Member postings for colin hawes

A hinged and latched notice board fixed to the ceiling could be a space saving way of hanging a drawing for those of us whose neck objects to looking up too long. Colin

The cutting speeds can be wildly different to the theoretical but generally the speed can be set by what the tool temperature and the machine can withstand; the feed rate can be increased with speed up to that limitation, for example, we often use far to slow a speed to cut screw threads because we can't handle the feed rate. The same applies to facing large discs where we need to consider the largest diameter although the speed is really too slow at the smallest diameter when you have no facility to continuously change the speed. By "feel" you can increase the feed rate as the surface speed increases. Colin

Commercial miniature boilers have to be CE marked or they can't be tested by clubs. They have to have a test certificate to be used in a public accessible place.

Keep HSS tools very sharp and with plenty of clearance rake at all cutting edges. I find that industrial recommended rake is too little for the sort of work we usually do. Colin

My HP printer will happily print my Word documents but when I try to print from the internet it now comes up with " unexpected configuration problem 0x80004005 ". I have little knowledge of these things and wonder if this has been caused by a windows update or some other cause? Colin

Double sided sticky tape. Colin

Place in 4 jaw with packing plates to cover the open sides. Set one face of the job to vertical. Wind in the cross slide to touch the job preferably with a DTI, but can be done with the tool tip, and set dial to zero then rotate chuck through 180 degrees and touch the job again. Note the difference and adjust the chuck jaws to move half of the difference. Repeat for other sides. Colin

It seems that an EV may be said to reduce on-the -road emissions and running costs but I am wondering what the true cost is for things like battery lifetime and the replacement of batteries. I haven't seen much printed about that.Colin

Duncan, I agree with your assessments, I was about to write the same points myself. Colin

Aluminium bronze, horrible stuff to drill. Colin

Normally a 2.1 drill would be used for M2.5 thread as there is likely to be slight deformation of most materials as well as the cutting action and that extra 0.05 mm allows for that. Colin

Qualified engineers are a highly intelligent but too reserved species which is why they are not rated as highly as doctors or lawyers by society. Everybody uses engineered equipment The misuse of the title "Engineer" is another reason for lack of appreciation by the average person. We need to greatly promote knowledge of the skills and mathematical abilities of people entitled to call themselves "engineer". Colin

Over many years my ex- scrapheap horizontal flat belt Clarke mill has often been very useful for cutting thick (3/8 to 2) inch steel plate that is too big to fit into my bandsaw. It has been used many times to turn 24 inch and bigger wheels. It's not a massive machine, with 18" traverse, but it is amazingly rigid. I also use the larger end mills and face mills with the job on its side. Very useful machine. Colin

I have often turned wood on my metal lathe ,it needs a very sharp high rake tool preferably a high speed and works best on hard woods. Colin

Tolerances are for making spare parts interchangeable or special fits such as force fits where a critical difference between parts is necessary so actual precise dimensions are unlikely to be essential on models. Colin

HSS tools are the most economical way to go for a beginner and will machine all the metals you are likely to use in model making but carbide tips are very useful to machine cast iron at a higher speed. Colin

A small built up layer of debris can cause your problem if it is the type with plain metal wheels (no rubber tyres). It can sometimes be cured by cleaning the wheels with emery cloth. Colin

When I was working as a toolmaker fractional dimensions were only used for an unimportant dimension such as the base of a drill jig and had a tolerance of +/- 1/64 th of an inch. Apart from standard threads, everything else was dimensioned decimally anyway, normally in "thous", e.g. 1.002, often in "tenths", e,g, 1.0002, so it was very similar to metric dimensioning apart from the basic unit of one inch as opposed to one millimetre.

Having many imperial tools and old but excellent imperial machines I naturally welcome imperial drawing dimensions but I have had to work professionaly with both systems so I really am not bothered by mixing them when making things. A lot of what I do now is restoring parts of vintage motorbikes which are generally measured in inches anyway. I do have a metric micrometer, digital calliper and a DRO so conversion is easy anyway. Incidentally , what's imperial weight got to do with machining things? Colin

Neil, thank you for your references, they are what I was really looking for and it has shown me that it would take too much of my model making time to attempt a rewind with uncertain results so I shall now consider whether to get a rewind done or convert to electronic ignition in the interests of reliability. Colin