As we have discussed off the forum, there are "magnetic" stainless steels.
Nickel is the major variable in the composition. It's added for physical properties, but also makes the metal austenitic (phase), and non-magnetic. These are the 300 series.
The 400 series stainless steels are Ferritic or Martensitic (phases) are magnetic. They're somewhat less corrosion resistant in acids, etc.
In practice, 300 series stainless steels are often very magnetic too, (eg ordinary cutlery) but that's because they've been cold worked, which forms the magnetic "phase" in the structure. If the material were annealed, then it would revert to the non magnetic phase.
I was surprised to hear that the sheet Robert acquired, wasn't magnetic enough. A possibility would be to bond a thin sheet of different material to it.
"Magnetic" is strictly an inadequate term here but we know what we mean - a magnet sticks hard to them. cf Paramagnetic, Diamagnetic, Ferromagnetic, etc.
Nikon MM-11 C Measurescope Vertical Set Up Project
Moderators: rjlittlefield, ChrisR, Chris S., Pau
RobertOToole wrote:Mag bases are so much easier to set up it's amazing. Just click and reposition! Zero hassle, and no wrenches needed.
So true!
I've been very happy with my powder-coated steel plate. Now in its fifth year of use, this finish has some scratches it it, but functions perfectly. Powder coating is also not expensive in my experience ($20 range). I use a local company for this, but would imagine the service is widely available.That means if I want to use my magnetic bases I will have to find another steel plate, have it surfaced, plated (for corrosion resistance), and maybe drilled and tapped for 1/4-20 holes (not necessary but it would be nice).
(snip)
Any comments and advice are welcome.
--Chris
About 10 years ago I got a cast iron base plate galvanic coated with nickel. Held up excellent and maintained the flatness of the machined surface what probably by powder coating would not have been the case. Before galvanic coating sweaty fingerprints showed up as rust over night.RobertOToole wrote:Or I could return the aluminum breadboard I have and use the credit against a standard ferromagnetic steel skinned breadboard with polyurethane coating and 1 inch spaced 1/4-20 holes! This would be about $260-350.
Any comments and advice are welcome.
See here the result:
http://www.photomacrography.net/forum/v ... c&start=15
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RobertOToole
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Thank to everyone for info and the links!
Finally I have some progress on my project to report.
Nikon MM block with Newport plate and Henjar QR clamp.
Since my Nikon MM variant did not feature a normal carrier/nosepiece/turret I went with a quick release clamp setup. The QR clamp knob looked like it would not have much clearance from the coaxial focus knob so I used a 4 x 6 x 1/2 inch spacer between the block and clamp. The plate came with 2 inch spaced holes to mount the QR clamp.
Newport 38 mounting plate was $35 plus free shipping: http://tinyurl.com/ngbfsgh
The Henjar 4.8 inch clamp was about $70 + shipping. Note that this clamp has grooves for safety stops and uses convenient 2 inch spaced mounting holes! Also the bottom edge of the clamp jaw has a .5mm step for clearance. This is not the case with lots if not most of the QR clamps on the market!
This view shows the block-spacer-clamp stack and the coaxial knob height.
The next and final step is just to mount the new ferrous steel plate as soon at it arrives in a few weeks.
All comments and suggestions welcome as always.
Robert
Finally I have some progress on my project to report.
Nikon MM block with Newport plate and Henjar QR clamp.
Since my Nikon MM variant did not feature a normal carrier/nosepiece/turret I went with a quick release clamp setup. The QR clamp knob looked like it would not have much clearance from the coaxial focus knob so I used a 4 x 6 x 1/2 inch spacer between the block and clamp. The plate came with 2 inch spaced holes to mount the QR clamp.
Newport 38 mounting plate was $35 plus free shipping: http://tinyurl.com/ngbfsgh
The Henjar 4.8 inch clamp was about $70 + shipping. Note that this clamp has grooves for safety stops and uses convenient 2 inch spaced mounting holes! Also the bottom edge of the clamp jaw has a .5mm step for clearance. This is not the case with lots if not most of the QR clamps on the market!
This view shows the block-spacer-clamp stack and the coaxial knob height.
The next and final step is just to mount the new ferrous steel plate as soon at it arrives in a few weeks.
All comments and suggestions welcome as always.
Robert
I'm considering a similar application, and I'm hesitant about using a single-screw Arca clamp. They aren't really designed for the twisting moment.
Compare with the strength /rigidity of the "original" in Charlie's post;
http://www.photomacrography.net/forum/v ... 389#144389
There are larger section Optical Rails of course, though most of them only have quite short clamps - two would be necessary.
If anyone has surplus "larger" rails, please let me know!
Compare with the strength /rigidity of the "original" in Charlie's post;
http://www.photomacrography.net/forum/v ... 389#144389
There are larger section Optical Rails of course, though most of them only have quite short clamps - two would be necessary.
If anyone has surplus "larger" rails, please let me know!
I can think of two ways to possibly make an arrangement more safe and/or rigid.
One would be to add a couple of screws, sideways through the movable jaw tapped/threaded into the body of the clamp, and left screwed in far enough to make it be impossible to remove the rail other than by sliding it out of the (top) end of the clamp.
That would help prevent accidents to do with uncertainty about whether the clamp was done up enough to hold, or not.
Then a couple more screws, alongside those, could be used to tighten the clamp after the thumbscrew. That would mean there would then be (say) three clamp screws instead of one.
Another way would be to use a different mechanism.
The cheap, oriental "4 way" focus rails on ebay come in two sections. One (the earlier one) is a symmetrical dovetail shape. (It happens to fit an Arca clamp.)
If three pieces of this dovetail rail were used, two fixed to one of the parts to be assembled, with one, fixed to the second part, the other way around between them, a much larger overlap of metal would result. It could be made tightenable, but with a bottom end stop, gravity would do most of the work.
The rail would probably benefit from a little reshaping with a file (red line):
One would be to add a couple of screws, sideways through the movable jaw tapped/threaded into the body of the clamp, and left screwed in far enough to make it be impossible to remove the rail other than by sliding it out of the (top) end of the clamp.
That would help prevent accidents to do with uncertainty about whether the clamp was done up enough to hold, or not.
Then a couple more screws, alongside those, could be used to tighten the clamp after the thumbscrew. That would mean there would then be (say) three clamp screws instead of one.
Another way would be to use a different mechanism.
The cheap, oriental "4 way" focus rails on ebay come in two sections. One (the earlier one) is a symmetrical dovetail shape. (It happens to fit an Arca clamp.)
If three pieces of this dovetail rail were used, two fixed to one of the parts to be assembled, with one, fixed to the second part, the other way around between them, a much larger overlap of metal would result. It could be made tightenable, but with a bottom end stop, gravity would do most of the work.
The rail would probably benefit from a little reshaping with a file (red line):
What I meant, with those dovetail rails:
The screws tapped right through the blue part would tighten the two (pink, and blue,) together. It might be better with screws just one side. And some clearances
If going from (say) a vertical mount to a horizontal where the pulling-out force is far less, then any of the dovetails could be used in a normal Arca clamp.
Other methods are still coming into my head
The screws tapped right through the blue part would tighten the two (pink, and blue,) together. It might be better with screws just one side. And some clearances
If going from (say) a vertical mount to a horizontal where the pulling-out force is far less, then any of the dovetails could be used in a normal Arca clamp.
Other methods are still coming into my head
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RobertOToole
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After waiting a couple of weeks for the new working surface plate this what arrived. The supplier thought it was okay to send a honeycomb 12 x 12 x 1 inch ferrous steel plate in a 12 x 12 re-used cardboard box with no added protection other than a plastic bag around the plate. I didn't even bother to open the box before I sent it back since you can see where the plate made contact on two sides.
Waiting for an update from the supplier on ETA for a replacement.
Robert
Waiting for an update from the supplier on ETA for a replacement.
Robert
Asher,
I don't know what method Robert employed. But be aware that drilling a hole and adding threads to it (aka "drilling and tapping") is very easy to do in aluminum, steel, or pot metal (materials typical of microscopes). Drilling and tapping are well within the capabilities of just about anyone, and there are lots of videos on YouTube that teach the process.
For some years, I've been working with an excellent fabricator, whom I value highly. Until recently, I've asked him to do all my drilling and tapping, in addition to more difficult tasks. This fabricator is a pearl beyond price, and I hope to continue working with him for a long time. But of late, I've been immersed in a metal-fabrication project (non-photographic--a specialized trailer) that has required a bunch of drilled and tapped holes in steel and aluminum. The need for such holes has come up daily--far too often to stop work for each hole and visit my fabricator. So I've learned to drill and tap metal for myself. Gadzooks, this turns out to be easy!
Going forward, I'll continue to work with my fabricator on difficult jobs; but whenever all that is required is a set of threaded holes, perhaps on a piece of aluminum cut from standard stock, I'll probably make it myself. (In fairness to my fabricator--a generous and honest man--he's long been suggesting that I might prefer to do simple things for myself. And he's graciously shown me how to do them.)
So Asher, if you wish to add another threaded hole, I'd advise you to watch a few good videos on YouTube, which should make the following instructions seem simple. Then purchase the needed tools (a good drill, an appropriately-sized drill bit, an appropriately-sized tap, a tap wrench, and a bottle of cutting oil). Then drill and tap the mounting holes you require.
The general idea is that you drill a hole with a drill-bit slightly smaller than the threaded hole, then cut the needed threads with a tap. Tables that specify drill-hole and tap sizes are easy to find. You'll want to buy a good drill bit and tap, some cutting oil, and an inexpensive wrench to hold the tap. Then you just screw in the tap, going forward a bit, then backwards a partial bit, then forward some more, then backward about half as much as you went forward. Trust me--this will turn out to be much simpler than it sounds, and will work great.
Cheers,
--Chris
I don't know what method Robert employed. But be aware that drilling a hole and adding threads to it (aka "drilling and tapping") is very easy to do in aluminum, steel, or pot metal (materials typical of microscopes). Drilling and tapping are well within the capabilities of just about anyone, and there are lots of videos on YouTube that teach the process.
For some years, I've been working with an excellent fabricator, whom I value highly. Until recently, I've asked him to do all my drilling and tapping, in addition to more difficult tasks. This fabricator is a pearl beyond price, and I hope to continue working with him for a long time. But of late, I've been immersed in a metal-fabrication project (non-photographic--a specialized trailer) that has required a bunch of drilled and tapped holes in steel and aluminum. The need for such holes has come up daily--far too often to stop work for each hole and visit my fabricator. So I've learned to drill and tap metal for myself. Gadzooks, this turns out to be easy!
Going forward, I'll continue to work with my fabricator on difficult jobs; but whenever all that is required is a set of threaded holes, perhaps on a piece of aluminum cut from standard stock, I'll probably make it myself. (In fairness to my fabricator--a generous and honest man--he's long been suggesting that I might prefer to do simple things for myself. And he's graciously shown me how to do them.)
So Asher, if you wish to add another threaded hole, I'd advise you to watch a few good videos on YouTube, which should make the following instructions seem simple. Then purchase the needed tools (a good drill, an appropriately-sized drill bit, an appropriately-sized tap, a tap wrench, and a bottle of cutting oil). Then drill and tap the mounting holes you require.
The general idea is that you drill a hole with a drill-bit slightly smaller than the threaded hole, then cut the needed threads with a tap. Tables that specify drill-hole and tap sizes are easy to find. You'll want to buy a good drill bit and tap, some cutting oil, and an inexpensive wrench to hold the tap. Then you just screw in the tap, going forward a bit, then backwards a partial bit, then forward some more, then backward about half as much as you went forward. Trust me--this will turn out to be much simpler than it sounds, and will work great.
Cheers,
--Chris
Easy is relative! Easy once you've done a few, I'd say. Like drilling a hole in a wall to fix a shelf. Easy to make a mess.
Chris_S only ever does things carefully!
Particularly in steel, you'll need good support. A flat wooden surface may do for aluminium.
A pillar drill aka drill press, is way better than a hand drill.
To drill the hole, first start with centre punches and a pilot drill or it WILL wander off.
It's quite easy to get the tap slightly crooked when startng the thread, If you have a pillar drill to hold (with power off) and let you turn the tap into the hole, it'll be straight.
Chris_S only ever does things carefully!
Particularly in steel, you'll need good support. A flat wooden surface may do for aluminium.
A pillar drill aka drill press, is way better than a hand drill.
To drill the hole, first start with centre punches and a pilot drill or it WILL wander off.
It's quite easy to get the tap slightly crooked when startng the thread, If you have a pillar drill to hold (with power off) and let you turn the tap into the hole, it'll be straight.
Last edited by ChrisR on Sat Sep 12, 2015 7:21 am, edited 2 times in total.
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RobertOToole
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Hi Asher,gameasher wrote:hi, Robert
It seemed there is only one thread hole on the nikon mm block, so how did you mount the newport 38 plate to it? and would you please tell me the thread's size of mm block?
Asher
To mount the newport 38 I borrowed a friend's drill press to bore and tap the MM block and to countersink the holes so the hex bolts would sit flush.
As the guys mentioned, it had to be done carefully, even with the drill press!
Robert
As a machinist who helps students in college metalworking class, I can say that having proper tools and proper theoretical understanding, everybody can get a decent threaded hole from the first attempt. Any questions about this process are welcome, by the way.
Indeed, having even a really simple drill press or drill angle guide for hand drill (especially, one of those with own chuck built into it) really helps. That's because the most important tolerance for threaded holes is perpendicularity.
Drilling a pilot hole is not actually required for making fairly small threaded holes - it is only required, if target diameter drill bit has significantly large web (dull tip), something larger than 1mm.
Another really helpful tool is the spring-loaded tap guide. It's a small cylinder with sharp rod built into it, and this rod is spring-loaded from the inside. So you can put this cylinder into the drill chuck and push its tip into the corresponding hole on your tap wrench body. It will keep the whole thing perpendicular.
I would recommend this tap drill chart for drill bit selection http://www.brokenbolt.com/images/starre ... -drill.pdf
Couple of warnings:
Indeed, having even a really simple drill press or drill angle guide for hand drill (especially, one of those with own chuck built into it) really helps. That's because the most important tolerance for threaded holes is perpendicularity.
Drilling a pilot hole is not actually required for making fairly small threaded holes - it is only required, if target diameter drill bit has significantly large web (dull tip), something larger than 1mm.
Another really helpful tool is the spring-loaded tap guide. It's a small cylinder with sharp rod built into it, and this rod is spring-loaded from the inside. So you can put this cylinder into the drill chuck and push its tip into the corresponding hole on your tap wrench body. It will keep the whole thing perpendicular.
I would recommend this tap drill chart for drill bit selection http://www.brokenbolt.com/images/starre ... -drill.pdf
Couple of warnings:
- --Do not use so called "thread forming" tap - it's a different tool. General purpose taps should be used.
--Do some chamfer on the hole edge using large drill bit before tapping, otherwise you will have ugly edge. Chamfering means drilling it just a bit, to make some sort of really small funnel with diameter slightly larger than major diameter of thread.
Thanks, Bushman.K, for your offer to provide advice as needed to forum members, and your specific advice in this thread. I hope your offer is widely and publicly taken up. Our community stands to gain a lot from the active participation of an experienced machinist such as yourself.
Let me say that I've lately been drilling holes and tapping threads into aluminum and steel over and over, with nothing but a hand drill and simple tap wrench. I don't have a drill press, drill angle guides, or other fancy items. (Though I would like to have such things.)
With these simple tools, I've so far had not a single misfire; not one misaligned hole or mistapped set of threads. As ChrisR observed, I'll admit that I work with care. But I'm also pretty sure that I have no unusual mechanical talent. So my thinking is that any similarly careful person can do this.
--Chris
Let me say that I've lately been drilling holes and tapping threads into aluminum and steel over and over, with nothing but a hand drill and simple tap wrench. I don't have a drill press, drill angle guides, or other fancy items. (Though I would like to have such things.)
With these simple tools, I've so far had not a single misfire; not one misaligned hole or mistapped set of threads. As ChrisR observed, I'll admit that I work with care. But I'm also pretty sure that I have no unusual mechanical talent. So my thinking is that any similarly careful person can do this.
--Chris