Here is a list of all the postings Bob Mc has made in our forums. Click on a thread name to jump to the thread.
|Thread: What Did You Do Today 2020|
Nice work John...
I made this fitting for the lathe so I can set the 4 jaw chuck up with the dti when working with small diameter stuff, I have a magnetic base with the dti on its arm and find it difficult sometimes to get the needle to be at the top of the small diameter piece.
I fixed an old microscope rack & pinion slide on the arm holding the dti and now the dti can be moved back and forth easily over the work piece after the magnetic base is set in the general position.
Its now nice and easy to set up...Bob
|Thread: DTI base|
I was having difficulties in setting the dti when small diameter work was being set in the 4 jaw chuck, the problem being that the needle of the dti needs to be moved only tiny amount to set it on the top of the work. The jaws can then be aligned, usually I move the magnetic base about and with a bit of luck just get it right..it takes some small but annoying faffing about......but no more!
I have fitted the base arm with a microscope slide which holds the arm with the dti fitted, the mag base is put in the general area and the fine adjustment is made with the microscope focussing slide... is it over the top?... yes... does it work better than before ...yes.
Seeing one result of coronavirus is that there are very few aircraft flying...could it be that the good weather we are getting just lately has anything to do with it?
Or have I spoke too soon!.
|Thread: This looks an interesting small milling machine|
Yes I have got one of those Dore Westbury... it has been quite good, the one on ebay has had some modifications which will make it better than normal ie the drive has an intermediate pulley but you can't see whether the owner has removed the planet/sattelite gearbox .
There are a couple of problems that I found with this type of mill, if the head is rotated for chamfering for example it is a job to get it back to exact perpendicular alignment, and the spindle does make a clattering noise when under power, I have fixed mine using delrin inserts in the spindle splines. Perhaps the modifications to this one for sale will address those problems but I can't say without more information which is a bit lacking in the ebay description.
I would advise that these mills were all home built with castings and you should be prepared to sort out problems, that said once fixed properly the mill is just the right size and power for model work and heavier stuff.
There is a Yahoo group for this mill.
As the head can be rotated, cutting flutes can be accomplished without using a rounded cutter see below
|Thread: Who invented the elastic band?|
Who invented the elastic band, there have been a number of people who claim the invention but I think this one I found whilst googling round is the most likely.....
THE RUBBER band is thought to be an ancient North Korean invention. They were made in such large numbers during the Tan-Gun dynasty that the country's capital was given the name Pyong-Yang after the sound made by people flicking the bands around.
David Legard, Singapore
|Thread: Anyone know about buying freehold to a house in the north|
I don't know if anyone has actually looked at the utube parliamentary discussion I mentioned in my last post, but with all due respect for those of you thinking of purchasing freehold...... I would at least consider that the National Leashold Campaign, the organisation trying to abolish leases, is gaining strength with the political help of Sir Peter Bottomley.
Listening to the parliamentary discussion of what the group said just a few days ago, on the 2/10/19 it seems fairly obvious that there are changes afoot and I think it would be best to wait and see what transpires before making a commitment to purchase.
What really makes me hopefull is the disparaging way in which Sir Peter talks about what is known as the "Leasehold Scandal"., and the companies that run them.
What I said in my last post I re-iterate... see utube "parliamentary discussion on Leasehold and Commonhold Parliamentary Reform" , it seems particularly coincidental that freeholds are being offered for sale at this time, and could be due to those companies wanting to make some money before the bottom drops out of their cash cow.
Hope the link below works
...Further to my last post...
There is a YouTube parliamentary discussion...see Progress on Leasehold and Commonhold Reform.. could it be that leaseholders are now trying to claw in as much as they can before legislation gets to them.
Yes I have just had a similar letter to purchase the leasehold.
I find it difficult to talk about this without feeling a distinct anger at being completely at the mercy of unscrupulous individuals who appear to take great delight in making a living out of what I consider to be legalised crime; an article in the Guardian ..."Leasehold houses and the Ground Rent Scandal" two years ago may give some hope that there could be a shake up of these Feudal laws some time in the future.
What annoys me is that these people seem to be able to put out prices for purchase of the leasehold which is based on the maximum of how much they can legally claim, they have no interest in providing any services whatever apart from making money .
Some time ago we were sent a letter from our Leaseholder indicating that we had to use their Insurance company to insure the property, the letter was written in a way that seemed to make it a legal requirement, and some householders were taken in by it and bought their inflated insurance policies.
At another time they sent a letter stating that THEY own the property and can enter the property at any timeTHEY deem reasonable, this was as I understand it not a legal condition and they had to retract the statement.
I understand that in Scotland Ground Rents have been abolished, but I do not know the details, I have written to my MP about the situation regarding English ground rents (some 8 years ago), and was told that there were no plans whatever to alter leaseholders rights.
The article in the Guardian says that a leaseholder was charged £2500 just for permission for a conservatory to be built, this is apart from Council planning permission which to my mind sums up leaseholders corrupt attitude.
I don't know if the article in Guardian which at the end states that the Government has proposed a ban on the future sale of houses as leasehold...and...As well as cutting ground rents to zero.. does this actually mean that my ground rent will eventually be free..?
Which magazine stated (2018) that a Government proposal to cap ground rents to £10 a year was being discussed, I haven't heard anything more about this, perhaps it might be an idea to wait and see if there will be any further moves in the right direction.... will have to look into it a bit more.
|Thread: B & R Tite "Digger" Oscillating Engine|
Will have a look into that one.
Thanks Chris I like it...!
Does the steam inlet come through the cylinder bearing? I have seen this type before but don't know if there is generic name for them, I am in the process of looking for a new project and I think this one may be simple enough to buld using stock materials...anyway thanks for sharing with us, keep us informed if you find out any more and are going to get started on it .
Hi Chris ...
can't find any reference to it on my search engine, any chance of a photo..?
|Thread: Annealing Chinese Machine Tooling?|
I can't give any information for annealing, but I did have a similar problem with my 70 year old Atlas lathe tailstock barrel which was badly pitted and not made of hardened steel.
The original barrel was 1&1/8th inch diameter and I couldn't find an equivalent sized barrel apart from second hand ones which were probably in the same condition as the one I had.
There were straight shank MT2 inner to MT3 outer adapters which had an outer dia of 1 1/4" and I thought of trying annealing it and having a go at machining, The plan was I would cut the MT3 end off and and after annealing and machining to the smaller diameter, fit the part of the old barrel with its acme screw thread to the new MT2 straight sided shank. In the end I didn't anneal it.
Pic below shows the end cut off the hardened steel new part and the badly pitted old tailstock barrel with its acme screw part also cut off.
After much deliberation I decided to grind the outer surface of the new straight sided MT2 shank, I only needed to grind off 1/16" radially, and I fitted a modified chain saw grinder in the toolpost for the job.
The job went quite well and I finished it by lapping with diamond paste, I found that the inside of the new part was not as hard as the outer surface and the finish was just as good as the originally purchased item.
Below....the new tailstock barrel fitted.... it works great and I set it true to the lathe axis using a dti method, it is absolutely spot on. As the barrel was now looking good I fitted a digital readout and partly embedded it in the tailstock casing so it didn't stick out so much.
I know it's not exactly what you were asking but other ideas are sometimes useful.
|Thread: Syncing up Arduinos|
Re; original posting Arduino based Leadscrew controller MEW Dec 2015.
Just to let those who were interested in the device that the Leadscrew controller is still going marvelously, I have made quite a few pieces of threaded work since then... some examples photo's below.
A spindle back end ring nut internally threaded made from EN1 steel.
A couple of telescope eyepiece adapters with outer very fine unusual thread and inner coarse focusing thread made from brass plumbing fittings.
Also an experimental LH trapezoidal internally threaded cross slide nut to eliminate play made with brass.
Screenshot shows the arduino programs which can be selected for individual threads.
My lathe is now well over 70 years old being, (I am led to believe), was part of the Lease-Lend agreement during WW2 from America, I wonder how many of these lathes lie at the bottom of the Atlantic.
|Thread: Aldi type bench drill|
I can't give much advice about removing the quill but I had the same problem on a brand new larger drilling machine, there was about 1/4" play in the quill caused by the pinion gear being too far away from the rack, as you say it is really annoying!
I remember I had to take out the return spring and remove the pinion or else the quill will not move down as the rack gearing finishes at the top of the quill.
I thought of stuffing some thin shim material in between the rack & pinion as a quick fix, but I doubt it would have kept in place very long, I also considered making a larger pinion gear to solve the problem but to get an accurate measurement to make a new pinion and actually making it seemed a difficult proposition.
I took it all apart and machined the drill head casting making the pinion shaft bearing hole larger in order to fit an eccentric bush which I then set over to cause the pinion shaft to move closer to the rack and fitted a screw to lock in position. I used a flycutter to machine the larger hole.
The result is that the quill moves with no slack at all and gives the drill a much more sensitive feel about it.
Hope that hasn't put you off having a go, I found the machining of the cast iron was quite easy, cast iron is ok as long as you don't have to go through the tough outer cast layer... hope you do ok with it.
|Thread: My digital calipersseems to give varying readings|
Are these the normal cheap Chinese calipers? ..if you are about to bin the calipers anyway, why not have a go at fixing them..?
If you peel the backing label off carefully you will see some small screws, undo these and remove the metal backplate, you will see a bronze coloured bar ... note how it fits in place and take it out, if there is any dirt on this bar it will give erratic readings, clean with white spirit and clean the metal surround and the backplate..clean also the steel ruler and put back together, I have had success doing this many times.
|Thread: What Did You Do Today 2019|
Blimey... ! that Oroville dam problem makes our situation at Whalley look like a leak in a bathtub..!
Thoughts are with those people of Whalley.
Yes I live in Poynton some 12? miles or so down from Whalley Bridge and there is a small stream at the top of my road which has overflowed its banks washed a stone bridge away completely, the fields have flooded and factories on a nearby industrial estate have been inundated with water.
As I understand it .. if the dam at Whalley gives way the water will inundate the town centre and follow the path of the canal probably taking all the boats with it.!
There has been a concerted effort by greedy developers who have no connection with the Poynton area to put hundreds of houses on what is basically an area of natural beauty, perhaps they might be put off when it is realized that the fields are in fact flood plains.
Lets hope the RAF at Whalley can save the day again.!
Andrew I hope you will reconsider, I can only class myself as an amateur/hobbyist and rely on experienced people as yourself to let us know how a professional tackles some of the problems.... as stated previously I find your input quite interesting and well presented... Its sometimes the case that people say things they don't really mean.
Anyway....best rgds for the future....Bob.
|Thread: What do you use your lathe for?|
I can now grind the edges of milling cutters on my Arduino controlled lathe...the ones I have ground have a pitch of 80mm. Bob.
|Thread: Sharpening Milling cutters|
I wrote an article for MEW in November 2015, No 235. The design uses 2 Arduino's which were coupled together so as to provide synchronism in providing pulses for the stepper motors, however it is not necessary to electrically couple them and I am assured that if the Arduino's have proper Xtal signal sources you can use them as they are.
The program could not be simpler for the Ard's ... it uses the Blink program and the article describes how to find the correct pulse times, there is also a circuit and explanations, someone with a small knowledge of Arduino programs could easily set it up. I can give you the progs no problems.
There is a Spindle speed program which just runs the Blink sketch continuously and there is a Leadscrew motor program which has an interrupt control to start the Leadscrew motor at a specific point in the spindle rotation.
I have used this lathe many times for making screw threads of various pitches, some quite peculiar for telescope eyepieces and suchlike, but the beauty of the system is that you can adjust the parameters for virtually any pitch you want, the only drawback is that my spindle motor is not as powerful as I would like, you could even vary the pitch within a pitch ... there is absolute full control over this.
The system however does not have any feedback and relies on the start pulse to set it running, if there is too much load for the motors there will be problems so light cuts are needed, in the case of a grinder for milling cutters there would be no problem.
Bob.. -.- -.- -.-
Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!
You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.
Click THIS LINK for full contact details.
For subscription issues please see THIS LINK.