Digital readout for small milling machine

[optima21]

after 500E posted a link to http://www.arceurotrade.co.uk/ on this thread on toolposts

http://www.mig-welding.co.uk/forum/...ck-change-toolpost-options.52427/#post-606620

I noticed they do a cheapish digital readout that looks to be based around modified digital vernier calipers

http://www.arceurotrade.co.uk/Catalogue/Measurement/Standard-Digital-Readouts

has anybody used them and if they have what are their experiences of them?

this is my hobbymat milling machine that I'm thinking about fitting with a digital readout.

I was originally toying with the idea of cutting a pair of digital verniers up and sticking them to the milling machine to get the X and Y co-ordinates, but one for front to back movement would be hard to see as the table is in the way. I still find it confusing when co-ordinate milling/drilling when having to take backlash from the slides into account, which is something the digital readout gets around.

or has anyone got an easy way of working to co-ordinates accurately without a digital readout but taking backlash into account, while using the slides in both directions.

 

[Digger6135]

Its difficult to accurately predict the backlash as this will probably vary over the length of the leadscrew as most wear, takes place in the centre of the X axis
A digital readout will overcome this because it measures the actual distance the table has moved, backlash is elliminated.
I have recently fitted a three axis DRO to my mill, and consider it to be one of my best purchases ever!
It has the PCD built in and will give the co-ordinates for how many holes you require to drill.

Digger6135

 

[scott0031]

Take a good poke about on http://www.machine-dro.co.uk/ they have a good array of bits and bob on there, digital scales, simple readouts and lots of goodies.

You should not have a lot of problem with backlash, remember backlash and general wear on the screw are different things. Most general homers etc (no disrespect intended as i don't know what you are doing) do not need the requirement for super accuracy for such things like dowel holes, even so the only problem you will have is if you have two parts that fit together and are produced different machines. Lets say one machine has a 'calibrated' DRO and the other machine is relying on the lead screw, you will likely get some variance pending condition of the screw and the machines typical use over the years, where that wear is on the screw as Digger has said. Most people as general/ home type work are only doing screw hole potions as such erm well that don't need to be super accurate as they a screw hole will have something attached that has a clearance for that tapped hole. so +- .1 is fine or what ever you are working too.

If you need two parts that are going to be doweled together and are made on the same machine and pitched from the same 'ish' area of the screw then you will not have any real issue unless the machine is totally hammered or you make a mess of that you are doing and get it wrong. Even so, worrying about what part of the screw you use is not really an issue on a average machine. I'm a toolmaker trained old school and never had an issue providing you follow some basic rules regarding backlash.

The rule for backlash is you 'always come from the same direction' Never try to guess the backlash to go back to a previous position in the reverse direction. Example

Example
lets say you want to make series of holes at X+ 10mm, 20mm, 30mm, 40 mm,

You start At X0 datum with 10 mm 20 and so forth in the X+ direction only, lets say you have got to the 4th hole at x+40 and somehow forgot to put the third hole in, you wind back beyond that point so lets say if you know by feeling the handles back lash its say approx .5 mm you will wind back beyond that backlash amount ie now X - so you are are at say 28 mm now wind forward in the x+ direction until you get the dials reading what you want, 30mm. You feel the back lash being taken up and then winding the table, you now have a back lash free position that is totally reliant on the screw. You have to keep your wits about you and count the dials revolutions but this is how you are taught pre DRO and we had to do scores of positional holes in the trade that had to be right down often down to half a thou or so. If the screw on the machine is English and you are working in metric just divide the dimensions by 25.4 this gives you a direct and quick conversion for the screw. 10 mm div 25.4 =0.3937" which would normally be rounded up to 0.394" (English)



Hope this was helpful,


Kind regards,


Scott

 

[hareng]

I noticed they do a cheapish digital readout that looks to be based around modified digital vernier calipers
http://www.arceurotrade.co.uk/Catalogue/Measurement/Standard-Digital-Readouts

Mount the Y as far back as you dare low down and make sure its mounted rigid not using supplied brackets. I did a compare some years ago with cheap scales, glass scales and magnetic scales, all showed the flex on supplied brackets.
X can go on front, easy way but will limit other things.
What you will need is the £88 readout, cost me £160 from Warco 16 years ago.
Problem is any liquids will render them scrap no matter how careful and how well they are shielded. Think at time 1999 worked out around £360 and lasted a few months, luckily yours shorter and cheaper. Full on glass scaled DRO was £463 on another larger mill and coolant proof.

My Arc vernier style drained SR44 batteries in 2 days linked in to 3 axis readout.

 

[optima21]

thanks guys,

its rarely use my milling machine these days, but its in case I need to do coordinate milling that I think it would be of advantage. most of the times in the past when I had to drill accurately, I've marked it out with ruler, square and scriber etc and drilled freehand. I've then the spotted though to corresponding parts so parts may fit one way but not another,but thats not an issue.

 

[hotrodder]

Not what you're asking about but somewhere on the forum is at least one thread (or links to a different forum) that's about making new acetal leadscrew nuts that you may find appealing

 

[Wallace]

I was looking at Arceuro and Machine DRO last year, this site had a lot interesting information about making your own.

 

[Mr shiney]

Not what you're asking about but somewhere on the forum is at least one thread (or links to a different forum) that's about making new acetal leadscrew nuts that you may find appealing

What's the advantage of them?

 

[lchris21]

I got a 3 axis set from our friends in the far east last year......Think it was about £300'ish all in with import taxes. Its glass scale type. Works well.

I retrofitted a cheapo vernier to the cross slide on my lathe, but as already pointed out when it gets wet, it goes bananas.........allright in the dry though

 

[Wallace]

What's the advantage of them?

A cheaper alternative to ball screws for CNC conversions and replacement lead screw nuts. Pete posted this link in another thread....http://bbs.homeshopmachinist.net/threads/43645-Making-Acetal-leadscrew-nuts-the-easy-way

 

[Wallace]

I got a 3 axis set from our friends in the far east last year......Think it was about £300'ish all in with import taxes. Its glass scale type. Works well.

I retrofitted a cheapo vernier to the cross slide on my lathe, but as already pointed out when it gets wet, it goes bananas.........allright in the dry though

I priced up a 3 axis with 25µ magnetic readers from Machine DRO last year then the mill gearbox went bang and so did the DRO money on bearings and gears. A year on there are cheaper sets about but these from Arceuro are tempting with a conversion to mains or rechargeable batteries instead of button cells but you know they are likely to be hassle!

 

[hareng]

I retrofitted a cheapo vernier to the cross slide on my lathe, but as already pointed out when it gets wet, it goes bananas.........allright in the dry though

That's what I was getting, clean it once maybe twice, next time its scrap.

 

[Geoffm]

I put a 3 axis readout on my Rong Fu RF30 drill mill. Best HXX Chinese from Aliexpress for $US270. Works well and money well spent. I looked at the vernier caliper scales, but the proper glass scales are more robust with armoured cables, seals, etc.

 

[Wedg1e]

I fitted the 'vernier caliper' type scales to my Perrin jig borer, with a 3-axis readout from Amadeal, cost about £200 all-in and work fantastically as long as you only do dry-milling... or be VERY careful with the coolant. If the scales do get wet you can dry them out but it may take a while...

 

[MrFluffy]

I was looking at Arceuro and Machine DRO last year, this site had a lot interesting information about making your own.

The problem with the yuri dro is finding a tablet with a true usb host capable port, all the ones I had lying round had only got support for memory or mouse/keyboard devices when I checked. I totted up the price of buying a tablet to suit, the cost of scales then the thailand seller of the real dro kits had a sale, and for not a huge amount more I ended up with a full 3 axis dro kit with glass scales and brackets and arm for the read head, proper seals on the scales, armoured cables up to the scales etc.
I also still have a working yadro adaptor to let a pc running dos be a dro, but that now is so long in the tooth it can't speak to the newest chinese scales.

Fitting the kit and using the pcd and other math functions built right into it made me wonder how the hell I've struggled with dials only for so long. And the real answer was I spent so long trying to do it the cheap way instead of just sucking it in and plumping for the kit.

 

[Wallace]

I wasn't aware of that with the tablets as I don't have or use one. I'm glad my gearbox went pop in a way as leaving the selection a bit longer has bought the prices down on the better quality gear and allowed me to improve the shocking accuracy of the original quill bearings. I can make do with dials just not the ones on this machine as they do my head in! 1.5mm pitch lead screws with the dials graduated metric & imperial as below......





Not 1mm, 10 divisions!

 

[optima21]

I eventually got round to ordering some ARC standard digital readouts

http://www.arceurotrade.co.uk/Catalogue/Measurement/Standard-Digital-Readouts

I'm thinking of them as being an early Christmas present, due to my slow rate of progress that it's likely to be next year before I get round to fitting them

 

[Mr shiney]

i started with a similar set up on my DW but the scales stopped working quite quickly when they got cutting fluid and crap in them. You need to keep them really clean!!!

I went for a SINPO system in the end on three axis. I may put the old unit on the lathe....