Author Topic: New DRO's (Read 36990 times)

John Rudd · « **Reply #25 on:** December 15, 2011, 09:37:05 AM »

Nice job!

I'm just waiting for funds to accumulate to a sufficient level to buy some for mine, after Ketan relieved me of £500 for a mini lathe the other weekend....

-steves- · « **Reply #26 on:** December 15, 2011, 09:42:09 AM »

That makes two of us waiting for sufficient funds to build up to get some of these, the problem I have is I need 5 of them, 3 for the mill and 2 for the lathe, I might just have to do the mill first and then save up again, decisions, decisions

ketanswali · « **Reply #27 on:** December 15, 2011, 10:44:48 AM »

Dale,

Does your 34" bar read 34"?. If possible, could you please measure and advise what is the overall length of this bar?

Jasonb · « **Reply #28 on:** December 15, 2011, 02:06:59 PM »

Ketan, I think the size stated is the reading range, have a look at this post about getting an extra 60mm of travel at each end of a 900mm scale, guy says it now READS 1020mm

J

http://www.ukworkshop.co.uk/forums/stretching-digital-scales-t54824.html

ketanswali · « **Reply #29 on:** December 15, 2011, 02:28:39 PM »

Brilliant,
Thanks for the link J. Very helpful. Ketan.

John Stevenson · « **Reply #30 on:** December 15, 2011, 02:33:56 PM »

Quote from: Jasonb on December 15, 2011, 02:06:59 PM

Ketan, I think the size stated is the reading range, have a look at this post about getting an extra 60mm of travel at each end of a 900mm scale, guy says it now READS 1020mm

J

http://www.ukworkshop.co.uk/forums/stretching-digital-scales-t54824.html

Jason,
When you quote links can you at least say what they are for.

The one above is for a WOODWORKING forum [ hawk, spit - ding ] now I will have to reformat my hard drive to get rid of all the damn sawdust....................

ketanswali · « **Reply #31 on:** December 15, 2011, 03:40:09 PM »

Quote from: Jasonb on December 15, 2011, 02:06:59 PM

Ketan, I think the size stated is the reading range, have a look at this post about getting an extra 60mm of travel at each end of a 900mm scale, guy says it now READS 1020mm

J

http://www.ukworkshop.co.uk/forums/stretching-digital-scales-t54824.html

Jason,
Any idea if there is an average or maximum length of reading range that woodworkers are looking for?

Jasonb · « **Reply #32 on:** December 16, 2011, 02:26:14 AM »

As its mostly going to be the home woodworker I would have thought the 900mm/35" would do for most.

Here are a couple more posts from the same guy about teh scales if its of use, watch out for teh sawdust!!!

http://www.ukworkshop.co.uk/forums/display-stand-t54544.html

http://www.woodworkuk.co.uk/forum/viewtopic.php?f=4&t=7296

ketanswali · « **Reply #33 on:** December 16, 2011, 05:17:01 AM »

Thanks again Jason. Still trying to get the sawust out

.........

jim · « **Reply #34 on:** December 16, 2011, 12:23:22 PM »

i bought some of these last week, 6",12" and 20" for my mill.

Had some bother with one of them not staying switched off, turns out i'd not aligned one of them very well

Used them today and i'm impressed with them!!

I've finally got around to doing some jobs that needed the chuck taking out to clock up a bore, so easy to zero out and wind off, sure beats standing there counting turns etc!!

very happy with them!!

mgnbuk · « **Reply #35 on:** December 16, 2011, 01:08:42 PM »

Has anyone checked the accuracy & repeatability of these scales in a metalworking environment ?

The quoted accuracy is quite a lot worse than the other (non-remote readout) scales that Arc sells e.g. a 300mm remote scale is stated as +/- 0.1mm, where the built-in unit is +/-0.03. There is no mention of repeatability, though other sellers are suggesting 0.025 ?

These errors are negligable to the sawdust-eating user, but may be more critical in metal machining ? I realise that these scales are a good price & may well be more accurate than the leadscrews on some machines, but I have not seen any comments regarding accuracies that users have actually achieved (i.e. the quoted values may be far lower than the scales actually achieve in practice) .

Regards,

Nigel B.

jim · « **Reply #36 on:** December 16, 2011, 01:48:58 PM »

i just checked they repeat, i.e. went to set point, zero'd out and moved away and back.
i'd guess that the stated error is over the full travel??

either way they'll do me.

Pete. · « **Reply #37 on:** December 16, 2011, 02:47:45 PM »

How much worse would they be than a worn screw? My cross-slide screw is not so accurate in the middle as it is at the ends. Use these to get you (very) close, mic the diameter and finish with the dial.

Davo J · « **Reply #38 on:** December 16, 2011, 10:08:40 PM »

I have 3 glass scale DRO's and always keep my eye out for anything new or new mounting ideas etc, because I am interested.
A few weeks back over on HMEM, Bogs brought something to my attention about the magnetic scales being sold by DRO UK.
He posted a chart from their website that shows the magnetic scales to be far lower accuracy than glass scales, which surprised me as a lot of people are paying more to have magnetic scales over glass scales.
Going by their chart below it states the magnetic scales are plus or minus 0.015mm in accuracy.

So if ARK are coming close to these numbers with their scales, it is around the same accuracy as the magnetic scales, but at a much cheaper price.

Dave

HS93 · « **Reply #39 on:** December 17, 2011, 02:26:50 AM »

I thought the amount they where out over the distance stated was such a small amount that the fact that they are not effected by swarf and coolant plus are easy to fit as they are so much smaller MAY outweigh the disadvantage, for me they are good enough as putting a full sized glass scale on my lathe would be difficult.

Peter

stovebolt · « **Reply #40 on:** December 17, 2011, 10:24:22 AM »

I installed and have been using almost daily, 4 of these on my X-3 last Feb. . No illusions that they would be as good as glass scales, just a poor mans DRO. I haven't had any problem yet. I have drilled one part for 2 press fit pins and the mating part and it was so close that the parts would only go together if they were square to each other, this is repeatable ( for me that's an accomplishment) . The only complaint I have is, my unit of measure is 1 inch = .999 , I tried the function for setting zero a few times, nothing changed , I've checked this against the dials and a 1" dial ind. , but I can live with it. I've drilled and tapped a series of 1/4-20 holes over a 6" length , I.E. drilled all the holes, then slightly counter bore , then tap, without any alignment/repeatability problems . I'm also still using the original batteries. Your mileage may vary.

Jonny · « **Reply #41 on:** December 17, 2011, 08:19:44 PM »

I reckon they will sell well for the average diyer.
Its when swarf collects and builds up constantly ripping the USB plugs out plus they wont handle liquids without giving errors.

Quite easy to fit glass on X axis on every lathe i have ever seen, its the Y axis where the trouble starts.

There are reasons why the magnetic scales are used, mainly due to the mounting arrangement, size and little room they take up still enabling existing lengths with little losses or monstrous bulk.

For the average installer of glass scales a few microns wont be held, have seen mm of play to a lot more than 20 microns due to machine flex.

HS93 · « **Reply #42 on:** December 17, 2011, 10:16:12 PM »

Quote from: Jonny on December 17, 2011, 08:19:44 PM

I reckon they will sell well for the average diyer.
Its when swarf collects and builds up constantly ripping the USB plugs out plus they wont handle liquids without giving errors.

Quite easy to fit glass on X axis on every lathe i have ever seen, its the Y axis where the trouble starts.

There are reasons why the magnetic scales are used, mainly due to the mounting arrangement, size and little room they take up still enabling existing lengths with little losses or monstrous bulk.

For the average installer of glass scales a few microns wont be held, have seen mm of play to a lot more than 20 microns due to machine flex.

I think you may have miss read I was asking about the magnetic scales from http://www.machine-dro.co.uk/digital-readout-systems/magnetic-tape-linear-encoders.html and the differnce between them and the glass scales as in the chart posted by Davo J

Peter

Davo J · « **Reply #43 on:** December 18, 2011, 10:20:05 AM »

Hi,
I don't want to run this topic off track and the only reason I posted that was as a compliment to ARC, as their scales are close in accuracy to what the expensive magnetic scales are at a fraction of the price. Fair enough that might not be as durable, but that comes at a cost of glass or magnetic scales. If you added covers similar to what the glass scales have, they would be able to stand up to a fair bit of abuse from swarf etc without any worries.

From what I have read on a lot of forums, is guys that are wanting something cheap and accurate, and the ARC scales fit the bill. A lot of people just cant afford, or don't want to spend the money on an expensive DRO system.

The off topic bit
With the glass V's magnetic, I was just surprised to see less accuracy, but at a higher price. I have been running glass scales for 4-5 years now and I have not had one problem, even with flood coolant.
If they are mounted properly and protected with the factory covers they are fine. There are those installations where a glass scale wont fit and magnetic are great for that, but you do loose accuracy.
On a lathe cross slide that 0.015 mm accuracy of the magnetic scale ends up 0.03mm on diameter. A fair way away from the Sino/Meister 5um glass scale accuracy of plus or minus 0.01mm on diameter in the same situation, or 0.002mm on diameter for the 1um scales at only $20-$25 each extra an axis, which is still under the magnetic price.

If you have a lathe that a glass scale wont fit on the cross slide, you will need to go with a magnetic, or if you want the accuracy of glass a lot of people with confined space are making a extended bar off the back of the cross slide to mount the scale out of the way.

I am not knocking any system here, I only brought this up for the reason I said above, and also that I was surprised to see these latest model expensive magnetic scales being advertised as 1 and 5 micron, when their accuracy is only 0.015mm, sort of makes paying the extra for the 1 micron scales useless in my opinion.

Sorry for the OT bit, I think if we are going to discuss these scales any more we need to start our own thread.

Jonny you have the axis's mixed up their, the X is the cross slide and the carriage is the Z.

Dave

dwentz · « **Reply #44 on:** December 18, 2011, 11:02:36 AM »

The scale advertized length is the usable length. They are repeatable, as far as accuracy goes. The shorter one on my lathe is within .001 of the dial readings on the compound. I do not know which is off I would suspect the lathe as it has both metric and imperial markings on the top side. The longer scale on the lathe the cable is too short to allow the bed of the lathe to make its full travel, but that is because of where I located the displays, and I don't think I have ever used the lathe out that far anyhow. I will extend the cable when I have a job I need that much reach for. I think I will order some F1 Felt from McMaster-Carr and build a holder to wipe the scales off based on some other comments here, I have not had any problems yet, but it won't hurt thats for sure. For the 7x10 I am going to have to cut one of the scales, which I have read is not a problem.

Dale

lsces · « **Reply #45 on:** December 19, 2011, 05:42:23 PM »

Good news ...
I've got a scale working on the DRO350 via a modified QCC100 dongle using Les Jones's code. Just needed to change one resistor on the LM317 to get 3.3 Volts out, and swap the output signals as Les has them wrong ... and the display fired up.
Just need to check prices on the USB socket assembly, and then I can add them to the Scale options page on the website.
Should just work with the DRO550 ... but I forgot I had shipped the last built one, and I've not assembled the remaining board yet

Pictures to follow ... up to Leicester in the morning to sort out a another Taig CNC mill ...

modeng200023 · « **Reply #46 on:** December 20, 2011, 02:19:38 AM »

Good work Lester, I knew you could do it. Thanks.

John

lsces · « **Reply #47 on:** December 20, 2011, 03:08:19 AM »

Quote from: modeng200023 on December 20, 2011, 02:19:38 AM

Good work Lester, I knew you could do it. Thanks.

Les Jones did the important stuff ... He deserves the praise ;)

modeng200023 · « **Reply #48 on:** December 20, 2011, 04:58:38 PM »

Thanks Les, I didn't know.

John

ibuildstuff4u · « **Reply #49 on:** December 20, 2011, 11:17:38 PM »

Here is a sneak peek at my DRO system on the X2 mill. The scales are installed, but the chip covers are not on in this photo as I still have some milling to do on them before they are ready to be installed.

I was worried about the life span of the watch batteries in the readouts so I soldered wires to the battery terminals and hooked them up to two "D" sized batteries. Two "D" batteries cost $3.00 and should last over a year, while six watch batteries are around $19.00 and if they are like my calipers they will only last 6 months so making the up grade was an easy decision.

I should have the chip covers done by the end of the week and post pictures of the whole project.

Dale P.

News:

Author Topic: New DRO's (Read 36990 times)