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I Forge Iron

Getting twisted


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Hello All,
Just shot a video of my new twisting machine in action.

http://www.doorcountyforgeworks.com/Videos.html
The video should be at higher resolution in a day or so.


There are a few hiccups in the presentation, but the tool is sound. I have wanted to work larger for some time on sculpture, architectural and damascus projects and this tool allows me to do so.
I have planed a larger tool, but such is the way of things.

Ric

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So RIc, we saw the twist, you have some specs on the machine?

Danger,
5hp 1140 rpm three phase motor double belt sheave pulley drive into a 30:1 gear box to a 2:1 #120 chain/sprocket to the shaft of the twister. 18RPM output. The sprocket/chain was about $1,000, but it works well and I had no surplus bits.
Deadman up on/off/down on switch which goes to off when not actively pushed (detent to off)....$7 from surplus center.
I had an on/off switch and a direction control, but I wanted an easy off so when things got interesting I would not get into trouble.

I have stalled it on stainless and when the carbon steel gets cold.

I have an idea for a 20hp unit which should twist 4" square....in the future.


Don,
Yes, it popped right out when the camera was off...such is the way of things. I had over-rotated and it was pinched, but when I freed the drive end the other came out clean. I could have done three or so "takes" and made it look good, but that was not the point really.
I normally do not use the "safety" top lever on the tailstock, but thought it best to show it on the video. I have not had a piece come out unless it rounded the ends in the twist..which occurs if I do not get a tight fit tool to bar ends.

Ric
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Excellent video. Is it an illusion caused by the camera or does the metal heat up at several points (points of crisis as far as the metal is concerned)?
I'm a big fan of Albert Paley's bench at the V&A (in London). The tightness of the twists where the corners rip (I think you used a term for it in this video) give a very satisfying texture.
Lastly, I did once see a fellow doing a twist on a length of large diameter threaded bar. It was a good effect.
-Dan

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Excellent video. Is it an illusion caused by the camera or does the metal heat up at several points (points of crisis as far as the metal is concerned)?

-Dan


Dan,
There is quite a bit of friction on twists that tight and friction causes heat...much like forging in one spot under a hammer...it will get hot. One can pound on a cold mild steel bar and get it glowing red or more if you can hit it hard and fast enough. This is one of the nifty things about modern rolling mills...if the reduction is designed "right" from pass to pass the metal stays hot and just gets longer.

I am seeing a lot more in the video then I do when its in front of me...too busy watching what I'm doing to pay attention to what I make happen.

Ric
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A big lathe with a 4-jaw might accomplish the same thing (of course, it might wreck the lathe too). My 15x48 Clausing has a 5hp motor and will get down to 30 rpm but I use it for machining and don't want to take the chance of breaking a gear. With that said, there are quite a few junk lathes out there in Ebay-Land which might qualify as a donor machine for a twister.

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Danger,
5hp 1140 rpm three phase motor double belt sheave pulley drive into a 30:1 gear box to a 2:1 #120 chain/sprocket to the shaft of the twister. 18RPM output. The sprocket/chain was about $1,000, but it works well and I had no surplus bits.
Deadman up on/off/down on switch which goes to off when not actively pushed (detent to off)....$7 from surplus center.
I had an on/off switch and a direction control, but I wanted an easy off so when things got interesting I would not get into trouble.

I have stalled it on stainless and when the carbon steel gets cold.

I have an idea for a 20hp unit which should twist 4" square....in the future.


Don,
Yes, it popped right out when the camera was off...such is the way of things. I had over-rotated and it was pinched, but when I freed the drive end the other came out clean. I could have done three or so "takes" and made it look good, but that was not the point really.
I normally do not use the "safety" top lever on the tailstock, but thought it best to show it on the video. I have not had a piece come out unless it rounded the ends in the twist..which occurs if I do not get a tight fit tool to bar ends.

Ric



Super cool.... But dont buy any more sprockets or chain without asking me first.. I am pretty sure I could get you want you need for about 20% of what you spent... (my dad has a warehouse full of surplus bits that can be had for pennies on the dollar)
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I'll bet a hydraulic torque wrench would work with similar results. Although they might be a bit slow.

I would think there are many ways to get the toque and control..electric motor, gear box and chain combo is but one.
I looked into hydraulic motors, but since I know very little about them and the Hyd torque wrench I did not go that route.

Speed is useful unless you can keep the bar hot (i.e. set a forge around it, gas axe or induction etc)..one rpm is OK if the bar stays hot.

Ric
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