Thread: Co-axial indicators

Pretty much all been covered. And though it doesnt matter much anymore, 20 rpm is a little slow. You're not trying to take reading, just make the needle "wiggle" less. (come over and have a go) My knock off seems to be pretty damn close, others havent been so lucky and needed to do a bit of work to get them working right. As others have said the amount of Z used is painful, as can the Z movement between centering and machining(unless you have power Z). If your tram isnt spot on and you're chasing the last 5 micron you're going to have issues . With a DRO I prefer a wiggler setup about the same length as the tool I'll be using.

One of these days I'll fork out for one of Phils goosenecks.

Stuart

Originally Posted by Stustoys

Pretty much all been covered. And though it doesnt matter much anymore, 20 rpm is a little slow. You're not trying to take reading, just make the needle "wiggle" less. (come over and have a go) My knock off seems to be pretty damn close, others havent been so lucky and needed to do a bit of work to get them working right. As others have said the amount of Z used is painful, as can the Z movement between centering and machining(unless you have power Z). If your tram isnt spot on and you're chasing the last 5 micron you're going to have issues . With a DRO I prefer a wiggler setup about the same length as the tool I'll be using.

One of these days I'll fork out for one of Phils goosenecks.

Stuart

Thanks for the offer Stuart. I don't think I would ever need to chase the last 5 microns. In fact I doubt that I have the test equipment to be capable anyway. 10 micron positional error would be the absolute limit I would suggest for me, even then I may be dreaming! Next time I'm over your way I'd still be interested to look at it.

Given the cost of that gooseneck and the availability of those plans, I find it difficult to buy a dedicated co-axial indicator now. I'd rather spend some money on a decent vertical face indicator and make the rest.

Thanks Ueee, I think I may make one similar to that. although I don't think I will use drill rod for the rods, I have some shafts from shock absorbers looking for a use. They are nicely polished.

Simon

Originally Posted by Michael G

There are two different beasts being talked about here Simon. If you want to use a DTI for small holes, something like this is really helpful -
Attachment 312591 Attachment 312592
Mitutoyo will sell you one (I think they call it a Zero-it), but this one was made from plans floating around the internet. One tip though is that it is better to use a vertical indicator like this one as you can see the dial more easily (A Stuart suggestion). I used mine today in fact for setting up something central on the R/T. These are used unpowered (rotate the spindle by hand)
Attachment 312593

Coax indicators are usually used with the machine running - the X and Y slides are adjusted so that the needle deviation is at a minimum. The top name is Blake. I managed to pick one up second hand for the right price but I don't use it much mainly because they gobble up Z (from memory 150mm or so?). The dial has 5/10th's divisions which is the same as the vertical DTI pictured above.

Attachment 312594

PM me if you think it needs a short holiday...

Michael

Hi Michael,

Been looking at your Zero-meter and also the plans posted from Ueee. Looks all pretty straight forward, but what I don't understand is the purpose of the secondary adjustment on the indicator holder (the part that has to 2 smaller drill rods adjustment). I can only assume that is to allow you to bring the indicator back in close to the spindle axis for when you want to indicate off very small holes?

My question is, given that most indicators have their own dovetail attachment post, would a hole drilled to suit this and a knurled screw to nip up the post suffice?

I like to keep things fairly simple. To quote a lecturer I had once: Things should be simple as possible, BUT no simpler!

Then again there is most likely another reason for the design that I have not yet appreciated…..

Simon

Hi Simon,
I think you'll find that's just the way they came up with to do the fine adjustment.

You want simple, how about this? As is will go up to about 2" bore. Some tweaks might get some more out of it. As pictured the Z length would be about 115mm(about 80 of that being the DTI)


On a side note.. anyone know what the makers think about DTI's being used "sideways"?

Stuart

Originally Posted by Stustoys

Hi Simon,
I think you'll find that's just the way they came up with to do the fine adjustment.

You want simple, how about this? As is will go up to about 2" bore. Some tweaks might get some more out of it. As pictured the Z length would be about 115mm(about 80 of that being the DTI)


On a side note.. anyone know what the makers think about DTI's being used "sideways"?

Stuart

Hi Stuart,

Doh! Of course, the fine adjustment. I didn't even think of that. The reason I didn't think of it is because the method I use ATM also has no fine adjustment. You have to fiddle to get it right. OK I'm liking this even more!

WRT using the DTI sideways, I have never given it much of a thought. I assume* it's OK.

* Yea, yea, never assume!

Simon

Originally Posted by Michael G

There are two different beasts being talked about here Simon. If you want to use a DTI for small holes, something like this is really helpful -
Attachment 312591 Attachment 312592
Mitutoyo will sell you one (I think they call it a Zero-it), but this one was made from plans floating around the internet. One tip though is that it is better to use a vertical indicator like this one as you can see the dial more easily (A Stuart suggestion). I used mine today in fact for setting up something central on the R/T. These are used unpowered (rotate the spindle by hand)
Attachment 312593

Coax indicators are usually used with the machine running - the X and Y slides are adjusted so that the needle deviation is at a minimum. The top name is Blake. I managed to pick one up second hand for the right price but I don't use it much mainly because they gobble up Z (from memory 150mm or so?). The dial has 5/10th's divisions which is the same as the vertical DTI pictured above.

"snip"

PM me if you think it needs a short holiday...

Michael

Michael, could you point me to plans for this device please. I am about to order a vertical dti so I can make one.

Dean

Originally Posted by Ueee

Did you find the plans for it Simon? They are floating around somewhere. I have them i can email you if i can't find you a link. I'm sure Michael posted them but where.....

Ew

Wow that was easier than i thought... http://www.homemetalshopclub.org/pro...old/hldr1.html

Here they are. Ueee posted them in the previous page.

I think I'm going to make one too. I can't see it in these plans but I have seen images of this (google images of zero-it indicator) at other places and the fine adjust drill rods have compression springs between the holder and the main body. I assume this is so it does not rattle from the thread backlash on the fine adjust. There is a small knurled screw to tighten once adjusted but the omission of these springs would make it a little annoying while adjusting.

Edit: like this one: images of zero-it indicator
Simon

Originally Posted by simonl

Here they are. Ueee posted them in the previous page.

I think I'm going to make one too. I can't see it in these plans but I have seen images of this (google images of zero-it indicator) at other places and the fine adjust drill rods have compression springs between the holder and the main body. I assume this is so it does not rattle from the thread backlash on the fine adjust. There is a small knurled screw to tighten once adjusted but the omission of these springs would make it a little annoying while adjusting.

Edit: like this one: images of zero-it indicator
Simon

Thanks Simon. I missed that. The indicator has been ordered. I will have to make some changes to suit the vertical DTI by the looks of that design.

Dean

Originally Posted by Oldneweng

Thanks Simon. I missed that. The indicator has been ordered. I will have to make some changes to suit the vertical DTI by the looks of that design.

Dean

Vertical should work better anyway since you will be able to view the dial easier when rotated.

Simon

I made it "pretty much to drawing" but found when putting a DTI in that the edge of the dial fouled the bit above the dove tail clamp. With hindsight I'd make that bit longer and then trim back once I had a DTI to check for size.
Lack of springs did not cause any aggravation. Biggest aggravation was having to make parts again because I didn't get the holes for the rods spot on parallel.
It's not a complicated or time consuming project but does need a little bit of precision.

Michael

Technically speaking I think my idea was a normal DTI laid down.(though I cant find the thread)
I'm wondering with a vertical DTI the rods will be to close to the face or you'll need to use even more Z.....

Of course if it works I'm happy to take credit

No one likes the idea of stealing the fine adjust off the end of an indicator stand? you guys must have bigger workpieces than I do hehe

Stuart

This one seems OK but looking at the way he has it set up, he must zero off some pretty large diameter holes!
http://home.earthlink.net/~bottlbob/...orSweeper2.jpg
Hey Stuart, if you bring the DTI higher to reduce Z use and it then fouls with the rods, I don't see why you couldn't keep the rods fixed at the DTI end and instead have them slide through where they attach at the spindle end?

Edit: fixed up the link.
It would also be more balanced for when spinning the setup at 500 rpm

Simon

Originally Posted by simonl

Vertical should work better anyway since you will be able to view the dial easier when rotated.

Simon

That is my intention. I don't fancy doing the mirror routine and I've got a bit of spare cash at the moment.

I made it "pretty much to drawing" but found when putting a DTI in that the edge of the dial fouled the bit above the dove tail clamp. With hindsight I'd make that bit longer and then trim back once I had a DTI to check for size.
Lack of springs did not cause any aggravation. Biggest aggravation was having to make parts again because I didn't get the holes for the rods spot on parallel.
It's not a complicated or time consuming project but does need a little bit of precision.

Michael

Looking at your pics I cannot see what you mean, but as I will have to redesign a little bit it does not matter. I am looking forward to playing with this project, but I am not sure at the moment how to finish those holes as I don't have anything to do them except for drill bits.

Technically speaking I think my idea was a normal DTI laid down.(though I cant find the thread)
I'm wondering with a vertical DTI the rods will be to close to the face or you'll need to use even more Z.....

Of course if it works I'm happy to take credit

If you cannot find the thread, then you have no proof! No proof, no credit! Bad boy. Go to jail. Do not pass GO.

No one likes the idea of stealing the fine adjust off the end of an indicator stand? you guys must have bigger workpieces than I do hehe

Stuart

Having read about how people dislike the fine adjust on indicator stands, I realised that they are more trouble than they are worth and I intend to get rid of the one on my stand. Mine is a cheapie and fairly useless tho.

This one seems OK but looking at the way he has it set up, he must zero off some pretty large diameter holes!
http://home.earthlink.net/~bottlbob/...weeper2.jpgHey Stuart, if you bring the DTI higher to reduce Z use and it then fouls with the rods, I don't see why you couldn't keep the rods fixed at the DTI end and instead have them slide through where they attach at the spindle end?

It would also be more balanced for when spinning the setup at 500 rpm

Simon

Link did not work. Maybe you have access to stuff that I don't.

I thought of having the rods work this way on initial evaluation, but this will only work for larger holes. Looking at Michaels picture, the dovetail clamp will have to be extended out further, but extra z's will only be needed when the dial is blocked by the chuck mounting block above it.

Dean

Originally Posted by Oldneweng

I thought of having the rods work this way on initial evaluation, but this will only work for larger holes. Looking at Michaels picture, the dovetail clamp will have to be extended out further, but extra z's will only be needed when the dial is blocked by the chuck mounting block above it.
Dean

Ah yes I see what you mean. For smaller holes you need to have the indicator facing the spindle axis, which means the rods will still be in the way. Whenever I think of changing a design, my first thought is.. there must be a reason the way it is. Someone has put a fair amount of thought into that design, certainly more thought than the 5 minutes I spent looking at the finished item!

I guess if Z use was really something you wanted to preserve, you could make the spindle attachment to fit straight into your mill spindle taper. A fair bit of stuffing around to save maybe 30mm of Z.

PS sorry about the link. I always try my links in preview before posting. Not sure why it doesn't work!

Simon