Most interesting when you add the two bits of steel - the pole fields are I guess a bit predictable but - very useful property. Never thought to try that. You are always full of great ideas Stefan. :) Love this whole project... only downside I'd have is, no surface grinder!
For super strength, I recommend Loctite 331, it's a magnet bonder used in the electric motor industry. Not that this will be spinning around... but you know, you never know!
Very good discussion of flux lines in a laminated magnet. Never heard of those magnets in Engineering school, but it makes sense to me. Saving part 2 till tomorrow. Machining, as usual, magnificent.
Very clever and well thought out. Not exactly unexpected for your channel Stefan. I think the full length pins are a good addition. Epoxy does hold well, but it's a brittle glue joint. Drop that magnetic parallel just once and you'd have a minimum of two pieces if your lucky.
Two thoughts, First, as surface finish makes a big difference in ultimate hold strength, would lapping the magnets and brass plate assembly so there is no gap between the steel and magnet help hold strength? Second, could you make some sort of tongue and groove assembly to slot the brass and steel sheets together? Perhaps you could use the shaper? (you could set up a channel like the Yule Log channel and just let us all watch the shaper do its work)
Very cool project Stefan! I might have to make one or two, have a good cry and then make some V blocks as well :). Keep them coming and I'll keep watching. Best Matt
Great :( Now I have another project to add to my (already too long) list. Pretty nice idea! I have some epoxy putty, pretty hard but easy to machine and grind, I might try to do the same but using that putty instead of the brass. About the transformer sheet metal, it's high silicon steel too reduce the Eddy currents and hysteresis loss.
Stefan, your mismatch with the slitting saw was because you were conventional milling. If the machining setup is rigid enough, climb milling with these type cutters is always dead-on. Do a test sometime and see. Thanks for the videos. I enjoy them all.
on the subject of magnetism i dismantled a deck top computer to access its modem and when i dismantled the modem there was a very strong magnet that accidently stuck itself to a metal work surface it took over 100kg of force to remove it .
how accurate does the length of the hole in the brass for the magnet have to be to the length of the magnet. in other words, does the magnet have to be in contact with the steel pole plates on both sides of the brass??
magnets are funny things. i think two magnets in a plate would creat some interesting issues when assembling. i did a project with embedded magnets recently, and only really found out how much i dont know. lol
It doesn't seem like Stefan is answering questions on this video anymore (understandable, it's 4 years old!), so if anyone else can answer, that would be cool. They sell these magnets in rectangular shapes. Would those work? I understand you'd still need to surround the magnets with brass, so that you can surface grind the surfaces, but I'm curious if there's anything about the shape of the magnets that would make the "redirecting the direction of magnetic pull" trick work differently (or not at all).
I'm far from an expert, but looking over this article, I think you could expect the behavior to be the same: en.wikipedia.org/wiki/Halbach_array Cylindrical and block shapes are considered for different sections of the article.
Stephen just to let you know I really enjoy your channel. In 1975 I was on a ship USS South Carolina and we stopped in Bremerhaven Germany...you have a beautiful country.
Interesting. I would have soft soldered the stack, bass and iron can be soldered easily with Soldering-paste (for pipework). And the magnet take no harm with the 300°C. Then no pinning would be needed i think. I did soft solder big parts on an old electric stove with an aliminium plate as flat base. I think i will make one from Galvanized iron sheets. They are often very low carbon steel and cheap. Simply soft solder stacks together and put a magnet in the middle. The zinc and tin are good enough magnetic isolation between the iron plates i think.
As a sign of respect and gratitude for teaching me the word 'stictivity', here's a small denglish mnemonic to help remember not to put 'would' into an if-clause: 'if+would=Satz kaputt'
Once again a great explanation. Can I ask about your Toolmakers vice which appears to have a ratcheting mechanism for adjusting the moving jaw. I've had a look on the web but failed to fine a reference to this type of vice would you be able to provide any info on this vice. Thanks
Been quite a while since you asked, but it's one of these: www.arceurotrade.co.uk/catalogue/department.aspx?node_id=deda9017-3d52-463c-b0b5-a1b701150583&ou=%2fcatalogue%2fworkholding%2fmachine-vices%2fprecision-tool-vices-type-2
Aluminum does work and is used for making laminated magnets. Brass is often preferred because it is often harder, less prone to scratches and dings, and is less easily corroded (all variable depending on the grades of both metals).
Isn't the epoxy like 3000psi shear strength? You don't think the fact it should take almost a ton of force to separate the magnets is enough to hold them together?
Never trust glue. It is a very brittle bond in my experience and should always be backed up by mechanical fasteners. If you dropped them, the shock could break the bond (or just let them snap to the surface). The glue is very strong in the laboratory under static load for sure, but one light tap and it can break. It won't of course if that was the plan. Then it will stick like a SOB, but if you want it to be permanent it won't be.
Barry Gerbracht Better tell most of the auto manufacturers, many of them have been epoxying structural body panels for the last 15+years instead of spot welding because it is stiffer and stronger. I am sure the grade and properties of the epoxy have a huge effect on its performance.
+bcbloc02 I think automotive epoxy is softer and a much thicker bond layer to allow for the epoxy to be more plastic instead of very rigid. I have used epoxy (Sikadur 31) to bond steel together and it is very brittle (it failed after applying the design load even though by calculation it should have had massive amounts of bond strength beyond the calculated demand). This was not some simple sticking two hunks of stuff together and hoping it works either. The surfaces were properly prepared and I had done all of the load calculations and shear flow checks to make sure the bond was adequate. No luck. A few well placed fillet welds stitched along the length and they never moved. I know adhesives are used in automotive applications and extensively in aircraft manufacturing. They are not using hardware store epoxies and will have extensively proof tested the assemblies prior to actually using them in production. I would not trust this epoxy and would back it up with some rivets. Once burned so to say...
All depends on the grade of epoxy you're using..........!!!! Cheap commonly available stuff isn't gonna glu anything, for serious gluing you need to get industrial products, and, those products aren't available to public. You can look into something like Miller Stephenson MS-907, I've glued parts like 30 + years ago and it still holds, you really need to hammer the parts in order to break the bond... They also have other excellent products like the ones used in automotive or aircraft industries...... ;) www.miller-stephenson.com/chemicals/epoxy-resins/
salut. Je suis français. pourriez-vous M' indinquer les épaisseurs du laiton et du fer en mm, merci, car l ' Anglais ne comprend pas . super votre chaîne CZcams . Cordialement Dominique
You should NOT use 5-min. epoxy, as it has very low strength. The longest-setting time epoxy will generally have the highest strength. Also, do not use "laminating" epoxy that is used for fiberglass layouts, as it often cures very hard, therefore being brittle when submitted to a shock. The best epoxy is "structural" epoxy.
This has to be because I'm just a machining aficionado through videos only (for now), because I swore that brass at the beginning of the video was actually wood XD.
Stefan, thank you for providing your knowledge free of charge. Some entitled people want to be entertained more than they would like to learn. I will be trying to make a set like these soon. Ignore this guy!
"You know the story. Sitting in a corner. Crying." Please make shop t-shirts with that on it. I'll buy a couple.
I tried that. I ended up sitting in a corner crying.
That must be the shortest 24 minute video I've ever seen! Anxiously awaiting part 2.
Most interesting when you add the two bits of steel - the pole fields are I guess a bit predictable but - very useful property. Never thought to try that.
You are always full of great ideas Stefan. :)
Love this whole project... only downside I'd have is, no surface grinder!
I'm sure you can do these jobs the old way. With a good vise, file and a square.
"Sticktivity" is my absolute new favorite word. I'm stealing this for sure. :D
Awesome! Wonderful DIY magnetic brick.
Loved the drill bit edge grinding tip! I will use that one for sure!
I'm already coming back to watch this a second time, I need part 2!
For super strength, I recommend Loctite 331, it's a magnet bonder used in the electric motor industry. Not that this will be spinning around... but you know, you never know!
Why worry about residual magnetism? These are permanent magnets you are making. Soft iron is for switchable poles.
Very good discussion of flux lines in a laminated magnet. Never heard of those magnets in Engineering school, but it makes sense to me. Saving part 2 till tomorrow. Machining, as usual, magnificent.
The spring on the parrels is something I never thought of doing to hold them lightly in place
To the man of infinite patience:
Now I know how these magnets work.
Thanks.
I'm smarter today than I was yesterday thanks to you!!! Going to see part two.....Razor!
"sitting in corner crying" have you been spying on my shop? Great work, as always. Craig
Very clever and well thought out. Not exactly unexpected for your channel Stefan. I think the full length pins are a good addition. Epoxy does hold well, but it's a brittle glue joint. Drop that magnetic parallel just once and you'd have a minimum of two pieces if your lucky.
Sticktivity. A great word!
Great idea but no shaper action?
BTW I believe most modern transformer laminates are made out of silicon iron
Two thoughts,
First, as surface finish makes a big difference in ultimate hold strength, would lapping the magnets and brass plate assembly so there is no gap between the steel and magnet help hold strength?
Second, could you make some sort of tongue and groove assembly to slot the brass and steel sheets together? Perhaps you could use the shaper? (you could set up a channel like the Yule Log channel and just let us all watch the shaper do its work)
Robert Szasz I would watch that channel all the time!!
Very cool project Stefan! I might have to make one or two, have a good cry and then make some V blocks as well :).
Keep them coming and I'll keep watching. Best Matt
Very interesting and I am already eager for part2.
Great :( Now I have another project to add to my (already too long) list. Pretty nice idea! I have some epoxy putty, pretty hard but easy to machine and grind, I might try to do the same but using that putty instead of the brass. About the transformer sheet metal, it's high silicon steel too reduce the Eddy currents and hysteresis loss.
Excited for part 2! Nice video. Love any project that involves the surface grinder!
Stefan, your mismatch with the slitting saw was because you were conventional milling. If the machining setup is rigid enough, climb milling with these type cutters is always dead-on. Do a test sometime and see. Thanks for the videos. I enjoy them all.
The 'Backing Off' of the cutting edge to prevent it "Grabbing" brass, also applies to the drilling of Perspex.
If you want to use two magnets per lamination, why not diagonally oppose them if you are worried about material for facing?
on the subject of magnetism i dismantled a deck top computer to access its modem and when i dismantled the modem there was a very strong magnet that accidently stuck itself to a metal work surface it took over 100kg of force to remove it .
I appreciate the way you think, explain and generally work in your shop....Thank you for your project...tm
if someone was motivated thoughts on two dovetails either side of the magnet for epoxy mechanical fit
Thats a very good idea - And it would probably look absolutely marvelous.
Hey man, I was waiting for the nice and shiny finished product ! Don't leave me hanging here ! ;-)
Very engaging. Pure joy to watch and to learn from. Thank you sir.
Holding my breath till part 2 is up..
Fortunately it did not take to long ;)
Good video Stefan and a neat little project keep the videos coming.
how accurate does the length of the hole in the brass for the magnet have to be to the length of the magnet.
in other words, does the magnet have to be in contact with the steel pole plates on both sides of the brass??
Yes, alternating direction stackup is definitely the way to go. (I misinterpreted the stackup on first viewing, but now I see you did it right. :-) )
Iron plates from old loud speakers should work nicely too.
Try letting 2 magnets snap together with the d~40mm neodymium magnets. =)
Damn...I had a project lined up where I was going to machine some neodymium magnets, think I'll be giving that one a miss now! 😂
magnets are funny things. i think two magnets in a plate would creat some interesting issues when assembling. i did a project with embedded magnets recently, and only really found out how much i dont know. lol
Your motor? That was a great project! Thats something I want to build one day too...
Excellent video Stefan, I'm looking forward to the next one.
Thanks! Next one? I just released two! Thats enough editing work for the next two months ;)
Ahh, I just noticed that. That's what I get for not checking my feed often enough for new videos.
It doesn't seem like Stefan is answering questions on this video anymore (understandable, it's 4 years old!), so if anyone else can answer, that would be cool. They sell these magnets in rectangular shapes. Would those work? I understand you'd still need to surround the magnets with brass, so that you can surface grind the surfaces, but I'm curious if there's anything about the shape of the magnets that would make the "redirecting the direction of magnetic pull" trick work differently (or not at all).
I'm far from an expert, but looking over this article, I think you could expect the behavior to be the same: en.wikipedia.org/wiki/Halbach_array
Cylindrical and block shapes are considered for different sections of the article.
use transformer laminations for the steel. can come from ignition coils.. or various power transformers..
I'm interested to see you square it up. Seems you might do battle with chips magnetically clinging to it.
If the grinding dust becomes hot enough (curie point) it should demagnetize itself by heat and just fly away. I think magnetic dust wont be a problem.
Morkvonork
Initially I thought he was going to mill it, but part 2 dispelled that incorrect assumption on my part. It ground out great.
You can buy carbide faced calipers , most tool suppliers will have them. Made by MANY manufacturers.
Thanks, yes I have seen that..and the price :)
Love it. Thanks for your content.
Does anyone know the model number on the mitutoyo caliper? Never seen one with a prismatic way
Stephen just to let you know I really enjoy your channel. In 1975 I was on a ship USS South Carolina and we stopped in Bremerhaven Germany...you have a beautiful country.
Interesting. I would have soft soldered the stack, bass and iron can be soldered easily with Soldering-paste (for pipework). And the magnet take no harm with the 300°C. Then no pinning would be needed i think. I did soft solder big parts on an old electric stove with an aliminium plate as flat base.
I think i will make one from Galvanized iron sheets. They are often very low carbon steel and cheap. Simply soft solder stacks together and put a magnet in the middle. The zinc and tin are good enough magnetic isolation between the iron plates i think.
The neodymnium magnets are toast after beeing heated to 300°C.
Hm. Good to know. Thanks :-)
I can only imagine what kind of pain grinding a magnet is!
As a sign of respect and gratitude for teaching me the word 'stictivity', here's a small denglish mnemonic to help remember not to put 'would' into an if-clause: 'if+would=Satz kaputt'
Once again a great explanation. Can I ask about your Toolmakers vice which appears to have a ratcheting mechanism for adjusting the moving jaw. I've had a look on the web but failed to fine a reference to this type of vice would you be able to provide any info on this vice. Thanks
Been quite a while since you asked, but it's one of these: www.arceurotrade.co.uk/catalogue/department.aspx?node_id=deda9017-3d52-463c-b0b5-a1b701150583&ou=%2fcatalogue%2fworkholding%2fmachine-vices%2fprecision-tool-vices-type-2
Would positioning two magnets per face as planned but positioned like the pips on a gaming die (the 2 on a dice) have helped with strength?
Great video Stefan
decades ago before dial calipers mitutoyo did offer carbide tipped jaws helios too special order
16:38 "brass has the property of being brittle" is brass brittle?
Thanks for sharing this, I've picked up some used ones and been wondering about them.... Now I know. Take Care
Brass is pretty expensive... Would aluminum be a possible alternative?
In theory yes, but it's quite a bit softer (easier to mess up the surface/wear it out), it expands more with heat and (IMHO) it doesn't look as nice.
Thanks for the explanation!
Aluminum does work and is used for making laminated magnets. Brass is often preferred because it is often harder, less prone to scratches and dings, and is less easily corroded (all variable depending on the grades of both metals).
Thx!
great video
Can you use copper instead of brass?
How are you finding that vice? It's the one I was looking at as it's a great price.
This is really cool idea!!
Isn't the epoxy like 3000psi shear strength? You don't think the fact it should take almost a ton of force to separate the magnets is enough to hold them together?
Never trust glue. It is a very brittle bond in my experience and should always be backed up by mechanical fasteners. If you dropped them, the shock could break the bond (or just let them snap to the surface). The glue is very strong in the laboratory under static load for sure, but one light tap and it can break. It won't of course if that was the plan. Then it will stick like a SOB, but if you want it to be permanent it won't be.
Barry Gerbracht
Better tell most of the auto manufacturers, many of them have been epoxying structural body panels for the last 15+years instead of spot welding because it is stiffer and stronger. I am sure the grade and properties of the epoxy have a huge effect on its performance.
bcbloc02 surface prep is also critical in automotive chassis applications
+bcbloc02 I think automotive epoxy is softer and a much thicker bond layer to allow for the epoxy to be more plastic instead of very rigid. I have used epoxy (Sikadur 31) to bond steel together and it is very brittle (it failed after applying the design load even though by calculation it should have had massive amounts of bond strength beyond the calculated demand). This was not some simple sticking two hunks of stuff together and hoping it works either. The surfaces were properly prepared and I had done all of the load calculations and shear flow checks to make sure the bond was adequate. No luck. A few well placed fillet welds stitched along the length and they never moved. I know adhesives are used in automotive applications and extensively in aircraft manufacturing. They are not using hardware store epoxies and will have extensively proof tested the assemblies prior to actually using them in production. I would not trust this epoxy and would back it up with some rivets. Once burned so to say...
All depends on the grade of epoxy you're using..........!!!!
Cheap commonly available stuff isn't gonna glu anything, for serious gluing you need to get industrial products, and, those products aren't available to public.
You can look into something like Miller Stephenson MS-907, I've glued parts like 30 + years ago and it still holds, you really need to hammer the parts in order to break the bond... They also have other excellent products like the ones used in automotive or aircraft industries...... ;)
www.miller-stephenson.com/chemicals/epoxy-resins/
thank you for the detail.
Very interesting!
Hi Stefan,
Just went looking for the webpage for this project, but it 404s with your new website, and I can't find it!
You can find his old articles here: gtwr.de/div/webold/
'Stictivity' Stefan Gotteswinter 2016...
Really enjoyed the video Stefan, what is the brand of the end-mill you were using?
Regards,
Matt
I thought stictivity was what happens after eating peanut butter...lol
wouldn't this magnetise the work and cause issues?
I'm not sure but I think the alternate field directions avoid that.
To some extent yes, but the alternating magnetic domains mitigate it to some degree and its always a good idea to degauss your parts anyway.
Good job!!
ja man goed informatief en je engels is goed dank voor al je werk
salut. Je suis français. pourriez-vous M' indinquer les épaisseurs du laiton et du fer en mm, merci, car l ' Anglais ne comprend pas . super votre chaîne CZcams . Cordialement Dominique
Salut . pouvez-vous me donnez les dimensions en métrique car l' anglais bof . super vos vidéos . Cordialement
You should NOT use 5-min. epoxy, as it has very low strength. The longest-setting time epoxy will generally have the highest strength.
Also, do not use "laminating" epoxy that is used for fiberglass layouts, as it often cures very hard, therefore being brittle when submitted to a shock. The best epoxy is "structural" epoxy.
This has to be because I'm just a machining aficionado through videos only (for now), because I swore that brass at the beginning of the video was actually wood XD.
Nice!
your CAD-drawing should be a PAD-drawing ;-)
It took a bit to get it. HaHa!
you didn't need to machine it again, you should've aligned them as you glued them together?!!!
"sticktivity" lol, that must be a technical machinists term (3:36)
It is! :D
Schnellfest.... haha
Hällt in Minuten, für Sekunden. Dreckszeug :\
Made in Germany
Except for the magnets themself, I am pretty sure they are China :)
Yawn...
You dont have to watch it, just walk away to the newest Kardashians video :)
Stefan, thank you for providing your knowledge free of charge. Some entitled people want to be entertained more than they would like to learn. I will be trying to make a set like these soon. Ignore this guy!