Member postings for MadMike

Jamie, all first class advice above. Where are you located? There is probably somebody close by who could come and help you with this. HTH.

Bob if this dynamo is for a motor vehicle then try contacting Pete at www.dynamoregulatorconversions.com

Hope this helps.

By dividing the air supply between 2 cylinders you have halved the potential volume to each, and you have also reduced the pressure to each. Thus it will not run correctly. Power is a function of work done (force x distance moved) divided by time taken.. As you can see you have reduced the force, and so reduced the distance it travels and also as a result increased the time element. So your engine will in fact produce greatly reduced power output. Simples. May the "force" be with you.

Chris initially it looks like a slight change in surface finish due to tool wear or a piece of aluminium welding itself to the tip.

Alternatively, depending upon your source of the aluminium bar, it may be the result of a weld during the extrusion process. As aluminium is extruded and they get to the end of eack billet in the press the process stops momentarily. The extrusion ram withdraws for a few seconds and a new billet is placed behind the last one. The process resumes and the presuure and heat causes the 2 billets to butt weld together. This will show as a sometimes visible weld mark around the circumference of the finished product.

Now normally comes the clever bit. As the length of each billet is accurately calculated before it is cut/sheared to length, this is designed to ensure that the press "knows" exactly where the weld will occur and when to add another billet. The extrusions are cut into 6.0 or 6.1 metre, or other custom lengths, on the press and when the weld approaches the saw the press adjusts the bar position to cut a piece containing the weld out of the process. This piece is scrapped. The good stock then goes into the ageing ovens.

However some low end extruders do not cut the weld out so it can appear at random in a stock length. Often it is not visible because no oxidation has occured at that stage to the outer surface. The scrap is sold commercially and some scrappies sell noggin ends of stock bar to the trade. It is often this that places welded noggins in the hands of small end users.

Sorry if that was a bit nerdish. HTH.

I had a Myford ML7 and do not recall any scraper marks on the bed. I now have a Myford 254S which was one of the very last Myford Refurbished lathes that they ever sold before closing. There are no scraper marks on the bed.

Featherbed frames? There are 2 bikes in my garage with Featherbed frames. One has a Wideline Featherbed and the other a Slimline. Wonderful to ride even today.

"Don't get hung up on number of flutes"????

That's not strictly true when using end mills or other multi tooth cutters. The feed in feet/inches/metres etc per minute equals the feed per tooth per revolution multiplied by the number of teeth. So the speed of spindle needs to be such that you can achieve the feed rate which is both safe and efficient.

Steve 40 fpm for cast iron, and 70fpm for mild steel is very low even for HSS tooling. For example cast iron should be roughed at around 170fpm and finished at around 250fpm. Mild steel at 100 and 150fpm respectively.

Carbide tipped tooling substantially increases all of the above such as 200 to 350 surface feet per minute.

Of course all of the above assumes machinery in good condition, tools ground correctly, machinery with sufficient rigidity to allow the speeds refered to.

Sherwood Tools are certainly based in Wigston in Leicester. Both Sherwood and Cromwell are based at 65, Chartwell Drive, Wigston. So I susupect that Sherwood is a trading name for Cromwell. Are the drills actually manufactured in Leicester? Who knows? I suspect they may import the blanks and perhaps finish them here at best.

A chain always was and remains 22 yards. The perpetrators of the Napoleonic measurement system can call 20 metres anything they like, BUT it is still only a mere 20 metres. Anyway a chain must remain at 22 yards in perpetuity, otherwise how will they know how long to make a standard imperial 22 yard cricket pitch?

So many points of view and a lot of truth but some missing fundamentals.

T nuts are OK provided that you do not allow the stud or bolt to bottom out in the slot. Should this happen and you create a "screw jack" then if the nut or bolt is continued to be torqued up then yes you can easily break the slot away on the table as the force is applied to the under surface only....particularly on a Mini-mill. If you use T nuts then throw away the Gorilla in your arms. So if you use T nuts ensure that the stud/bolt dies not penetrate and come into contact with the bed.

T bolts do not act in the same way. They will only tighten when the nut and any clamping piece are in full contact at the end of the tightening process. Here is where the change occurs. You now are exerting equal compressive forces on opposing surfaces on the table slot. Under these conditions the forces cancel each other, and thus much more force can be applied with impunity before you crush the cast iron

So as always proceed with care and remember not to apply jacking forces to the underside of the T slot. Simples as the Meerkats say.

.

Firstly some body filler to fill the flaking, as it always looked to me as though Myford did that anyway to fill any discrepancies in the castings and then paint it, say MyfordGrey. For the paint itsel have you considered simply contacting Myford? Now owned by RDG at www.myford.co.uk or RDG themselves on www.rdgtools.co.uk HTH.

It's not often that I write on here, but I do read this message board avidly. There is clearly a lot of knowledge here gained through real work experience and training, or through simply reading, asking and practising at home. This wealth of knowledge is shared freely and that is a credit to everybody.

Now the next bit is a bit critical, but please do not become offended. I have read through the flatness/concavity debate as it has developed, and it is not the first time it has been discussed, and I have to say that I have never seen so much written, about so little, by so many, so often. Concavity when facing is not a natural or designed in feature of a lathe. Indeed the machine is designed to produce a flat face. There may be tolerance limitaions caused by a number of factors including machine design, machine manufacturing quality and of coorse machine wear. Machine wear is inevitable particularly on the cross slide and the bed near to the spindle. How many of you actually know what flatness tolerance your machine is designed to produce I wonder? Remember, even if you do know it, that it is only truly applicable at the time the machine is new. Are there many old, worn machines among the gathered throng? There certainly are. I also agree with Phil Whitely in his re-defining of OCD.

Sorry to ramble on but, whilst all of this effort goes into debating the realities and perhaps the philosophical views on concavity, you are missing out on real machining time.

Remember this is not written to offend anybody. Rambling rant over.

Similarly you must be aware of the flatness tolerance called for in your component design, and as Michael has pointed out above surface finish is a key component of component/surface matching.

Hi D s. I have a Myford 254 S. It is a great machine. It may have some limitations but frankly there isn't a lathe made with no limitations. Mine has the Camlock chuck. If you are anywhere near Leicestershire you are welcome to come and try it out. HTH.

Chris when you measured the "chuck runout" what exactly did you measure? If it was a bar inserted in the chuck, was it just as you tightened it, or did you take a cut first along the bar?

If as you say nothing had changed on the lathe/chuck since last time you used it, then frankly nothing will have changed with the run out. The lathe and chuck are after all simply inanimate objects.

When you say " the far end of the chuck is 0.06 out" are you clocking the chuck body itself?

No self centring chuck will hold a work piece that runs true initially. All that matters is whether it cuts round and parallel. Only measuring a work piece agter turning is relevant. Like Dusty says remember to that the total amount shown has to be halved to identify if you are cutting accurately. HTH.

Errrrr. Flat on the table. Clamp the long thin face. Clamp the machine finish centre section and off you go, just mill the black areas down. You could mill one end at a time and clamp the other end for more rigidity. Other solutions are no doubt available.

Nick, I am in Leicestershire, near J21 of the M1. If you want to come and dabble with some metal cutting just let me know. HTH.

Ooooooops. Man fingers.......I meant to type "....I bought a set of ER32 and some MT2 collets.............it was ArcEuroTrade".

Like Ketan says sweeping statements almost incriminate everybody, thus my request to Jonathan to confirm his actions and to name the supplier.

Jonathan I don't know which of the usual suspec ts you purchased from, however if they are "junk" as you say then presumably you have complained and got a refund. Out of interest who did you get them from and what exactly was wrong with them?

In my case I bought a set of ER32 collets with MT2 from "one of the usual suspects". In my case it was Arc EuroTrade. They are absolutely spot on and this becomes even more evident when I randomly turn a test piece. The ArcEuroTrade collets have spot on repeatability. I have no connection with Arc Euro except as a very happy repeat customer.

Colin have you spoken to Hardinge in Leicester? Tel: 0116 201 3000.

They are Bridgeport manufacturers/suppliers including spares as I understand. HTH.

As a person who mostly reads the messages on this site I have always been impressed by the ability of model engineers to make model steam engines etc. I do not make models but use my machines to make full size parts for my classic bikes and those of friends. Bearing this in mind I have read this thread with some interest and a great deal of surprise. Without wishing to piss on anybodys parade, and also asking you not to be ofeended.......i have to say that i find it incredible that reg asked somebody to make this item in the way it appears to have ben done. That is a verbal description using terms like parallel holes and maybe not even recognising that a hole created the way is has will only be round when viewed on axis.

I served my apprenticeship as a tool maker, and I well remember the first day when the Toolroom Manager told us nice wet behind the ears newbies "Remember this and it will serve you well all of your toolmaking life. Always, but always have a drawing with dimensions and tolerances before you cut any metal." As a result even today I keep a book on my workbench, and everything i make is drawn and dimensioned before I start work, regardless of whethet it is a simple wheel spacer or a reworked cylinder head.

I was most concerneed when reg offered to prepare a drawing so that we could understand what he meant. It begs the question how did you transmit the information to your original supplier? They refunded your money and offered to remanufacture, after you obviously explained the problems and you refused. Why on earth didn't you simply prpare a drawing and then let them remake?