Re: Unimat Vertical Column
The DB etc is 25 mm by memory.
On 08/13/2023 2:26 PM EDT Peter Brooks <peter@...> wrote:
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Don¡¯t know about the DB200 but the U3 is around 28mm in diameter.
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I have worked on BSA, Triumph and Norton Motorcycles for 50+ years now. I have a large selection of the BSW, BSF taps dies and tools to work on these. You can also add the BA and the BSC threads to that lot. LOL, and when working on metric remember that Japan used their own Metric up until 1969, the JIS threads. And if you work on older American stuff you will also run into some interesting threads, like the Extra Extra fine and Special threads. Many decades ago when stuff was still made in the USA, we even had two special 1/4" extra fine threads for thin tubing. One was used for electric lamps and the other was for reostats where the shaft came out.? ?Very early American wrenches also used a system very close to the Whitworth where the wrench/spanner opening did not equal the hex head on the bolt , but was related to the shaft size. They also used a code on the wrench/spanner to signify the size of the opening and each manufacturer used their own code.The code was normally three numbers. Most of this stuff did not start to get standardized until after the SAE was formed 1905 and even then it was not until a few years more when the US supreme Court ruled that the Patent on the automobile did not include every nut and bolt that manufacturers started to standardize. Most consider WWII as the point where Nuts and bolts became more standard in sizing and threads. ?Here is a good link to dating tools.?
Jeff
On Monday, August 14, 2023 at 08:28:45 AM EDT, Keith S. Angus <keithsangus@...> wrote:
On Mon, Aug 14, 2023 at 06:40 AM, Peter Brooks wrote:
- is there a standard formula for the size (width and thickness) of bolt hex heads? ?(I¡¯m making some M14x1 bolts).
When Mr Whitworth devised his system of screw threads he made the hexagon twice the size of the thread across the points - not across the flats.?This means there is a factor of ¡Ì3 involved, so the AF size is never going to be rational in any system of measurement. This is why Whitworth size spanners never fit anything else, and I believe it is why the French and Italians (at least) refer to an adjustable spanner as an English spanner - it's the only thing that fits those daft British bolts! To add to the confusion British Standard Fine (BSF) bolts use the next size down hexagon. During the war this was then applied to Whitworth (BSW) bolts as well because it saved metal. The Whitworth formula for the size of a bolt head is still being taught in British drafting classes, and it is almost always wrong. Metric (SI) bolts do not use aa formula for the hex size. An M1 nut is 2.5 mm AF, M100 is 145 mm, so as the thread size goes up the nut is proportionately smaller. In general practice (my experience) M14s are 22 mm AF, but the latest ISO standards say 21 mm. I suggest you use 22 mm, then your standard 7/8 AF spanner will be a good fit. The metric nut thickness is roughly 0.8 of the thread size, but the numbers are rounded off to something a bit sensible. Bolt heads are 2/3 of the nominal size, again rounded off (M14 is 11 mm thick). So some of the metric dimensions follow a formula, but plenty don't. Beyond that there seems to be no limit to the imagination of engineers when devising "rational" fastener families.
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On Mon, Aug 14, 2023 at 11:52 AM, Carl wrote:
Stainless bolts in stainless are prone to galling,
Stainless bolts in anything are prone to galling. They are also nothing like as strong as the best high tensile steel. I only use them if it's absolutely necessary, as in the water filters I'm working on currently.
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On Mon, Aug 14, 2023 at 06:40 AM, Peter Brooks wrote:
- is there a standard formula for the size (width and thickness) of bolt hex heads? ?(I¡¯m making some M14x1 bolts).
When Mr Whitworth devised his system of screw threads he made the hexagon twice the size of the thread across the points - not across the flats.?This means there is a factor of ¡Ì3 involved, so the AF size is never going to be rational in any system of measurement. This is why Whitworth size spanners never fit anything else, and I believe it is why the French and Italians (at least) refer to an adjustable spanner as an English spanner - it's the only thing that fits those daft British bolts! To add to the confusion British Standard Fine (BSF) bolts use the next size down hexagon. During the war this was then applied to Whitworth (BSW) bolts as well because it saved metal. The Whitworth formula for the size of a bolt head is still being taught in British drafting classes, and it is almost always wrong. Metric (SI) bolts do not use aa formula for the hex size. An M1 nut is 2.5 mm AF, M100 is 145 mm, so as the thread size goes up the nut is proportionately smaller. In general practice (my experience) M14s are 22 mm AF, but the latest ISO standards say 21 mm. I suggest you use 22 mm, then your standard 7/8 AF spanner will be a good fit. The metric nut thickness is roughly 0.8 of the thread size, but the numbers are rounded off to something a bit sensible. Bolt heads are 2/3 of the nominal size, again rounded off (M14 is 11 mm thick). So some of the metric dimensions follow a formula, but plenty don't. Beyond that there seems to be no limit to the imagination of engineers when devising "rational" fastener families.
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That's great, thanks for the reply Carl.? Sounds like it's full of reading for the winter evenings...
Cute toolbox !
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Hello Peter:
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Machinery's Handbook also has Metric information, it will tell you USA measurements are based on the meter. Check Ebay or bookstores for a copy, even the early editions are useful. New they are about $100, but I've found used for $10. The book is a great read, everything from flooring to finance. It's size has stayed the same to fit in that small drawer in Girshner tool boxes.?
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In tool making we always used stronger bolts. Aluminum would only be used for appearance or weight. Stainless bolts in stainless are prone to galling, this week I had a 1/4" screw gall in a stainless flange and I had to saw it free. I'm on the road with no grease so I used butter and finished the job.?
On 08/14/2023 2:45 AM EDT Peter Brooks <peter@...> wrote:
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Thanks Bill. Is that an American book? ?We are (for our sins) now?generally metric over here in the UK, I wonder if there is an equivalent?
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Thanks Phil for that and the tip. I¡¯ll keep my eyes out for a copy.
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Hi Peter, we have the book (Engineers Bible) over here in the UK it's about 80mm thick so it has every bit of information you could need in it keep a look out for a copy.
On another note over the use of stainless bolts I use nothing else in many different metals and have done so for many years, but I always brush a film of copper grease on them and have never had any problems at all.
Phill?
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Thanks Bill. Is that an American book? ?We are (for our sins) now?generally metric over here in the UK, I wonder if there is an equivalent?
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Lay hands on a copy of Machinery's Handbook, and you will find several hundreds of pages of tables, discussion, and formulae. I keep picking at it, but I'm mathematically challenged, and unlikely to live long enough to understand it all even if I live a hundred years longer. :)
Bill in OKC?
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Monday, August 14, 2023 at 12:40:47 AM CDT, Peter Brooks <peter@...> wrote:
Some queries about bolts.
- common sense would say that a bolt should be softer than (or equal in hardness to) the thread that is is going in to, the bolt being replaceable where the threaded item is maybe not. If threading into aluminium there seems little option than to use an aluminium bolt but in the back of my mind I am highly suspicious of aluminium (like it might meld back together like the Terminator!). It¡¯s strange stuff. I¡¯ve heard that you shouldn¡¯t use stainless steel in aluminium (galvanic reaction apparently), are there any other combinations of metals that are unadvisable? ?I have anti-seize compounds, one copper based and another, from bicycle maintenance days, do folks use these in general engineering?
- is there a standard formula for the size (width and thickness) of bolt hex heads? ?(I¡¯m making some M14x1 bolts).
- given light loadings (we¡¯re not dangling stuff from cranes, or pulling supertankers) is there any difference in the strength of fixing between (say) a 10mm, a 20mm and a 30mm bolt? Is there any point to the length of a bolt apart from reaching down to a thread?
(I think this nearly qualifies for the ¡®Dumb questions¡¯ thread !)
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Some queries about bolts.
- common sense would say that a bolt should be softer than (or equal in hardness to) the thread that is is going in to, the bolt being replaceable where the threaded item is maybe not. If threading into aluminium there seems little option than to use an aluminium bolt but in the back of my mind I am highly suspicious of aluminium (like it might meld back together like the Terminator!). It¡¯s strange stuff. I¡¯ve heard that you shouldn¡¯t use stainless steel in aluminium (galvanic reaction apparently), are there any other combinations of metals that are unadvisable? ?I have anti-seize compounds, one copper based and another, from bicycle maintenance days, do folks use these in general engineering?
- is there a standard formula for the size (width and thickness) of bolt hex heads? ?(I¡¯m making some M14x1 bolts).
- given light loadings (we¡¯re not dangling stuff from cranes, or pulling supertankers) is there any difference in the strength of fixing between (say) a 10mm, a 20mm and a 30mm bolt? Is there any point to the length of a bolt apart from reaching down to a thread?
(I think this nearly qualifies for the ¡®Dumb questions¡¯ thread !)
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Re: Unimat Vertical Column
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On 14 Aug 2023, at 4:26 am, Peter Brooks <peter@...> wrote:
?Don¡¯t know about the DB200 but the U3 is around 28mm in diameter.
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Re: Unimat Vertical Column
Don¡¯t know about the DB200 but the U3 is around 28mm in diameter.
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Is the vertical column diameter the same on both the DB200 and the Unimat 3?
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Re: Unimat 3 belting tightness
Hello Bill:
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On Sat, Aug 12, 2023 at 05:27 PM, Bill in OKC too wrote:
Always replace gaskets and springs ...
Indeed ... It would not have been any trouble (taking apart and assembling the headstock spindle was) to just change the Bellvilles. Now I not only have to source them but I have to do it all over again.
... always enough time to do it over.
Not really, as I still have a lot of fixing/replacing/tuning on my U3 so I can actually use it to finish a project. Thanks for your input. Best, JHM
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Re: Unimat 3 belting tightness
The aphorisms to live by, 1st & 5th, are basically how I learned these things. That and working on, and occasionally actually fixing stuff. Always replace gaskets and springs, if at all possible! Particularly where there are bearings involved! I'm a cheap bastrich, but it's a false economy to not do it right the first time. One of my bosses in the USAF once told me that there is never enough time to do it right, but always enough time to do it over. Which was not a positive in his opinion!?
Glad I could help even a little bit!
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Saturday, August 12, 2023 at 01:57:33 PM CDT, Julius Henry Marx <sawbona@...> wrote:
On Sat, Aug 12, 2023 at 02:33 PM, Bill in OKC too wrote:
... springs deteriorate over time. | ... happens pretty quick.? | ... clean and dry and protected, it takes longer ...
Indeed ... As with any tool/part made of steel.
?... faster when they're under constant compression or tension.
That's what I was getting at. Thinking it was enough, I replaced the pair of OEM Unimat 3 bearings (as I mentioned, totally gone) with a new pair of SKFs but did not think to replace the eight OEM Belleville springs. Undoubtedly ignorance/lack of experience on my behalf. But then I would not think twice about replacing the thrust bearing in a car's gearbox when replacing the clutch, even if it was newish. Dumb is dumb. What I don't understand is that, of the many articles/web pages I have read on the subject of replacing the U3 spindle bearings,why not one mentions the need to replace the springs. If you took into account the age of the lathe (in this case 43 years) and the existing bearings being the original ones, there are more than sufficient reasons to do so. But I digress ... Fortunately, the parts list indicates that they are part # ZFD 94 3461 and the DIN number is 34.6x20.4x0.4 (in this case the part's dimensions) for the springs on the spindle. A quick look at a brought me up to speed, these chaps call them Bearing PreLoad Disk Springs. "With dimensions to suit most standard roller bearings (radial ball bearings), this range of plain bearing preload disc springs are manufactured from CK75 Carbon Steel (DIN 1.1248) with a zinc phosphate and oiled finish.
The preload disc springs (or washers) assist in maintaining positioning accuracy of the bearing (with no end play) and also minimise vibration and shaft deflections. Correct preloading will also increase bearing rigidity and negate excessive running noise."
So there you go: if there's fatigue (leading to incorrect preloading) bearing rigidity will decrease and and running noise will increase. The part number for the 34.6x20.4x0.4 size is and they are manufactured in the UK. I'll have to look up a local manufacturer first, I have the feeling that a set of eight won't cost me less than US$60.00/75.00 Thanks for your input. Best, JHM
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Re: Unimat 3 belting tightness
Hello Bill:
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On Sat, Aug 12, 2023 at 02:33 PM, Bill in OKC too wrote:
... springs deteriorate over time. | ... happens pretty quick.? | ... clean and dry and protected, it takes longer ...
Indeed ... As with any tool/part made of steel.
?... faster when they're under constant compression or tension.
That's what I was getting at. Thinking it was enough, I replaced the pair of OEM Unimat 3 bearings (as I mentioned, totally gone) with a new pair of SKFs but did not think to replace the eight OEM Belleville springs. Undoubtedly ignorance/lack of experience on my behalf. But then I would not think twice about replacing the thrust bearing in a car's gearbox when replacing the clutch, even if it was newish. Dumb is dumb. What I don't understand is that, of the many articles/web pages I have read on the subject of replacing the U3 spindle bearings,why not one mentions the need to replace the springs. If you took into account the age of the lathe (in this case 43 years) and the existing bearings being the original ones, there are more than sufficient reasons to do so. But I digress ... Fortunately, the parts list indicates that they are part # ZFD 94 3461 and the DIN number is 34.6x20.4x0.4 (in this case the part's dimensions) for the springs on the spindle. A quick look at a brought me up to speed, these chaps call them Bearing PreLoad Disk Springs. "With dimensions to suit most standard roller bearings (radial ball bearings), this range of plain bearing preload disc springs are manufactured from CK75 Carbon Steel (DIN 1.1248) with a zinc phosphate and oiled finish.
The preload disc springs (or washers) assist in maintaining positioning accuracy of the bearing (with no end play) and also minimise vibration and shaft deflections. Correct preloading will also increase bearing rigidity and negate excessive running noise."
So there you go: if there's fatigue (leading to incorrect preloading) bearing rigidity will decrease and and running noise will increase. The part number for the 34.6x20.4x0.4 size is and they are manufactured in the UK. I'll have to look up a local manufacturer first, I have the feeling that a set of eight won't cost me less than US$60.00/75.00 Thanks for your input. Best, JHM
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Re: Unimat 3 belting tightness
They are springs. All springs deteriorate over time. Corrosion, stress fractures, etc. Get them wet, and let them rust, and it happens pretty quick. Keep them clean and dry and protected, it takes longer, but it will still happen. Happens faster when they're under constant compression or tension. Think of it as cheap insurance!?
Bill in OKC
William R. Meyers, MSgt, USAF(Ret.)
Aphorisms to live by: Good judgement comes from experience. Experience comes from bad judgement.? SEMPER GUMBY!
Expect in one hand, expectorate in the other. See which one gets full first.
On Saturday, August 12, 2023 at 02:52:18 AM CDT, Unimat Matt <matthewtay2020@...> wrote:
I am not sure about the Belleville washers to be honest, I would have thought they would be way too strong for the belts to overcome, especially when the forces from the belts are in the opposite (vertical) direction. That said, the washers are inexpensive so it my be worth a try.
If you are having issues with play, you might want to also check your bearings, even though they are new! Unfortunately there is a massive problem with fake bearings. I've had fake ones that felt like they were worn out straight from the box!
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Re: Unimat 3 belting tightness
Hello:
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On Sat, Aug 12, 2023 at 04:52 AM, Unimat Matt wrote:
... not sure about the Belleville washers ...
I have had a brief look on the web and it seems that they can suffer from fatigue. It is all way over my head, can't begin to grasp any of it. But one thing I understand: a Belleville washer is a disk spring made from a special steel to certain specificacions eg: DIN2093. And just line any other spring, it is designed (and tested) to work to spec up to a certain number of cycles.? Not the same scenario, but think shock absorber springs in a car/truck. At one point in time and depending of their use history they may have to be replaced.
... would have thought they would be way too strong for the belts to overcome ...
Well, that's why I asked, I thought so too. Although overcome would not be the adequate term for what the belt does, it is just a small difference in the reading while measuring runout. But they are designed to be overcome is cases like the one I described in the OP. eg: a tool jamming.
... forces from the belts are in the opposite (vertical) direction.
The forces from a tool would be perpendicular to the rotation axis ie: along the X axis, like in any other lathe. If we trace a line from the motor spindle axis to the lathe spindle axis (standard U3), it seems that it is at a ~ 30¡ã below the X axis. So I think that is the direction of the belt tension.
... washers are inexpensive so it my be worth a try.
Of course, but I want to check on what is the right/expected behaviour in a properly working U3 before taking the spindle out. It is a bit of a hassle.
... issues with play ...
I detect no play in the bearings ie: no runout and they were puchased from a SKF distributor. Thanks for your input. Best, JHM
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Re: Unimat 3 belting tightness
I am not sure about the Belleville washers to be honest, I would have thought they would be way too strong for the belts to overcome, especially when the forces from the belts are in the opposite (vertical) direction. That said, the washers are inexpensive so it my be worth a try.
If you are having issues with play, you might want to also check your bearings, even though they are new! Unfortunately there is a massive problem with fake bearings. I've had fake ones that felt like they were worn out straight from the box!
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Carl
Bill in OKC too
OldToolmaker
Unimat Matt