top, 2x2 (50x50) is more than adquate to give stable base for a tray and lathe. Regarding the tray, its not that difficult to copy Myfords idea.I made mine out of 3mm sheet steel bought from local firm, I cut the corners with a hacksaw Myford style, I took it back and they bent it for me. I then Mig welded it up, all for £30, which included two pieces for two shelves. I have made two other for friends since, using the machines at the "Tec" college evening class, where I could use their welding gear.Maybe you could do the same, you can buy a lot of gear for the workshop for £250. Ted