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View Full Version : How do I get this widget made (a small rectangular bit of 1.6mm mild steel)



HankMcSpank
26-04-2013, 11:31 AM
It's now looking like I'll need to source some of these in number, not even sure what it would be called (presently I refer to it as 'a small bit of rectangular 1.6mm thick steel'! - not that catchy - would there be a more appropriate name as used int he industry?)...

http://hostmypicture.com/images/part.jpg

If I know how it would be made, then I know who to approach.

Spec is ....1.6mm thick mild steel, about 33mm(ish) x 4mm (I'll also need some about 20mm x 4mm)

From what I can gather....laser cutting is out (deformation?), water jet cutting is a possibility but would probably need tabs...else the part falls into the water tank below! (which means a bit of a hassle tarting up the de-tabbed part) ....could something like this be stamped/pressed out of 1.6mm sheet? (sorry if this is a naive question....but this is all a brave new world to me!)

Ideas on the back of a postcard please!

John S
26-04-2013, 11:36 AM
laser cutting is not out, in 1.6 there would be no problem

HankMcSpank
26-04-2013, 11:41 AM
cool...so it wouldn't deform? (from hazy recollection, I was told some time ago by a laser cutting firm, that it's the 4mm dimension that's the problem - not the 1.6mm thickness) how much effort do you reckon would be needed on the laser cut part to make it look presentable? I need one of the sides in particular to look visually decent (as looking down on the part if it were standing up - not on its side as photographed). I can tell you from making the one photographed with a hacksaw & file, these are not nice bits to work with - way too piddly - so looking for a way of manufacturing that won't take me ages to clean up once received.

Also how thin can you go with steel sheet before deformation from the laser cutting becomes a problem?

martin54
26-04-2013, 04:15 PM
What is it ? A key of some sort like a woodruff key?

Could you not do them easy enough with a jigsaw? Use a guide & cut longish lengths, clean up the edges then cut them to correct lengths.

HankMcSpank
26-04-2013, 05:48 PM
It's a 'blade' for the inside (pole piece) of a guitar blade pickup, I found this on google images to give you an idea....
8850

But these will be very low profile....& I really need the accuracy that I'd not be able to attain with a jigsaw (each long thin edge needs to be nice & flat...the top visible edge must look good, the bottom nice & flat so the magnets attach well) ...also, I'm not talking a few - probably at least one thousand pcs initially (& that'll get old very quick with 'me and a jigsaw!)!)

Swarfing
26-04-2013, 06:29 PM
Hank if it was me i would be tempted to buy 4mm flat bar and rip down the length at your 1.6mm thickness on a bandsaw. You could then stack and cut multiples to the length you need? I'm sure you bog standard metal supplier could do that for you rather than going to fabricators and such like?

drumsticksplinter
26-04-2013, 06:42 PM
Hi Hank,

I would suggest that you should be able to obtain 14g x 4mm flat wire in stainless, which would probably be better suited to your application. You'd then only have to worry about the length, but a guillotine would make a neat job of the ends. If you did a detailed google search I'm sure your find a wire supplier. I think they might use this type of wire within the craft / jewellery trade, maybe worth going down that route?

Ross77
26-04-2013, 07:26 PM
It's a 'blade' for the inside (pole piece) of a guitar blade pickup,

33mm long? where did the other 2 strings go?

For looks I think ground would be best, but then again gutiarists being the funny lot hey are you will probably have to have the option of chromed, black chrome, polished steel, ground and nasty gold plated.:thumsup:

I've cut 1.5mm in a guillotine before, not sure I would want to do it a 1000 times tho, if its 20 or so for R&D then no prob, also leave shear marks on the edge so would still need finnishing. since its for a production run you will probably be best getting a quote from a fabrication company.

HankMcSpank
26-04-2013, 09:39 PM
33mm long? where did the other 2 strings go?



Good spot...perhaps I could sell to banjoists or maybe back to the drawing board ;-)

Joking apart, that's just the blade for EADG...there's a small gap of 1mm & then B & E get their own blade/treatment (I didn't want to cloud the issue, hence only showing the EADG blade!)


Hank if it was me i would be tempted to buy 4mm flat bar and rip down the length at your 1.6mm thickness on a bandsaw. You could then stack and cut multiples to the length you need? I'm sure you bog standard metal supplier could do that for you rather than going to fabricators and such like?


I just don't think I could get the accuracy for a 1.6mm width cut ...& all places I've been in touch with (admittedly only Ebay metal suppliers), can't seem to cope with anything that can't be guillotined (anything less than about 13mm cut width seems to get a "No can do, guv" type response)


Hi Hank,

I would suggest that you should be able to obtain 14g x 4mm flat wire in stainless, which would probably be better suited to your application. You'd then only have to worry about the length, but a guillotine would make a neat job of the ends. If you did a detailed google search I'm sure your find a wire supplier. I think they might use this type of wire within the craft / jewellery trade, maybe worth going down that route?

Alas, stainless is no good for this application (stainless isn't very magnetic, and the material I need to use must be very magnetic)

I'd pondered one of these....

http://www.arceurotrade.co.uk/Catalogue/Shearing-and-Bending (I can get 1.6mm steel cut 33mm wide) ...then I'd only have the 4mm strip to cut - but I reckon a 4mm strip will curl/deform (& then there's a gripping square problem as it's beinf fed in)

They tout this precision shear as having little deformation....

http://www.monstermarketplace.com/esslinger-watch-and-jewelry-supplies/precision-6-inch-bench-shear-benchtop-metal-cutter but only available Stateside & it'll cost a pretty penny for them to put it in an oversize jiiffy bag & post it to me!

m_c
26-04-2013, 10:39 PM
I'd think laser or waterjet will give the cleanest 'as cut' edge with minimal distortion, however I'd think you'd really need to get them ground after that to get a clean edge.

However I'd guess laser/waterjet will be pretty expensive unless you go for a large batch. Grinding would involve somebody with a surface grinder and small vice.

Jonathan
27-04-2013, 01:09 AM
Grinding would involve somebody with a surface grinder and small vice.

Surely a magnetic 'vice' would be easiest, or is it just too small?

m_c
28-04-2013, 01:06 AM
Magnetic chucks are only any good for items with large flat surfaces, not holding a small flat bit on edge.

A small vice mounted on the magnetic chuck, with the metal spaced appropriately would work fine.

Jonathan
28-04-2013, 01:13 AM
Magnetic chucks are only any good for items with large flat surfaces, not holding a small flat bit on edge.

I was just thinking of using the magnetic chuck to hold it whilst grinding the larger faces, but fair enough if it's no use for either...

m_c
28-04-2013, 01:27 AM
It would be fine for that, but not for doing the edges which is what the OP is looking for.

One option would be cut them from slightly thicker metal, then grind them to thickness.

Swarfing
28-04-2013, 01:49 AM
Or stack multiples on edge together and grind the lot?

HankMcSpank
28-04-2013, 11:36 AM
I am wondering here if my lowly cnc machine could be pressed into service to get a reasonable finish on on the top visible edge ....drop a part into a pre cut slot on a holding jig....tighten a couple of holding screws, then run a dremel (fitted with a grinding wheel) along the top edge to a very fine depth? (the depth being so minute, that I doubt my machine would get stressed?)

m_c
29-04-2013, 01:02 AM
Try it and see?
Not going to cost you much, and might produce a good enough finish for what you want.

Another option I just thought of, is cut to near size then finish on a linisher (aka belt sander) using a jig to set depth. You're not really needing the accuracy of grinding, and a linisher can produce as good a finish, but just not as accurately, but they are capable of removing metal far quicker than a surface grinder.
And thinking along similar lines, maybe a worden style of grinder?

birchy
29-04-2013, 01:35 AM
I would probably get a length of flat and cut it to size with either a metal chop saw (the ones with a grinding/cutting disc) or a Rage saw (http://www.screwfix.com/p/evolution-rage3-s-210mm-sliding-compound-mitre-saw-240v/60839). I have a Rage saw and it cuts through steel like butter.

EDIT:
Just realised the quantity is 1000+. You'd probably be better off finding someone with an automatic feeding bandsaw and get them to cut the 1.6 "length" from a 4mm thick flat. The company I used to work for some years ago had an automatic bandsaw which was accurate to 0.05mm on auto feed. The only other option I can think of would be a CNC punching machine with a custom made punch and die but you'd still have sheared edges, though you wouldn't lose material to the "kerf" of cutting processes such as sawing. If you get them made slightly over size, you could finish the edges on a surface grinder. You'd need to make a clamping jig but could do about 250 pieces in one setup.

My question is...why are you making these pickups? Maybe something ready made from here will be suitable? http://www.mojotone.com/store?search=blade&x=0&y=0

IanS1
29-04-2013, 10:36 AM
A strip slitting company might be able to handle this. You would need to cut them to length though.

Stainless Steel & Mild Steel Stockists; steel cutting service etc from steel stockists UK - Reddifast West Midlands (http://www.reddifast.co.uk/index.html)

HankMcSpank
29-04-2013, 06:47 PM
Thanks for all the valuable input...lots for me to chew on.


My question is...why are you making these pickups? Maybe something ready made from here will be suitable? Search Results (http://www.mojotone.com/store?search=blade&x=0&y=0)

A standard guitar pickup is quite tall & obviously guitar has a pickup cavity routed out the wood for them to fit...I'm wanting to make a low profile variant that sits on top of the guitar body (hence the blade needs to be rather squat) ...there ain't nothing out there in the dimensions that I seek.

Ross77
29-04-2013, 08:31 PM
I'm wanting to make a low profile variant that sits on top of the guitar body (hence the blade needs to be rather squat) ...there ain't nothing out there in the dimensions that I seek.

How about getting the blades from mojotone (addiction-fx are usually cheaper if they do them) and ask some one with a guillotine to cut them down? the cut edge could go at the bottom where it wont be seen so doesn't matter if there are slight shear marks. if you could get away with cutting it in the middle you could get curved and straight from one piece.

HankMcSpank
29-04-2013, 11:31 PM
I like your train of thought...and yes, I'd end up with a lovely top finish, but I'm then still back to the problem about cutting thin pieces of metal (& I'd imagine a guillotine on such a small piece of steel will see curling deformation).

oscar
30-04-2013, 12:00 AM
Get a length of 4mm thick ground flat stock, 1"1/2 wide. Mill the width down to 33mm (if you can get away with a width of 31.75mm, just get 1"1/4 and no milling involved). Then take it to a local wire EDM place and get them to slice it down into 1.6mm pieces. Quick rub of all faces on some wet and dry placed on a flat surface, jobs a goodun.

Robin Hewitt
30-04-2013, 04:47 PM
I have a notion that you need soft iron if you want to do magnetic stuff. I could be wrong but hot rolled sounds a lot more appropriate than gauge plate. Sure cuts easier.

spluppit
03-05-2013, 01:43 AM
If you need this job looking at its pretty straight forward. Lots of very elaborate and overkill ways have been suggested to make this part and its really very simple and is not a job that warrants fancy machining methods to produce at a cost, A lot that have been suggested will cost you a small fortune. It's some 1/16 cold rolled sheet stripped up and machined to a size............... that's all it is really. If you need a super finish on the visible edge then there are methods that are available to achieve that finish without fancy and expensive grinding.

If I can be of any help please feel free to contact me.


Kind regards,


Scott

HankMcSpank
03-05-2013, 10:31 AM
As it transpires, since my initial post, I've now established that I probably need the part to be something like 430fr stainless (on account it has higher electrical resistivity, therefore less eddy currents - and eddy current heat seems to be more of a problem than I first realised - especially at higher frequencies) ....430fr also resists corrosion (which was something else that was troubling me)...so right now, I'm on another quest to find a 430fr supplier that won't want me to buy 0.5 tons as a minimum order! (& the early indications are that it's likely to end in a cul-de-sac, because 430fr seems to be mainly supplied in rod form ...& in large quantities - it's a wonder anything new gets to market made by the small guy!)

Thanks to all who contributed ...& Scott, I'll definitely be in touch when I need such work done.