Member postings for jason udall

Andrew.. sorry thought it was attachment to lathe..

Futher reading of the suggested link gives a more balanced concept of the "horrors" of grinding on a lathe..

if it was not for the abrasive problem using a toolpost ( live tooling) grinder might be useful to me ..cutter /work holding check / .indexing on lathe spindle check.. / feed and angle advance check ./

. just to me seemed half way at least to a T & C grinder...

Now what about bonded diamond as apposed to grinding wheels ?..

regards

Thought just struck me.

How do you keep the grinding effluvia away from the lathe bed etc..with the almost tabbo of grinders vs machine tools ( NOT EVEN IN SAME ROOM !)..

Seriously, the two don't mix well. so whats the solution ( tool post grinder seems good alternative to T&C machine ..) Good extraction? way covers?..

TIA

Maybe develop relationship with local engineering firms..Get it before it hits the skip?

Small firms are best since you can find someone to ask, who might be able to say yes..

Also lots of gear gets heaved to.

What you offer in exchange is up to you.. Jig /tool making etc. biscuit funds etc.

At very least they sometimes can source material too.

Obviously they are busy ( we hope) but patience always helps.

Further cautions.

dust extraction....needs EXCELLENT filtration before passing through motor comutator...( ask me how I know )...also though ('cos it conducts) not as bas a explosive haZad as say sawdust or coal or flour ..if using vaccum or air line ....BANG! ( think lots of surface area lots of air....)..

oilly "rag" seams best way to wipe up...also recomend barrier cream ....

in short nice to machine ( apart from work holding)... horror to clean up!

Nice to note Harold 's comments here.. in another thread the response of a designer( to queries over drawings published / commercialy) is less err..helpfull. although to be fare his comments are only reported not directly made in fora

I would like to take this opportunity to commend HH for his "contribution to the art."

Edited By jason udall on 11/09/2012 12:12:29

 Michael,..Quite and i doubt that anyone need proof testing of steam boilers anywhere near that.

but care needs taking.. not just with item under test..hydralics is "safer" for the reasons already mentioned..but can still bite.

P.S. I do prefer to be called Michael, not Mike.

.. so slight implied

back to the OP..relief valve...MMM stop pumping?

Edited By jason udall on 11/09/2012 12:03:40

Indeed Kwil.. inductance and back emf and various others.. but the OP started simply and a rule of thumb type approach appeared usefull.

A motor is not even a pure inductor , motors are more complex and theres phase angle to include in the V.I product.( vector vs scalar arithmatic ) I know or at least have forgotten much of my AC theory.

But ..but the OP has made some sensible tests.. might suggest test motor off load measure I and work from there...

Mike G.. ever seen 3000 psi pin hole leak?

true with hand pump its up to you when to quit pumping but even hydralic leaks can be deadly

you have measured the "DC" resistance of the COLD windings..

I say cold since that value varies with temperature and rises as the motor heats up.

Simpler way to power( watts or horse) would be ( 230*230/R) ( just algerbra)

1) your calculated current would be closer to the stall current (0 rpm) of the motor ( again cold but would drop as the windings heat up ..eeek!)

2 FLA is a term oftern used with motors ( full load amps ) this figure would be closer for that calculation of horse power..( and is rule of thumb about 1/10 of stall current)

3 You say delta...so lets assume three phase ... thus each "phase " is doing the (230 *230)/R thing so hp would be triple what you calculate... ( but see 1 and 2)

so my guess would be (3*230*230/12.3 )/10(ish !) =1290 W or1.7 hp

stall/fla guess --------kW------ hp

5------------------------- 2.5 ------3.4

8 ------------------------ 1.6------ 2.2

10 ---------------------- 1.3 ----- 1.7

12 ---------------------- 1.0 ----- 1.4

hope this helps and not just fogs the matter

Indeed edited by Jason..to fix the formating decisions made for me by this PXXXXY editor 

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Edited By jason udall on 11/09/2012 09:34:20

Sorry forgot to mention that EN also refers to European Normative....Have also received DIN EN1A as spec. on a drawing(same customer !) to which we also got same reply.." ....no mill cert. must be exactly as on drawing...."...you couldn't make it up.... Just trying to point out automotive industry drawing offices also "unclear" on standards....

Way back in '99 we had to make declaration for every part,,"the parts supplied will continue to process time and date correctly before ,during & after midnight 31 Dec. 1999/1 Jan 2000.." pretty sure that the turned parts would CONTINUE to do so at least as well as they did before... again same firm.

And as to "when will your components be leadfree?"..deserved one answer.."when the drawing no longer specifies leaded alloys(LB4 AND ENIA Pb in that case"..

....btw unleaded alloys still may have enough lead to be "leadbearing" for COSHH...

just found this thought the fora might be intrested...

"

I got to handle a 2012 Olympic Torch yesterday, and it is a really nicely made bit of kit.

Even up close all the joints are neat.

I particularly like it that the burner is made by Bullfinch (see a photo there), a company I have a soft spot for - for no better reason that years ago I needed a propane burner, wanted to buy British, and found one from Birmingham-based Bullfinch......."

**LINK**

Just a thought ...

Model engineers are not alone in "having trouble" with "new" EN specs Eg EN 230M07

At work we are increasingly seeing drawings with EN numbers ( not to be confused with EN1A)

so faro good..now customer wants this spec and this spec only needs mill cert. for metal

BUT has to say (for exmple) EN 230M07 . A mill cert. declaring EN1A will not do.

No the mill can't put both on cert. or supply cert saying (for exmple) EN 230M07..

nor can any other mill...."funny" says customer.."had all our suppliers saying them same thing..."

Used En1a as example but real nightmare in bronzes even when the specifed bronze has wider spec. than an available alloy...

So you are not alone ,at least many tables of equivalents are available online to model engineers and sec.s are "converted" easily...shame customers can't read for themselves

"with a long length of ducting(leaky) to the organ at the front of the Church"...

might not been better to replace DUCTING?.. odds is the fan etc was probalby mounter remotely for a reason...

BTW Ian , one of the successful (commercially) uses for stirling engins (C19) was to drive church organ pumps...quiet and easier to "use" than steam .... at least until electric motors...

3 .. used for round endworking tools.. ( norrmally) two piviots allow adjustment of center height..( boring bars)..

still used in production to this day.

4 again drill / reamer..holder ..... hex bit is adaptor bush to fill in gap from ( looks like 1/4" to the holder size.

"There is a posting from Jason Udall that seems to confirm that my ideas for the operation of the digital slow feed can be acheived, but again no hard details."

Ok My thoughts.

With a suffienctly powerful stepper motor coupled to the ( extended towards the headstock) leadscrew no gear train would be needed and no clutch required since steppers are relativly free moving .

A gear train would allow smaller stepper but more complex coupling arrangement.

An encoder wheel of some type attached to the spindle, maybe even using an existing gear wheel ( pardon my ignorance of the EW ), would provide pulses syncronised with the spindle..

( simplest.. "index wheel I holes per rev..)

these pulses ( produced by either OPTO interuptor or inductive pick up of say gearwheel)

are feed to stepper interface "board"..one pulse (from spindle encoder ) steps lead screw one step ( depending on gearing of stepper/leadscrew) wich coresponds to a fixed movement of leadscrew..( N steps per rev of stepper G reves of stepper to lead screw S inches/mm per rev of leadscrew..thus N*G*S per inch etc.)

Thus leadscrew advances for one rev. spindle I /(N*G*S) inches etc. thus I needs to be large and G not excessive if resonsonble feeds are to be achived.

so far so good.

Varible feed.to produce varible feed you need to " divide" down the pulses so D pulses now produce 1 step of leadscrew (your Knob might be really a multipostion switch)

Varible values of D can be done "on the fly" , in my guess for low volumes( number of units) best handled with A MICROCONTROLLER....

which would also handle foward neutyral reverse from a (as simple as desired) switch(1-0-1) or even pushbutton select.. style at users choice..

once the above is done you can clearly see screwcutting is possible..(to a finite accuracy)..think of metric and imperial encoder "disks" and away you go...

These are all thoughts cosidered for my own SL lathe even more petite .but simple mechanical ( pullies and belts) soulutions would have seemed too bulky..

No I haven't got anyway to wards this myself but the method outlined above is the route I would take when I do. ..

BTW yes "wiper motors" can be reversed but the would need the field coil windings lead out first.(did it with startermotors once)

unless you have a PM type.

Alan.

I do not know (beyond your postings) either you or michael

I also do not know The EW.

Or the problem/challenge being discussed..

Thus I cannot suggest other than in general terms anything.

1. the stepper motor solution for a screw cutting gear train ..might be simple enough to have merit (works for cnc)..

2. as to powerfeed ..."simiple knob for speed switch for direction"...certainly do able...

Much the same hardware for both..

things to note..ungeared stepper motors when unpowered have little or no resistance to movement..so could quite happilly remain coupled when using lead screw in "manual"...

a pickup off the spindle giving a suitable number of pulses could drive the stepper drive board..( and with dividers in the path provide for the "change" wheel function and yes "on the fly" whilst in motion)

In anycase whether a purely mechanical or electro mechanical solution is "BEST" would depend on individual taste...

C2H5OK

SPELLCHECKER?..All I get under Opera is.."......Not supported" or some such.. That I can live with

Just a thought.

Would you consider using a supplier if they had sign written thier name across the side of your car.

The advert thing is no more than a minor pain( three diff. browswers / OS and "pc"'s)...BUT it is still not showing the advertisers PAID impression in a good light.

Maybe the editor could use this tack...to get some action.. maybe..

btw is it some sort of wrap thingy? ie if the s/w tries to insert too wide a field in the post section ?

Might start new thread/threads looking for ways to trigger effect...