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John Stevenson
12-16-2008, 07:30 PM
http://i187.photobucket.com/albums/x175/Ken_Shea/MePro.jpg

Ken Shea posted this program in the threading video post.
Looked interesting but I found that the demo version didn't work with the lathe infeed distance when using BSF and BSW

So I decided to do my own spreadsheet which i have been doing tonight.
Decided to cheat and take the figures from this program before it timed out and found some queries.

I posted before about the 27 thread being deeper but look at the pic above.
This is for 3/8" x 16 UNC now from various books including screw threads of the worldd and MH, the depth of this thread is 0.0406"

[ Nowhere on this chart does it tell you this ]

Now the infeed depth from the table is 0.0389"

?????? how can this be less than the depth?/

The formula is depth x 1.1433 which should be 0.0464

Checked some more figures and they are all wrong as well.

Started posing this and noticed that Kens picture posted at the top shows the infeed of 0.0441 ??

Mine shows 0.0389

http://www.stevenson-engineers.co.uk/files/mepro.jpg

WTF ???

Can anyone see any differences between these pics? All you can do is select the thread and inch or imperial

.

lazlo
12-16-2008, 07:33 PM
John,

Michael Rainey, the author, is a frequent poster on PracticalMachinist. You should post this over there.

I've never tried his software, but his website is here, and his contact information (which I don't want to post) is on the upper right corner:

http://closetolerancesoftware.com

Robert

mochinist
12-16-2008, 07:36 PM
I have that program at work and I dont see any difference. Maybe your demo version is an older one and he updated some values??? He does send out updates a couple times a year, or atleast has since I got a year or two back.

John Stevenson
12-16-2008, 07:43 PM
Right so last year it was 0.389
This year it's 0.0441 so will it show the correct figure of 0.464 next year.

What about leap years.

Lazlo,
I have sent Michael an email, I just wondered if it was me doing something silly.

There are also errors in the UN series compared to the metric series but both use the same formula as they are both 60 degree threads.

mochinist
12-16-2008, 07:58 PM
so is it just the lathe infeed that has the errors?

motorworks
12-16-2008, 08:11 PM
John
I have the older free one, but seldom use it
Made up my own chart years ago.
Made a few copies and stuck then on the wall next to each lathe.
Not hard to do just some grade seven math :)
eddie
ps Perhaps you should write a program

pps about that book I email u on. Do you want it?

Ken_Shea
12-16-2008, 08:17 PM
John, there was a recent update V2.06, click help and about on the demo and see what that it.

It seems to me that something was said regarding thread data output with the last update, but nothing specific or absolute comes to mind.

John Stevenson
12-16-2008, 08:34 PM
Ken, Thanks for replying.
The demo has 2.07 on the top.
Michael has replied by email and he's looking at it as to why the BSF and BSW don't work.

He's also explained the reason for the differences but I'm not 100% certain we are both reading off the same hymn sheet but at least he come back prompt enough.

Eddy,
I'm in the process of doing a spreadsheet at the moment, that's how I spotted the differences.
Thanks for the offer of the book but I'll pass thanks.
I'm in the process of thinning down my collection it's gotten too unmanageable.

I have sold off two collections of Model Engineer from 1940 to present day.

That has freed up some much needed space. I have also sold off my collection of vintage aircraft books that I have collected as to be honest I have never had an interest in them, they just kept appearing in job lots and swaps etc.

Somewhere they are over 500 old motorcycle books, not magazines and to be honest I don't have a clue where they are.
We have been here 22 years and I have never seen them. It's got to silly proportions.
After the sort out of the ME's I found I had 8 foot shelf space just on gear cutting books alone.

oldtiffie
12-16-2008, 09:11 PM
Thanks John.

I was going to address this matter on "the other thread" - but I will do it here.

If you look at the tolerances for the major diameter, pitch diameter, minor/root diameter and "distance over (3?)wires" etc. you will see that there is quite a possible range of "in-feed" variations that are within the tolerance band/s.

The biggest "feed in" to the root diameter is the from the largest major diameter (aka "OD") to the smallest root diameter and the least is between the smallest OD and the largest root diameter.

The "in-feed" at - in this case 29 1/2 degree -which is shown as being to "four decimal places" (eg. 0.0441") is highly problematic as well.

If the in-feed is by the "scratch to set zero on the OD" method is used, I can't see it "all happening" as it seems to presume that the angle (60 degree) and the radius of the end of the screwing tool are extremely accurate. I might assume that the angle is OK but given that many use the same tool with the same radius for all or most screw-threading, it sort of makes the whole process a bit "suspect". Calculating the "slope feed" (at 29.5 degree) is a PITA and prone to error as well.

I cannot see why a short "spigot" about 1/4" to 1/2" long can't be turned on the end of the job (tail-stock end). The diameter can be in two parts - "right on" the root diameter and the other about 0.010" (10 "thou") larger so that I can see where the tool is. The +0.010" diameter will soon let me know when the tool depth is getting "close" as the thread will "show" as a "scratch". After that it can be either a case of "make it fit" a mating or known part and then take note of the "required" diameter as set the top and cross-slide dials to "zero". That way I will know "how far to go to zero" and I don't have to be too fussy about the 29 1/2 degree top-slide setting either.

Some times - but certainly not always - some of these "aids" are more hindrance than help.

An "aid" should be just that. It should not be the end in itself but only a means to an/the end.

mrainey
12-17-2008, 09:11 AM
Good morning, John.

I've updated the program again, by adding "Ref" to the labels for thread height and infeed distance. As oldtiffie explained quite well, there are too many variables in play for height values to be precise. Tolerance on the major and pitch diameters (external), vague published values for minimum minor diameter (external), and variations in tool geometry all have an effect.

I wish you had written me before starting a thread that implied that my program was full of errors, but I guess MEPro came out just a little bit better in the end, hopefully with no damage done.


Mike

motorworks
12-17-2008, 05:10 PM
John
Check your mail
as well if you have an interesting book or two and you want to
send it my way...
I paypal the post :)

Thomas Staubo
12-17-2008, 10:19 PM
Mrainey, the link in your signature is not working properly because it's buggered up. ;)

The link goes to:
http://www.\"http.com//closetolerancesoftware.com\"

To enter correctly, change it to:
http://closetolerancesoftware.com


.

oldtiffie
12-17-2008, 10:19 PM
Good morning, John.

I've updated the program again, by adding "Ref" to the labels for thread height and infeed distance. As oldtiffie explained quite well, there are too many variables in play for height values to be precise. Tolerance on the major and pitch diameters (external), vague published values for minimum minor diameter (external), and variations in tool geometry all have an effect.

I wish you had written me before starting a thread that implied that my program was full of errors, but I guess MEPro came out just a little bit better in the end, hopefully with no damage done.
Mike

Hi Mike.

First - back to the subject:

http://i187.photobucket.com/albums/x175/Ken_Shea/MePro.jpg

First of all, I feel that I should and do offer an apology for seemingly "tearing into" your program. If it happened, and it may well have at least seemed to have happened, I am sorry.

I don't want to "pick a fight" with John S or "all and sundry", but I thought - and still think - that I needed to make what I intended to be "fair comment".

I certainly did not intend to use your software as a stick or a weapon to beat anyone over the head with either.

What really raised my eye-brows was the tolerance ranges for "measurement over (3?) wires" given that in recent threads and posts that some had been quoting dimensions or measurements "over the wires" in the range of "tenths" - +/_ 0.000?" based on tables that come with sets of "3 wires" such as:
http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/3-wire2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/3-wire3.jpg

I would agree that if the form/angle of the threading tool was very accurate as regards angle and symmetry and that the axis of symmetry was accurately normal to the axis of the work-piece/job and the lathe head-stock spindle axis and that a minimal maximum radius at the tool tip were provided, that the "Measurement of (3) wires" at the pitch diameter - or for that matter any points of tangency - on the flanks of the thread that the accuracy of the thread would have been defined.

If that is the case, then any accurate round stock (think - "drill rod" (in the USA) or "Silver Steel" in the UK, Australia and New Zealand) - both/either "inch" and/or "mm" of a standard size that can/will contact both flanks should be likewise able to define the thread.

I accept that varying the depth at which the "wire/s" form a tangent with the flanks will likewise vary the helix angle at the diameter at/on which the tangents lie/occur and that that can have an effect of widening or narrowing the effective "thread angle" at which the wires contact the flanks as the effective helix angle varies from least at the OD and largest at the root diameter and that "mean" or "pitch" diameter is the best effective compromise.

The problem I have with the "Tables" that come with the "3 wire" set/s is that they do not define the limits of the basic outside diameter "D" nor do they give or infer the limits of the measurements over the wires.

As I see it, neither your tables nor the ones that come with the 3-wire sets have regard only to the standard US/UN(ified)/metric/ISO 60 degree thread forms and do not address nor define or tabulate anything for the "Brit/UK" 55 degree "Whitworth" form/profile.

There is no reason - that I can see - why all thread forms are not or cannot be defined for "3-wire" "treatment". That includes but is not limited to: acme, buttress and all threads with non-parallel sides/flanks - "square" form threads are therefore excluded.

The tables that come with the "3-wire" sets are straight out of antiquity in that they are pre-digital/computer.

Computers and calculators are as much valid shop tools as are DRO's, digital calipers, height guages, protractors, micrometers etc. and should be regarded and used as such - as they are with CNC.

It had occurred to me that any 1, 2 or 3 wires should be able to define a thread if the "angle" of the thread and its symmetry were accurate. The wires need not all be the same diameter although that may make it easier.

I had a "stab" at this some time ago with this sketch:
http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/3-wire1.jpg

I just sketched this on a pad in a matter of minutes after I thought it over. It could easily be drawn or replicated in any 2-D CAD system and the quantities/dimensions etc. extracted from it for any thread or profile (other than "square"). It eliminates any need for accuracy in the OD of need for accuracy in/of "in-feed" whether at "29 1/2 degree (US) or 27 degree (Whitworth - UK), or any other angle - it works for a "straight in" (zero off-set) as well.

It originated in a method I've used for a long time to replicate a screw thread from the "mating part" or one that I considered to be a "Pattern" or a "master" for the specific occasion/job. I just accurately grind the screwing tool -usually on a pedestal grinder - with a good protractor and bevel guage. I check the profile against the "master/pattern" screw for "angle" and the "flat" (acme, buttress etc.) or "radius" of the "nose" ("Vee" threads - BSW, Whitworth, UN(ified), "metric" etc) and then I hone it and set it up in the lathe.

I turn the new "blank" to accurately be the same diameter as the "Pattern" (or note and make allowance for any difference/s). I use any accurately ground "rod" that "suits" in the shop that will fit in the "groove" in the "pattern" and project above the OD and note that measurement over the single "wire" and the OD on the opposite side of the "pattern". I am now "set to go" and just keep turning that thread until it is near the measurement over the pattern "just in case!!". I try the "nut" from there on to completion.

The other method I use is to turn a "spigot" on the end of the job, the diameter of the spigot being in two parts - at the "root diameter" (nearest the tail-stock) and another abutting it being 0.010/0.020" larger. I just keep "screwing" until the tool "touches" and leaves spiral "witness" on the larger diameter. I start trying the "nut" from there on to completion. This method pretty well eliminates any concerns or accuracy as regards off-set angles or in-feed/s in the top/compound slide or the cross-slide.

I find that "long-ish" threads (ie "thin" or "skinny" compared to its length, even if supported on a tail-stock centre, some-times have a "barrel" shape/effect as the job is "pushed away" from the cutting tool. A "traveling steady" correctly set up usually fixes this "problem".

I have had a good look at the "3 wire" matter in Machinery's Handbook (27). It is "heavy going" and a "slip" is too easily made either in reading the text, extracting infomation from the tables, selecting formulae and applying them. There is all too often no-one else in a HSM shop to run the figures/logic/reasoning/result "past".

"Internal" threads are another matter.

mrainey
12-18-2008, 12:40 AM
Thanks Thomas, I fixed the link in my signature.

Oldtiffie:
I've really enjoyed all your comments.

The tolerance on the measurement over wires is identical to the tolerance on the pitch diameter (three-wire method is generally taken for granted, except for tapered pipe threads). The diameter of the wires themselves must be held to an extremely close tolerance to give the expected results.

MEPro doesn't allow you to input alternate thread wire sizes - you're stuck with the so-called "best" size (the diameter that's tangent to the flanks at the pitch diameter). In addition to the 60-degree threads, it makes calculations for BSW, BSF, ACME, Buttress, BA, NPT, and NPTF.

I agree that it's much too time-consuming and all too easy to make a mistake when making manual threading calculations. That's why I wrote my programs.

I also wrote Threadpal, a much more powerful thread data calculator which allows you to enter any major diameter, pitch, or wire diameter you want (okay, there are some limits).

I have a lot of customers who make threads for a living and for whom time spent making thread calculations is money down the drain. It's probably overkill for home shop machinists, but I'll invite you to give it a look and come back with comments, positive and negative.

http://closetolerancesoftware.com/METhreadPal.html


Mike

oldtiffie
12-18-2008, 02:52 AM
Thanks Mike - heaps - for taking my comment as you did and in the spirit in which it was intended. It takes a "very good man" to take it as you did and to continue the discussion "in public" on an "open forum". I am very impressed - thank you.

I've had an initial/cursory "look" and am very impressed, the more so now that I've read your post and had a look at your site instead of being limited (by myself as it happens) to assuming that all that was/is in the posts (two threads) covered all that there is - which it - now - very clearly did not.

My impression thus far was that the "Pro" is not for me as I am retired and time is not an issue. I could get very interested in the advanced threading module though.

I do have a question as regards portability etc. I have two computers on my desk (W2K Pro and XP Pro) that are fully net-worked. Each is intended as a "hot" clone of the other. I am the only one using them. I will also be buying another computer for (if and) when I get around to getting the Mach3 CNC package up and running in my shop. That shop computer will "live" in the shop. My question is: how do I or can I run the software on any computer with me as the sole user in a "Home Shop" environment that is not used for commercial or "Trade" purposes?

As regards your Pro software, I have "rules of thumb" for most machining and I "try" my machine and see "how it feels" on just about every job. That would be very hard to "pin down or to quantify". So I really only need the advanced "threading" module.

I will have a better look and make some comment later in the day or tomorrow (perhaps Saturday as tomorrow, Friday, is our wedding anniversary!!). I "live dangerously" - but there are limits!!.

I will think about the "internal measurement" as it - like all other/s - is a bit "hit and miss" to the extent that there is no method comparable to or using the principles of the "3 -wires". There was a method I used many years ago that addressed that issue and it works surprisingly well. It was from my time in the Tool-Room and was a Tradesman/Apprentice discussion during a "break" that started it - but is was while ago. I think I have the basics and fundamentals right, I just need to re-think it and check it out. I will "get back" to you.

One thought I did have, following on from my previous post, was that for those who only use the "off-set angle" and "in-feed" method and who may relay on the "scratch to set dial zeros" procedure, it may be an idea to specify the maximum tool-nose radius that should be used or alternatively allow an option to input the tool-nose radius if they can accurately determine what it is.

[Edit]
I would think that rather than have peope look at it as a "(big?) cost" item that they "cannot afford", perhaps if it were addressed as a "show cause" approach it might be better. By that I mean that potential users/buyers should have to ask themselves to "show cause" why they DON"T buy it. ie it should be regarded as an investment to the extent that it is no so much how much it costs to buy it, but rather what it will or may cost them if they dont (buy it)!!!

[End edit]

Thanks, Mike - later.

macona
12-18-2008, 04:11 AM
I would kill for a iphone version...

derekm
12-18-2008, 07:27 AM
Thanks John.

I was going to address this matter on "the other thread" - but I will do it here.

If you look at the tolerances for the major diameter, pitch diameter, minor/root diameter and "distance over (3?)wires" etc. you will see that there is quite a possible range of "in-feed" variations that are within the tolerance band/s.

The biggest "feed in" to the root diameter is the from the largest major diameter (aka "OD") to the smallest root diameter and the least is between the smallest OD and the largest root diameter.

The "in-feed" at - in this case 29 1/2 degree -which is shown as being to "four decimal places" (eg. 0.0441") is highly problematic as well.

If the in-feed is by the "scratch to set zero on the OD" method is used, I can't see it "all happening" as it seems to presume that the angle (60 degree) and the radius of the end of the screwing tool are extremely accurate. I might assume that the angle is OK but given that many use the same tool with the same radius for all or most screw-threading, it sort of makes the whole process a bit "suspect". Calculating the "slope feed" (at 29.5 degree) is a PITA and prone to error as well.

I cannot see why a short "spigot" about 1/4" to 1/2" long can't be turned on the end of the job (tail-stock end). The diameter can be in two parts - "right on" the root diameter and the other about 0.010" (10 "thou") larger so that I can see where the tool is. The +0.010" diameter will soon let me know when the tool depth is getting "close" as the thread will "show" as a "scratch". After that it can be either a case of "make it fit" a mating or known part and then take note of the "required" diameter as set the top and cross-slide dials to "zero". That way I will know "how far to go to zero" and I don't have to be too fussy about the 29 1/2 degree top-slide setting either.

Some times - but certainly not always - some of these "aids" are more hindrance than help.

An "aid" should be just that. It should not be the end in itself but only a means to an/the end.

In short inappropiate or irrelavent accurracy obscures utility...

Imho I think the world should be taught to use slide rules before calculators and spreadsheets... not because they are more useful but because they teach a mental discipline to understand if the figures look right or whether the apparent accurracy of the calculation and the displayed significant figures are relavent.
I remember be marked down at school and Uni for including significant figures beyond the margin of error of application.
example sin (29.5+/- 0.5) is not 0.4924 +0.076/-0.086
but 0.49+/-0.01

Derek - from a world where the acceleration of gravity can be 10m/s^2 or 9.8m/s^2 9.81m/s^2 or 9.80616-0.025928cos(2LAT)+0.000069cos^2(2LAT)-0.000003h... but used 10 most times and the equation never.

oldtiffie
12-18-2008, 10:32 PM
Derek,

you are quite right.

What Mike Rainey has done with his utility is to both deliver a "reality check" as well as "nailing" some of the simply absurd "accuracies" that some have been promoting here from time to time.

I would doubt that many here could repeatedly - even if initially - achieve those levels of accuracy let alone have the metrology resources to ensure that the results were in fact as accurate as they presumed or assumed.

Mike R has done everyone a favour - a huge big, big favour - by "laying it out" as it (really) is in "Machinery's Hand-book" and just just about every credible reference there is - many of which are in HSM-ers shops, but apparently rarely if ever used and/or just neglected. Perhaps - just perhaps - they may now either use the tables that are available or get/buy software that will "do the job" for them.

That Mike's utilities are as successful as they are in commercial shops speaks volumes for the usefulness, credibility and value of them.

I think that the price he is asking is more than reasonable given the ready access to such a vast range of threads, tolerances and options.

I am very pleased that the bull-$hit about having to measure over "3-wires" in the order of "tenths" has been laid to rest. The same applies to angular off-setting and "in-feeding" on the top-slide for the "29 1/2 degree" - or there-abouts for the (US) - and the 27 degree for the UK/Brit 55 degree Whitworth thread forms.

That "top-slide" in-feed accuracy crap was always suspect - especially so as I have rarely, if ever, seen mention of a DRO on the top-slide even when they were fitted to the carriage and cross-slides. It was all "off the dial" stuff which while a "bit suspect" certainly cannot be relied upon for "tenths" as there is no way of checking it "on the job" - so its all "blind" and "dead-reckoning" with a healthy (???) serve of "hoping for the best".

The more I see of Mike's utility the more I like it. I can see me buying it as soon as Mike answers my questions about my installing it on my three computers.

I take your point about ridiculous "levels of computation" where there are so many digits after the decimal point are taken seriously - too bloody seriously. I usually "round-off" to the third or fourth "significant" (note the "significant") decimal point/place depending on the job.

When I had my HP41CX calculator I had it set to read to three or four significant points/places and it worked fine. That machine lived at my left hand on the desk and on my right hip for surveying field and "out-of-shop/office" work - a great machine but it was eventually beyond repair. I have a HP48GX now - which is more a computer than a calculator - I must sort out how to set the significant figures to three or four, but the bloody manuals are thicker than our local phone books!!!.

I had a 6" and a 10" "folded" (at pi) "Faber-Castell" "flat" slide rules that I used for years. I gave them away in a weak moment to some-one who collects old drawing office memorabilia - and a lot of other "good stuff" too. I must buy a another new one. I used it with indices and it was amazing how accurate and fast it was. I was usually within 5% - usually better - which put me "in the zone" to see if I needed to re-start or to use a calculator. I used the "trig" functions extensively.

"Orders" or "degrees of accuracy" should be consistent with the "REAL need" - especially so as regards work in the shop. The orders of accuracy are determined by the job and the capacity and ability of the machines and equipment I have to make and measure them. So it varies according to the job. If "Plan A" can't "do it", I use or revert to or work out a "Plan B" that will "do the job".

Mike's utilities fit in very neatly with that shop philosophy of mine.

I just hope that Mike is neither offended not embarrassed in this post and I sure didn't intend it to be adverse in any way.

mrainey
12-18-2008, 11:58 PM
Hello again,

Whoa, you're about to give me a swelled head! But, I do appreciate your comments about my efforts. The programs aren't perfect, but I'll keep working to try to get them there.

To answer your licensing question - you're welcome to install the programs on as many computers as you like. The understanding is that you're the only person using them, but that's on the honor system. As you may have noticed, I even offer portable versions that run from a USB thumb drive on any Windows computer.

I have a background in commercial machining, and my attitudes are shaped by that. Because I'm used to making parts for paying customers who have bad-ass inspectors, I think more in terms of "what's right" (the blueprint) rather than "what works" (the home shop). Both approaches have their place.

I did balls-to-the-wall CNC programming for twenty-five years. Virtually all modern CNC programs are written using a minimum of four (inch) or three (metric) decimal places. Thread standards and specifications are written that way. CNC nachinists and inspectors are accustomed to it and even expect it, even though they mentally round up or down as tolerances allow. It's automatic.

That being said, engineers who dimension bolt clearance holes with .002 tolerance or a 32 finish are fair game for ridicule.

In generally increasing order of accuracy, you can check threads with nuts and bolts, mating parts, pitch micrometers, wires, or gages.

If you're a home shop guy making parts for yourself or your friends, or maybe producing your own product, you can sometimes get away with things that wouldn't fly if GM or Martin Marietta was your customer. Thay CAN and WILL pick up on those tenths. You can make threads that "feel good" when mated with a commercial nut or bolt - just don't try to sell a bunch of them to Ingersoll Rand or GE.

Say you get an order for a 1/4-20UNC-3A thread. Per ASME B1.1, the pitch diameter is .2175/.2147 (total of .0028 or +/- .0014). The thread is going to be plated, buildup to be a maximum of .0005 and a minimum of .0001. You can't control it, the plater needs all that tolerance to do his job. To cover all possibilities, the pitch diameter of your pre-plate thread must be .2155/.2143 (total of .0012 or +/- .0006). Not much tolerance left, it's tricky to check. Temths matter, how much depends on the end use.

Miking over wires works great until the tip of your threading tool breaks down just a little and you don't discover it until you've made eight more parts. The pitch diameter still checks fine, wire measurements are great, part won't assemble because the thread root has too much material left in it by the tool. A thread gage, even a good homemade one, would have caught it. Maybe you can rework the parts. That costs money, and it's really bad for your image if the customer is the one who catches the mistake.


You guys could teach me a million things about machining, I only know a lot about a little. I hope I haven't put anybody to sleep with my rambling.


Mike

oldtiffie
12-19-2008, 03:12 AM
Just for interest, here is Mike's "ThreadPal" web page:

http://closetolerancesoftware.com/METhreadPal.html

It addresses all the concerns I may have had - especially the "non-Vee" threads and "multi-starts" and non-standard pitches etc.

Mike, how big is the down-load? My ADSL (OZ) = DSL (US) connection is not very "speedy".

I'd like to down-load the non-transportable option to see how it works for me. I intend to buy/purchase a licence from you - but all I need is a "run-through" on my computer.

As a matter of interest, there are two other current threads that directly or indirectly address the topic here at:

start here:
http://bbs.homeshopmachinist.net/showthread.php?t=32030&page=7

and:
http://bbs.homeshopmachinist.net/showthread.php?t=32120

mrainey
12-19-2008, 09:43 AM
Good morning,

The download for the installer version is roughly 1.75 megabytes.
http://closetolerancesoftware.com/Downloads/METhreadPalTrial.exe

The portable download is about 1.5 megabytes.
http://closetolerancesoftware.com/Downloads/METhreadPalTrial.zip


They have exactly the same features. The installer creates a directory and start menu entries, the portable version you just unzip into the directory of your choice.

The trial versions are uncrippled and last for ten days.


Mike

motorworks
12-19-2008, 07:31 PM
Mike
I down loaded your threadpal
I noticed that your output for British pipe and british tapered pipe are the same?!

I cut these threads on a regularly, being on the East Coast of Canada
and seeing equipment from all over the world coming in my shop via ships
etc. I know there is a difference in BSP and BSTP.(BSPP BSPT).

Is this something you are looking into?
I may buy the program later,after the trial
take care
eddie

ps I bet you did not think that the "home shop"
would pose so many questions.
(some very knowledgeable people here and I am not one :) )

I

mrainey
12-19-2008, 08:29 PM
Hi Eddie,

ThreadPal shows data for external BSP (BSPT) tapered threads, internal BSP (BSPT) tapered threads, and internal BSPP parallel (straight) threads. Per the standard, external straight threads aren't suitable for joining applications, so I left them out.

I've run into BSP and BSPT both being used to represent tapered threads. Since I used BSPT in the thread type selector window, I should probably do the same in the data display for the sake of consistency.

Major, pitch, and minor diameters are measured at the gauge plane, which is a specified distance back from the face. In the spec, these values are identical for BSPT and BSPP threads of the same size. The minor diameter at the face of the internal tapered thread is the only dimension that differs between the two, and I only included it as a reference for machinists or programmers when figuring out what diameter to bore or ream for the tapered tap. I could probably make it more clear.

Mike

oldtiffie
12-19-2008, 10:56 PM
Wow MW - you ARE "on the ball".

Well done.

The only/main difference/s between BSPP (British Standard Pipe Parallel) and BSPT (British Standard Pipe Tapered) is that the tapered version has a taper of 1:16. I will post a diagram of it later with other screw-threads.

The BS taper threads are not too clearly defined in my "Machinery's Hand-book" (27th. Edition) at pages 1870 and 1871. I will post a copy of that as well.

As has been pointed out only too clearly in this and other threads, "Tables" present a problem if they only define "nominal" sizes as there must be "tolerances" as well as "limits (of sizes)" which need to be both used and stayed within. Mike's utility addresses all those topics, other than - as you say - the BS tapered pipe threads.

I have yet down-load and install Mike's ThreadPal - later today, hopefully.

For Mike Rainey:
Mike, when I load your ThreadPal, can I have your permission to load and post a representative pic ("screen-shot") of a page each of Acme and Buttress as these, other than "V" threads are most likely to be required by HSM-ers?

I haven't checked yet but I presume that as you cater for multi-start threads that you cater left-hand threads. So far as I am aware, left and right are the same - is that so?

mrainey
12-19-2008, 11:30 PM
Mike, when I load your ThreadPal, can I have your permission to load and post a representative pic ("screen-shot") of a page each of Acme and Buttress as these, other than "V" threads are most likely to be required by HSM-ers?

I haven't checked yet but I presume that as you cater for multi-start threads that you cater left-hand threads. So far as I am aware, left and right are the same - is that so?

Feel free to post any screenshots you feel would be of interest.

Left and right hand threads have the same dimensions, so ThreadPal doesn't distinguish between them. The next version, due out in January, will have an option to add "LH" to the thread description.

ThreadPal uses a collection of complex formulas (developed by a man named Vogel) to account for the effect of lead angle on wire size and measurement over wires. This becomes increasingly significant as lead angles get larger than five degrees, which is often the case with multiple-start threads. Unfortunately, Vogel never found a way to apply his formulas to asymmetrical threads such as buttress. So, there really is no special support in ThreadPal for multi-start buttress.

oldtiffie
12-20-2008, 01:22 AM
Feel free to post any screenshots you feel would be of interest.


Many thanks Mike.



ThreadPal uses a collection of complex formulas (developed by a man named Vogel) to account for the effect of lead angle on wire size and measurement over wires. This becomes increasingly significant as lead angles get larger than five degrees, which is often the case with multiple-start threads. Unfortunately, Vogel never found a way to apply his formulas to asymmetrical threads such as buttress. So, there really is no special support in ThreadPal for multi-start buttress.

I realised that when I did the "Sketch for CAD" for 1,2 and 3 wires. I realised that under 5 degree that any no-provided for error would be pretty well insignificant in many HSM projects. I realised to that 5>10 degree was a bit "iffy" as well but probably OK for "looser" or "easier" jobs.

Using one wire and the OD instead of two wires would reduce the "helix" error by about half.

I can see the reason the the errors in the larger helix angles if a "rod" or "wire" is used, but my initial thought is that if a pair of "balls" were fixed to the spindle and anvil of the micrometer that it would/should "work" in place of the "rod/wire". Not too dissimilar to a "thread micrometer" which has "attachments" on the spindle end and the anvil.

Using one complete ball of the required "wire" size and the OD should be OK as well - I think. It might be awkward but not as bad as juggling "3-wires"!!!

I had thought about having a ball on the end of a depth micrometer spindle as well. Or perhaps just a ball in the thread "groove".

My biggest problem would be the "distortion" of the thread "true shape" which is parallel to the thread/job axis but is "twisted" through the helix angle such that the "rod" or "ball" - as the case may be - is effectively in a groove normal to the thread form axis that varies as the Cosine of the helix angle at the pitch diameter which if my math is OK varies the effective groove in which the ball/rod sits and is tangent to at the flanks as the tangent of the effective "thread width" at the tangent points due to the helix angle.

I need to re-think that later.

oldtiffie
12-20-2008, 05:48 AM
Here are the scans/pics of the thread forms/profiles that I promised. They include tapping data as well.

A note of caution though.

As previously, these sizes are pretty well "nominal" and do not have tolerances attached. You will have to use your own judgment and your copy of Machinery's Hand-book or equivalent - or perhaps better yet, Mike Rainey's utilities which are the subject of this thread.

Note the detail for taper pipe thread = 3/4" per foot = (3/4)/12 = (3/4 X 1/12) = 3/48 = 1/16 = 1:16 (applies to British as well as US taper threads). Note to the sizes of the "rod"/circle that is the inscribed circle for the OD and thread flanks for the US/UK and metric "acme" thread forms.

Note too, that although not stated, that all thread forms as shown are correct at and when "normal to" and "along" the axis of the work cylinder except that the "worm" is the odd one out as it is formed normal to the helix as it must mesh with a worm-wheel which has an involute form that is normal to its helix but has a pressure angle the same as the form of the worm "thread form".

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form1.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form2.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form3.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form4.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form5.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form6.jpg

http://i200.photobucket.com/albums/aa294/oldtiffie/Screw_threads/Screw-thread_form7.jpg

And while I was searching I found this as well which might help with using and grinding drills:
http://i200.photobucket.com/albums/aa294/oldtiffie/Drilling/Drill_point_grinding1.jpg

Black Forest
11-27-2012, 05:49 PM
What do you all think of the latest version of ME consultant? I downloaded it today and tried it and it seems to give reasonable results for speeds and feeds. I like that it has a turning category. It helps those of us that are Machining Challenged!

Price seems reasonable at 50 Euros.

rklopp
11-27-2012, 06:07 PM
Please, please, please make an iOS version! I'd pay good money for it.