Member postings for Bob Jepp

MichaelG,

Had a Google at LiPoly batteries and it would appear that a 6s battery, as specified as maximum in the ad, gives 22.2 volts - therefore we are expecting 1600 rpm/v x 22.2v = 35,520 rpm. Sorry, but that still sounds impractical when compared to an industrial 24,000 rpm spindle.

Putting the motor design to one side, the practicality of running a 9:1 worm at 35,500 rpm also sound impossible - maybe an epicyclic gear could cope, but I would expect that cooling and lubricating will be an issue here also.

Motors in CNC machine spindles are usually direct drive, axis drives are usually via ball-screws giving a reduction ratio of the pitch / circumference of the ball pcd and robots tend to use Harmonic gearboxes, Cyclo-drives or RV reducers all of which are driven with servo motors running at max 4000 rpm.

I've read the ad several times and so far, I can't see the RPM quoted. Working backwards 4000 rpm spindle through a 9:1 worm would require 4000 x 9 = 36,000 rpm at the motor spindle - I can't see that happening, industrial routers running at 24,000 rpm have bearing issues and they are totally enclosed, built in semi-clean room conditions.

Have a look on Arc Euro Trade\s web site at the high speed spindles to see the difference. I've also looked at Zapp Automation for ideas.

Funnily enough, I've not had any trouble parting off ( that's it - I've done it now - next time will be a wrecked parting tool ! ). I use a couple of Glanze 2mm wide throw away tip parting tools - for small diameter stuff, the tool-holder with a maximum capacity of about 25mm diameter and larger, one of the blade type.

I reduce my RPM, then plough straight in and it all seems to work out. With steel or stainless, a few drops of thin oil every few seconds, aluminium a squirt of WD40 and, brass and plastics dry.

I think that confidence has a lot to do with it - we were taught in the training school to 'get stuck in'. I remember parting off rectangular section bar about 50mm x 25mm for some EITB ( Engineering Industry Training Board ) exercise or other ( now I'm going to have to go and look in my apprenticeship made toolbox to find out what we used that rectangular bar for .

When I was in the apprentice training school in 1974, the machines were much larger than those in the usual home workshop. The standard issue knurling tool was the rotating disc with three sets of knurls, just pushed into the job with the cross-slide.

Although I have a reasonable size lathe - a Warco VS1224 12" swing - I went for the clamping type knurling tool as I thought it should be best since, as we all agree, the forces are contained within the tool rather than being transferred to the machine.

When knurling, I firstly set the clamping screw to make the knurls touch the diameter and for them to start rotating without making much of a mark. I withdrew the cross-slide and added a bit more to the clamp screw then fed in the cross-slid again taking the knurls just over centre.

As I said, the first knurl I did was really good, but adopting the same process on the second part left me with a knurl with the peaks broken away and the knurls covered with the remnants.

I took in posters suggestions on knurling speed, maybe I was over-egging it bit at 150 rpm. Maybe too much depth of knurl, maybe feeding in the cross-slide does something to the geometry of the knurl and causes it to break up, or, maybe a combination of all those things ?

I have a much smaller Soba knurling tool as well - I'll try that when I get in the workshop again - it's much more rigid side-to-side than the one I used this time. There must be some logic somewhere in getting a good knurl !

I've just come in from the workshop where I tried making a couple of small thumbscrews in brass - 9mm od.

I turned the outside diameter and applied the medium diamond knurl using a proprietary clamp type knurling tool. The first thumbscrew knurl was pretty good, so I finished the screw and parted off.

When applying the knurl to the second screw ( making sure that the diameters were the same within 0.01mm, without altering the setting of the knurling tool and using the same speed of 150 rpm ), the knurl as terrible. I did clean the knurling wheels between screws but I didn't use any lubricant either time - maybe I should have ?

I notice that the knurling wheels don't line up - the top arm as skewed relative to the bottom arm by about 1/2 a knurling wheels width and the fit between the pivots and the arms seem very loose.

Any thoughts ?

Bob

Having completed a small extension to the workshop ( amazing how much extra space you get from an 8 foot long extension on a garage ), there is now enough space to swing the proverbial cat !

Well, a few gallons of water have gone under the bridge - I've managed to get most of the frames completed, together with the stays, axle boxes, pilot beam etc. and some of the bits for the leading and trailing trucks.

Back to the 3D CAD again and trying to sort out how the cylinders are attached. I've found that there is some steering contained in the construction series - it says that the horizontal centreline of the cylinder bore should pass through the wheel centres ( when axle-boxes are in mid-travel ), but then there seem to be some more anomalies surrounding the position of the exhaust tapping. Additionally, there seems to be an error of 1/16" in the positioning of the smoke-box saddle so, I've made the assumption that the distance from the leading axle should rule ( haven't checked it all out yet though !).

Anybody else got any more comments please.

I tried to order the cylinder castings and wheels from GLR Kennions Ltd. today, but there seems to be a problem with the coupled wheels part number - I'll send an email and await a reply.

Bob

Regarding the two robots handling batteries, they are in fact Fanuc not ABB robots. Fanuc robots are manufactured in Japan and have a UK sales / integration office in Coventry. Fanuc robots are predominantly yellow - their new slogan " Welcome to the Yellow World ". I was Engineering Manager there before starting my own robot installation business.

The full video can be seen at Fanuc USA Web Site - you need to scroll down the page to " LR Mate 200iD and M-1iA/5L Intelligent High Speed Battery Grouping " in the video section ( hope the link works ).

The explanation of the operation of the robots is spot on - the upside down spider looking robot being the M-1iA/5l and the human arm shaped robot being the LR Mate 200iD.

There are some fascinating videos on the website including some of a robot handling a railway wheel set. Robots are always attention grabbers - I've been fascinated by them and working with them for the last 41 years !

Over the last few months, Neill ( the local builder ) has been extending the double garage - extra workshop space for me and an executive potting shed for the 'dragon'. I spent the couple of weeks before Christmas finishing off the potting shed and then took out all the gardening gear so the house was habitable for Christmas guests.

After Christmas, I managed to fill and paint one wall, put up the cupboards in their new positions and, with the help of the youngest son Tom, moved the lathe to its new position ( he couldn't understand how it cold be done without a keyboard and mouse ! ).

So now its down to me to fill and sand the remaining plasterboard joints in the additional space in the workshop - I look like a snowman after a couple of hours with the orbital sander and the workshop looks like the USA.

Off to have a shower now - hope I don't block up the plumbing with filer dust !

I've used a few of these for work - they need a supply such as laptop power brick, but they give a good switched regulated supply.

Bob

That's fantastic - thanks Ed.

I've filed that info away until after holiday time - going to the USA and doing the 'touristy' thing as well as visiting the Nevada Northern Railway Museum in Ely and the 1880 Train from Keystone South Dakota ( near Mount Rushmore ).

Bob

Ed /

Your lever operated holder on the QCTP looks good - I can imagine using it for cutting keyways in bores - any change of a write-up ?

I design and install industrial robot systems and have done so since the fourth year of my apprenticeship ( 40 years ago ). I don't have a qualification which allows me to perform domestic electrical installations.

Some of the installations carried out by "professional" electricians leave a lot to be desired - I've had electric shocks from some of them !

I guess that we should understand that the requirement of Part P is to bring all new installations up to a level playing field. This attempts to ensure that electrical installations are carried out to an acceptable standard by competent electricians ( it also attempts to ensure that sufficient tests are carried out to weed out those electricians who are less competent or who cut corners ).

As is normal with all types of legislation, there are always numerous ways to interpret the script ( heaven knows, I have battled with Health and Safety legislation for 40 years ! ) - this means that there is always a mass of points of conjecture.

Where - oh - where does one go to get a definitive answer to ones questions - there are far too many experts around, and they never agree !

Just to throw in my three penneth - during my apprenticeship at Colchester, I spent many hours ( happy ? ) scraping in large Colchester lathes.

The specification for the alignments of the machine were very precise for a relatively low cost industrial machine.

From memory ( 30 years ago ! ), the headstock alignments were specified by clocking a nose bar over the top for horizontal and on the front for skew ( headstock should point up towards the tailstock to allow for the weight of the chuck etc. ). There were many other checks carried out on the spindle to ensure concentricity etc.

The saddle was scraped to turn concave by a few tenths of a thou' and the cross-slide movement checked for straightness on a 'T' bar in the spindle socket.

The tailstock was scraped to get the barrel horizontal and straight with a check made with a precision bar between centres to ensure the tailstock and headstock were level with each other.

After the machines were completed ( before painting ), a turning test was done, skimming the OD of the test piece. This piece was then checked for roundness using a Taylor Hobson Talyrond - maximum allowable out of round was one tenth of a thou'. A circular graph was produced ( rather like a truck tachometer disc ) and was included with the machine accuracy chart.

So, final comments, I started a thread early last year about the quality and accuracy of the Axminster Sieg C0 - the one I bought was unbelievably poor. Axminster were very good and I got my money back without any arguing. I phones Cowells and talked to Colin Childs - we discussed their accuracy policy ( just what the doctor ordered ) and, suffice to say, I am now the proud owner of a sparkling 90ME ( has 'some' swarf on it now ) - fantastic machine !

Good to see that there is still some interest in Josie.

I have spent some time working on a 3D model of Josie ( just because you can, and its warmer indoors during the winter ). I have discovered that there is an awful lot of information missing ( as we used to say - Left To Toolmakers Discretion ! ).

I've had some problems understanding the geometry of the Pilot Beam - there seems to be some contradictory dimensions relating to the overall height of the front of the beam, the hole positions for the cowcatcher and the round top slots which don't appear to work out as they are shown on the original drawings - any ideas as to what is right or wrong ?

I also have the appropriate ME's but I find the mixture of Josie with the other locomotive etc. quite frustrating - even thought of trimming out those superfluous texts by some means or other.

Made a start on making swarf - the bar frames worked out well from BMS ( took some off both edges of the stock to stop it bending ).

I was lucky to get hold of some castings from GLR before they closed in Daventry, but having made a start on the pilot beam, I realise that there is nowhere near enough spare metal on the casting to allow it to clean up once the bends and twists are removed, so, have now acquired a suitable lump of brass and have to start again. Will be ready to start assembling the frames once I have bottomed out the pilot beam.

Just a little bit confused as to who is posting what !

I was an apprentice at the Colchester Lathe Company about 40 years ago and, if memory serves me correctly, they used UNC threads and apart from the 55 degree Whitworth form against the 60 degree UNC form, I think that the only difference was 1/2", where the thread pitches differ.

Sorry can't be any more help.

Best regards

Bob Jepp

Went to Cowells Small Machine Tools in Colchester to pick up my new ME lathe.

Had a good chat with Colin and set the world to rights.

Can't wait to get home tomorrow to unpack the machine, get set-up and do some turning.

Decided to make a start on Josie - an O Gauge Hudson.

I've spent some time accumulating bits and pieces - castings etcetera - I did mop up the last few castings from G. L. R. before they closed.

So, I am just about to start cutting out the frames from the prescribed 3/4" x 1/8" BMS and I noticed that it is bowed about 1/8" in the middle of the 12" length. Thinking about it, I can't leave it bowed and expect the stays to straighten the frames since there are some quite small sections around the horns.

It then occurs to me that this might not be the right material at all - maybe it would be better to use black MS or even to purchase the laser cut frames from Model Engineers Laser - any suggestions ?

And, how straight can we expect BMS to be ?

I believe that Tellus 37 is the nearest available nowadays.

This afternoon, I popped in to Axminster ( local Nuneaton branch ), had a fiddle with the display machines and discussed my machine with their after-sales specialist. He agreed to swap out the machine, but he will check over their boxed / stock machine first then give me a ring.

No less that I expected really - I'll keep you posted.

Whilst I am quite prepared to admit that all the faults could be rectified for £2786.40, this is irrelevant. The additional 'features' could have quite simply never been included - I never supply equipment to my customers in such a state whatever price the customer pays.

As a teenager, I started building a Tich and proudly presented some parts to a friend of my fathers ( time served toolroom turner ) who immediately commented "take those bloody burrs off"!

So, having been through a 5 year apprenticeship at Colchester Lathes, I have applied the teachings of the instructors ever since, making sure that precision is ensured at each stage of manufacture.