Taper Turning

[RussellT]

One day while using the lathe I had the not very original thought that if I could turn two handles at the correct rate then I wouldn't need the taper turning attachment that I can't afford anyway.

Some time has passed and I have finally developed the idea to a stage where I have something to show.

Here's the lathe with a gear tooth position sensor counting the revolutions of the spindle.


This is the cheap ebay topslide with a worm drive and stepper motor added.


This shows the general arrangement with an old laptop, an old computer power supply and a box with some home made stepper motor drivers.  I wrote a program for the computer to control the topslide based on the number of revolutions of the work.  It works with the lathe on its finest feed.


The fourth shows the results of a test with a MT2 socket on the taper - I was delighted with this as the fit is excellent although the surface finish could do with improvement.


The last picture shows the result.


Russell

[BillTodd]

Neat & Simple - I like that

Bill

[Rob.Wilson]

Nice going Russell  Very clever idea 

Looks like your getting a good finish too 

Rob

[Jonny]

I like that idea in general, smarten it up you may have a market.

[trevoratxtal]

Oh I doooo love innovation, especial when using old bits, as in recycling.
Brilliant ! I award you Madmodder, Star off excellence.
 
Well I would if I had one, it is time some recognition system was set up to recognise great ideas perhaps with a button for "I love this", get so many and get a star.
I know all members are stars, I mean one like we got on our books at school if we were really good.
Many thanks for a great article Russell
Trev

[Swarfing]

Russell what software are you using? great job 

[RussellT]

Hi All

Thank you for the kind remarks.

Rob - the finish looks better than it feels - but I've seen the finish on some of your projects  and I appreciate the comment.

Jonny - I hadn't thought about that  but it ought to be possible to reduce it to a sensor, microcontroller and stepper driver.  A mechanism that could be mounted in the toolpost and advanced by stepper would make it usable on virtually any lathe.

Trevor - I'm very keen on recycling stuff  - or maybe just averse to spending money.  The only thing I bought for this project was the spare topslide which was missing the dial and handle anyway.

Swarfing - The old laptop is running Windows 98 (which is an advantage as later versions make access to the parallel port more difficult).  I've written a program in QuickBasic to control the stepper motor.  (QBasic would have worked too.)  There is a little bit of machine code in the program as the sensor uses the parallel port interrupt to make sure it doesn't miss counting any teeth.  I've not done any programming in assembler before so that was a challenge.

I ought to record my thanks to Allegro Microsystems who made the gear tooth position sensor (ATS616LSG).  I couldn't find a supplier in this country and they gave me some free samples.

Thanks again for the comments.

Russell

[trevoratxtal]

Russell
Please post copy of the qbasic program, I would love to see you version.
Many thanks
Trev

[RotarySMP]

If you replace the threading program with TurboCNC or LinuxCNC or Mach3, there they will be a whole lot of other things it will be able to do then just tapers.

[Divided he ad]

That's mental! (meaning cool!)

Some people just have genius DNA    Very ingenious /Russell    



Trev... IMHO  "recognition system"  =  Route of many evils!  (I.E. karma junkies!!!)





Ralph.

[RussellT]

Thanks Ralph.  Some people have said I'm mental too.

RotarySMP I've thought about that and I downloaded Mach3 to have a play but found the learning curve a bit steep.  I don't quite see how it would help as I only have one motorised axis.  I did think that it should be possible to turn funny shapes like cams or possibly even squares but that would need a bigger stepper motor as the current one is only capable of very slow movement.

Trevor No problem.  I've attached a copy of the program.  It still needs some refinement and features - I haven't put anything in for custom tapers although I have set up MT 1, 2 and 3 for my lathe.  There are some portions (to do with interrupt addressing) that came from an internet tutorial so I would give credit for that if I could remember where I got it from.  If you want to know more about any of it then please ask.  You'll need the change the file extension to bas to run it.

Russell