Re: RideTheGearTran has a new feature
I cannot lay hands on my copy right now, as it has vanished into a pile of boxes :-( ?but Machinery’s Handbook recommends that same for thread depth, and has a larger table for a variety of materials and reccomended thread % depth. IIRC it is also somewhat dependent on thread pitch, as well. On Jan 29, 2022, at 8:16 PM, Charles Kinzer < ckinzer@...> wrote:
Well, I don’t know if I’m a “real” engineer (mechanical anyway, maybe electrical), but I have done quite a bit of machining. ? The thread depth is a tradeoff between strength and how difficult it is to tap the hole.? More thread depth, more strength.? Less thread depth, easier to tap the hole. ? It turns out that 75% is a very good ball park percentage where if you go higher you aren’t really getting more strength to speak of.? But the torque required to tap goes way up.? 75% is good for soft metals and hard metals.? But for hard metals you can often go even lower such as 65% thread depth and still have more than adequate strength, yet be able to tap it easier.? For thin sheet metal you would go up in percentage as sort of a special case. ? The bottom line is that there is no reason to try for “100% thread depth” because it is not needed.? Really sharp crests, such as what you get with 100% thread depth, aren’t desirable, either. ? Chuck K.? ? Sent from??for Windows ? From:?EvanSent:?Saturday, January 29, 2022 6:55 PM To:?[email protected]Subject:?[7x12MiniLathe] RideTheGearTran has a new feature ? [Edited Message Follows]
Drill Sizes:?
The latest addition to the menu has an orange border around the button as it is independent of the main program. If you click it you can choose a thread from the metric or imperial thread reference tables, and choose the diameter you want. ?The program then displays all the thread specifications and tables of drill sizes that could be used to tap a thread of that size.
I previously thought that a drill equal to the minor diameter at the root of the thread would be ideal to give 100% thread depth. But with ordinary, straight fluted, taps that is not the case. Generally they recommend 75% thread depth. The reason is that there is a forming process, whereby the tap pushes metal up into the crest and can produce a 100% thread depth even though the drill would suggest 75%. Consequently tables recommending drill sizes are typically based on 75% depth. Since they are designed as printed tables they usually only give you one option. But we may not have exactly the right sized drill. Then what.?
The choice of 75% is somewhat arbitrary. Softer materials like aluminium may form more easily and could accommodate drills less than 75%. Harder materials like stainless steel form less readily and ideally should use a higher percentage. On the other hand, if there is little load on the thread the designer might be happy to accept a lower percentage, particularly if the material is strong.
Since the computer program can deal with a single thread without having to produce a table for all threads, it gives us an opportunity to produce tables with a range of common drill sizes showing what percentage of thread depth would be covered. That is what I have done with RideTheGearTrain. The hobbyists can look at the drills they have available and decide whether they are happy with the percent depth they will achieve.
So, what do the REAL engineers think of this idea? ?Any comments or suggestions? Is this idea unusual? Unique? Or general knowledge.
PS?RideTheGearTrain?now has several entries for mini-lathes with or without a thread cutting gearbox.
For those who don't know, the primary purpose of this free program is to calculate what gears are needed in the gear train to cut a thread of any pitch or TPI.
Evan
--?
Evan
Lathe: 1955?Boxford?Model A with screw cutting gearbox and power feed.
My Free Online Geartrain Software:
My YouTube Channel and Playlist about using an engineers lathe: ?
Project to build a Greek Hero steam engine and measure its power output:?
?
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: RideTheGearTran has a new feature
Evan,
I have been using tap drill charts for most all my tapping needs for my entire career. This info is always available to me on large wall charts and has served me well. In special cases I have other resources such as Machinery’s?Handbook.
Software is the wave of the future, is here now and will eventually replace printed information entirely I believe. My machining career has spanned well over fifty years and change is the one constant and it is here to stay.
I wish you well!
Dick
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Re: RideTheGearTran has a new feature
Thanks Chuck.?
Yes ease of tapping is another factor. Hard materials may not form so well, but they are also harder to tap so a lower percentage thread depth would help, and since these materials are also stronger you can get away with a shallower cut.?
The idea of the tables is to give people some idea of how close the drill is, when you don't have exactly the right drill.
--
Evan
Lathe: 1955 Boxford Model A with screw cutting gearbox and power feed.
My Free Online Geartrain Software:
My YouTube Channel and Playlist about using an engineers lathe: ?
Project to build a Greek Hero steam engine and measure its power output:?
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Re: RideTheGearTran has a new feature
Well, I don’t know if I’m a “real” engineer (mechanical anyway, maybe electrical), but I have done quite a bit of machining. ? The thread depth is a tradeoff between strength and how difficult it is to tap the hole.? More thread depth, more strength.? Less thread depth, easier to tap the hole. ? It turns out that 75% is a very good ball park percentage where if you go higher you aren’t really getting more strength to speak of.? But the torque required to tap goes way up.? 75% is good for soft metals and hard metals.? But for hard metals you can often go even lower such as 65% thread depth and still have more than adequate strength, yet be able to tap it easier.? For thin sheet metal you would go up in percentage as sort of a special case. ? The bottom line is that there is no reason to try for “100% thread depth” because it is not needed.? Really sharp crests, such as what you get with 100% thread depth, aren’t desirable, either. ? Chuck K. ? Sent from for Windows ?
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From: EvanSent: Saturday, January 29, 2022 6:55 PM To: [email protected]Subject: [7x12MiniLathe] RideTheGearTran has a new feature ? [Edited Message Follows] RideTheGearTrain.com
Drill Sizes:?
The latest addition to the menu has an orange border around the button as it is independent of the main program. If you click it you can choose a thread from the metric or imperial thread reference tables, and choose the diameter you want. ?The program then displays all the thread specifications and tables of drill sizes that could be used to tap a thread of that size.
I previously thought that a drill equal to the minor diameter at the root of the thread would be ideal to give 100% thread depth. But with ordinary, straight fluted, taps that is not the case. Generally they recommend 75% thread depth. The reason is that there is a forming process, whereby the tap pushes metal up into the crest and can produce a 100% thread depth even though the drill would suggest 75%. Consequently tables recommending drill sizes are typically based on 75% depth. Since they are designed as printed tables they usually only give you one option. But we may not have exactly the right sized drill. Then what.?
The choice of 75% is somewhat arbitrary. Softer materials like aluminium may form more easily and could accommodate drills less than 75%. Harder materials like stainless steel form less readily and ideally should use a higher percentage. On the other hand, if there is little load on the thread the designer might be happy to accept a lower percentage, particularly if the material is strong.
Since the computer program can deal with a single thread without having to produce a table for all threads, it gives us an opportunity to produce tables with a range of common drill sizes showing what percentage of thread depth would be covered. That is what I have done with RideTheGearTrain. The hobbyists can look at the drills they have available and decide whether they are happy with the percent depth they will achieve.
So, what do the REAL engineers think of this idea? ?Any comments or suggestions? Is this idea unusual? Unique? Or general knowledge.
PS RideTheGearTrain now has several entries for mini-lathes with or without a thread cutting gearbox.
For those who don't know, the primary purpose of this free program is to calculate what gears are needed in the gear train to cut a thread of any pitch or TPI.
Evan
--
Evan
Lathe: 1955 Boxford Model A with screw cutting gearbox and power feed.
My Free Online Geartrain Software:
My YouTube Channel and Playlist about using an engineers lathe: ?
Project to build a Greek Hero steam engine and measure its power output:? ?
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RideTheGearTran has a new feature
RideTheGearTrain.com
Drill Sizes:?
The latest addition to the menu has an orange border around the button as it is independent of the main program. If you click it you can choose a thread from the metric or imperial thread reference tables, and choose the diameter you want. ?The program then displays all the thread specifications and tables of drill sizes that could be used to tap a thread of that size.
I previously thought that a drill equal to the minor diameter at the root of the thread would be ideal to give 100% thread depth. But with ordinary, straight fluted, taps that is not the case. Generally they recommend 75% thread depth. The reason is that there is a forming process, whereby the tap pushes metal up into the crest and can produce a 100% thread depth even though the drill would suggest 75%. Consequently tables recommending drill sizes are typically based on 75% depth. Since they are designed as printed tables they usually only give you one option. But we may not have exactly the right sized drill. Then what.?
The choice of 75% is somewhat arbitrary. Softer materials like aluminium may form more easily and could accommodate drills less than 75%. Harder materials like stainless steel form less readily and ideally should use a higher percentage. On the other hand, if there is little load on the thread the designer might be happy to accept a lower percentage, particularly if the material is strong.
Since the computer program can deal with a single thread without having to produce a table for all threads, it gives us an opportunity to produce tables with a range of common drill sizes showing what percentage of thread depth would be covered. That is what I have done with RideTheGearTrain. The hobbyists can look at the drills they have available and decide whether they are happy with the percent depth they will achieve.
So, what do the REAL engineers think of this idea? ?Any comments or suggestions? Is this idea unusual? Unique? Or general knowledge.
PS RideTheGearTrain now has several entries for mini-lathes with or without a thread cutting gearbox.
For those who don't know, the primary purpose of this free program is to calculate what gears are needed in the gear train to cut a thread of any pitch or TPI.
Evan
--
Evan
Lathe: 1955 Boxford Model A with screw cutting gearbox and power feed.
My Free Online Geartrain Software:
My YouTube Channel and Playlist about using an engineers lathe: ?
Project to build a Greek Hero steam engine and measure its power output:?
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Re: A (maybe?) different cross slide travel extension?
Thanks Bruce. Here I kinda thought I had a novel idea LOL!??I was staring at my lathe the other night, wondering how to gain some travel in both directions.??I don't have, nor do I have access to a mill any more and that's when the idea about moving the nut came to me.?
I made up a spacer and it's just over an inch long so if I move the nut the same distance back I should gain that much travel towards me according to the link from Mike Weebly.? ?And I need a little more travel away from me so I'm thinking adding about 2", 2.5" to the screw should do it.?
I think drilling and taping the screw and then threading the extension in and soldering. Then I can indicate the screw in off the threads, turn the extension to diameter, then pick up the thread to thread the extension. I think that's a good way to keep the screw as straight as I can. Any better way I'm missing?
I probably have a drill bit with a junk point I can grind down too. Thanks for the idea!
Ryan
On Jan 25, 2022, 7:48 PM -0500, Bruce J <bruce.desertrat@...>, wrote:
On Jan 25, 2022, at 2:19 PM, Ryan H via < ifly172@...> wrote:
Wow!??That's awesome Dick!??I'm sure mine won't turn out near so fancy but I hope it'll be functional!??You wouldn't happen to know the center to center distance on the two screws that mount the feed nut by chance???I think getting those holes located, and making the flat bottoms for the screw heads is going to be one of the bigger headaches of this.?
Flat bottoms can be done by finding a HSS twist drill of the correct size and carefully grinding the end flat,
--?
Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: A (maybe?) different cross slide travel extension?
On Jan 25, 2022, at 2:19 PM, Ryan H via < ifly172@...> wrote:
Wow!??That's awesome Dick!??I'm sure mine won't turn out near so fancy but I hope it'll be functional!??You wouldn't happen to know the center to center distance on the two screws that mount the feed nut by chance???I think getting those holes located, and making the flat bottoms for the screw heads is going to be one of the bigger headaches of this.?
Flat bottoms can be done by finding a HSS twist drill of the correct size and carefully grinding the end flat,
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: A (maybe?) different cross slide travel extension?
There are a number of sites and youtube videos discussing this very common mod:
?(who is on this list)
There’s detailed instructions on both doing this and changing the cross-slide from the existing mechanism to a ball-bearing design in Ted Hansen’s Minilathe book from Home Shop Machinist. He moved the nut like youre describing, (after milling it out!) because it was much easier than milling it out and gives you the extra movement in the right direction, so you can easily use the full 7” swing.
On Jan 25, 2022, at 10:18 AM, Ryan H via < ifly172@...> wrote:
I have added two ball bearings to the cross slide screw by boring a hole into the retainer for the bearings and head on the screw to recess into. Doing that cost me about 1/4" of travel towards the??operator. Not much but I'd like that back and them some while I'm at it. If I'm going that far I might as well add some away from the operator while I'm at it.?
For the away part I'm thinking about all that is going to be required is to extend the screw. I'm thinking drill and tap the end of the screw, threadlock an extension in, turn to diameter and pick up the left hand thread and thread the new section. I know it's 20 tpi but I'm not sure what diameter so I'd just match the existing size???I'm thinking that should work. Am I missing anything?
For the towards the operator end I know LMS sells an extended travel kit that includes a milled saddle to allow for the travel because the nut hits but what I'm thinking is this...??Move the nut farther back on the slide, away from the operator. Wouldn't that effectively do the same by giving the nut more room to travel towards the operator???I realize all the other parts would need making and the screw would need an extension on the operator end of course. Am I missing something???
Thanks!
Ryan
--? Bruce Johnson
"Wherever you go, there you are." B. Banzai, PhD
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Re: A (maybe?) different cross slide travel extension?
Thanks Dick. I appreciate the help!
Ryan
On Jan 25, 2022, 5:00 PM -0500, OldToolmaker via groups.io <old_toolmaker@...>, wrote:
Ryan,
The center to center distance is .590” for the nut mounting holes.
Dick
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Re: A (maybe?) different cross slide travel extension?
Ryan,
The center to center distance is .590” for the nut mounting holes.
Dick
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Re: A (maybe?) different cross slide travel extension?
Wow!??That's awesome Dick!??I'm sure mine won't turn out near so fancy but I hope it'll be functional!??You wouldn't happen to know the center to center distance on the two screws that mount the feed nut by chance???I think getting those holes located, and making the flat bottoms for the screw heads is going to be one of the bigger headaches of this.?
Ryan
On Jan 25, 2022, 3:57 PM -0500, OldToolmaker via groups.io <old_toolmaker@...>, wrote:
Ryan,
I did a similar cross slide extension about 3-4 years ago on my MicroMark 7x16 minilathe.
There are pictures in the photos section of this group. Look in “old_toolmakers album cross slide travel extension”.
Dick
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Re: A (maybe?) different cross slide travel extension?
Thanks Dick. I'll take a look!
Ryan
On Jan 25, 2022, 3:57 PM -0500, OldToolmaker via groups.io <old_toolmaker@...>, wrote:
Ryan,
I did a similar cross slide extension about 3-4 years ago on my MicroMark 7x16 minilathe.
There are pictures in the photos section of this group. Look in “old_toolmakers album cross slide travel extension”.
Dick
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Re: A (maybe?) different cross slide travel extension?
Ryan,
I did a similar cross slide extension about 3-4 years ago on my MicroMark 7x16 minilathe.
There are pictures in the photos section of this group. Look in “old_toolmakers album cross slide travel extension”.
Dick
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A (maybe?) different cross slide travel extension?
I have added two ball bearings to the cross slide screw by boring a hole into the retainer for the bearings and head on the screw to recess into. Doing that cost me about 1/4" of travel towards the??operator. Not much but I'd like that back and them some while I'm at it. If I'm going that far I might as well add some away from the operator while I'm at it.?
For the away part I'm thinking about all that is going to be required is to extend the screw. I'm thinking drill and tap the end of the screw, threadlock an extension in, turn to diameter and pick up the left hand thread and thread the new section. I know it's 20 tpi but I'm not sure what diameter so I'd just match the existing size???I'm thinking that should work. Am I missing anything?
For the towards the operator end I know LMS sells an extended travel kit that includes a milled saddle to allow for the travel because the nut hits but what I'm thinking is this...??Move the nut farther back on the slide, away from the operator. Wouldn't that effectively do the same by giving the nut more room to travel towards the operator???I realize all the other parts would need making and the screw would need an extension on the operator end of course. Am I missing something???
Thanks!
Ryan
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This looks like a SCAM.?
Unless you have actual knowledge to the contrary, please let this topic die.
John 7x12 Mod
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Oh and lastly... if it sounds too good to be true, it's because it isn't
true.
Michael - California, USA
Micro-Mark MicroLux 7x16
LMS 3990 Hi-Torque Mill with power feed
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alan Muller Sent: Sunday, January 23, 2022 11:45 AM To: [email protected]Subject: [7x12MiniLathe] Anybody seen this? al-gear-brushless-2250rpm-2-chucks?spm=..collection.collection_detail_1.27&s pm_prev=..index.header_1.1
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My first thought is that it is a scam!
They show a Costco website but the URL is from makenye.com
Scam-detector shows this:
< >
Another way to detect a scam website is to refresh the page. When you do the
Available number goes down every refresh. This page goes down to 8 then
stalls.
Their contact is an outlook.com webmail address:
"We would love to hear from you, contact us on:
Email: vipservice77@..."
Please don't fall for this. You'll be fighting with paypal to get your money
back.
Call Costco and ask them about this lathe and you'll get a big "Huh!"
Michael - California, USA
Micro-Mark MicroLux 7x16
LMS 3990 Hi-Torque Mill with power feed
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-----Original Message----- From: [email protected] < [email protected]> On Behalf Of Alan Muller Sent: Sunday, January 23, 2022 11:45 AM To: [email protected]Subject: [7x12MiniLathe] Anybody seen this? al-gear-brushless-2250rpm-2-chucks?spm=..collection.collection_detail_1.27&s pm_prev=..index.header_1.1
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? ? I TEST? THE SHIPPING? FOR VERMOND? ? FREE?? ?????? ? ? NOT POSSIBLE? FOR QUEBEC CITY? CANADA? QUBEC PROVINCE? ??????? ? SNIF??? SNIF ? JACK 47 71 ? Dug a bit deeper and although the site claims to be Cotsco wholesale, it isn't.? They are also only accepting Paypal. Not looking so good now. On Sunday, January 23, 2022, 12:10:58 PM PST, Jonathan Mackenzie via groups.io <jonathanmackenzie@...> wrote: I checked out??on whois - it's registered in China. On Sunday, January 23, 2022, 12:00:32 PM PST, Alan Muller <alan@...> wrote: I don't know if it's a scam.? Might well be.? Yesterday the price was 87 $US 10% off) and free shipping.
Alan
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At 07:56 PM 1/23/2022 +0000, you wrote: Wow. An 8 x 16 for $ 97 plus shipping!
I started the checkout but didn't want to enter my email address, so I have no idea what the shipping cost is.
But that price seems to include both 3jaw and 4 jaw chucks!
- Jonathan
On Sunday, January 23, 2022, 11:45:33 AM PST, Alan Muller <alan@...> wrote:
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Sadly it is 98.5% likely to be a scam! Too bad, I first thought it to be a cleaned up 7X12 with a misprinted price. Even at $970 with reasonable shipping it could have been a fair deal. Keep your credit cards in your wallets folks!?? Bill ? Sent from for Windows 10 ?
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From: Kaj WiikSent: Sunday, January 23, 2022 13:23 To: [email protected]Subject: Re: [7x12MiniLathe] Anybody seen this? ? ? On Sun, 23 Jan 2022 at 21:45, Alan Muller <alan@...> wrote:
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OldToolmaker
Evan
GadgetBuilder
