poor mans dro setup.

[lather]

have been modifying a poor mans dro to get as narrow as possible.
decided to use it without the front plastic cover, and unsolder-ed a usb cable socket to reduce the thickness.
had to cut down about 5mm from the top side,as it would have been higher than the cross slide once a protective cover is fitted.
It was tricky soldering the wires onto the circuit. will place rubber sealer over the top of the circuit board and use a thin brass shim as a cover.

have attached pics of the mods so far, also shows the clearances compared to the cross slide.

Now at the stage of attaching the scale,
would it be o.k. to araldite aluminum flat bar to the side of the cross slide, don't intend to drill holes in the cross slide, and is it o.k. to have the bottom of the scale unprotected ?

it won't be a normal fitting, as there will be about a 5mm gap for access to the cross slide lock bolt.
the original grub screw has been replaced with a modified hex head nut, so now a narrow spanner can be used to lock the cross slide from above.

[snowyskiesau]

I take that there is a remote display somewhere? What are you using?

I did something similar to mount scales to my X2 mill for a Shumatech DRO, there's a few pictures of a scale conversion I based mine on here (http://cnc.turkeys.net.au/workshop/scales/).

[lather]

it has a remote display.
same as below.
DRO Digital Readout Display With 600mm / 24" Scale Kit | eBay (http://www.ebay.com.au/itm/DRO-Digital-Readout-Display-600mm-24-Scale-Kit-/380396621983?pt=LH_DefaultDomain_15&hash=item589167d09f)

would have preferred using a vernier, the slide being stainless steel would be more durable compared to the aluminum scale.

[Dave J]

Your going to a lot of work to get those few extra millimeters out of it, will be interesting to see how little space it takes up. I think araldite will hold, try it and if it does come off you can always try something else, but as long as the surface is clean you should be right.

Dave

[lather]

Dave, taking my time setting it up, hoping that the total width when finished, including the 5mm gap for the lock bolt is 20mm, gained about 9mm with the conversion.

[Dave J]

It sounds like you have got the most out of it, is that including a cover, or are you not having one?
Also your question earlier I missed about the bottom being open, it should be fine.

Dave

[lather]

with the cover, if the lock bolt wasn't needed it would only be 15mm.

[Bryan]

Lather, one concern I have is I think I see coolant spooge on your machine, and the ebay listing says

(this scale is only suitable for using in dry condition)That aside, I'm interested to hear what you think of its performance. They're cheap enough that I may consider one for Z on my lathe - if they're reliable and accurate enough, though it seems like a long shot for the price. I have a dial indicator on my X.

[pipeclay]

Excusing my ignorance here but what is SPOOGE?

[Bryan]

Gunk, goo, muck, slime, etc. One of the better words invented by the Americans. :)

[pipeclay]

He may need to change the type of coolant he is using,if he is using it,no good having that sort of spooge on the machine let alone in the sump,good pickup noticing how bad the spooge was.

[Dave J]

Hi Bryan,
He is installing covers so that should take care of the coolant or chips etc. He asked above about covering it up from the bottom, but I don't think it is necessary as long as the cover is slightly lower than the scale.

Spooge :?, when I first read that I thought you meant spout, but that is a new word to me also.

Dave

[Bryan]

Don't mention it Dave. I learn stuff from you all the time. :D
Edit: Pipeclay too for that matter.

[lather]

it's good spooge it don't stink, "tastes great as well", the majority is oil, there's no slim, though the way it shows up in the photos looks like milky slim, must be an unusual effect due to the camera.
when looking at it, it's just oil floating on the green coolant, no milky slim.
usually fill the recces with oil, whenever taking off the compound, eventually the coolant gets in.
between the ways is just oil, had got carried away when modifying the way wipers, and making tailstock wipers.
probably use much more oil than needed when oiling, even when not in use for a week would oil it every day, so it starts to get a build up of oil on the bed.

same situation with the tank, when there's too much oil, usually just scoop it out, and its fine.

the dro is cheap enough, if the coolant defies gravity and gets up under the cover, ruining the dro it won't be much of a worry.
the cover should stop the coolant getting in.
have had coolant and oil on the digital vernier slide, and it still works fine, adding felt wipers would reduce the chance of coolant flooding the unit.

[lather]

Finished installing the poor mans DRO.
works fine.
the only problem is if coolant gets onto the slide, the readings go berserk, but does not kill the unit.
works well under normal coolant use, took it a bit too far ( as a test) when cleaning down the saddle with the coolant at full flow,which must have shot some into the unit.
after a few wipes cleaning the slide, all was back to normal.
overall width ended up being 22mm.

pic 6 shows the basic way of using the chuck as a reference when placing the tool tip against an isolated plate glued on the chuck.
when the tool tip makes contact with the plate, a beeper sounds, the DRO is zeroed, the carriage is brought back 0.25mm then zeroed.
when using the 3 jaw chuck, it is now 80mm to the center.

[Dave J]

Looks good and will be a handy feature for you. Smart thinking on the zero set up also :2tsup:
You maybe able to sandwich a thin piece of alumium (bent at a right angle) on the back to stop the coolant getting in, as in time it might do damage.

I will one of these days get around to doing my cross slide lock like that :doh: I have a thick backing plate so I am hoping I will be able to mill it out and not have to go right though it.

I am it will give others ideas, so thanks for posting it up.

Dave

[Bryan]

So the point of the buzzer is to set the dro in relation to the tool, yes? I'll be interested to hear how you find this in use. I've never used a dro, but find myself frequently re-zeroing my X-slide DI because it saves calculations. I'll cut, calculate, zero, then read cuts cumulatively straight from the dial. If I didn't zero I'd have to do more sums to know what the dial should read. Am I doing it wrong? Or just lazy?

[Dave J]

Hi Bryan,
I think once he gets it to 80mm he would be able to wind the cross slide in 80 and zero it out.
On my DRO, I take a cut and then move the tool away with out moving the cross slide, measure with mics/verniers (depending on the job) the input that measurement directly into the DRO.
Lahter's DRO wont allow inputs so he has to go about it differently.
It could sometimes have an repeatability error after mounting and re mounting the chuck, but it would only be small, (probably less than the resolution of his DRO)

Dave

[RayG]

Hi Lather,

Clever way of calibrating the DRO without having the ability to input a number. :)

With mine I zero the DRO take a cut, back out and measure the part, then with the DRO wound back to zero enter the measured value, and (usually enter 1/2 as well)

From then on it's calibrated to that tool.

Regards
Ray

[Bryan]

Hi Bryan,
I think once he gets it to 80mm he would be able to wind the cross slide in 80 and zero it out.

Ok, so the readout should then show the radius of the workpiece? Makes sense. I kind of do the opposite, but I can see this way would be better.

[Dave J]

Hi Ray,
Have you ever used the tool storage on your DRO?
I have used it a few times on repetitious jobs where I needed to change tools a lot and do a lot of the same parts, but find it's more trouble than it's worth for day to day use, especially using HSS.

Dave

[lather]

Dave,
have thought about gluing the thin part of a wiper blade onto the bottom of the cover, so there is no gap where it meets the tops of saddle.
when washing down from above it's fine.
use a T piece of aluminum that just sits over the gap for the lock nut access to stop swarf getting in the gap.
will have a better cover made later that bolts on from its ends, not from the top.

Bryan, yes,
it saves time having to constantly re zero the dial, and having to re-measure as a reference.
had used it previously with the hand dial, but at times had to measure due to loosing count of the number of turns of the dial.

had a written a reference chart for each mm from 150mm o.d. to 10mm o.d and it's hand dial readout.
when using it with the 3 jaw chuck, the hand dial was set to 7.40mm, so that the dial was reading zero when the tool tip was on center.
only measured the work when it was about 0.1 mm from it's final O.D.

still set the hand dial when using the DRO as a backup, in case the cheap DRO has a faulty reading.
the DRO makes it easier not having to keep count of the hand dial turns.

had tested it using the carbide tooling, and found it to be within 0.02mm, from repeated tests, though i take a measurement when with in 0.05 mm of the final cut when using the carbide tooling.

had unusual results when using HSS, not due to the reference system, but due to a build up of crap on the HSS tip which caused it at times to cut 0.2 mm deeper, though it's noticable when this happens, as the cuts gets rough.

[lather]

Dave, once the dro is zeroed, it is not wound to the center then re zeroed,
had considered this, but at times the lathe is set up making it more complicated to move the tail stock / carriage back e.t.c. to get the tooling on center for re zeroing.
the idea was to save time each time the tooling was moved or changed, thought it would be quicker to look at a reference chart.

when the DRO reads 70mm the o.d would be 20mm, e.t.c..
a reference chart for each mm of O.D. will be used.

it can be re zeroed at 80mm when boring, this was the reason for using left handed boring bars, so once the DRO is zeroed at the chuck reference point, when the cross slide is wound in 80 mm it would be zeroed so 10mm on the dro readout would be a 20mm bore.

[Dave J]

I see what you mean, and setting it up all different way for different jobs could get confusing, so best to stick to one way.

Dave