Here is a list of all the postings Roger Woollett has made in our forums. Click on a thread name to jump to the thread.
|Thread: New member from Bath|
I have a Cowells 90ME and would not be without it. I have turned aluminium discs 120mm diameter using the faceplate and the gap bed. This is about as big as it will take. They are expensive but very accurate and capable of very good work. The back gear allows low speeds with plenty of torque - particularly useful if using a slitting saw with the wokpiece on the vertical slide.
I am also lucky enough to have their milling machine which is also very accurate and extremely rigid for such a small machine.
|Thread: Hi from lockdown in London|
Another society you might like to consider is the SMEE (Society of Model and Experimental Engineers). Their headquarters are near Loughborough Junction which is an easy ride from Harrow. Like all societies activities are on hold for the moment but when things are back to normal come to one of our general meetings - you are welcome to come as a guest. In the mean time the website give more information.
Many SMEE members are also members of a local society.
|Thread: Engine with Watts linkage|
I saw a photo of an engine with Watts linkage on this forum and liked the look of it. This is my effort.
|Thread: 4 Wire motor wiring|
It may be possible to take the motor apart and reverse either the commutator or the field winding connections. I did this a while back with a similar motor.
|Thread: Tug - Amolco mill attachment|
I think Ramon Wilson also goes by the name of Tug
|Thread: Rear parting|
I agree with Jason the toolpost is "old school" and designed for quarter inch tooling.
|Thread: Resistance Soldering question|
The term "soldering" covers a range of filler alloys. "Soft soldering" usually means using a lead or tin based alloy with small quantities of other metals to change the melting point. Temperatures around 200 - 350 degrees Centigrade are common and heat can be applied by a flame or soldering iron.
Fillers that melt above 450 degrees C are strictly brazing alloys although the terms "hard" or "silver" sldering are often used. Model engineers tend to use silver solders thart melt from 630 degrees C and upwards. Silversmiths use a different range of silver based alloys described as "easy" ,"medium" or "hard" with melting points above 700 degrees C. These can be used on items that will be hallmarked. Most people will use a flame for these temperatures.
I hope this explains the confusion.
|Thread: Silent compressor problem|
I have had this problem with a Bambi compressor. I decided the motor was only suitable for a quite low duty cycle. I had been using too much air and it got very hot.
Because of this the rubber diaphragm in the regulator failed. The first time this happened I got a replacement from Bambi. When that failed I found that it is a standard item. Machine Mart had them but I found one a lot cheaper on eBay.
|Thread: Annealing Chinese Machine Tooling?|
I think the Cowells uses the short end of the taper. I agree with Hopper - buy one to try. If I am right then you should be able to put the short end directly into the headstock and turn the unwanted large end down to suit your needs. If it is hardened you might be able to use a carbide tool.
|Thread: Help choosing a Chinese lathe please|
Since distance between centres is important to you remember that the quoted distance is with the chuck removed and plain centres in head and tail stocks. The maximum size of workpiece you can realistically turn may be a lot less.
As has been said Arc Euro have an excellent reputation. Their range is smaller than many of their competitors but seems to be carefully chosen.
|Thread: Piston Rings|
Possibly from Direct Plastics
Not used them for a while but happy when I did.
|Thread: Should I begin with mild steel on lathe?|
If you are aiming to machine silver steel then mild steel would be fine to practice on.
Do buy free cutting mild steel from a reputable supplier (there are many who supply model engineers). With a small lathe like the Sherline it is important to use a sharp tool.
When you come to silver steel halve your speed.
|Thread: Help needed north London Enfield|
I may be able to help - I have sent a PM.
If you do decide to make them for youself the most difficult part is setting the top slide to the correct angle. Once you have done this make several so you have some spares.
|Thread: Hardening a form tool made from Gauge Plate|
As has been said you need to get it hot enough but not too hot. Use a dim light and aim for a carrot colour. Soak times are to get the material hard right through but for a cutting tool it is only the outer millimetre or so that really maters. If the core is still tough as supplied so much the better. I wait maybe a minute after I have got it to carrot colour.
Oil is correct for gauge plate but I am afraid I just use warm water. Keep the water bath close to the hearth so the part does not cool on the way. Plunge straight in and stir to get rid of any surface bubbles.
Clean up and temper by colur or in the oven. I use a flame and quench as soon as the cutting edge gets to light straw.
Having tempered use a stone to get the cutting edge sharp again.
Finally when you use the tool go easy. If the cutting edge goes above the temper temperature it will blunt very quickly.
|Thread: How to machine Acetal|
I have machined Acetal from time to time. I use a HSS - keep it sharp with plenty of rake. I usually use quite high speeds - the same as I would use for brass. This gives a nice finish.
|Thread: A kitchen table workshop. Tool grinding problems|
If you keep them sharp you do not need a wheel. Get some diamond laps like these
I have a similar size lathe and find all I need is a quick rub with the finest grade to keep tools sharp.
|Thread: Stainless Steel Metric Fasteners|
Sorry I am a bit late but I have used these people a couple of times and have had good service.
They have a wide range of stainless fastners.
|Thread: Unique engineering training courses offered by SMEE|
A quick note to say the the Part I course starts on February 9th. This course covers setting up a workshop and the tools and machines you might want to use.
We will be at the Alexandra Palace Exhibition (18 - 20 January) so if you are interested (or just want a chat) please visit our stand.
|Thread: Lathe bearing oiler wicks/felt|
I have a rather more recent Cowells. As Tom says the oil does come out and can be sprayed around. The worst bit is it can get on the headstock drive belt.
I do not have to top up every time I use the lathe but have found that if the level goes down too fast it is worth checking the headstock bearings. These can be tightened using the pinch bolts. You only need to adjust them by a tiny amount.
|Thread: M3 blind thread in ali about 4mm thick. How?|
Following the helicoil idea - drill out to say 4mm. Use a 4mm end mill or make a D bit to get a flat bottom to the hole. Then make a plug tapped through at the original M2.5 and loctite in place.
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