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

[Robert ButlerParticipant @robertbutler92161]

Just the tool on the Home Workshop site

Robert Butler

[John Smith 47Participant @johnsmith47]

Posted by Dave S on 06/09/2021 17:16:32:

Posted by Dave S on 03/09/2021 17:15:39:

Literally a 5 second design sketch:

If you look I’ve done the design, it just needs dimensioning…

The pins on the angle, in conjunction with the table over the belt set the max DoC.

make it from MDF -more than robust enough for your current run, and simple to work with hand tools.

The accuracy will be limited by the amount of care you take, but your making 1, and then the 64 will end up as matching.

Again I think are overthinking the problem

Dave

Dave – Yes, thank you for that. I have rotated the photo of your "5 second" sketch but truth to tell, I still simply didn't understand your drawing. It looks like you are suggesting:
A) I buy a belt drive sander and
B) I build a bridge out of (e.g.) MDF and somehow cut a hole or slot into it and
C) lower the part which I have attached to another piece of MDF, that is somehow lowered to the correct height over the belt.

Something like that?

J

[John Smith 47Participant @johnsmith47]

Posted by Robert Butler on 06/09/2021 17:29:58:

Just the tool on the Home Workshop site

Robert Butler

 

https://www.homeworkshop.org.uk ??
https://www.homeandworkshop.co.uk ??
https://homeworkshop-design.com ??

J

Edited By John Smith 47 on 06/09/2021 17:40:18

[Dave SParticipant @daves59043]

Yes. The bridge over the belt does not need to be 1 piece, the slot can be formed by leaving a gap between 2 pieces.

atrach the plate over the belt of the belt sander – details left to the reader as it will depend on the actual sander. Make sure the gap belt to plate is small as possible.
the wedge hold the to be chamfered plate and you guide the plate through the slot until it stops cutting. DoC is limited by the jig – you can’t push the large flat bottom through the slot – a bit like how the cut on a wood plane is limited by its sole

Dave

[Robert ButlerParticipant @robertbutler92161]

Try the first on your list.

Robert Butler

[Dave SParticipant @daves59043]

**LINK**

[Nick WheelerParticipant @nickwheeler]

Posted by John Smith 47 on 06/09/2021 17:26:55:

Nicolas – yes the part needs to be as photographed and yes, the entire edge has to be angled.

I am warming to the idea of a small good quality sander. Do you have any specific recommendations?

I am also warming to the idea of buying that damned Proxxon MF70 as it might be useful for various other small jobs… although it I know it's not very well made and looks like a bit of a toy… but at least it's small and light.

A quality sander is going to be several hundred quid. You don't need one! I have one of THESE although it was half that price with a different sticker on it. I use it for all sorts of things; knocking edges off cut part(which is all you're looking at doing), putting brushed finishes on steel parts, making square chunks of wood round, trimming exhaust tube to make manifolds, whatever needs doing. It will need fettling, but that's only a few minutes work.

A tiny, light, flimsy, not particularly cheap mill is not going to help you much…

Baz's advice of outsourcing is good, but should have been applied once you found out how long each one would take to do by hand. And that should really have been done to a prototype before you ordered lots of blanks. Or refused the job because it's not feasible.

Dave's 'bridge over the belt' is just a robust stop to prevent you grinding too much off the part being fed through the slot. I would use the same sort of block to hold the part(more than one if at all possible), but attach the stop to the table that comes with the sander. That's because it's a job that doesn't justify spending much time on producing tooling.

[John Smith 47Participant @johnsmith47]

Posted by Dave S on 06/09/2021 17:53:49:

Yes. The bridge over the belt does not need to be 1 piece, the slot can be formed by leaving a gap between 2 pieces.

atrach the plate over the belt of the belt sander – details left to the reader as it will depend on the actual sander. Make sure the gap belt to plate is small as possible.
the wedge hold the to be chamfered plate and you guide the plate through the slot until it stops cutting. DoC is limited by the jig – you can’t push the large flat bottom through the slot – a bit like how the cut on a wood plane is limited by its sole

Dave

I'll need to think about this. Cutting that slot sounds like a challenge…
Btw, "DoC" = "Depth of Choice" ?? (Google suggested "Drug of Choice"!)

[Robert ButlerParticipant @robertbutler92161]

Try Depth of Cut. Did you look at the item on Home Workshop website? It may be the answer to a Maidens prayer.

Robert Butler

[Pete.Participant @pete-2]

Are you using mild steel on a diamond stone? This would explain you noticing the coarse side not being as effective as it was new.

[JasonBModerator @jasonb]

well assuming the 8mm was a typo and you meant 13mm as the photos and your earlier thread would seem to confirm then taking John's suggestion a stage further and bearing in mind you don't really have any tools how about this.

The Vee blocks that you have, a random round bit of rod, bar or even a drill bit, a washer and a CSK screw

Add a cheap Clarke sander from machine Mark odd bit of bar or strip of wood that loosely fits the notch in the vee block and two odd clamps. The bar stops the work and jig going too far and cutting too much off. The table was set at 90deg with a tri-square but a kiddies plastic set square from a geometry set will do

Less than to seconds work on the sander once bar position has been fine tuned so say 60secs per item allowing for swapping over in the jig

 

Edited By JasonB on 06/09/2021 18:22:13

[Frances IoMParticipant @francesiom58905]

since you now have 30 or so surely this is enough to be able to demonstrate your idea (whatever it is) actually works and a saleable device can be produced – personally at this point since it is obvious that your engineering knowledge and tooling is insufficient for a 1-man operation, to take a demo to a trusted agent under a NDA and pay for advice as (a) if there is indeed a market, (b) if so then at what manufacturing price and then (c) get professional advice as to production engineering.

[John Smith 47Participant @johnsmith47]

Posted by Pete. on 06/09/2021 18:18:06:

Are you using mild steel on a diamond stone? This would explain you noticing the coarse side not being as effective as it was new.

Er yes. It that likely to be problematic? I thought that they are designed for sharpening knives – if so why would some relatively soft mild steel be a problem?

[John Smith 47Participant @johnsmith47]

Posted by Dave S on 06/09/2021 17:55:07:

**LINK**

Interesting suggestion.
However, I would prefer to invest in more general purpose tools.

J

[Nick WheelerParticipant @nickwheeler]

It also occurs to me that 15minutes per part with files and a diamond hone suggest that you don't have the right files.

A large coarse cutting one would remove the material in half a dozen strokes, swap to a #2 cut to take out the marks and remove from the vice. That's what, a minute? When they're all done, stick some 120grit wet&dry to a hard, smooth surface, give it a squirt of cheap glass cleaner and polish the edges.

You have spare parts to practice on a couple to refine your technique, and even doing a few spares for quality control that's only 90 minutes work. And a £15 file.

[John Smith 47Participant @johnsmith47]

Posted by JasonB on 06/09/2021 18:21:01:

well assuming the 8mm was a typo and you meant 13mm as the photos and your earlier thread would seem to confirm then taking John's suggestion a stage further and bearing in mind you don't really have any tools how about this.

The Vee blocks that you have, a random round bit of rod, bar or even a drill bit, a washer and a CSK screw

Add a cheap Clarke sander from machine Mark odd bit of bar or strip of wood that loosely fits the notch in the vee block and two odd clamps. The bar stops the work and jig going too far and cutting too much off. The table was set at 90deg with a tri-square but a kiddies plastic set square from a geometry set will do

Less than to seconds work on the sander once bar position has been fine tuned so say 60secs per item allowing for swapping over in the jig

Edited By JasonB on 06/09/2021 18:22:13

I'd need to find screw/bolt with the correct thread… Do you happen to know what the pitch & diameter are?
It's probably time I bought some more clamps too…

But I have to hand it to you, that's darned clever!

[John Smith 47Participant @johnsmith47]

Posted by Frances IoM on 06/09/2021 18:30:58:
since you now have 30 or so surely this is enough to be able to demonstrate your idea (whatever it is) actually works and a saleable device can be produced – personally at this point since it is obvious that your engineering knowledge and tooling is insufficient for a 1-man operation, to take a demo to a trusted agent under a NDA and pay for advice as (a) if there is indeed a market, (b) if so then at what manufacturing price and then (c) get professional advice as to production engineering.

Please stop making all these assumptions. You have no idea how many of these parts go into each product do you?

Honestly! All this ad hominem sniping…

Would it be too much to ask for everyone who is interested stick to answering the question?

[JasonBModerator @jasonb]

M5 Screw

Washer for M10 so the screw sits as low as possible, would help if you ran a CSK bit into the washer or just used the sander to reduce the screw height slightly

Bar or drill about 5mm dia

[Nick WheelerParticipant @nickwheeler]

Posted by John Smith 47 on 06/09/2021 19:07:11:

Posted by Frances IoM on 06/09/2021 18:30:58:
since you now have 30 or so surely this is enough to be able to demonstrate your idea (whatever it is) actually works and a saleable device can be produced – personally at this point since it is obvious that your engineering knowledge and tooling is insufficient for a 1-man operation, to take a demo to a trusted agent under a NDA and pay for advice as (a) if there is indeed a market, (b) if so then at what manufacturing price and then (c) get professional advice as to production engineering.

Please stop making all these assumptions. You have no idea how many of these parts go into each product do you?

Honestly! All this ad hominem sniping…

Would it be too much to ask for everyone who is interested stick to answering the question?

It's exactly the opposite of ad hominem, because it's aimed at your problem not you. I'm due at a practice so won't look up the phrase. The reason for asking other people how to do something you're stuck on is to get ideas.

It's not unusual for someone who doesn't have all the time and effort invested to come up with a much better solution. That can mean chucking all your existing parts, and starting again. It's why quick and dirty prototypes are recommended – this part should have been drilled, cut out and finished to assess how feasible it was to make before you paid for 100 part finished ones.

[Grindstone CowboyParticipant @grindstonecowboy]

Aldi special buy, online only, £89.99, belt and disc sander

https://www.aldi.co.uk/ferrex-belt-and-disc-sander/p/805501490545800

Rob

[John Smith 47Participant @johnsmith47]

Posted by Nicholas Wheeler 1 on 06/09/2021 18:53:37:

It also occurs to me that 15minutes per part with files and a diamond hone suggest that you don't have the right files.

A large coarse cutting one would remove the material in half a dozen strokes, swap to a #2 cut to take out the marks and remove from the vice. That's what, a minute? When they're all done, stick some 120grit wet&dry to a hard, smooth surface, give it a squirt of cheap glass cleaner and polish the edges.

You have spare parts to practice on a couple to refine your technique, and even doing a few spares for quality control that's only 90 minutes work. And a £15 file.

Look, as I have said, the files are absolutely excellent. Why are you questioning what I have stated?

Yes, OBVIOUSLY most of the required metal can be removed with a just a few of strokes of the coarse file and finished off with a few more of the fine file. My problem is accuracy.

I need to create a 45° chamfer that goes to exactly the right depth, leaving maybe 0.1mm of the original face on the end of the steel. And the angle on the chamfer needs to be within c. 0.5 to 1.0 degrees, such that when two chamfers are put together a credible 90° angle will be created.

As I have said, I am using a honing guide that I have modified fairly aggressively to enable me to create and angle of attack of 45°. Great care is still required to make sure:
A) That I don't cut slightly more on one side of the mild steel than the other
B) That I don't take off too much metal

And then, to be fair, I then need to clean up both surfaces and round off the dangerously sharp point caused by cutting the chamfer. So it does ends up being quite a manual process. ==> c. 12 to 15 mins all in.

J

PS Wait, OK purely as a bit of fun… here are a couple of photos of the tool I am using on the diamond whetstone:

[NOTE: I only include it for your interest. As a honing guide it works GREAT. So please just cut the ad hominem attacks. It's actually quite rude.]

[John Smith 47Participant @johnsmith47]

Posted by Nicholas Wheeler 1 on 06/09/2021 19:18:55:

Posted by John Smith 47 on 06/09/2021 19:07:11:

Posted by Frances IoM on 06/09/2021 18:30:58:
since you now have 30 or so surely this is enough to be able to demonstrate your idea (whatever it is) actually works and a saleable device can be produced – personally at this point since it is obvious that your engineering knowledge and tooling is insufficient for a 1-man operation, to take a demo to a trusted agent under a NDA and pay for advice as (a) if there is indeed a market, (b) if so then at what manufacturing price and then (c) get professional advice as to production engineering.

Please stop making all these assumptions. You have no idea how many of these parts go into each product do you?

Honestly! All this ad hominem sniping…

Would it be too much to ask for everyone who is interested stick to answering the question?

It's exactly the opposite of ad hominem, because it's aimed at your problem not you. I'm due at a practice so won't look up the phrase. The reason for asking other people how to do something you're stuck on is to get ideas.

It's not unusual for someone who doesn't have all the time and effort invested to come up with a much better solution. That can mean chucking all your existing parts, and starting again. It's why quick and dirty prototypes are recommended – this part should have been drilled, cut out and finished to assess how feasible it was to make before you paid for 100 part finished ones.

I've learned my lesson. There is absolutely no point in engaging in a war of words, but I do find it tedious when people start criticising the number parts that I have made… or telling my I have no idea about engineering and should give up and outsource the job. It IS quite offensive. …Just sayin.

[Robert ButlerParticipant @robertbutler92161]

The forum has provided plenty of advice as the OP requested and think now is the time for him to test some of the methods suggested and report back.

Robert Butler

[Bill PhinnParticipant @billphinn90025]

Posted by John Smith 47 on 06/09/2021 15:06:02:

T

PS If I do buy a Proxxon MF70, maybe I could buy "tilting vice", and shave off the metal with a cutting disk??

e.g. This sort of thing (if it fits?!)

Being the owner of both that vice and a Proxxon MF70 I can tell you with absolute certainty that it will not fit on to the standard Proxxon's milling table.

I suggested a different, much simpler, and much cheaper solution using the Proxxon. Would you not consider it?

[RedsetterParticipant @redsetter]

OP, people on here are doing their best to advise you.

Several useful ideas have been suggested. Without knowing more about the design, or the purpose of the parts, it is difficult to be more constructive. It does seem that in your circumstances it would be best to outsource the job, then you can move on to the next stage of your project. It is not clear why you won't do so.

We are a helpful bunch by nature, but we all have busy lives and projects of our own. Please don't waste our time.

[Author]

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