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Been playing with my new minilathe.
Found that machining a brass bar the tool leaves fine ridges like small screw threads.
is this normal and I just clean them up with a file, or is the tool blunt or speed too slow or what?
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Rank: Member
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Joined: 24/11/2013(UTC) Posts: 24 ![Australia]( "Australia")
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Not sure about the lathes , hope your enjoying the new toy....
Any chance use could copy a radio adjustment knob for a Ferries radio cera 1969??? Would love to get one made somewhere..
Best of luck on working out the correct speeds and tooling...
Cheers BHT..
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Rank: Veteran
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Joined: 1/03/2005(UTC)
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could have a go but remember absolute amateur.
send a pic if I think I can do it will need real thing to copy
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Rank: Member
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If its a new lathe, I assume the tool is new also so not blunt.
Ensure the tool tip is set to the centreline height of the workpiece by shimming it in the toolpost. This is critical for any turning operation.
A high speed and slow feed should give you a better finish.
Hope this helps, but if you need actual speeds and feeds, let me know what diameter brass you're turning and I'll look up the cutting speeds for you.
Cheers,
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I will add to what MRHT69 has said, make sure the work piece is not to far out from the chuck jaws as this can cause the brass etc to flex giving an uneven surface finish. If you need to turn a longer work piece, 1st centre drill the work piece and use a running centre located in the tailstock then into the brass for support. There could be many reason for the uneven finish, some covered above and by MRHT69. If these don't remedy the bad surface finish it would be better to have a machinist physically check whats going wrong. I am in western Sydney, if your near by would be happy to have a look or alternatively send me a video of you taking a cut over the surface and I should be able to tell whats going wrong. |
j.williams |
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Rank: Veteran
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Thanks guys. I am in country wa so not likely to be dropping in!but thanks for the offer.
am away from home at the moment so have not had a chance to try other ideas.
discovered that if the piece is too far out it flexes and you can see the free end waving about so have to watch that.
I have a couple of charts that show speeds etc but does not help much as lathe does not have a rpm counter so just going by seat of pants and tongue in cheek.
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