Here are a couple of thoughts for anyone trying to do this. The friction mechanism for this device is not what is mentioned at about the 3:45 mark (I think that is a wiper or dust sheild and I'd keep it). The friction spring is actually under the side. The slide can be removed from the carrage with a twisting motion at the back (around the 0 label) when the slide is in the zero position. Once this is out it is also easy to enlarge the recess at the tip to allow the magnet to recess into the carrage, thus preserving the full range of motion.
Looked good so I decided to give it a try. Bought very similar looking depth gauges and the magnets etc and set it up pretty much as shown (my lathe looks damn near identical). Did some test turning i.e. increment top slide according to gauge reading and measure result and got some seriously undersized diameters! On detailed checking I find that a) the gauge is about 10-15% inaccurate (compared to mechanical dial gauge) but worse than b) that suffers about 0.3mm hysteresis. For those not familiar with that term its like backlash in the lead screw. So starting at zero wind in say 1.0mm - then wind back to zero and the gauge reading fails to change until you get back to 0.7mm and when back at zero still reads 0.3mm. Given that these are cheap gauges designed for tyre tread measurement not that surprising I suppose, but not as usefull as I had hoped. Still top marks Mike for coming up with the idea in the first place. Always easy to criticise after somebody has done the hard work!
Top job and well presented, A very useful addition to our lathes (and other precision equipment). The DRO measures on the slide, and shows tool tip to stock exactly, negating the effect of backlash completely. Well done. Kind regards. Michael. Australia.
I just made one of these today using strip magnets. I'm able to just snap it on the cross slide and go. It also will attach to the tailstock and the magnet attaches to the back of the chuck allowing easy indication of drilling or tapping depth. VERY handy indeed and easy to make.
Hi Mike, It's an interesting project and for additional info the digital tire gauge is manufactured by a company in China that also makes digital calipers. Now it's well known that the Chinese like to keep the prices low and to do so for the digital tire gauge they have used the electronics unit that is also used for the calipers. I purchased a couple of PCB's that are identical to the PCB in the tire gauge but are 1 Meter long for £15 each and ascertained that the electronics unit is capable of indicating 99.99 mm. To cut a long story short I cut the first PCB into two pieces to use on my milling machine and cut the other into three pieces, two for the lathe and the odd piece for the 'Z' axis on the mill. A dual axis readout from WARCO completed the total digitization on both my lathe and my mill on all 5 axie's for under £100.
Mo King Hi Mo, Thanks for the info. I am going to buy a Seig Super X2 mill after I have acquired a plasma cutter and a few other things, so will be looking for a low cost DRO solution for that. I would be interested to hear how your setup stands up to swarf and cutting fluids.
Thank you so much from across the pond. Your have a way of presentation that is enjoyable and educational. Plus, a pretty darned good idea there. Cheers!
That isn't backlash in the lead screw. The threaded lug on the bottom of the cross slide has come loose. Tighten the 2 screws on the top of the cross slide that hold the lug in place. Use some threadlock.
+Emgee Radian An excellent suggestion that would work for many lathes. On my lathe the compound rest limits the visibility for a DRO fitted on the tailstock side. Also I have fitted a carriage lock on that side so there is now no room for the DRO. Swarf is only a problem when turning ferrous metals of course.
its a M9 x 0.5mm Leadscrew but main problem is you cant screw the handle tight since then you cant turn the handwheel. Thats where additional backlash is introduced. I plan to add custom made acial ballbearings to counter that (its not hard, just steelbals a cage and then turn a groove in the handle so it fits inside)
I know neodynium magnets are strong but so is vibration. Is it possible that this method of attachment is not secure enough for accuracy due to vibration? Also, please address the hassle of trying to get swarf off of your magnets.
great idea mike i will be making one asap as ive got a chester conquest also with slack on the cross slide. Since buying your lathe 2013 have you bought or know anywhere in u.k. for the quick release tail stock? im so fed up with the nut.
paul maddison Hi Paul, Amadeal used to sell a quick release tailstock that fitted the Real Bull lathes but they don't seem to list it any more. Might be worth asking them though. I wish I had bought one when I first saw them - that clamping nut drives me mad when doing a complicated series of operations.
Here are a couple of thoughts for anyone trying to do this. The friction mechanism for this device is not what is mentioned at about the 3:45 mark (I think that is a wiper or dust sheild and I'd keep it). The friction spring is actually under the side. The slide can be removed from the carrage with a twisting motion at the back (around the 0 label) when the slide is in the zero position. Once this is out it is also easy to enlarge the recess at the tip to allow the magnet to recess into the carrage, thus preserving the full range of motion.
Looked good so I decided to give it a try. Bought very similar looking depth gauges and the magnets etc and set it up pretty much as shown (my lathe looks damn near identical). Did some test turning i.e. increment top slide according to gauge reading and measure result and got some seriously undersized diameters! On detailed checking I find that a) the gauge is about 10-15% inaccurate (compared to mechanical dial gauge) but worse than b) that suffers about 0.3mm hysteresis. For those not familiar with that term its like backlash in the lead screw. So starting at zero wind in say 1.0mm - then wind back to zero and the gauge reading fails to change until you get back to 0.7mm and when back at zero still reads 0.3mm. Given that these are cheap gauges designed for tyre tread measurement not that surprising I suppose, but not as usefull as I had hoped. Still top marks Mike for coming up with the idea in the first place. Always easy to criticise after somebody has done the hard work!
Top job and well presented, A very useful addition to our lathes (and other precision equipment). The DRO measures on the slide, and shows tool tip to stock exactly, negating the effect of backlash completely. Well done.
Kind regards. Michael. Australia.
I just made one of these today using strip magnets. I'm able to just snap it on the cross slide and go. It also will attach to the tailstock and the magnet attaches to the back of the chuck allowing easy indication of drilling or tapping depth. VERY handy indeed and easy to make.
Hi Mike,
It's an interesting project and for additional info the digital tire gauge is manufactured by a company in China that also makes digital calipers. Now it's well known that the Chinese like to keep the prices low and to do so for the digital tire gauge they have used the electronics unit that is also used for the calipers. I purchased a couple of PCB's that are identical to the PCB in the tire gauge but are 1 Meter long for £15 each and ascertained that the electronics unit is capable of indicating 99.99 mm. To cut a long story short I cut the first PCB into two pieces to use on my milling machine and cut the other into three pieces, two for the lathe and the odd piece for the 'Z' axis on the mill. A dual axis readout from WARCO completed the total digitization on both my lathe and my mill on all 5 axie's for under £100.
Mo King Hi Mo, Thanks for the info. I am going to buy a Seig Super X2 mill after I have acquired a plasma cutter and a few other things, so will be looking for a low cost DRO solution for that. I would be interested to hear how your setup stands up to swarf and cutting fluids.
If you want more magnetic grip use the neodymium magnets out of a scraped hard drive, very STRONG grip
They are stronger and attract a lot of steel chips. 👍
Thank you so much from across the pond. Your have a way of presentation that is enjoyable and educational. Plus, a pretty darned good idea there. Cheers!
It is a really great alternative to a CNC machine. And a very nice implementation.
This Mike fella is so pleasant to listen to.
Hmmm, one could take those cheap gages and make new slides for whatever length you want. Thanks for the vid!
Doesn't the depth gauge read actual movement, while the cross-slide dial reads total cut, ie. twice the movement?
That isn't backlash in the lead screw. The threaded lug on the bottom of the cross slide has come loose. Tighten the 2 screws on the top of the cross slide that hold the lug in place. Use some threadlock.
Great idea Mike but why not fit it at the tailstock side of the saddle, out of any swarf.
+Emgee Radian An excellent suggestion that would work for many lathes. On my lathe the compound rest limits the visibility for a DRO fitted on the tailstock side. Also I have fitted a carriage lock on that side so there is now no room for the DRO. Swarf is only a problem when turning ferrous metals of course.
Mike Moore
Some backlash you got there. I would definitely try to sort that out before fitting any DRO device. Great idea just the same.
its a M9 x 0.5mm Leadscrew but main problem is you cant screw the handle tight since then you cant turn the handwheel. Thats where additional backlash is introduced. I plan to add custom made acial ballbearings to counter that (its not hard, just steelbals a cage and then turn a groove in the handle so it fits inside)
Really nicely done!
Great idea and a good video. Thanks
I know neodynium magnets are strong but so is vibration. Is it possible that this method of attachment is not secure enough for accuracy due to vibration? Also, please address the hassle of trying to get swarf off of your magnets.
Brilliant!.. Thanks very much for sharing this idea :D
great idea mike i will be making one asap as ive got a chester conquest also with slack on the cross slide. Since buying your lathe 2013 have you bought or know anywhere in u.k. for the quick release tail stock? im so fed up with the nut.
paul maddison Hi Paul, Amadeal used to sell a quick release tailstock that fitted the Real Bull lathes but they don't seem to list it any more. Might be worth asking them though. I wish I had bought one when I first saw them - that clamping nut drives me mad when doing a complicated series of operations.
Mike Moore MANY THANKS MIKE
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You can't engineering experience. Good job!
This is what youtube is all about! Too many videos with people spending hundereds and thousands!
Hmmm, one could take those cheap gages and make new slides for whatever length you want. Thanks for the vid!