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: Digital caliper remote display|
Ken Weeks said...
" I have a modified digital caliper fitted to my Myford tail stock.
The display on the caliper is difficult to read (eyes are not what they used to be) I would like to attach a remote display nothing fancy just to display the read out figures.
Any Ideas/suggestions? "
I made a simple DRO using an Arduino Nano and LCD display to show X&Y values from digital calipers, there is lots of information on the web available showing the Arduino programs although I couldn't find anything to show how to get 2 displays up at the same time so had to think about that one for a while....
Any reading can be reset to zero with the push buttons...the whole assembly is fitted in a 13Amp outlet socket and a blanking plate is used for the front panel..
|Thread: Can my pillar drill be improved|
On the subject of 'can my pillar drill be improved' , I recently purchased a new pillar drill from a well known Mart which had a well known makers name on it... however I assume it was made in Asia somewhere.
I was expecting it to be of reasonable quality, it was certainly not cheap, my hopes were dashed when after putting it together I noticed that the quill could be shoved up & down some 1/4 of an inch without engaging the pinion rack gear, the control of the quill was not good and became a nuisance.... I complained to the supplier who did offer me some compensation but this was in the form of sending me their sales brochure...!
I was thinking of sending it back but the thought occurred to me that this sort of shoddy quality is what we customers are now obliged to put up with even if I exchanged it for another would it be any better...? I doubt it...
So I bit the bullet and started to think about how I could sort it out myself, I wish I had heard about the article: Re-engineering a low cost Chinese drill press, by Brian Smith as mentioned in an earlier post by OurBallie, it would probably have made it an easier job, but what wrangles me is that a book has to be written in order to put something in order in the first place.... it may be 'cheap Chinese' but in my opinion if it isn't fit for purpose then it shouldn't be for sale..!
Anyway rant over...! I decided to make eccentric bushes to take the pinion axle and therefore the pinion nearer to the rack, it wasn't an easy job, the thing had to be dismantled and two jigs made in order to bore out the pinion axle holes, then the two eccentrics made and some means of fixing them in place when positioned correctly.... the result...fantastic...!
Why is it that for the sake of a simple small change in the design which might incur some slight cost to the product, a profound increase in quality could be gained.....oh ***t ranting again...
better go.... Bob.
|Thread: Appreciation of Contributors|
How much time did Michael G spend in giving information on finding links ? it must amount to 100,s of man hours, much of which has been interesting, useful and for many, including myself encouraging!
Come back Michael.... don't give up....you have many friends in this forum.
|Thread: MEW 246 article 'Model Eng Exhibition at Brooklands'.|
I see what is happening now, nice job Ken..Thanks again, its great to be able to find information like this from
experts as yourself.
In MEW no. 246 page 17 there was an article about exhibits at Brooklands produced by MEW readers, one of which was a nice looking topslide made by Ken Wilson.
I was hoping for some more information about how Ken had managed to fit what is described as a "very compact toothed belt drive" to the leadscrew drive; was there...is there... any more information on how this has been done... I have searched the forum and not found anything, perhaps I am not looking in the right place.
In case Ken is reading this and there has been no previous discussion or article is there any chance of you giving me and others some more information.
Thanks in anticipation... rgds...Bob.
|Thread: Helping dad vertical engine|
Yes the flywheel is thick perspex as are the bearing housings, It was the only material in my junk box and I was concerned it would not be heavy enough but it runs ok and it was an education and a pleasure for me to make this model.
I think a heavier flywheel would be more appropriate ... one tip I can give is... bolt or clamp the engine base to a good solid bench, its probably my workmanship at fault, but when running it resembles a drunken Scotsman dancing over the crossed swords....! (not a derogatory remark to Scotsmen)... I am myself related to Scotland.
|Thread: What Did You Do Today (2017)|
Knocked this together to repair me trains...
|Thread: Helping dad vertical engine|
Yes..... I made one of those just to see if I could make anything that actually worked..!!
|Thread: What Did You Do Today (2017)|
My solution to a problem which has bugged me for some time...perhaps there is a simpler way...
I needed to turn down some threaded rod to fit a handle, the problem is that the dti needs a flat plate fitting to run over the threads so the rod can be centred in the four jaw chuck; a quick job in the lathe to make a flat plate fitting for the dti ... so I thought..!
But there was a problem, the dti has a step at the probe end so I couldn't just make a hole to fit the shank of the dti, after some head scratching I thought of a simple idea, but first see the stepped end of the probe.
I didn't know ... and still don't know, if the probe be unscrewed, but I was worried I might destroy it .. I wasn't going to try and force it.
So.... I rummaged about and came across an 8mm brass plumbing compression fitting... it was actually a coupler....would that be of any use? .... see below.
The picture is of an 8mm end stop which would also be suitable for the job.
I turned down some 8mm brass rod and bored it out to fit the diameter of the dti shank .... the part was then cut in two along its length, next I cut a slit in the olive so that the two parts would fit together in the olive, the cut in the olive made sure that when the accessory was assembled it was not going to be a permanent fixture on the dti..!
Next the end of the fitting is faced off, this forms the flat surface to ride over the threads of the rod.
The end part of the compression fitting with the internal thread is now placed over the shank of the dti and the two brass pieces are put over the dti shank with olive slid over them holding them on the shank.
The flat plate end is now screwed in place.
Below.... the two brass parts fitted in the olive.
The fitting in use.
It does slightly limit the travel of the dti probe but a couple of mm is more than adequate.
Hope it might be of use...Bob.
|Thread: Ignition Coil|
Re:- ignition coil ebay item ............0043
Hi Neil... looks like an inductive relaxation oscillator to me.
|Thread: Local mirror silvering services ?|
I have used the same company as John Carruthers mentioned, VCSM in London, they cleaned and re-silvered two 6" mirrors for my binocular scope and for £10 carried out some optical testing.... Focault test..Knife shift..Focal length..Parabolic figures.. Surface irregularities...Astigmatism pinhole test... Cost in Dec 2015 was £104 for the pair...nb I have no connection with this company.
|Thread: Lathe use|
Thanks Clogs../ Ian..
Yes I do worry if there ever was an earthquake all my potted meat jars full of screws/drills/taps etc would be a miasma of glass and metal on the deck... honestly I am running out of room!! they never told me that the metal bashing hobby combines several others at the same time all requiring in-depth knowledge whilst you have to have pockets with a good depth as well..!
Hi John ...
thanks for your appreciation.., yes you are correct, the handle is a Singer balance wheel .. I make use of these as they give good control and feel just right... I used them on my Atlas lathe and Dore Westbury miller... see pics
I too had an old Atlas lathe which was in a poor condition and I thought it would be a shame to scrap it, I used some of the parts to re-furbish my own Atlas lathe and decided to make a grinder out of what was left, somewhat along the lines of the Quorn.... I also had a load of bits I collected over the years the main item of interest was part of a height measuring gauge with a nice spiral groove very similar to the Quorn pillar....It had to done!
I cut the lathe bed in half.. which is a considerably sized lump and does need all the safety gear for cutting with an angle grinder as the wheel can easily get stuck and give a nasty kick back, I can't say it is aesthetically pleasing to look at as a Quorn and I am in the process of finding a better motor and drive belt, this I must add is still in an 'experimental' stage and I also need to make a wheel guard as yet ... however trial runs with a much underpowered motor have given good results with mills and drill sharpening, some of the jigs I use are shown on the baseboard...nb... the handle for the cross slide is what you think it is but I had a job explaining why there was a pair of mole grips on the bog handle..!
Anyway a picture explains more than words..
|Thread: Singer sewing machine motor.|
Another 'for what its worth'...
I used a singer sewing machine motor to power a small filing machine I made using a 2 stroke crankcase ... it has enough power to file an 1/2" piece of mild steel but I wouldn't like to try it on anything thicker, after saying that, the poor thing has to move a piston up and down and blow out any air in the cylinder as well..!
|Thread: What Did You Do Today (2017)|
I had a go at making the Universal Screw Mod Fixture in latest issue of MEW 251.
This is my rendition of John Ashtons design which I desperately needed for reducing diameters & lengths of small screws for an 00 gauge rolling road I am about to make. ... Thanks John for your article; not only is the fixture usefull for small screw holding but I found that it helps when holding bushes which need to be cut to precise lengths.. I hope John doesn't mind my alterations .. I didn't have any hex bar so I just used some round stock and put a knurl on it..
see photo's of screw fitted ready for trimming to size and how I use it to hold a nylon bush also for trimming to size.
|Thread: Astronomical Binoculars.|
Michael.... I suppose a portable head mounted version of the scope would be possible... you would have to make sure you didn't whack the missus on the head with it and a strong neck would be advisable.
John... Mirrors can certainly be made, but they need to have very similar focal lengths or you would have 2 images with different magnifications...and probably a headache to go with it...! The FL's have to be longer than the normal for a Newtonian as the optical path is longer...the FL for the binocs is 43inches.
JA.. I too suffer from a similar problem... I take my time is deciding what project to take on and have a good think about it before committing myself to something far too difficult ... its a bit like deciding to get married..
All..... I have microscope eyepieces as they are purchased in pairs which are x5, x10 & x20 ... although I haven't determined what the FL's of these are perhaps someone might know... the x20's seem to give a magnification of around 100.
Due to the differing eyepiece body diameters I have had to make sleeves for them to fit the holders, I have made the main holders out of plumbing fittings, however the very fine thread needed to fit the holders I made on my Arduino controlled screwcutting lathe.
The plumbing fittings already have an internal thread which has a tpi suitable for focusing, however, the thread is a bit sloppy and I made some friction compound using around 6 parts Vaseline to one part plumbers jointing compound... it doesn't seem to have dried out over a 4 month period...so far.
There is a problem when trying to find objects in the sky, and some sort of angle gauge is helpful here, I use the Stellarium program to find the Az and Alt coordinates and with the lowest mag eyepiece in one holder and a higher mag eyepiece in the other it makes it a little easier to get an overall view of the area before homing in on the object and replacing the x5 with the paired eyepiece for binocular vision.
By the way... if you are interested, some members of the Bolton Group of Astronomers have made really nice looking versions, albeit open frame aluminium on small stands, try Googling it.
nb...have booked my tickets to the London Model Engineering Exhibition...anyone else going..?
I have posted 2 pics as below.... rgds....Bob.
Various eyepieces and sleeves and threads to go with them.
No...! I haven't got one eyeball 1 inch bigger than the other..! this is to show that you can use the x5 for finding and then whilst it is fixed on the object move it out of the holder and go over to the x10 or x20 eyepiece.
Just in case anyone is thinking of using one of these auto gearbox lifters for mounting a scope.... the rams are not really steady enough for a good telescope and have to be modified; sleeves need to be fitted down the ram/housing interface and these are quite thin... about 1mm thick and wrapped around the ram with a gap of about 3/4inch along the length.... I made mine about 6 inches long out of nylon/delrin.
The bottom ram housing is of course filled with hydraulic fluid and you need to wear gloves for this stuff...
The ram bushings are easy enough to remove but the large nut on the bottom housing requires a large spanner ... I made one... see pic..
Below.. Large home made spanner..
Below... A look down one of the tubes.
Hi JA.....thanks fizzy.
There are a number of benefits from having a binocular telescope as opposed to a single reflector, the main one being that we are naturally accustomed to using both eyes and it makes observation easier than having to close one eye... in effect I would say it is more comfortable, just try using one eye to read this ... it's not as good is it..?
I find I can see more detail, whether this is because it is more comfortable is debatable or whether it is because of a stereoscopic effect I don't know, there also seems to be an increase in light gathering and the consensus of opinion seems to be that this 2x6inch binocular scope has a similar aperture to an 8inch single reflector.
Other binocular fans have stated that there is an increase in field of view, I don't know how true this is but I must say that those who have a scope of this type are certainly impressed with them.
There are binoscope eyepieces that split the image of a single scope so that there is a way to use both eyes, however I understand that there is a significant loss of light using one of these devices and they ain't cheap!
All in all I would say that for planetary observation and especially lunar observation the binoculars do have an advantage, it seems as if you are actually hovering over the surface ... but whether all the work in manufacturing the thing is worth it is justified.... probably not.... in my case I was given the parts to put together, I would certainly not have entertained making all the optics as well.
There is a problem in that pointing the thing without any instrumentation does pose a problem, and when the desired object is found I find that a slow motion drive is a help, however this must be on a slipping clutch so that the body of the thing can be grabbed at will and manually positioned; I made a simple clutch using magnets.. on the Altitude bearing ....see pic below
Interpupil distance adjuster.
Right hand collimation adjuster... adjustment can be made whilst observing.
Below.. mirror cells showing collimation adjuster gearing.. also shows how the auto gearbox lifter rams are used for Azimuth bearings...very smooth as well.
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.