Hi Samuel, a valiant effort and you learnt from it as have others therefore 100% success 👍. Another approach would be to 'stage' the broaches into 2 or 3 shorter lengths and turn the taper onto the blank meaning your clearance would be much easier to apply as you would only be applying clearance up to the turned diameter. This would allow you to have many more teeth per linear length fairly easily which would need less swarf clearance thereby strengthening the whole broach. I think if you remade this the same way as your original, applying angular clearance to the flat sections as you correctly called out, and gave the wire wheel a miss you would find it much better. The wire wheel will have definitely taken the keen edge off all the teeth, even in the hardened state. A final tip if you ever do anything similar is to ensure your quench is absolutely perpendicular to the tool, this avoids any bending caused by uneven quenching etc. None of the above is to criticise or take away anything from what you have achieved by the way, just paying forward my experience in the hope it helps others 😉. Well done.
Thanks. Yes " turn the taper onto the blank meaning your clearance would be much easier to apply" is the way forward. Or may be just turn the O/D in steps as required, before cutting out the clearance. One needs to be able to chuck it along its length, so turning is always close to the chuck, due to thinness. The wire wheel was a bad idea, and it went black again after tempering anyway. Hardness after tempering was between Rockwell 55C and 60C. I may try again for fun.
Hi Samuel, the simplest way to create the D shaped hole is to make the hole round, then on a bar of the same diameter, mill flat down to the chored required, cut off & fix the segment into the hole with an appropriate method depending on the material (glue, solder etc). Ideal for this situation.
Hi Samuel, thanks for an interesting video, that was a valiant effort and the tempering of the steel must have been good for the tool not to shatter. Rotary D broaches are commercially available see slater tools or polygon solutions. The advantage of a rotary broach is you can form a blind hole as well. For a one off i would go for the cheats option of drilling a full round hole and silver soldering in a piece of metal to fill in the minor segment of the circle. Or the brute force way for a plastic boss would be to pilot drill and press a suitably hot D shape bar through to mould it. Then mount the bar in the lathe between centres and turn concentric, and hide the evidence 😁
Thanks. Neither Slaters nor Polygon mention D-shaped broaches on their web sites, although they have a wide variety of other shapes, including double D. I'm sure they would make a custom one, at a price. And of course they're both in USA so there'd be duty and carriage across the pond.
The end result looked to me to fully fit for purpose. It fits, it may be slightly off centre but who would know. I doubt if one could tell by rotating the knob. I made the same mistakes re amount of cut and depth of gullet. I have a large fly press so as long as I use machine grade alloy it works ok. However mine is a double D for a throttle body, so I can use a central hole. By the way, 2011 works much better than 6061 in my case. I have used a hex rotary broach to cut thousands of holes, but only as deep as the hex on a cap screw. In your instance I would broach as deep as I could, then drill out the back of the hole to the 6 diameter. Broaches and broaching holders are not cheap. If you look at the prices of these tools, I am sure you will realise just how “perfect” your attempt is. LOL. Nigel
Thanks. I know nothing about aluminium alloys. My scrap piece of aluminium could be anything, but 6061 or 6063 seems common. The shear strength of 2011 seems higher than 6061, but perhaps the coppper makes it more ductile. Ali8express has some cheap rotary broaches, I might get one and make a D-shaped tool for it.
@@samuelfielder If you need to weld it, 6061 and suffer the machinability. If you need to machine it, 2011 but it does not weld well. That is the sum of my knowledge on the subject
I have some commercial punches for making holes in thin panels (drill a small hole for a bolt, tighten it and it pulls the two halves of the punch together and makes a bigger hole). Don't know if one could get a D-shaped punch like that,
Hi Samuel, a valiant effort and you learnt from it as have others therefore 100% success 👍. Another approach would be to 'stage' the broaches into 2 or 3 shorter lengths and turn the taper onto the blank meaning your clearance would be much easier to apply as you would only be applying clearance up to the turned diameter. This would allow you to have many more teeth per linear length fairly easily which would need less swarf clearance thereby strengthening the whole broach. I think if you remade this the same way as your original, applying angular clearance to the flat sections as you correctly called out, and gave the wire wheel a miss you would find it much better. The wire wheel will have definitely taken the keen edge off all the teeth, even in the hardened state. A final tip if you ever do anything similar is to ensure your quench is absolutely perpendicular to the tool, this avoids any bending caused by uneven quenching etc. None of the above is to criticise or take away anything from what you have achieved by the way, just paying forward my experience in the hope it helps others 😉. Well done.
Thanks. Yes " turn the taper onto the blank meaning your clearance would be much easier to apply" is the way forward. Or may be just turn the O/D in steps as required, before cutting out the clearance. One needs to be able to chuck it along its length, so turning is always close to the chuck, due to thinness. The wire wheel was a bad idea, and it went black again after tempering anyway. Hardness after tempering was between Rockwell 55C and 60C. I may try again for fun.
Many thanks for a very interesting project, Samuel 👍
Hi Samuel, the simplest way to create the D shaped hole is to make the hole round, then on a bar of the same diameter, mill flat down to the chored required, cut off & fix the segment into the hole with an appropriate method depending on the material (glue, solder etc). Ideal for this situation.
Hi Samuel, thanks for an interesting video, that was a valiant effort and the tempering of the steel must have been good for the tool not to shatter.
Rotary D broaches are commercially available see slater tools or polygon solutions. The advantage of a rotary broach is you can form a blind hole as well.
For a one off i would go for the cheats option of drilling a full round hole and silver soldering in a piece of metal to fill in the minor segment of the circle.
Or the brute force way for a plastic boss would be to pilot drill and press a suitably hot D shape bar through to mould it. Then mount the bar in the lathe between centres and turn concentric, and hide the evidence 😁
Thanks. Neither Slaters nor Polygon mention D-shaped broaches on their web sites, although they have a wide variety of other shapes, including double D. I'm sure they would make a custom one, at a price. And of course they're both in USA so there'd be duty and carriage across the pond.
The end result looked to me to fully fit for purpose. It fits, it may be slightly off centre but who would know. I doubt if one could tell by rotating the knob. I made the same mistakes re amount of cut and depth of gullet. I have a large fly press so as long as I use machine grade alloy it works ok. However mine is a double D for a throttle body, so I can use a central hole. By the way, 2011 works much better than 6061 in my case.
I have used a hex rotary broach to cut thousands of holes, but only as deep as the hex on a cap screw. In your instance I would broach as deep as I could, then drill out the back of the hole to the 6 diameter. Broaches and broaching holders are not cheap. If you look at the prices of these tools, I am sure you will realise just how “perfect” your attempt is. LOL. Nigel
Thanks. I know nothing about aluminium alloys. My scrap piece of aluminium could be anything, but 6061 or 6063 seems common. The shear strength of 2011 seems higher than 6061, but perhaps the coppper makes it more ductile. Ali8express has some cheap rotary broaches, I might get one and make a D-shaped tool for it.
@@samuelfielder If you need to weld it, 6061 and suffer the machinability.
If you need to machine it, 2011 but it does not weld well. That is the sum of my knowledge on the subject
Thanks Samuel. I've been looking to do the same for broaching D shaped holes for BNC plugs in thin equipment panels
I have some commercial punches for making holes in thin panels (drill a small hole for a bolt, tighten it and it pulls the two halves of the punch together and makes a bigger hole). Don't know if one could get a D-shaped punch like that,
@samuelfielder good suggestion thanks!
14:44 nice vice grips, which model is it?
It's an Irwin 10R. The release lever operates in the opposite direction to that on my other vise grips, but is just as effective.
@@samuelfielder That's great. Thank you.