Thank you for another interesting letter and help on a wood clamp restoration. There has been loads of helpful suggestions and advice. ( It made me think about even making a new one with a very long reach, if required for things in the future. Steel with wooded jaws? ) Thank you all so much. The advice offered is exactly what I wanted, a wide range of information to mull over, over the next ¡®X¡¯ weeks while I actually consider my course(s?) of action.
May I therefore suggest, that we close down this topic, as I don¡¯t want the group to drift(?) too far from metalworking. Although I am not deeply interested In some of subjects, I often always scan them and I am amazed at the detailed knowledge base available in this group (from anywhere in the world). ?
On 30 Jan 2024, at 07:10, Miket_NYC <mctaglieri@...> wrote:
?
Not trying to put down the craft of woodworking, but have you thought of just converting this screw to metal?? McMaster-Carr, a big mail-order hardware store in the US, sells 5/6-6 Acme-threaded rod with matching nuts for affordable prices.? (You don't say what you mean by "longest reach," but here's a photo of their catalogue page showing prices for 3-foot and 6-foot lengths).?
I used one of of the nuts they sell for these leadscrews for a project myself a few years ago. I was restoring a South Bend metal shaper in derelict condition. It had an Acme leadscrew for the side-to-side travel of the shaper table that was in fine condition, but the matching nut was long gone and the manufacturer out of business (and making an internal Acme-threaded nut, with the outside of the nut properly shaped to get the bore into the right location for a leadscrew I couldn¡¯t measure directly seemed impossible, since I not only didn't have a nut to copy but had never even seen one before).??
So I made a carrier to fit the shaper table that was the shape of the outside of the original nut and was a light press fit on one of McMaster-Carr's Acme-threaded nuts. Then I coated the nut with epoxy and assembled the shaper table, allowing the leadscrew itself to pull the nut into the proper location while the epoxy set.? Here's a photo of my cobbled-together nut. It's ugly but strong (and invisible after the shaper was together), and the shaper is working fine today.?
?
Your problem for a nut would be simpler, because you would just have to drill out the clamp to accept a steel shaft pushed in from one side. That shaft should be drilled and tapped with a 5/6-5 thread to match the threaded rod. (Or, if you don't fancy buying a gigantic tap you'll use once in your life, you could epoxy a matching nut into the steel shaft the way I did on my shaper).
BTW, I doubt McMaster-Carr ships to the UK, but I expect a large industrial supplier there could offer similar products.
This repair isn't woodworking, but it should work fine (and if the other screw ever breaks you could do the same thing for that).?
Mike Taglieri?
On Mon, Jan 29, 2024, 02:31 DAVID WILLIAMS via <d.i.williams=[email protected]> wrote:
Dear All,
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~? 5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
?I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?)? I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
Regards,
David (UK)
> On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote:
> ?like these ?
>
>
> thanks
>
> animal
>
> On 1/28/24 12:01 PM, David Wiseman wrote:
>> They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood.
>> Best regards
>> David
>>
>>> On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote:
>>> ?Are these clamps the " hand screw " clamps ? They have left & right hand
>>> threads . I've never seen a set with wooden screws .
>>>? ? ?animal
>>>> On 1/15/24 11:39 PM, DAVID WILLIAMS via wrote:
>>>> Dear All,
>>>> I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all.
>>>> I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads.
>>>>? I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe.
>>>> [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?]
>>>> The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle?
>>>> Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread?
>>>> I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end.
>>>> I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant?
>>>> Thank you in anticipation.
>>>> David of Abingdon(UK)
>
>
>
Not trying to put down the craft of woodworking, but have you thought of just converting this screw to metal?? McMaster-Carr, a big mail-order hardware store in the US, sells 5/6-6 Acme-threaded rod with matching nuts for affordable prices.? (You don't say what you mean by "longest reach," but here's a photo of their catalogue page showing prices for 3-foot and 6-foot lengths).?
I used one of of the nuts they sell for these leadscrews for a project myself a few years ago. I was restoring a South Bend metal shaper in derelict condition. It had an Acme leadscrew for the side-to-side travel of the shaper table that was in fine condition, but the matching nut was long gone and the manufacturer out of business (and making an internal Acme-threaded nut, with the outside of the nut properly shaped to get the bore into the right location for a leadscrew I couldn¡¯t measure directly seemed impossible, since I not only didn't have a nut to copy but had never even seen one before).??
So I made a carrier to fit the shaper table that was the shape of the outside of the original nut and was a light press fit on one of McMaster-Carr's Acme-threaded nuts. Then I coated the nut with epoxy and assembled the shaper table, allowing the leadscrew itself to pull the nut into the proper location while the epoxy set.? Here's a photo of my cobbled-together nut. It's ugly but strong (and invisible after the shaper was together), and the shaper is working fine today.?
?
Your problem for a nut would be simpler, because you would just have to drill out the clamp to accept a steel shaft pushed in from one side. That shaft should be drilled and tapped with a 5/6-5 thread to match the threaded rod. (Or, if you don't fancy buying a gigantic tap you'll use once in your life, you could epoxy a matching nut into the steel shaft the way I did on my shaper).
BTW, I doubt McMaster-Carr ships to the UK, but I expect a large industrial supplier there could offer similar products.
This repair isn't woodworking, but it should work fine (and if the other screw ever breaks you could do the same thing for that).?
On Mon, Jan 29, 2024, 02:31 DAVID WILLIAMS via <d.i.williams=[email protected]> wrote:
Dear All,
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~? 5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
?I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?)? I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
Regards,
David (UK)
> On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote:
> ?like these ?
>
>
> thanks
>
> animal
>
> On 1/28/24 12:01 PM, David Wiseman wrote:
>> They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood.
>> Best regards
>> David
>>
>>> On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote:
>>> ?Are these clamps the " hand screw " clamps ? They have left & right hand
>>> threads . I've never seen a set with wooden screws .
>>>? ? ?animal
>>>> On 1/15/24 11:39 PM, DAVID WILLIAMS via wrote:
>>>> Dear All,
>>>> I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all.
>>>> I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads.
>>>>? I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe.
>>>> [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?]
>>>> The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle?
>>>> Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread?
>>>> I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end.
>>>> I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant?
>>>> Thank you in anticipation.
>>>> David of Abingdon(UK)
>
>
>
If use gear for engagement then form of thread dial.
I lot of lathes will use on haft nut for automatic engagement.? Costly to buy.?
On turret lathes they use a thread leader and sometimes a gear box 1 to 1 , 1 to 2 , 1 to 3 and 1 to 4. But takes a lot of leads znd very fast to single point thread.??
Dave?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~ 5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?) I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
Regards,
David (UK)
On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote: ?like these ?
thanks
animal
On 1/28/24 12:01 PM, David Wiseman wrote:
They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood. Best regards David
On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote: ?Are these clamps the " hand screw " clamps ? They have left & right hand threads . I've never seen a set with wooden screws . animal
On 1/15/24 11:39 PM, DAVID WILLIAMS via groups.io wrote: Dear All, I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all. I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads. I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe. [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?] The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle? Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread? I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end. I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant? Thank you in anticipation. David of Abingdon(UK)
On Mon, Jan 29, 2024 at 11:03?AM davesmith1800 <davesmith1@...> wrote:
Like said before only selecte number of threads can use a dog clutch. A multiple 1x 2x 3x 4x 5x 6x 7x of the lead screw.? You can not cut 1.5x , 1.27x and the list goes on.?
Dave?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
I did watch the Screw Box for Wooden Threads on the Wood Wright show when first came on.? It was interesting to see how did work before the 1900's. You could see how the threading die was developed.??
Dave?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
As I said every one had been amazingly helpful. I may have to actually make a die or thread chaser as 6 TPI doesn¡¯t seem a perfect march.?
(It reminds me of antique gun threads - really odd in the UK. eg the ramrod of the 1853 Enfield, (used in your civil war, I believe) had a pitch of 26 1/3 TPI for the ball puller etc¡.)
On 29 Jan 2024, at 15:36, Bruce J <bruce.desertrat@...> wrote:
?The Woodwright¡¯s shop on PBS has a episode on making a screw box (aka die) for wooden threads:
This appears to be free to watch.
On Jan 29, 2024, at 12:30 AM, DAVID WILLIAMS via groups.io <d.i.williams@...> wrote:
Dear All,
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~ ?5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?) ?I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
Regards,
David (UK)
On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote: ?like these ? https://ponyjorgensen.com/product/classic-jorgensen-adjustable-handscrew/
thanks
animal
On 1/28/24 12:01 PM, David Wiseman wrote:
They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood. Best regards David
On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote: ?Are these clamps the " hand screw " clamps ? They have left & right hand threads . I've never seen a set with wooden screws . ???animal
On 1/15/24 11:39 PM, DAVID WILLIAMS via groups.io wrote: Dear All, I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all. I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads. I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe. [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?] The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle? Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread? I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end. I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant? Thank you in anticipation. David of Abingdon(UK)
<image1.jpeg><image2.jpeg><image3.jpeg>
--? Bruce Johnson
The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism.
Like said before only selecte number of threads can use a dog clutch. A multiple 1x 2x 3x 4x 5x 6x 7x of the lead screw.? You can not cut 1.5x , 1.27x and the list goes on.?
Dave?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
The Woodwright¡¯s shop on PBS has a episode on making a screw box (aka die) for wooden threads:
This appears to be free to watch.
On Jan 29, 2024, at 12:30 AM, DAVID WILLIAMS via groups.io <d.i.williams@...> wrote:
Dear All,
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~ ?5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?) ?I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
Regards,
David (UK)
On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote: ?like these ? https://ponyjorgensen.com/product/classic-jorgensen-adjustable-handscrew/
thanks
animal
On 1/28/24 12:01 PM, David Wiseman wrote:
They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood. Best regards David
On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote: ?Are these clamps the " hand screw " clamps ? They have left & right hand threads . I've never seen a set with wooden screws . ???animal
On 1/15/24 11:39 PM, DAVID WILLIAMS via groups.io wrote: Dear All, I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all. I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads. I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe. [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?] The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle? Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread? I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end. I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant? Thank you in anticipation. David of Abingdon(UK)
<image1.jpeg><image2.jpeg><image3.jpeg>
--? Bruce Johnson
The less a man knows about how sausages and laws are made, the easier it is to steal his vote and give him botulism.
"" by Martin Cleeve discusses the compound set over method vs advancing both cross and compound slides.? This book is well worth its modest cost.? Cleeve made his living doing short production runs threading parts for companies.
Cleeve suggests that set over should be 29 degrees rather than 29.5 to ensure that the right flank is shaved with each pass so it does not develop a stairstep roughness due to minor effects.
Cleeve favored keeping the compound at 90 degrees, so he advanced both cross and compound slides.? Rather than using trigonometry he simply advanced the compound half of the amount that he advanced the cross slide - this ensures the right flank is shaved on each pass, similar to a set over of 29 degrees.? This allows using a tool ground for the finest thread, then when depth is reached the compound is advanced to achieve the correct thread root width.? With the set over method the tool point width should be reground to the correct width for each different TPI to achieve the correct root width.
Also, since Cleeve made his living threading, he designed and built a dog clutch for his Myford lathe.
John
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
My original one, (complete) is probably 150 years old, possibly more.
The broken one is probably the same vintage, albeit smaller. This is the one I would like to restore at some point. I have got quite a few clamps for woodworking but the working one has the longest reach.
The original thread(s) measures ~ 5/8¡± x ~ 6. Look at the detailed image.(You can see even the 6 TPI is not perfect.) JFI - Hence my scribble says ¡°Seems to be ~ 5/8 x 6 TPI. (I¡¯m sure you all understand but just in case the symbol for approximately is ~.)
I don¡¯t think anyone makes a 5/8 x 6 wood tap/die any more. Hence my request for assistance and using my 7 x 12 mini lathe. (Dare I mention the words after the recent discussion ?. ?) I was wondering if I could increase the thread to the more usual 3/4¡± x 6?
I think(?) the thread is made of beech.
I hope this is useful.
Thank you to all those who have offered help and assistance.?
PS As we all say, ¡°You never stop learning - Every day is a day at school!
On 28 Jan 2024, at 20:03, mike allen <animal@...> wrote: ?like these ?
thanks
animal
On 1/28/24 12:01 PM, David Wiseman wrote:
They are of the style of an engineers hand clamp but really HUGE in comparison and of course made of wood. Best regards David
On 28 Jan 2024, at 19:01, mike allen <animal@...> wrote: ?Are these clamps the " hand screw " clamps ? They have left & right hand threads . I've never seen a set with wooden screws . animal
On 1/15/24 11:39 PM, DAVID WILLIAMS via groups.io wrote: Dear All, I realise this is both part Mini lathe and part wood lathe. But to me the metal lathe part is more important. Hence my question to you all. I have a couple of these old wooden clamps - probably antique. They are just like the metalwork ones we use, but much much larger. One has a severely damaged (external) threads. I would like to try(?) and cut the replacement long wooden thread on my 7 x 12. So, I bought a second hand thread chaser on eBay. It¡¯s 6 TPI and according to the chart on the Little Machine Shop site - the gear set up is no problem on my imperial lathe. [JFI it¡¯s Real Bull model purchased from Chester Machines (in the UK) some 20+ years ago. If that¡¯s at all relevant?] The thread chaser cuts multiple threads at the same time and the tool (normally hand held I understand) needs to be held at ~ 90 degrees to the thread, unlike the usual angle for cutting one side of a metal thread. OR, if you are doing it by hand, do you angle the thread chaser so it cuts a series of slightly deeper threads. Thus the tool needs to be held in the tool post at a similar angle? Assuming I can sharpen it correctly and clamp it to the tool post, can anyone offer any suggestions or guidance? Do you cut it in multiple passes, in a similar way to a metal thread? I assume I¡¯m going to have to make and use some sort of a travelling steady. My idea is to clamp it in the chuck and use a small freely rotating chuck at the tailstock end. I believe I can get a much better quality and accurate thread using the gears than trying to use it hand held - on a very long tool holder, the same as the ones on a wood lathe. I have to check but I think the wood for the screws is normally Beech, if that¡¯s relevant? Thank you in anticipation. David of Abingdon(UK)
The first sentence of that post ended with, "...another way to do it." I see the word "do" there. And even if it were not, I could certainly respond to the proposed idea whether anybody actually used it or even if just a pipe dream
They have use Direct Reading cross feed dial since the late 1950's on most lathes.??
I do not know why we see standard read on mini lathes today?
Dave?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
The first sentence of that post ended with, "...another way to do it."? I see the word "do" there.? And even if it were not, I could certainly respond to the proposed idea whether anybody actually used it or even if just a pipe dream.
Charles E. "Chuck" Kinzer
I
On Sunday, January 28, 2024 at 04:07:54 PM PST, davesmith1800 <davesmith1@...> wrote:
I like 90¡ã for picking up threads if need to redo. Setting for shoulder work.? Snap ring groves Cooling fins
Some this could be done with a dial indicator or DRO.?
If compound is set at 29 to 30¡ã it makes harder to setup and have the carriage which not ideal.??
That is why I like direct reading dial on the cross slide only.?
"I find numerous problems with the scheme of moving both handwheels like that for the purpose of making a 29.5 degree vector."
I could be wrong, but I didn't read it as him DOING it that?way or suggesting that we do it that way.? Rather, he was using vector analysis to CALCULATE how far the tool? move directly into the work when you advance it a certain amount on the diagonal and to work out a table of those values.
On Sat, Jan 27, 2024, 18:14 Charles Kinzer <ckinzer@...> wrote:
I find numerous problems with the scheme of moving both handwheels like that for the purpose of making a 29.5 degree vector.? That's all that is happening.? Two vectors at right angles combining to produce a vector at an angle.
First, the standard way doesn't require any trig at all.? You simply view the compound dial as direct reading.? Of course, this is an approximation because the sine of 30 degrees is 0.5 which would relate to exactly a direct reading.? the sine of 29.5 degrees is0.4924 so, technically, there will be an error.? But it is so small that it is typically ignored.? For example, if you had a 0.100 thread depth (pretty big thread in the mini lathe world at least) you get 0.0985" thread depth or a 1.5 thousandths error which is going to be within pretty much anybody's spec for a thread like that.? For typical smaller threads the error is in tenths because the error is about 1.5%.? How much absolute error is that for a 10-32?
Second, the primary purpose of the 29.5 degree compound is to have most of the cutting done on one edge and the other just as a skim cut.? By using the cross slide as part of creating the vector, that goal is substantially degraded as there will be too much cutting on the right edge (for typical right to left threading).? Since the scheme violates the primary goal, anyway, why not just go straight in and be done with it.
Third, you have to accurately set NEW positions on two handwheels.? That certainly increases the exposure for an error and a spoiled part.? Machinists typically don't want to do things a hard way when there is an easier one.
Charles E. "Chuck" Kinzer
On Saturday, January 27, 2024 at 11:17:39 AM PST, davesmith1800 <davesmith1@...> wrote:
Take a sharpie and cross out the numbers on your dial, then double them and write the new numbers in.
?
Brian?
Sharpie may last 30 seconds. I like the look of manufacture type dial. My second lathe had most of marks worn off and I used a center punch to fix it look tacky
Dave??
Dave?
?
Re: New topic ¡ª- Cutting a thread for a very old wooden clamp.
Ok , huge brain fart over here , yea I have seen those . Looking at that pic linked the wooden ones look like they have a same direction thread full length of the screw ? I know on the ones I have with the steel screw the thread's? change direction on each screw so each screw has left hand & right hand threads . Lookin at one of mine some threads run right into each other & on the other screw on the clamp there looks like there's a break in the thread before they meet? on the screw . Before & after lunch maybe ?