Member postings for terry simpson 1

I am refurbishing a small Instrument type lathe from hand long travel to Stepper Motor drive using electronic means..

I have considered to fitting the leadscrew to the Stepper as a direct drive in both longitudinal directions of the toolpost. However thinking back to schooldays 70 odd years ago, I seem to remember that rotating electric motors without application of power, as in this case when using hand feed, can create a back EMF and possible damage to the electronics involved.

I am trying to do away with the complications of fitting a small clutch type device to the leadscrew drive.

I am sure within our fraternity this question may have been answered many times in the past and would welcome any help in solving any problem involved.

I have had a Kennedy Saw in my workshop for the last 45 years, retrieved from my workplace scrap bin on completion of precision trimming ends of stainless steel tubing for seven Nuclear Submarine Steam Generator Tube Bundles.

The saw was fitted with a 1/4 HP Hoover Motor fitted with a level operated built in trip switch.

After a major initial rebuild I ran this saw in my workshop for about twenty years until wear on the slides reduced positioning of the saw bow and blade impossible to set up for an accurate cut so a decision was made to renew all worn out parts, including sliding hex bars, bushes and drive belting.

Because of the difficulties of finding new drive belts, originally supplied as a sticky rubber band, and my use of a not very good canvas belt drive I decided to change the drive to chain wheel and chain using parts from an early computer printer unit. This change of drive has been very successful since installed with no broken blades and real square cuts every time cutting up to 2" square bar on occasions.

The reason for this post is just to highlight what a good and useful saw compared with the current comment as to what a poor machine the Kennedy was or is.

Has anybody managed to bring back into use any of the cheap Auto Centre Punches currently on the market. I have had two units fail miserably after a short time in use

I used to have a superb M&W punch which failed after many years of use, how do the suppliers come up with replacement prices for the better tools, hence my purchase of the cheapy punches.

Yes I know you only get what you pay for, however the amount of material used in the manufacture of each useless punch hence my query to see if any of our brethren have come up with a repair solution.

The file in question is one used for refreshing magneto points having seen one being used. The occasion being during weekends as members of the ATC in 1950, at RAF Thornaby , being instructed as to how the systems work for routine servicing of aircraft and to how the fitters completed the work and signed off all actions they were responsible for. One instance demonstrated was the cleaning of engine electric breaker points, if I recollect was completed on an Anson engine, using a very fine file just like the one subject of this post. I cannot remember how awkward the access was to the magneto in this instance. One assumption regarding the subject file handle 1.5mm square, surely if working in a confined space, one would need to know that the one or two flat file surfaces were in the correct plane to complete the work where as a round handle needle file correct positioning could not be guaranteed.

I seem to remember in the early fifties seeing and reading an article in Model Engineer issued during the war years for the repair of leaking aluminium pans. Remember that aluminium was not available for domestic purposes, all materials were diverted for aircraft production. The article was printed to explain how to fit repair washers to the worn out part of the pan and covered repair of small holes only. Repair washers were, if my memory is correct, available from many hardware and provision stores and hung up to be torn from a cardboard sheet as required. The repair principal was for two steel washers with a small hole in the middle, each washer was dimpled, placed one inside, one outside and the steel screw provided tightened through each washer making the dimples deform the aluminium to form a seal. I assume the article was included into the ME of the time to instruct those modellers away on duty to instruct their wives, assuming that the magazine was still delivered, how to overcome a difficult domestic problem. This article has stayed with me all these years as to why ME printed the article as it seemed to me to be outside the scope of the magazine.

Having the need to remove and remount both grinding wheels on my Tool and Cutter Grinder I find that the manufacturer fitted paper blotter on each wheel has become, shall we say unusable again (knackered otherwise). As it is impossible to buy new paper pads what other materials have our brethren used to soften the compressing forces of the spindle clamping devices on the grinding wheel.

Have thought about actual blotting paper from the likes of Ryman or Smiths but apparently wet ink as was known is not used nowadays.

I was actually advised to try some very fine sand to dry the ink as in Dickens time.

Still unable to find out if my Myford S7, circa 1966, spindle bearing specified as of Hoffman manufacture was or is imperial or metric dimensions. Current replacements 7205 BEP,52x25x15mm may fit OK if Myford had gone metric at the time of manufacture or even Hoffman only supplied in metric form. If imperial sizes were fitted I may have to make mods to the lathe to accommodate the metric range. Please help.

Whilst on this subject, I am in the process of changing my 1966 S7 spindle bearings. I have not stripped the current bearings out yet to get the sizes of the Hoffman bearings to replace. I have been advised that the present bearing details are Angular Contact 7205 BEP size 52x25x15 mm, I am expecting that the bearings currently installed, due to the age of my S7, to be of imperial classification, if so how would the proposed new bearings fit correctly? Any advice from our brethren would be appreciated.

Do not use this system, it is a health hazard, the air that you breath in whilst working is saturated with tiny globules of coolant. Not good for your lungs.

This system was primarily designed for totally enclosed CNC machines.

My Myford S7 rear bearing has started to rumble a little and need to renew, has done some work since new in 1966.

Myford handbook specifies Hoffmann 125 AC ball races, these seem to be unavailable at the moment, even ARC want to know the bearing sizes before helping. Has any of our brethren changed these bearings recently, if so where were they procured from.

I need a new or fabricated lubricating wick for my Myford S7 front spindle bronze bearing. Where can they be purchased from or has anyone made one using felt as from the original material? Unable to keep up with oil usage at the moment. Regards to all Terry.

I have an original Multifix Toolholder attached to my Myford S7 with 3 holders at the moment. I am considering purchasing a further two holders from EU and China suppliers but am in doubt as to the compatability of other manufacturers holders to fit to the Multifix column giving the rigidity of the original toolpost.

Has any of our brethren bought any of the toolholders, if so, what was the fit and performance of the copied parts.

Many thanks.

Terry S.

Just received latest catalogue from Coopers of Stortford showing their floor tiling, reduced and at very good prices. Reason I have reported these items, originally intended for use over garden beds and lawns, is that when they were introduced a couple of years ago, I fitted my workshop concrete floor with them.

What a difference they have made, no swarf transmitted to the house, warmer than all other coverings tried, being perforated allows all bits and pieces to fall through ready for the vac cleaner to suck all rubbish away, and being interlocking can be lifted individually to pick up dropped nuts, screws and small tooling.

This product as well as being cost effective, is brilliant in use, at a price of 20 12" square tiles for £14.97.

I have no connection with Cooper except form being a satisfied customer.

Hope our electronic friends can help. I am conversant with the basic principals of low (24 V DC) motors using the cheap units available on ebay for speed control of brushed motors.

What I need now is information to control and direction and speed of brushless motors, again low voltage. Can anyone help in advising how to solve this problem without too much technical input and using cheap components.

Neil, Going for my paper 06 00 this morning, what a wonderful surprise to see the new moon and a couple of stars as per your photograph, never seen it like that before. However to a person like me totally devoid from any info as to star position in the universe, could you please identify for me which star is which in the photograph.

Terry.

Finally given up, sick of pouring oil into the lubricator cup to have the lathe swarf tray swimming in oil due to the deterioration of the felt wick feed to the bronze headstock bearing.

Unable to find replacement part for the felt pad, what method has been used to make and replace the old pad has been devised over the years by our Myford user friends.

Unable to find any topic for the subject on the forum.

Remember this tool, used as a portable hand drilling machine on equipment where access or lack of power was not available to use. Example:- On site drilling of railway fishplates, or by Boilermakers when drilling is needed in the confines of tanks and vessels.

The drill is really incomplete as the bolt on or fixed backstop is needed to apply downward pressure to the drill point.

I would suggest that the tool, apart from being a talking point, would have very limited uses in the home workshop.

This is my opinion however, the brains of our fraternity have not yet replied to this query.

Have built a small laser pointer built into a No2 Morse Taper blank with softened end fitting, and available from most tool suppliers, very useful to use except the dot and cross hair projection is too fuzzy to give accurate true location to a point.

I understand that by fitting a Polaroid film over the laser end will cure the fuzz, any help from our kind hobbyists who may have cured the problem this way including sources of Polaroid used would be most welcome.

Terry S.