MadModder
Gallery, Projects and General => Neat Stuff => Topic started by: Corvus corax on August 03, 2011, 04:55:30 AM
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Very interesting idea.
http://users.tpg.com.au/agnet/microdro.html
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Way cool idea
BR
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That's a handy little weapon! :bugeye:
What a great idea! :clap: :clap:
David D
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I found the depth gauge on Ebay for around €5 shipped. I think I will take two and experiment. I have some Neo magnets that are drilled and countersunk for screws.
Will be interesting to see if they also have a data port like some of the cheap callipers have.
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Just ordered one meself........
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=360382393482&ssPageName=STRK:MEWNX:IT
Looks to be a crackin' little tool! :D
David D
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Does a left-hand version exist or can the read-out be turned upside-down?
That would be ideal for a high-precision saddle-stop I think?
BR
/Peter
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Well worth a go for a fiver
Just orderd one
John
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Me too
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Just ordered one meself........
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=360382393482&ssPageName=STRK:MEWNX:IT
Looks to be a crackin' little tool! :D
David D
Yep those are the guys. I wasn't sure if I could post the auction link. I've got two on the way.
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Does a left-hand version exist or can the read-out be turned upside-down?
That would be ideal for a high-precision saddle-stop I think?
BR
/Peter
Just arrange for the 'probe' to extend from the back/top instead of the bottom/front.
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Does a left-hand version exist or can the read-out be turned upside-down?
That would be ideal for a high-precision saddle-stop I think?
BR
/Peter
Just arrange for the 'probe' to extend from the back/top instead of the bottom/front.
Yes of course!
Thanks a lot for that, seems like I will get one as well!
BR
/Peter
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I don't see those anywhere near that cheap on ebay at the moment. But I just got in 4 6" digital calipers for $5.99 each so I'll devote a couple of those to DRO duty.
I'll make one of these when I see them at a cheap price again.
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Here in the UK prices on eBay currently range from £4.99 with free shipping to over £50.00 plus shipping from the more optimistic traders.
It's a neat idea and for those of us machining mainly in brass, aluminium and stainless the use of earth magnets shouldn't pose too much of a problem.
John-Som
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Yea i have also just ordered one from EBay £5 inc P/P.Now i must look again and buy some of those magnets,,I was thinking of just araldite on the mags to the rear of it. (don't know if that's poss )Then installing the spring on the round probe with a collar on it close to the end.That way i don't have to open the thing up.Mind you when i receive it and give it the close inspection i may have to mod it like in the pics.
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Just a couple of words of warning about using magnets to fix things onto machine tools:
While they won't magnetise the iron, they will magnetise any steel swarf and dust, making it stick to the bed and a pain to clean off.
If you knock the magnetically attached thing while the machine is in operation, Sod's laws states that it'll be attracted to the the thing that'll cause the most harm (e.g. the chuck) .
Rigging these things with a clamp might be a better option.
Bill
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Hi,
It also seems it could be used just as it is, ready, steady, go depth gauge especially on a mill when head room is a problem.
:beer:
DaveH
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Mine arrived this morning! :thumbup:
Rather stiff to slide, straight out of the pack. Easing now, as it is operated/ run in.......
David D
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Just look at the rip off price on
EBay Australia
http://shop.ebay.com.au/?_from=R40&_trksid=p3907.m570.l1313&_nkw=%09+Digital+LCD+Tyre+Tread+Depth&_sacat=See-All-Categories
br
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Got a couple from ebay. The slide is rather stiff - controlled by a leaf spring that can be bent a bit to adjust. Thing I like about these is their fast display update. Should make good carriage or cross slide guage.
-Dick
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Just look at the rip off price on
EBay Australia
http://shop.ebay.com.au/?_from=R40&_trksid=p3907.m570.l1313&_nkw=%09+Digital+LCD+Tyre+Tread+Depth&_sacat=See-All-Categories
br
Wow. :loco:
For those of you elsewhere that are having trouble finding them. Try here:
http://stores.ebay.com/Land-Mart
These guys operate out of Asia and will ship anywhere. I previously bought some digital indicators from them.
Question for those of you who have received yours. Is there an accessible data port, like on some of the cheap digital callipers?
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Yes
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Yes
:thumbup:
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I've ordered a couple (never know I may break one) from Hong Kong.
Some Ebay UK sites don't ship to SA. (Misserable so & so's)
DaveH
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I've ordered one, with the idea of fitting it to the Z axis of my Dore Westbury mill.
No doubt I'll crick my neck reading it, but that's better than using the dial on a fine feed which shifts the quill 0.130" per revolution and often involves too much arithmetic.
Andy
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Mine came yesterday
Not bad for a fiver considering you can zero it and it goes both ways (metric imperial) :lol: :lol: :lol:
John
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Looking at the circuit board and mounting holes, it looks like the read head could fit straight on to replace one on the chopped digital calipers that hobbyists use as DROs.
The beam cross section dimension is the same.
There is even a cutout in the read head for the locking screw on a digital caliper, so these are probably used on ABS calipers as well.
The end result is that the existing chopped DROs would read much faster with the 3 volt read head.
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Had a Email from the company i ordered my Tyre gauge from,It said ..Sorry i can not sell any more as there have been a fault on them,And untill im happy with them i wont sell any more,????????????I will return your £5 sorry..
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Had a Email from the company i ordered my Tyre gauge from,It said ..Sorry i can not sell any more as there have been a fault on them,And untill im happy with them i wont sell any more,????????????I will return your £5 sorry..
Oh!? :bugeye:
Not done anything with mine, yet. But, apart from the stiff slide compared to the normal digital glide, I've not found a problem! :scratch:
Will have a closer look, this morning....... :thumbup:
David D
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Marauder, who did you buy from?
I got mine from "ejoytune" off ebay UK. They haven`t arrived yet but I wonder if they are getting wind of the the sudden higher purchase order of these things and are ready to up the price?
Chris
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David D
Discard the tension spring - it's not required.
Bought mine from dealnts on eBay - no problems so far. You can see my build on my website.
Rob who designed this neat unit also commented on the situation with eBay dealers who must be very curious on the sudden rise in global demand.
JohnSom
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Has anyone tried one of these with a DRO like the shumatech?
I know I`ve purchased single heads at near this price and they won`t work with my 350 shumatech - it would be even better if this one did.
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Thanks Corvus corax
Ordered two
br
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You can see my build on my website.
Your idea with the brass pipe nipple is great.
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David D
Discard the tension spring - it's not required.
JohnSom
Sorted John! :thumbup:
Straightened, and left in place. Just in case......
David D
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David
Oh ye of little faith - mind you if it helps you to sleep better at night then that's a good decision !
JohnSom
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David
Oh ye of little faith - mind you if it helps you to sleep better at night then that's a good decision !
JohnSom
John.
I had a fine Yorkshire upbringing....... :thumbup:
I paid good money for that little strip of steel. Wouldn't want to lose it. And certainly wouldn't just, throw it away! :bugeye:
:lol: :lol:
David D
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I paid good money for that little strip of steel. Wouldn't want to lose it. And certainly wouldn't just, throw it away! :bugeye:
:lol: :lol:
David D
Absolutely :thumbup: :clap:
:beer:
DaveH
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David
As a Yorkshire lad myself I can appreciate your reluctance in discarding anything that has cost true brass.
John
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:doh: Hi all,I ordered mine from same place John had is from "dealnts",Just had a Email from them this morning refunding my £5,If i had the knowledge i would put there email on here but i don't know how to.So i will have another look on EBay for a replacement tyre depth gauge.Only ever happens to me lol.Same as i ordered a tool post lever for my Myford S 7 ( Replaces the, i think its a 19mm nut )So what arrived a small bent lever that i think is a 6 or 8 mm nut !!!!.
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Marauder.
My man's still selling, at the same price....... :thumbup:
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=360382393482&ssPageName=STRK:MEWNX:IT
David D
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Hi.
I manage to order one
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=190561486248&ssPageName=STRK:MEWNX:IT
I will try to build one. :D
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EJOYTUNE on ebay - must have caught wind, after telling me it has been sent, I got this this morning.....
Dear buyer
Sorry to tell you that we must refund you for the item you bought, because we double checked the quality, it is not as good as our previous product, we do not want to make you disappointed when you receive it, but still wish you may satisfied with our solution to arrange full refund to you. We are trying to solve this issue with our supplier now, to avoid any future buyer complaint, we also have ended this item on eBay.
If you received the delivery message , it is sent by our systerm automatically when your payment received by us , please ignore it .
We apologize for the inconvenience again , please confirm whether this is your paypal email for refund XXXXXXXXXXXXXXXX@XXXXXXXXx We will process it for you immediately when we get your reply .
Thank you for your understanding and patience .
If you have any questions please feel free to let us know.
Have a nice day : )
Best regards
emma
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EJOYTUNE on ebay - must have caught wind, after telling me it has been sent, I got this this morning.....
Dear buyer
Sorry to tell you that we must refund you for the item you bought, because we double checked the quality, it is not as good as our previous product, we do not want to make you disappointed when you receive it, but still wish you may satisfied with our solution to arrange full refund to you. We are trying to solve this issue with our supplier now, to avoid any future buyer complaint, we also have ended this item on eBay.
If you received the delivery message , it is sent by our systerm automatically when your payment received by us , please ignore it .
We apologize for the inconvenience again , please confirm whether this is your paypal email for refund XXXXXXXXXXXXXXXX@XXXXXXXXx We will process it for you immediately when we get your reply .
Thank you for your understanding and patience .
If you have any questions please feel free to let us know.
Have a nice day : )
Best regards
emma
Me to Pain in the BUT :scratch:
Peter
where have people got them from ?
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Marauder
What's going on ? ,dealants, like you say are out of stock so I ordered a second unit from another alledgedly UK company at £4.99, order was accepted and despatched with email confirmation - from dealnts ! Seems to be a Chinese co with stocks held in the UK. All very strange.
Incidentally these units have 3V batteries in the read head rather than the 1.5V batteries used in conventional digital calipers. When fitting remote DROs to my mill run from a transformer I had to go to great lengths to provide a dual voltage supply 3V for the DRO and 1.5V for the read head. Anyone now wanting to fit a similar system can use these 3V read heads and run it from one of those switchable mini transformers.
John-Som
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John-som, just searched dealnts with no luck - I can find the supplier but can`t see any for sale... do you have a link?
Chris
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I ordered mine from "autoeshop" rather than "ejoytune", and got exactly the same messages from Emma as Chris did.
:scratch: It looks like the same outfit is selling on Ebay under various names.
Andy
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Hi Chris
UK Home Shopping, no URL but I think they are in Mansfield. Reckoned they had over 200 in stock (can't remember the exact number).
Let me know if you can't find them and I'll have another rummage.
John-Som
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Here you go Chris
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280674140546&ssPageName=STRK:MEWNX:IT#ht_919wt_1140 (http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=280674140546&ssPageName=STRK:MEWNX:IT#ht_919wt_1140)
John-Som
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I've just ordered two - to swap the read heads on the two 6" calipers I already have. One has failed and the other flashes no matter how new the battery fitted was. They also were quite slow in the displays.
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A good guess would be that the dealer that has backed out on these deals and refunded the money has run out of stock, is telling everyone he can't bring himself to sell you rubbish, is getting more of the same in, and is going to jack up the price because these are "better quality units".
Or am I just cynical ::)
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... and it goes both ways ...John
Like AC/DC or like Machester screw driver?
Pekka
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Just got an email marking mine as despatched (Stilldrillin's link, user i.d. ejoytune).
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lol, me to. Got an email this morning saying:
Dear eBay Member: XXXXXXXX,
Thank you for your email.
Sorry for our last wrong message,It's not for you.
BuyerID: XXXXXXXXX ItemID: 36038239XXXX address: XXXXXX Shipping Date: 2011-08-08
Your product had been shipped out on 8th-AUG,HOPE you can receive it asap.
If you have any other questions, please feel free to let us know . We are very glad to help you.
Welcome to our ebay online store!
Have a nice day:)
Best regards,
Customer Service Dept.
eBay Seller
2011-08-11
I`m actually a bit annoyed because I went and purchased another couple off another ebay user after I got yesterdays email! And on another thought... is mine one of the inferior ones????!!
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Got mine today - fast update versions too!
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Yea, one of mine just arrived!
Chris
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Half-way through modding one of these. I haven't discarded the spring just flattened it out to give a light pre-load.
Managed to get 30mm of travel on mine :D
EDIT: here it is. Couldn't find a rubber band of the right size so I had to make a band from dressmaker's elastic (tried to get the elastic out of the wife's knickers but she wasn't in a forthcoming frame of mind :D).
Advantages are that you get a much longer travel than by using the spring, and the elastic is a lot lighter in spring weight so there's no chance of pushing the readout along against the magnetic force when the spring gets bound.
Disadvantages - well it's very Heath Robinson but seems to work well. Magnets came from a hard disk and were cut in half with an angle grinder.
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Pete,
Bought 4 of them via Hong Kong a while ago for $4 a piece delivered and have been trying to figure out how to mod them for my lathe. I like your idea of loading them from the back. Putting a spring on the front wastes about a 1/3 of the possible travel.
My only concern is that I am sure to get these things covered in swarf. How to protect the inner mechanism?
-Dick
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Ok Guys/Gals,As i had tried at 2 different EBay sites and had no luck getting any delivered to me with the above problems........Can some one please put the site on here for me,The EBay site that are still selling them £5 ones.Thanks." Allen "
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Allen.
My man's still selling.....
http://www.ebay.co.uk/itm/Digital-LCD-Tyre-Tread-Depth-Brake-Shoe-Pad-Gauge-0-1-/360385983921?pt=UK_Hand_Tools_Equipment&hash=item53e8adb5b1
David D
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Allen.
My man's still selling.....
http://www.ebay.co.uk/itm/Digital-LCD-Tyre-Tread-Depth-Brake-Shoe-Pad-Gauge-0-1-/360385983921?pt=UK_Hand_Tools_Equipment&hash=item53e8adb5b1
David D
Yeah, but not to Denmark ... what have we done to be excluded ! :bugeye:
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Allen.
My man's still selling.....
http://www.ebay.co.uk/itm/Digital-LCD-Tyre-Tread-Depth-Brake-Shoe-Pad-Gauge-0-1-/360385983921?pt=UK_Hand_Tools_Equipment&hash=item53e8adb5b1
David D
Yeah, but not to Denmark ... what have we done to be excluded ! :bugeye:
ksor.
Here is one option.
http://www.machine-dro.co.uk/25mm-digital-tyre-tread-depth-gauge-.html
Think they send to Denmark.
CS
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Allen.
My man's still selling.....
http://www.ebay.co.uk/itm/Digital-LCD-Tyre-Tread-Depth-Brake-Shoe-Pad-Gauge-0-1-/360385983921?pt=UK_Hand_Tools_Equipment&hash=item53e8adb5b1
David D
Yeah, but not to Denmark ... what have we done to be excluded ! :bugeye:
Here you go, an Asian seller who will ship anywhere:
http://cgi.ebay.com/Digital-Tyre-Tread-Depth-Break-Pad-Gauge-Caliper-0-25mm-/320740979385?pt=LH_DefaultDomain_0&hash=item4aada6f2b9
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:thumbup:
I found one in UK !
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NO - I didn't - he just send me a massage, that he can't deliver to Denmark !
What is wrong with posting to Denmark from the UK ?
Sometimes I see the same in Germany.
Is something special papers to fill in or what .... I just don't understand !
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Hi Ksor
Revenge for Danegeld maybe ? .... :D :D
BC
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Amazon have them for £4.99
http://www.amazon.co.uk/Wolf-Digital-Tread-Depth-Gauge/dp/B004CZ3X3K/ref=sr_1_10?ie=UTF8&qid=1313431073&sr=8-10
Brian
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Amazon have them for £4.99
http://www.amazon.co.uk/Wolf-Digital-Tread-Depth-Gauge/dp/B004CZ3X3K/ref=sr_1_10?ie=UTF8&qid=1313431073&sr=8-10
Brian
:doh: but still they will NOT send to Denmark :doh:
I don't get it !
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Here's where I got mine:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemVersion&item=330590145322&view=all&tid=570505047014
-Dick
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Here's where I got mine:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItemVersion&item=330590145322&view=all&tid=570505047014
-Dick
Not at that price, I hope!! :bugeye:
David D
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Stilldrillin,
Yep. I got 4 delivered from Hong Kong for just under $16 including postage. Sounds totally nuts doesn't it?
Bought a fair amount of electrical components from Hong Kong. Most of the time the postage was quite a bit more than the price of the merchandise, but in total still cheaper than here in San Francisco.
-Dick
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Stilldrillin,
Yep. I got 4 delivered from Hong Kong for just under $16 including postage. Sounds totally nuts doesn't it?
Bought a fair amount of electrical components from Hong Kong. Most of the time the postage was quite a bit more than the price of the merchandise, but in total still cheaper than here in San Francisco.
-Dick
Hi Dick
Would you please give a link to the store ?
You send me a link to the ITEM (Thx!) but is't sold out !
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Thanks to all of you who will send me one, but
I think I have made a deal with "JohnC" - what worries me is, that I can't see a "JohnC" in here ... or do I sleep !
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Definitely here, Ksor. Sleep well! :beer:
John
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:beer: :beer:
Long to see them !
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Both mine arrived. Nice little things.
Now if I could just figure out how the hell to mount one to my 9x20 everything would be perfect. Looks like I will have to make some kind of clamp to put on behind the cross slide hand wheel. There is nowhere to stick anything magnetic and get a reading :doh:
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Mine arrived today...
Runs off a 3v CR20xx coin cell battery...Shame it wont accept the data plug on my remote readout...So cant tell if its compatible or not..like my scales are..Something to work madmodder I guess :dremel:
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These reader heads DO work with the cheap 6" digital caliper scales, coz I've tested it. Can't fit the boards onto the metal slides of the calipers though without milling a step in each side of the PCB.
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I'll got my today, but I am not shure how to build it. I have a minilathe and it don't looks exactly as the project show. :scratch:
Here is a pic of my lathe.
I need a good advice how I should do. ::)
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I think the idea with the magnets is good - I'll use mine - when I get them - for both my mill and lathe - then the idea with the magnets is good, I think !
With the magnets you can place it whereever you want on then mill or the lathe - if it's iron of cause.
I'll make mine with magnets I'm sure.
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Now I got mine in hand - thanks JohnC !
I dicovered a small hatch opposite the battery hatch - looke like 2 wires could be solded on the pcb !
Do some of you know what this is good for ?
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It's the dataport - you can run a cable to a serial interface and hook it up to a pc to make a cheap DRO, among other things.
www.yadro.de
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It's the dataport - you can run a cable to a serial interface and hook it up to a pc to make a cheap DRO, among other things.
www.yadro.de
If anyone has a 'scope, I'd be interested in pictures of the waveforms etc. to see if is possible to add it to my PIC based DRO (http://www.cnczone.com/forums/pic_programing_design/62704-pic_based_dro.html) project
Bill
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If anyone has a 'scope, I'd be interested in pictures of the waveforms etc. to see if is possible to add it to my PIC based DRO (http://www.cnczone.com/forums/pic_programing_design/62704-pic_based_dro.html) project
Bill
The most commonly used protocol is this one. (http://www.shumatech.com/support/chinese_scales.htm)
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I just tried to replace the moving "ruler" with a small "ruler"-like peace of aluminum - it seems to work too = the digits changes as I move the aluminum !
This implies that I can use all the full range of the digimeter 0-999.99 mm by just replacing the original ruler with a longer one !
I wonder what is the theory behind this small peace of magic - any link ?
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It's the dataport - you can run a cable to a serial interface and hook it up to a pc to make a cheap DRO, among other things.
www.yadro.de
If anyone has a 'scope, I'd be interested in pictures of the waveforms etc. to see if is possible to add it to my PIC based DRO (http://www.cnczone.com/forums/pic_programing_design/62704-pic_based_dro.html) project
Bill
That's exactly what I was wondering about. I have been looking at your PIC DRO for some while now. Good work BTW!
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Yes you can. You can use any length scale you can find. Longest I heard of was 1.5m.
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... any length scale ...
Yeah, but just a peace of aluminum ?
How does this work - it must have something to do with the pattern on the PCB and maybe small current circles induces in the aluminum or ... ?
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Forget about springs - the adaptation is easier than we all thought. As Aussie Jim pointed out why not simply put a magnet on the end of the probe. I am showing Mk l and Mk ll versions on my website and soon we will have Aussie Jim's Mk lll version on show.
John-Som
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... any length scale ...
Yeah, but just a peace of aluminum ?
How does this work - it must have something to do with the pattern on the PCB and maybe small current circles induces in the aluminum or ... ?
No, the slide has to have a pattern of conductive pads (it cannot be just plain) the sensor is capacitive
see:
http://madmodder.net/index.php?topic=4444.msg48960#msg48960
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I've tried with a peace of ordinary aluminum and it worked - the digits changed as I moved the aluminum and was fixed when I hold it still.
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Maybe so, but plain aluminium won't have the proper pattern for the quadrature encoder to give an accurate result.
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Maybe so, but plain aluminium won't have the proper pattern for the quadrature encoder to give an accurate result.
I see no pattern on the original slider - OK, maybe it's on the backside of the aluminum strip of the slider.
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Maybe so, but plain aluminium won't have the proper pattern for the quadrature encoder to give an accurate result.
I see no pattern on the original slider - OK, maybe it's on the backside of the aluminum strip of the slider.
Curious :scratch:
The typical digital vernier has a plastic cover over the patterned 'pcb'
Is the aluminium strip actually aluminium or just aluminium coloured (like paint)?
A typical read-head will see almost any change of capacitance as movement, so I'm no too surprised a plain metal strip will cause the digits to change, but I would be surprised if they have found a way to 'read' the surface capacitively in a similar way an optical mouse can with reflected light.
Bill
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Maybe so, but plain aluminium won't have the proper pattern for the quadrature encoder to give an accurate result.
I see no pattern on the original slider - OK, maybe it's on the backside of the aluminum strip of the slider.
It's under the silver sticker. The pattern itself is a stick-on part too.
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Yesterday I tried one on my mill.
Since I wanted a bit more travel I left the spring out altogether. Just gravity allowing the probe to touch the head.
Worked very well and it gave me the the full 25mm of length.
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I think you need the spring to keep the slider aligned. I just flattened mine so that it has very little friction.
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This is my Mk lll version of the Micro DRO and IMHO the best so far in terms of both ease of construction and use. As suggested by Aussie Jim I have dispensed with the use of springs to maintain contact with the lathe cross slide (or carriage) and fitted 3mm rare earth magnets to the tip of the probe.
(http://i256.photobucket.com/albums/hh200/cormorant2/P1020321.jpg)
Many thanks to Rob in Australia for the concept and Corvus Corax for bringing this useful little gizmo to our attention.
John-Som
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John-Som,
Your post about using a magnet is simply brilliant!
I have some small cylindrical magnets with a appropriately sized bore that will fit my gauges. As you say, this will eliminate the need for springs.
:bow:
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> John-Som
Did you drill a hole in the magnet or ... ?
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John.
Love your Mk lll version! :thumbup:
Such a simple/ clever solution...... :clap: :clap:
David D
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ksor
No drilling of magnets. Made up a 6mm long tube with 3mm bore. One end slips over the probe the other takes two 3 x 1.5mm rare earth magnets. A dab of two part epoxy adhesive holds everything in place.
Full details of the construction are at http://start-model-engineering.co.uk/2011/08/mk-lll-mini-dro/ (http://start-model-engineering.co.uk/2011/08/mk-lll-mini-dro/)
John-Som
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Just ordered 50 off, 3mm magnets..... £4.99. :thumbup:
David D
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I used my micro DRO again today to do some precision milling on the lathe and I can only say that it does an absolutely great job, regardless of the price. Very accurate.
This whole concept has really taken on a life of it's own, and it's good to see Madmodder kick it around to get the best possible outcome from the original idea.
Maybe one day we might even see a commercial unit with the same capabilities.
This is good discussion group with a good attitude - and it's a refreshing change.
Rob
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Just note that digital thickness gauges have been showing up of late on ebay:
http://www.ebay.com/itm/0-15mm-Digital-Thickness-Gauge-Precision-0-01mm-Meter-/110730443767?pt=LH_DefaultDomain_0&hash=item19c80c7bf7#ht_3252wt_1260
It appears to have a very similar body to the thread depth gauge discussed here - and would be so if bits were milled away.
-Dick
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Unfortunately it only has a 1.5 battery, so readouts will probably be slower.
Still, it has potential :smart:
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Life has become simpler. In providing a battery free supply for DRO systems commonly fitted to X2 mills it's worth pointing out that the need to provide both 3v (for the remote read out) and 1.5v (for the read head) power supplies can be avoided if read heads from digital tyre depth indicators can be utilised as these operate on 3v.
So, unless I am very much mistaken, all you would need is an adjustable power supply unit set at 3v feeding both the remote DRO and the read head. This would make my battery free power supply unit obsolete - such is progress.
John-Som
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Anyone know what the shiny stuff is on the slider? If one had a longer piece of it it would read longer than 1 inch. Also, is the thing under the tiny cover a data port, if so with what and how do you use it?
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>> kd0afk
Just read the thread ... the answer to ALL your Qs is there ! :coffee:
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>> kd0afk
Just read the thread ... the answer to ALL your Qs is there ! :coffee:
99% of this thread is "I got mine today" and "where do you get one?" but I did get the entire thread read and while it answered a lot of but not all my questions. I got the links answering the data port question but the question about the shiny layer needs closure. Is it a sticker, a textured strip of metal? Does it need a uniform texture to read accurately? Could a person have a strip of SS media blasted or etched to make it more accurate?
I can see real potential in this system with the AC power system and remote readout. Add a strip of "C" channel to keep the svarf out and I think it would be a great tool. You might be able to purchase a DRO system for the same money or less than the final cost of the project but it wouldn't have the satisfaction factor of a DIY.
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I believe this application is some kind of copy magnascale:
http://www.mgscale.com/mgs/language/english/product/Magnescale.html
Inductive or capacitive. I have worked with sony magnascales and these looks like stainless steel tape, but really should not be heated, stretched, kinkked, welded nearby or anything that stupid.
There are many same type of copies available, I know this one:
http://www.machine-dro.co.uk/digital-readout-systems/magnetic-tape-linear-encoders.html
The cheap tyrecauges and calibers probably have "sticker tape" next to read head. Probably best used as it is. Might be difficult to duplicate or improve at typical home workshop.
Pekka
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my finger isn't made of magnascale, why does it work when I run my finger across the sensors?
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Magnascales use a magnetic sine wave signal recorded on to a steel tape or wire. The read heads use a magneto-resistive element (the elements electrical resistance drops in the presence of a magnetic field)
Newall Spherosyn (http://www.newall.co.uk/technology/) devices use magnetic (not magnetised) precision balls in a tube. Sensing is done by inducing a magnetic field with one coil while sensing the strength of the induced field with two other coils (to give a quadrature sine output)
Those cheap digital caliper devices (including the tyre depth gauges and expensive Mitutoyo etc.) use an array of capacitive sensors, that detect gaps in a conductive layer within the sticky backed tape. They will happily detect the motion of anything conductive (including fingers) if close enough to the sensing array.
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I don't doubt you but it just seems a bit sophisticated for a device this cheaply made.
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Wixey sells these things as a "saw fence digital readout" and they sell the strips in 31-1/2" strips for $35 and you get two of them. Here is the link:
http://www.wixey.com/fence/spareparts/index.html#wr7003 (http://www.wixey.com/fence/spareparts/index.html#wr7003)
(http://www.wixey.com/fence/spareparts/images/wr7003.gif)
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Wixey resolution is .005" which is fine for wood but is a bit coarse for metal. Some of the depth gauges will register .0005".
http://www.wixey.com/fence/index.html Scroll to bottom for specs.
Joe
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I think that is just the reader head. If the pcb strip is made the same way as the ones in the digital tire gauge then I think the resolution should be better if used with the cheap Chinese dro heads. I sent an email to the folks at Wixey to get the measurements.
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I don't doubt you but it just seems a bit sophisticated for a device this cheaply made.
They are cheap because they use pretty standard printed circuit manufacturing techniques to form the sensor strips. Expensive (accurate) ones will have additional laser trimming and checking phase, taking extra time and hence money to make).
They all use chip-on-board bonding (i.e. rather than use a separate plastic package for the silicon chip, the chip is glued onto the PCB directly) with an elastomer (conductive rubber sandwich) connection to the LCD.
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When I said PCB I am speaking of the slide. The sensors in the read head read the distance between the gaps in the copper pads on the slide pcb. If the dimentions of the strips are the same ie: copper pads are the same width and the gap is the same, you will have the same accuracy as with the caliper head or the tire depth gauges. Pretty sure the level of accuracy is established in the read head itself.
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When I said PCB I am speaking of the slide.
As was I.
The sensors in the read head read the distance between the gaps in the copper pads on the slide pcb
Yes, they read the change in the capacitance at the edges - The accuracy is wrapped up in the measuring of the change in capacity, straight clean edges of all the parts contribute.
The tyre depth gauges use exactly the same heads as the cheap callipers :) They're just re-purposing the heads to find a niche in a flooded market place.
I guess the Wixey devices have the same kind of accuracy (~10um) but have chosen not to display it (it's only wood after all)
[edit] interestingly the early callipers used a 24 bit binary output format that resolved to 1/20480th of an inch (~2um) but the LS bits are too noisy for any kind of use.
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Just got a reply from Wixey and the pitch of the pattern and gap is the same. Should have the same accuracy as a digital caliper. Most of what I do is accurate to the hundredth and if I need to get down to the thou I use a mic.
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Just got a reply from Wixey
Nice to actually get a reply from a vendor......... :coffee:
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I'm putting something together for my south bend lathe. There are other sites out there dedicated to this concept and using the info from those sites I will be able to have a nice and fairly accurate dro with remote access and read out and it will be linked through a computer. I think the rail system that Wixey sells would be nice but covered with a length of aluminum c-channel would be better. Don't want svarf in the works.
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I'm putting something together for my south bend lathe.
I had a set up like this on my old SB9 (even built the PC interface and DRO (http://www.cnczone.com/forums/pic_programing_design/62704-pic_based_dro.html)). It was OK, but the scales do not really have enough resolution for the cross-slide of a lathe. :(
Although the scales read to 0.0005 which appears OK, this is the least significant digit, so it's actually no better than 1 thou" accurate. This error gets doubled on a cross-slide because you're cutting diameter so you could be ~2thou" out.
Those cheap scales are OK on a drill/mill but you'll probably find them frustrating on a lathe.
Bill
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I have looked at some of the schematics and plans for a computer interface for these gauges and part of it is increasing the frequency or something like that so that it reads quicker. Couldn't a person also increase the precision electronically?
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I just got a second one in the mail. It's one of the black ones but it is nice. It holds it's reading after a power down so it has memory. I plan on getting a few more of this model on payday. Here is the link. http://www.ebay.com/itm/290703672736?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 (http://www.ebay.com/itm/290703672736?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649)
I hope they are selling these out of a larger lot and that all of the ones they are selling are the same.
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I have looked at some of the schematics and plans for a computer interface for these gauges and part of it is increasing the frequency or something like that so that it reads quicker.
Some of the early types had a fast and slow read speed (usually 100-200mS for improved precision & 30-50mS for easy adjustment ). For use with my DRO I had to switch them to fast read mode (which is a right royal PITA for a little PIC)
Most of new ones read a little faster at one fixed speed (they don't have the high speed option at all).
Couldn't a person also increase the precision electronically?
Not with the newer ones, they output a BCD signal that is essentially what is displayed on the screen. With the older 24 bit binary versions it might be possible to filter (average) the data but it would make the reading speed too slow for use as a DRO
Bill
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I also noticed that if you turn it off, not only does it remember the last possition it will automatically come on when you move the slide. And if you remove the data port cover reveals the copper traces and what looks like power contacts.
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I also noticed that if you turn it off, not only does it remember the last possition it will automatically come on when you move the slide. And if you remove the data port cover reveals the copper traces and what looks like power contacts.
They don't actually turn off, they just blank the display (to prevent damage the the LCD with a static display)
Bill
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just my luck...Santa brought me one of theses gauges...
... and its only 1.5 v.. :doh:.......(the black one)...
So is this one going to be to slow then.? :(
..mike..
alias= lucky ace macwinnin
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just my luck...Santa brought me one of theses gauges...
... and its only 1.5 v.. :doh:.......(the black one)...
So is this one going to be to slow then.? :(
..mike..
alias= lucky ace macwinnin
Too slow ?
Not necessarily, the 3v lithium cell should last a bit longer than the alkaline, type but internally they all appear to run at 1.5v. - Push the thing in and out a few times and ask yourself 'does the display keep up with the movement?' - The two cheap ones I have here seem to be OK.
Bill
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Bill,
It does'nt seem too bad ...it does seem slightly different from the others although it appears the same..
it does'nt have the metal spring ive heard folk talk about, ...and the data port?? it does have an extra hole under the rear sticker but it does'nt seem to lead to anything,, or is data port tech talk for an extra hole? :scratch:
While messing about with it i took the lip/stopper off the end of the ruler piece to see how long it would extend out to if it was'nt restricted, and it read/measured 70mm+ from probe tip to the end of the silver coloured coating on the ruler bit...
but i dont think i would need that extra, but it would'nt take much to make a little extension on the rear to stop it going past its readable/measurable limit...or am i over looking something ? :wack:
...Mike...