I need to cut chamfers into x64 pieces of mild steel - any advice?

Hello

I need to make a 45° chamfer on one edge of each of these small pieces of mild steel - which are 16mm x 8mm x 1mm in size.

FWIW, the steels have been laser cut.

Below are two "before and after" photographs.

Note: I have cut a chamfer on one of the parts by careful filing the steel (by hand) and by then finishing off with a diamond sharpening stone. My problem is that it took me far too long to make just one chamfer and I need to make at least x64 of them!

[NB Please ignore the scratches!]

Problems:

1. I must not change the (8mm) width of the part, so I must not cut too deep in order to leave a small amount of the original face behind

2. The face of the chamfer needs to be as close to 45° as is reasonably possible (i.e. within say 0.5° to 1°

3. I have at least 64 of them to make!

Background
I only have a basic home workshop. As discussed elsewhere I might conceivably by a Proxxon MF70, but I can't afford a more grown-up milling machine (like a Sherline).

If I bought a milling machine I would need to find a way to cut at 45 degrees. I do own a couple of pairs of V-blocks but I'm not sure how I would use them.

OR should I try to buy avice that can rotate along a horizontal axis?
i.e. This sort of thing??

New toosl budget: £400 max

All suggestions welcome!

J


PS Fwiw, these parts are to be used as magnetic guides. (Long story...)

Edited By John Smith 47 on 03/09/2021 14:43:11

what job is this for?

Could this be done with a belt sander and suitable jig?

I don't own a belt sander.

The parts are to be used as magnetic guides. (Long story...).

J

Can you make a jig to be held on the cross-slide, and take it off with a milling cutter held in the lathe? Once you have everything lined up, it should be pretty quick - lock the carriage and away you go.

Belt sander and simple jig is what I would use. You can make a jig out of a large door hinge and some odd bits with a bolt for a stop. Should easily come in under your budget and it'll be quick.

Edited By Frances IoM on 03/09/2021 14:59:15

If you did buy a milling machine with a vertical head like a drill press, there are a lot of ways to do it. The vises with tilt have already been mentioned, and I suggeat that you go to the ebay start page and put this in the search box: "45 degree milling cutters".

.

At that size you could probably ‘sharpen’ them on a diamond hone, using a slightly modified plane-iron jig.

MichaelG.

.

https://www.ezelap.co.uk/

https://www.screwfix.com/p/magnusson-honing-guide/6342V

.. or any variation on that theme

Edited By Michael Gilligan on 03/09/2021 15:23:07

To save us all repeating ourselves you asked the same question in this thread some time ago.

.

Ah but … at least John has now broadened his original specification; which was:

”The tricky bit is that I need to put a chamfer on one edge of the steel that is EXACTLY 45°. ”

MichaelG.

Edited By Michael Gilligan on 03/09/2021 16:19:11

Like I said, I have been using diamond hone, but it's too slow. To speed things up I have been using a hand file first but great care is required and ultimately it's still too slow.

I think that's pretty unfair.

1. Since posting that question things have changed quite a lot. For one thing I have bought a diamond hone + a honing guide, and I still intend to finish off using the diamond hone to get required accuracy. 

2. I have also bought V-blocks.

3. I have explicitly specified the degree of accuracy that I need.

4. I have stated my budget precisely - which rules out many of the "buy a proper milling machine" suggestions

5. The point is that given my new situation/different requirements I specifically DIDN'T want everyone to have to trawl through multiple pages in order to make a sensible contribution.

6. Furthermore although I have now worked out how to create a few parts, using diamond hone (and hand file) as suggested, the new requirement is that I need to make them FASTER.

7. Furthermore the parts are laser-cut to exactly the correct (8mm) width so it is crucial that I do not cut too deep. 

8. Furthermore, given the number of parts that I'm going to need to 'manufacture' - at least 64 - I don't want to wear out my diamond sharpening tool.

J

Edited By John Smith 47 on 03/09/2021 16:34:42

One of these: **LINK**

add a simple jig to hold the part at the correct angle, with a stop to prevent grinding too much off

edited to add: use the belt in horizontal mode, not the disk. 

Edited By Dave S on 03/09/2021 16:35:16

Yes that's not a bad idea. My slight reservation is that the only sanding machine that I have tried using before wasn't very accurate. i.e. Nothing was at 90° and was at quite the angle that it was supposed to be.

But either way how would I make sure that I don't cut sand off too much material?
I don't really know what is meant by a "jig". Do you mean that I somehow try to accurately cut blocks of wood/MDF that have a built in 'stop' of some sort, that would stop too much material from being machined off?

Either way do you particularly recommend that model?

This might give inspiration for a future tool and I’d guess one could 'knock up' a working occasional version out of timber. **LINK**

If you own a router then a cheap 45degree router bit about a tenner on amazon or ebay (might be able to do the job directly on steel that thin or) could be used to make an accurate angle on some timber to be lined with a flat piece of steel and presented to a cup wheel in a drill on stand.

pgk

Jig is a simple work holding device that allows a quick, repeatable setup.

in this case it probably looks a lot like a block with a 45 degree face and a strap clamp.
Add a plate over the belt with a slot in it - think wood plane sole sort of thing.

poke jigged plate through slot into belt. Large block of jig lands on the plate repeatably.

all you have to do is make sure the jig sets up so the plates to be ground are in the same place each time - assuming the holes are at a known location 2 dowels in the face of the jig will do that.

I do not have that unit, and I would do this sort of thing in my chuffing enormous mill, with a different but similar function jig.

Dave

What grade diamond lap did you get, a coarse one first will speed things up before final run on a file one. Or glue some wet & dry or silicon carbide paper to a piece of glass and use that first to remove most of the bulk of the metal.

I'll still stand by my suggestion from the other thread using a simple jig and your proxon even though you say things have changed

So simple jig from a bit of scrap, even the Proxxon will be able to mill the shallow 1mm pocket and drill a couple of holes that can be tapped

Simply hold the jig in a regular vice with the jig tilted at 45deg, screw one of your plates to it and mill or use a grinding bit to machine the upper edge to 45degrees, note the height of the mill or simply lock it in place. remove completed plate and screw on the next one repeat 63 times.

Edited By JasonB on 03/09/2021 17:14:53

Edited By JasonB on 03/09/2021 17:15:47

Literally a 5 second design sketch:

I have used the following tools in a Proxxon MF70 to cut exactly the chamfer you picture there, though mostly on bronze, brass and aluminium, not steel. The cutters are carbon steel, so will cut mild steel, but I'm uncertain what the lifespan will be if this is all they are used for cutting.

EtA: You can get HSS ones, though I can't find a UK supplier at the moment.

Edited By Bill Phinn on 03/09/2021 17:36:14