Okuma LS Adventures Part 7: Forkhardt Manual Power Chuck

[@aaronbaird3533]

That chuck is quite a piece of engineering work! Just found your series on the LS. I really appreciate you that you've taken time to document your work. It will be helpful if I need to work on my LS. It's also interesting to see the differences in construction between your lathe and mine.

[@korishan]

I had wondered how the chuck moves the jaws. I always thought there was a large ring gear with threads on it that turned, not that there were 3 blocks with partial teeth. Pretty interesting. Thanks for the tear down and reassembly :)

[@joell439]

Very interesting. Thank for showing us this unique design 👍😎👍

[@BLECHHAUS]

Our lathe operators always said: "Throw it away if it's not a Forkardt chuck". I was lucky enough to get an unused 125 F chuck for my minilathe.

[@bartharkemametalworks2299]

Yes there great. Nice that you got a unused one.

[@BLECHHAUS]

@@bartharkemametalworks2299 What do you mean, how happy I was when I found it. And I'm already envied for it :-)

[@CHIPLOAD]

i always wanted to know some more details about these chucks, thanks for a great video!

[@bartharkemametalworks2299]

Your welcome. I also couldn't find a good video about it so I thought let's make one and share it.

I would have made one if you had shown me this sooner 🙃

[@bartharkemametalworks2299]

😄👍 a 6 jaw version would be very impressive

[@bartharkemametalworks2299]

The straight jaw teeth would have been a bit easier I guess

[@CHIPLOAD]

Haha if someone can do it then you! I am not sure if 6 jaws would even be possible based on the inner alignment of the parts at least I have never seen one 🧐

@@bartharkemametalworks2299 judging from what i've seen on your video. It will only take me 50 years to make.

[@benalter7316]

hi Bart, good to see u again. what a nice machine u got! great i like to see more thnx

[@bartharkemametalworks2299]

Thanks Ben 👍

[@MattysWorkshop]

Gday Bart, I’ve never seen this type of chuck before, interesting the way it works, the jaw pressure would be amazing, thanks for sharing mate, cheers

[@bartharkemametalworks2299]

Thanks Matty, it's a great design. Pressure on the jaws is almost to much that is has less feeling to it. You can just keep turning the key and end up with triangle shape parts.

[@jpsimon206]

There are a handful of metal working items that I have been introduced to by you. It's very exciting for me when I get to learn about a tool that I was completely unaware of. I was curious if there is a particular publication or other resource that you recommend?

[@bartharkemametalworks2299]

Thanks, not sure about recommendations. I did studie Metalwork a long time ago. No it's just online resources like KZbin, Instagram, podcast or just the internet. Many people focus on one particular craft within Metalwork but I like many and always curious to find and learn more.

[@greasemonkeypol]

nice work great machine

[@glennstasse5698]

Incredible chuck. Can the 3 jaws be moved independently from one another? I didn’t catch what caused them to be in sync like a regular scroll chuck. I would guess you’d want them synchronized but maybe it can do that plus work like a 4-jaw? Anyway, fabulous workmanship, as always. Happy Hollidays!

[@bartharkemametalworks2299]

I think you can. The jaws are independent from each other but do need to fit into the drive gear threads. So only increments of around 4mm offset

[@glennstasse5698]

@@bartharkemametalworks2299 an odd feature for a 3-jaw chuck. Maybe not the intended use but a side effect of the design.

[@janvanruth3485]

@@bartharkemametalworks2299 i think you are mistaken. the jaws cannot operate independently from each other. if one moves they all move.

[@jpsimon206]

Wow! I have never seen a chuck like that! That seems like it would be extremely handy. Are the teeth completely straight? Does that make it very easy to make some custom jaws or replacements?

[@bartharkemametalworks2299]

Thank you. Yes the teeth are completely straight (and can be flipped around) so you can make your own. But hardening and the ground surface would be a challenge. Not sure that is worth it to make your own or just buy some new or second hand.

[@lordRW]

seeing how something might have already been touching the outside of the chuck, you should hold something known to be round in it for the last adjustment of the 3 bolts holding it in place right?

[@bartharkemametalworks2299]

Do you mean the bolts that hold the backplate to the chuck? That is like a press fit. I don't think that will move much but its interesting to test it out.

[@janvanruth3485]

hoe meer pruisisch blauw hoe beter ie past.... zie een pistonpen van een grotere diesel motor te pakken te krijgen. die dingen zijn gehard, goed rond en qua diameter mooi consistent. opspannen en rondloop meten. stang in de holle pen schuiven en meten terwijl er zijdelings kracht op gezet wordt. dan kun je zien hoe goed de klauwen zijn. en voor heel precies werk een stel zachte klauwen maken.

[@bartharkemametalworks2299]

Goed punt Jan, een geslepen as heb ik er al op gehad en gemeten. De klauwen zijn wat versleten en moeten voor nauwkeurig werken opnieuw geslepen worden. Dit ga ik nog doen en ook een paar sets zachte klauwen maken. Belangrijkste was nu schoonmaken en zorgen dat de adapter goed op de spindel past. Met de 0.015 mm op de adapter ben ik tevreden.

[@janvanruth3485]

@@bartharkemametalworks2299 zolang de klauwen rond lopen maakt de rest niet zoveel uit. vraag is of de klauwen rond blijven lopen als je ze verzet hebt. probeer maar eens de rondloop te meten nadat je de klauwen een stukje opgeschoven hebt. als je dan verschillende waardes krijgt heeft slijpen van de klauwen weinig zin, tenzij je meestal een standaard diameter gebruikt. die klauwen zie je trouwens redelijk vaak op ebay.de soms gloenieuw en voor niet teveel.

[@bartharkemametalworks2299]

@@janvanruth3485 ik zal de verschillende posities eens opmeten, wel interessant. Ik denk dat het mee valt. Ik zal wel regelmatig wisselen met een ander klauwplaat dus is nette montage op de spindel ook wel belangrijk voordat ik de bekken ga slijpen.

[@janvanruth3485]

@@bartharkemametalworks2299 repeatability bij de montage van de 3 klauw is voor de rondloop van het grootste belang. ik laat de onafhankelijk vierklauw er altijd op zitten. als ie er al af gaat is het voor een collet houder. maar ik heb dan wel een livhterebank met een, hele goede, drieklauw als standaard montage er langs staan.

[@huibhoogendoorn503]

Toch maar weer en bod gedaan op een andere draaibank Bart?

[@bartharkemametalworks2299]

Bedoel je deze Okuma of iets anders?

[@huibhoogendoorn503]

Zag je volgens mij op MP bieden op een andere draaibank.

[@bartharkemametalworks2299]

@@huibhoogendoorn503 Ja kan kloppen. Maar die was al snel weg. En eigenlijk heb ik er ook niet zoveel ruimte voor. De Okuma en Schaublin wil ik zeker houden.