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: 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.
|Thread: Hello from London|
Just to add to Bazyles comment re SMEE. Our general meetings are on Saturday afternoons (usually the first in the month) and we are near Loughborogh Junction station which is on the Thameslink line. Also accessible by bus or car - no restrictions on Saturday..
There is a meeting this Saturday if you are free - you are welcome to attend as a guest. Just turn up and make it known you are a guest and we will be happy to show you round.
More details on **LINK**
|Thread: hardening/tempering a bit of steel|
The first thing you need to check is that you are using a suitable steel. It must have a high enough carbon content, silver steel (drill rod in some countries) is the normal choice although there are others. Mild steel does not have enough carbon and will not through harden although it may be possible to harden the surface (called case hardening)..
Stage one is to heat to red heat and then quench (usually in water or brine). This fixes the atoms in the steel into a very hard but brittle state. Your torch will need to be powerful enough to get the countersink red hot.
The second stage is to gently heat the part to get the right compromise between hadness and brittleness. This usually entails getting the surface to a nice clean shiny state and watching the colour as you gently heat the part. In this case I suggest a straw colour would be right. Once the colour is there quench to stop it overheating.
Metalurgist will go into much greater detail but this might help get you started.
Sorry for the repeated info Clive beat me to it.
Edited By Roger Woollett on 02/01/2018 14:19:32
|Thread: Arduino &c for dinosaurs|
I think I can shed some light on the programming aspect. The Arduino IDE tries to make programming easier for beginners but can be confusing if you have some experience.
The language used is often said to be C but is in fact C++ . A sketch is essentially a source code file. When you compile the IDE generates a header file so you do not have to provide prototypes for functions. There is a main function but it is in the library - it just calls setup and then loop repeatedly.
Let me know if I can help with other confusions.
|Thread: 3D Printer Test Piece|
I did this on a Prusa built from a Thames Valley RepRap Group kit. It has the screwed rod frame and was demonstrated on the SMEE stand at Guildford last weekend. Just used my standard settings for PLA.
|Thread: Cross drilling|
A method I have used involves a custom V block.
Clamp a bit if MDF to the mill table and use the tip of a centre drill (or something else that produces an approximate V groove) to cut a V groove across the MDF. Lock the table so the groove is directly under the mill axis. Now clamp the round bar into the groove and drill in the normal way. I have done this with 1mm rod and a 0.5 mm drill successfully.
|Thread: Grandfather Clock|
Certainly oil the pallets/escape wheel teeth. Just put the tip of a small screwdriver into the oil and transfer the droplet of oil to the pallet face.
Also put a drop of oil on the pendulum where it passes through the crutch. If the pendulum is very loose in the crutch it might be possible to squeeze the crutch slightly. There should just be the slightest play.
|Thread: Outstanding Service|
Simply Bearings. I ordered one pack of 50 viton o-rings yesterday morning for about £10 with free delivery. They arrived today by Firtst Class post. Very happy customer and this is in line with other small purchases in the past.
|Thread: Hobbymat milling machine|
Lathejack - thanks for the tip about the column clamping screws. I wish I had known that then!
I find that the head nods forward if the two clamping levers are loose - particularly the top one. I have often thought about fitting some sort of "gib" adjuster but never actually tried it. Do others have this problem?
Does anyone know why you should not remove the right cover. Before I had been told better I had them both off and as far as I know no harm was done.
My mill had not been used for some years so I scraped out as much of the old grease as I could and replaced with Molyslip. I do not know if this was correct but it is still working.
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