I "R" a Machinist

[bilcoh]

Hey all:

As a follow-up to a previous topic about what machinery helps you maintain your Lotus (elan-plus-f13/machine-tools-for-maintaining-your-cars-t23656.html), I thought I'd post my first results with my little lathe/mill.

When removing all my front suspension, one bushing froze onto the suspension pin. I ruined the bushing taking it off, and since my intent is to make Delrin front bushes, I needed all 8 inner sleeves, and was one short. I made an appeal for someone's throw away, getting one kind response from the UK (Thanks, John). But once I got the lathe set up, I realized that I needed to learn about how it works, and what better way than to fabricate something. So, off I went, and a ridiculously inefficient use of my time later, here's the result:

Halfway there, and "Yes", restoring the chuck to remove all the rust is on the list.

Bushing halfway done.

And, finished.

Left was the frozen sleeve that took a torch and die grinder to remove. Right is my first attempt. It's about 20 thousandths too long, but don't think that matters, does it? I can always trim it down. OH, lest anyone think I was being stupidly indulgent, I already had the 1"x1"x1-1/2" solid stock on hand, so it made the decision really easy. Used my new (to me) travel indicator and everything. Who new math could be so fun.

Anyway, great times, and thanks to those who gave advice and support in my quest. There are a few computer geeks at my office who are amazed at seeing something created by one of their peers. They could code an entire website, but forget about something like this.

Cheers,

Dave

[GrUmPyBoDgEr]

Well done Dave, that's exactly what it's all about; a great start it's fun 'innit

Cheers
John

[bilcoh]

Surprisingly so. I dragged my daughters into the garage with me. I had them measure the model part and the piece in the mill with calipers, then made them do the math and set up the travel indicator, then take off the last 40 thou. It was pretty amazing when the caliper read exactly what we'd calculated. Wow, this stuff really works!

Helped underscore the "what's the practical application for this math we have to learn". Not that they're likely to be machinists, but I think one of them understood the point.

BTW, I've been watching a series of videos on YouTube by a guy called Tubalcain. He's in Illinois, a retired shop teacher of some 40 years. He's got a couple hundred uploaded, but there's a series called "Machine Shop Tips". Very clearly stated and packaged in 8-10 minute segments. Everything is mostly analog, no CNC at all, and I'm learning a ton. Highly recommended for any newbies, and I've no connection to him.

Go here: http://www.youtube.com/user/mrpete222#p/u, then search for "Machine Shop Tips". They're numbered. He also did a lot of videos before he started the numbered series.

Happy cutting,

Dave

[alexblack13]

THAT, is exactly the reason for having the right kit. Well done! The 020" should not make too much difference but if it were me I'd take it down to size. Well you have the machine to do it!

Result! Onward and upward..

Don't get stuck for some round stock peeps.. I have loads of round bar offcuts (bms EN8 mainly) If you need just ask.. 25mm/40mm/ etc...

Al'......

[GrUmPyBoDgEr]

Loved reading that you got the kids involved, nothing beats practical examples to make maths come to life.
You remind me of the way my Dad dragged me up

I hope you managed to sneak in a differential equation & that for the next time you get them to calculate the correct cutting speed, just to show the use of geometric progression

Kind offer Alex but both Seattle & Somerset are a bit too far away to take you up on that bar stock.
I'm pretty well set up having borrowed a fair bit from a past employer

Cheers
John

[bilcoh]

Don't get stuck for some round stock peeps.. I have loads of round bar offcuts (bms EN8 mainly) If you need just ask.. 25mm/40mm/ etc...
Al'......

If you have loads of postage to spare as well, then send me all your extra You're a most generous bloke, Alex, in spite of what they say.

I hope you managed to sneak in a differential equation & that for the next time you get them to calculate the correct cutting speed, just to show the use of geometric progression

I wish I could teach them any of those things. The 15 year old could probably be the one to sneak in the diff equation. And I don't know the first thing about calculating correct cutting speed. Care to point me to a good online tutorial?

BTW, I notice that this forum software automatically capitalizes the first letter of each work in post title. So, it looked like IRA Machinist, rather than "I R a Machinist." Not sure if that raised any hackles, but it was unintended. Modified the title, just in case.

[reb53]

"Tubal Cain" was also for many years the "nom de plume" of a major contributor to the magazine "Model Engineer" in the U.K.
Now sadly gone but wrote many excellent engineering books in his time.
I believe the name has some sort of Masonic connection so all you Masons out there can chip in and enlighten us.

Getting your kids to make things in your workshop can be hugely rewarding. Making a cool little toy and taking it to school to show off elevates them in the eyes of their peers, and their teachers.
When my 15 year old son asked his metal work teacher for a set of centres to enable him to machine a one piece crankshaft, (for a model V12), the teacher was so taken aback that he had to admit that no-one had ever asked for them before and he didn't know where they were.

With that practical experience, and a couple of engineering degrees under his belt, he now works for New Zealand's only rocket company as a test and development engineer.

(Sorry.....just being a proud Dad )

Ralph.

[bilcoh]

Nice. Rocket scientist! Good reason to be proud.

From my understanding, Tubalcain is a reference to the first ironmonger referenced in the Bible, I think in Genesis, chapter 4. This is actually a question answered in the machinist's videos early on. He's a "Christian man", and thus the reference. May also have Masonic connections.

Now you've got me thinking about slightly harder-than-normal science fair project. Hmmm.

[alexblack13]

lumps of metal are heavy and do tend to cost postage wise. But the offer is there. Some of it is quite rusty 'cause at one time I just chucked the offcuts into a 45 gal drum outside my workshop door. They are now unmovable!!

So if anyone needs a 'lump they are all under a foot long ( 5 -6" ave) and various diameters.

All it will cost you is the postage.. I will take an 'average' lump along to the local PO and get a cost for middle England as an indicator.. I'll get rid of it yet!! Always expecting it to disappear but nope.. To heavy I guess

Sod's law dictated that a lot of the cable fasteners I sent out FOC for the donations to BHF were all abroad!!

Oh well!!

[persiflage]

Cracking job Dave.
Great sense of satisfaction when you produce something pretty out of a lump of stock metal.

[elj221c]

So if anyone needs a 'lump they are all under a foot long ( 5 -6" ave) and various diameters.

All it will cost you is the postage..

Very interested, Alex, but yes, the postage will be a shock!

[alexblack13]

What do you need? I will get a postage cost. Don't think a 1st class stamp will do it!

Pos' not Econ' viable. but I will find out for you...
Alex..

[gjz30075]

Good job Dave. You're obviously a good manager, too, delegating authority to the right personel Keep us posted on the Delrin part of this process. Do you plan on making it 'top hat' style, or simply a cylinder?

Greg Z

[GrUmPyBoDgEr]

Don't get stuck for some round stock peeps.. I have loads of round bar offcuts (bms EN8 mainly) If you need just ask.. 25mm/40mm/ etc...
Al'......

If you have loads of postage to spare as well, then send me all your extra You're a most generous bloke, Alex, in spite of what they say.

I hope you managed to sneak in a differential equation & that for the next time you get them to calculate the correct cutting speed, just to show the use of geometric progression

I wish I could teach them any of those things. The 15 year old could probably be the one to sneak in the diff equation. And I don't know the first thing about calculating correct cutting speed. Care to point me to a good online tutorial?

BTW, I notice that this forum software automatically capitalizes the first letter of each work in post title. So, it looked like IRA Machinist, rather than "I R a Machinist." Not sure if that raised any hackles, but it was unintended. Modified the title, just in case.

Dave,

cutting speed calculation is simple but dependent on so many factors, including:-
Cutting tool type & Material being cut.

A lot of the tools being sold these days are the replacable, indexable, ceramic tip types which keep their edge for a long time & the suppliers of such usually have cutting speeds on their web sites.
However they are generally designed for high cutting speeds & the trouble is that most "hobby" machines just cannot achieve those speeds.

If you take a look on to hobby machinists/model makers forums you will find that the majority favour the use of HSS (High Speed Steel) tools.
A small bench grinder is well capable of re-sharpening these tool, which can lose their edge fairly quickly.
Another plus is that you will be able to play tunes on the rake/clearance angles on your own tools to achieve the cutting effect that you prefer. i.e. finish, depth of cut, swarf breaking etc.

Cheers
John

[bilcoh]

John wrote:

Another plus is that you will be able to play tunes on the rake/clearance angles on your own tools to achieve the cutting effect that you prefer. i.e. finish, depth of cut, swarf breaking etc.


OY! I've got so much to learn. I'm looking for a set of tools and was thinking of going HSS, maybe carbide, but staying away from the indexable, so I guess I'm on the right path there.

Greg, I previously machined Delrin for the rears, and did not go "top hat", but just a round cylinder with the steel liner. The bolt clamped the liner, and I believe I left the Delrin just long enough to stand proud of the A-arm housing so that the Delrin contacted the flanges before the a-arm would. Same should hold true for the fronts. I'll need a washer on the back of the suspension pin, or it's possible the suspension arm could work it's way off the bushing and toward the frame cross-member. That would be bad.