Gilliandrea
Full Member
Really looking forward to your updates 
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Bentwood Ring - The Journey begins
- Thread starter Jimjam66
- Start date
Lons
Fellow
C'mon, c'mon, David where's the next bit. Can't wait, stop bl**dy slacking man
Penpal
Grand Master
Think you would open a can of worms.
Looking forward to this David if made them but only wood .
isn't it finished yet David, what you been doing man????
wm460
Grand Master
- Joined
- Mar 16, 2013
- Posts
- 23,128
- First Name
- Mark
Weekends coming up he be finished then.
Hmmmmm ... at the rate I work, this project could take months. Don't be so impatient, you lot!
Good for you, I'm gonna be hooked on this for sure.
Bentwood ring - some progress
First, the drawing of what I am aiming to achieve in case my 'word picture didn't make sense:
And a pic of the mandrel I made up to hold the ring in the lathe chuck (made out of acetal):
I threaded the mandrel (M6x1) and turned a cone to squeeze the 'jaws' outward to hold the ring.
So, after boiling the walnut strips I wrapped them over a round rod, secured them with masking tape (because it was to hand) and left them to get used to their new shape:
After a few days when I peeled the masking tape off they popped out a bit but mostly held their pigtail shape BUT ... they were still wet:
Since I was going to use CA I didn't want any moisture left in the timber so I blasted them with a hot air gun - as the heat hit them they straightened noticeably, but the moisture disappeared pretty quickly given how thin they are. Now for the fun bit - wrapping and gluing. There is a trick to this bit, and when I find out what it is I'll share it with you!
Basically you are trying to wrap a strip of timber that is resisting you around a mandrel sized to about a millimetre smaller diameter than your eventual ring size. First, I learned the hard way that it was best to first wrap a strip of masking tape around the mandrel or you just glue the ring to the mandrel.
Second, you need to lay a bead of glue along the outside edge of the inner 'tail', the bit that will be underneath as you complete the first wrap. Then you need to keep everything tight down on the mandrel as you make that wrap WITHOUT sticking your finger into the bead of glue ... !!! Simples ... Anyway, once the first wrap is down it gets easier, keep coating the inner surface with glue and wrapping until the entire strip is wrapped. I did leave bits of nitrile glove behind quite frequently, so I had to keep grabbing a sanding block to remove them before they got incorporated into the ring.
I then left the glue to dry, removed the ring from the mandrel and mounted it to the expanding mandrel for trimming and sanding on the lathe:
For internal sanding I used the Dremel:
You can still see the laminations looking sideways on:
Next step is to add the holly sandwich to each side:
And that's where I am at the minute.
First, the drawing of what I am aiming to achieve in case my 'word picture didn't make sense:
And a pic of the mandrel I made up to hold the ring in the lathe chuck (made out of acetal):
I threaded the mandrel (M6x1) and turned a cone to squeeze the 'jaws' outward to hold the ring.
So, after boiling the walnut strips I wrapped them over a round rod, secured them with masking tape (because it was to hand) and left them to get used to their new shape:
After a few days when I peeled the masking tape off they popped out a bit but mostly held their pigtail shape BUT ... they were still wet:
Since I was going to use CA I didn't want any moisture left in the timber so I blasted them with a hot air gun - as the heat hit them they straightened noticeably, but the moisture disappeared pretty quickly given how thin they are. Now for the fun bit - wrapping and gluing. There is a trick to this bit, and when I find out what it is I'll share it with you!
Basically you are trying to wrap a strip of timber that is resisting you around a mandrel sized to about a millimetre smaller diameter than your eventual ring size. First, I learned the hard way that it was best to first wrap a strip of masking tape around the mandrel or you just glue the ring to the mandrel.
Second, you need to lay a bead of glue along the outside edge of the inner 'tail', the bit that will be underneath as you complete the first wrap. Then you need to keep everything tight down on the mandrel as you make that wrap WITHOUT sticking your finger into the bead of glue ... !!! Simples ... Anyway, once the first wrap is down it gets easier, keep coating the inner surface with glue and wrapping until the entire strip is wrapped. I did leave bits of nitrile glove behind quite frequently, so I had to keep grabbing a sanding block to remove them before they got incorporated into the ring.
I then left the glue to dry, removed the ring from the mandrel and mounted it to the expanding mandrel for trimming and sanding on the lathe:
For internal sanding I used the Dremel:
You can still see the laminations looking sideways on:
Next step is to add the holly sandwich to each side:
And that's where I am at the minute.
Penpal
Grand Master
fascinating so far David not a fast process and along the way you have made several jigs of interest.
Peter.
Peter.
TrevT881
Apprentice Member
David, this is fascinating. Can't wait for the next instalment.
donwatson
Fellow
Great stuff David.
Incognitouk
Full Member
Ive made quite a few of these and its nice to see someone else trying their hand at it, i have smiled at the story so far and also chuckled as i recall doing some similar things lol
if you get stuck anywhere (and i dont mean literally) give me a poke and ill stick my pennies worth of knowledge in here follows a few examples of some of the rings ive done in the past
First is a his and hers padauk and silver ash reversed matching set
next is a another matching set ebony and mother of pearl with a sycamore inlay (these i made for my own wedding yeah yeah i hear you saying making your own wedding rings cheap skate :P) sorry about the poor quality picture
next are sycamore and walnut, one has a sycamore inlay
sycamore and ebony
another sycamore and ebony
i could post a lot more but i think i have hijacked this thread enough :)
i hope i got the pics in the right order LOL
if you get stuck anywhere (and i dont mean literally) give me a poke and ill stick my pennies worth of knowledge in here follows a few examples of some of the rings ive done in the past
First is a his and hers padauk and silver ash reversed matching set
next is a another matching set ebony and mother of pearl with a sycamore inlay (these i made for my own wedding yeah yeah i hear you saying making your own wedding rings cheap skate :P) sorry about the poor quality picture
next are sycamore and walnut, one has a sycamore inlay
sycamore and ebony
another sycamore and ebony
i could post a lot more but i think i have hijacked this thread enough :)
i hope i got the pics in the right order LOL
Attachments
Well that's me well and truly put in my place! Lovely work there, hopefully I can eventually emulate some of them!
As a matter of interest how long a length of veneer do you use on a ring? And what thickness is the veneer?
As a matter of interest how long a length of veneer do you use on a ring? And what thickness is the veneer?
Incognitouk
Full Member
David this is something i spent a long time trying to get right, i started off with a 0.6mm thickness, but found that even that was to thick, and didnt want to invest in an expensive thickness machine so i made a gadget to go across the lathe bed which i could raise up and down and made a sanding wheel for the chuck (homemade thicknesser) so i could run the veneer down to about 0.4mm sometimes thinner depending on what type of veneer i was using, once dampened and a bit of heat applied this bent like a dream, as for length i would always use about 12" and then just trim it down to where i wanted it to be.
wm460
Grand Master
- Joined
- Mar 16, 2013
- Posts
- 23,128
- First Name
- Mark
Your are making me want to go out and make rings.
Lons
Fellow
Brilliant - love it, get back in the workshop David
Well, I got some more done - unfortunately a case of 'two steps forward and one step back' as you will see.
First, finished the holly sides. Then I wrapped the ring in a number of turns of masking tape and mounted it in the chuck jaws to finish the inside:
I applied about eight coats of CA with the lathe spinning at 350rpm. This decreased the inside diameter by about 0.1mm which I can polish out toward the end of the journey.
Then I mounted the ring to the mandrel and applied about eight coats of CA to the outside, again with the lathe spinning slowly. Once that dried, I mounted my Dremel holder in the banjo with a 0.8mm end mill to cut the groove for the silver wire:
And that's where I took the backward step! Again, there is no fine adjustment to the banjo, so I cut the groove about 0.4mm too deep - the silver wire is actually under the surface of the groove!
So somehow I have to raise the floor of the groove slightly to allow the wire to be slightly proud of the surface so I can sand it back to flush. Any ideas?
Anyhow, while that is on hold I started on mounting the stones in their tube settings. Here are the three setting with the stones loosely seated:
With the tube sitting on a hard surface, the edges of the setting where they are proud of the stone's 'pavilion' (widest part of the skirt) are gently flattened inwards over the edges of the stone to grip it firmly. This is done with a Bevel Setting punch of the correct size:
The next photo shows the settings after bevelling, with the top fraction of a millimetre of the setting now sloping inward at 45 degrees and burnished by rotating the bevel punch while firmly pressed against it:
I have to say that a 10x loupe was of immense help with this, the detail is just too tiny for a tired old human eye. The paperclip was used to push against the stone from underneath to ensure it wouldn't just pop out.
So - anyone able to suggest a fix for the groove that's too deep? Apart from that I think we might be on the home straight ...
First, finished the holly sides. Then I wrapped the ring in a number of turns of masking tape and mounted it in the chuck jaws to finish the inside:
I applied about eight coats of CA with the lathe spinning at 350rpm. This decreased the inside diameter by about 0.1mm which I can polish out toward the end of the journey.
Then I mounted the ring to the mandrel and applied about eight coats of CA to the outside, again with the lathe spinning slowly. Once that dried, I mounted my Dremel holder in the banjo with a 0.8mm end mill to cut the groove for the silver wire:
And that's where I took the backward step! Again, there is no fine adjustment to the banjo, so I cut the groove about 0.4mm too deep - the silver wire is actually under the surface of the groove!
So somehow I have to raise the floor of the groove slightly to allow the wire to be slightly proud of the surface so I can sand it back to flush. Any ideas?
Anyhow, while that is on hold I started on mounting the stones in their tube settings. Here are the three setting with the stones loosely seated:
With the tube sitting on a hard surface, the edges of the setting where they are proud of the stone's 'pavilion' (widest part of the skirt) are gently flattened inwards over the edges of the stone to grip it firmly. This is done with a Bevel Setting punch of the correct size:
The next photo shows the settings after bevelling, with the top fraction of a millimetre of the setting now sloping inward at 45 degrees and burnished by rotating the bevel punch while firmly pressed against it:
I have to say that a 10x loupe was of immense help with this, the detail is just too tiny for a tired old human eye. The paperclip was used to push against the stone from underneath to ensure it wouldn't just pop out.
So - anyone able to suggest a fix for the groove that's too deep? Apart from that I think we might be on the home straight ...