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[Southern Sailor]

I thought I had posted this query before but had no responses and can't find it now.  The question was either too dumb to publish or I misfired? So at the risk of repeating a dumb question here goes again.   I am a novice machinist and I have an Optimum lathe D180 x 300 Vario. When using the slides, particularly the cross slide, the wheel "falls back" in certain positions during a cut and it is difficult to remember where it was when setting the next cut.  It appears that the only way of keeping track of where one is, is either by improving one's memory, or writing down the reading from the latest setting.  Any comments or tips?   Thanks. Brian

[Mark T]

Hi Brian - when you says the wheel falls back are you talking about the slack on the wheel due to the slack in the drive threads of the particular slide?  I hope that makes sense 

[Southern Sailor]

Hi Mark.  Yes I am talking about the slack.  Brian

[Mark T]

Unfortunately the only way is as you have said, you need to remember your last setting on the wheel.  If you forget the only thing left to do is to mic up where you are and then touch the cutting tool on the piece again to obtain a new datum 


All lathes suffer from this backlash and the cheaper the machine the worse it is.  Just keep track of where you are and you will be ok - Oh and mic up as often as you possibly can 

[Southern Sailor]

Hi Mark.  I am going to rig up a chalk board within easy reach and write down the readings as I go.  Like a lot of things it helps to have a procedure and stick to that. Thanks for you response.  Brian

[Shipmate60]

The cross slide should have a thrust arrangement to remove backlash.


Bob

[TailUK]

Try an arrange it so you always either advancing or returning the lead screw.  If you have to wind it back to a point on the slip ring always go past the point and then reverse direction and wind it in until you reach the mark you want.  This way you minimise the effect of "backlash" 
If you're having trouble keeping track of the cuts you're making "zero" the slip ring every pass and then the amount you need to advance is more easily gauged.

[Southern Sailor]

Thank you. The problem arose when cutting a screw thread.  I am changing my procedure - instead of withdrawing the tool completely before reversing the lead screw, I will only withdraw it a few thou because that is sufficient to allow the tool to backtrack through the thread for the next cut. Makes it easier to keep track of where you are. Thanks again.  Brian

[chuffy]

Another way of keeping track of exactly where you are or were as the case may be is to fit Direct Read Out.


These units can be bought for just a few pounds now and you never loose track and you can work in imperial or metric.


Paul.
.

[Southern Sailor]

Hi Paul, do you have more information or a link for me? Brian

[chuffy]

Hello Brian



You might like to have a look at the link to give you an idea of what i'm talking about.


[size=78%]http://start-model-engineering.co.uk/machines-and-tooling/minilathe/micro-dro/[/size]


There are dozens out there, have a look at this link
https//www.google.co.uk/search?biw=1440&bih=818&tbm=isch&source=univ&sa=X&ei=jsX9VNCWJojdap3cgbAI&ved=0CHwQsAQ&q=cheap+digital+read+out+scales#tbm=isch&tbs=rimg:Ca7UIL02jRS3IjihElHvLmKHPRN11ayRx4XfF-4yz8Tx5qs20uQFzVXPI5mqKwb05vtADmp9AFcC4kHn49X69vahfioSCaESUe8uYoc9Ef16YCeObyGPKhIJE3XVrJHHhd8RWoPH8vGcJmwqEgkX7jLPxPHmqxFsze0h6lQs9CoSCTbS5AXNVc8jETSawe5iQOWDKhIJmaorBvTm-0AR5KQsm3ce5LcqEgkOan0AVwLiQRE0msHuYkDlgyoSCefj1fr29qF-EVqDx_1LxnCZs&q=cheap digital read out scales&imgdii=_

A google search for "cheap direct read out for lathe" yielded that result with loads of information and video's on many other ideas in the same search, though I am not sure what you can Google in SA or whats available retail wise.


Paul.

[Southern Sailor]

Thanks Paul.  A great idea.  We do have pretty much the same access to the internet as you do.  The problem comes in the delivery from UK - everything has to be couriered (due to theft along the way in the post) so getting the items here is not cheap.  I know however that tyre depth gauges are available in SA. Regards. Brian