Thread: Should CI Straight edges have Frosting?

Thanks, it should be a good buy at that price, and if you have a use for it then well done.

The only point I was making is that to fully recondition a machine you'll need a straight edge long enough to do the longest surface (kinda, sorta, not really, but that's beyond the discussion here), but because something like that is so heavy, you'll also need at least one shorter one. PDW could possibly set you right on the shorter one. Yes the cycle times will be a fraction of what they would be if you could just lift the SE off, however it's also quite possible you won't need as many cycles as the surface won't need to be as precise.

Originally Posted by simonl

Hey just had a thought. After i have finished using it for the longer stuff i could always shorten it with an angle grinder!

Simon

In any case I'd be keen to purchase just because it's a piece of Australian history.

It depends on the design. A camelback, probably not. However long straight edges aren't as common as smaller ones, and I think you would be better to sell it on when finished and buy a couple of smaller ones with the proceeds.

I must admit I can't follow the logic in buying something that you feel is a piece of Australian history (with which I agree), and then taking an angle grinder to it

Pete. I was kidding. The thought of taking to it was an angle grinder makes me cry. I would on sell it if anything although i havent yet decided on that. I may decide to keep it and make it available to other members of the forum. Argeing is offering the use of his biax and shed is offering the use of his surface plate so why not?

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The other thing is this. After i scrape the longer surfaces and may be able to use then as the reference surfaces to do the shorter surfaces like the saddle. I cant remember the exact sequence of operations, ill have to drag out my copy of connollys book on machine rebuilding and have another read about it including scraping to datums etc...

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Yes I did wonder if you were joking about the grinder, but can't judge by written word. I made the comment as I've read that idea suggested on various forums MANY times ... and they weren't kidding! At the end of the day, it's just another tool and I think some of us get a bit precious about our tools. On the other hand it is a piece of history, and goodness knows history is about the only thing we have left of Australian manufacturing

Good luck with the scraping

Originally Posted by Pete F

Yes I did wonder if you were joking about the grinder, but can't judge by written word. I made the comment as I've read that idea suggested on various forums MANY times ... and they weren't kidding! At the end of the day, it's just another tool and I think some of us get a bit precious about our tools. On the other hand it is a piece of history, and goodness knows history is about the only thing we have left of Australian manufacturing

Good luck with the scraping

Can't see the problem, I've cut some down with an angle grinder (well, bandsaw actually). So has variant22. In fact I have a number of castings I'm going to cut in half and make matched sets of parallels from them.

Agree that cutting down a camelback type wouldn't be real sensible.

FWIW I've scraped in one of my 1m long parallel flange castings and it was heavy enough to handle. I only needed it for one job too.

PDW

Yes. Its bloody sad. It doent have to be this way forever though. Things happen in cycles and who knows we may ond day sed a resurgence of manufacturing here in years to come.

Funny thing is a had to do a little job for a local hydraulic repair shop using my SG. Turns out that no one locally has access to such machines anymore. How crazy is that!

Wrt i have an 18" shaper that has a badly worn ram and ways. I will tackle that first to regain my scraping confidence and also for experience. I envisage the shaper job to be less complex than the mill.

Simon

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I'm reasonably confident we won't see any manufacturing in this country during our lifetime. In the US it's a different story, and the sector is actually growing. The difference is large investment in automation (ie lights out manufacturing etc), but we haven't followed that trend here. Lots of reasons for that, beyond this thread. So while the manufacturing percentage of GDP is increasing, the number of people employed in the sector is not. However while we're on the topic, unfortunately for us, successive Australian Governments have continued to dispense with key strategic assets, either directly or indirectly by lack of support many foreign countries enjoy, in order to fund a nation of welfare recipients. Over 50% of Australian households now receive some form a Government handout, a figure that, to me, is just shameful. Meanwhile the country itself is essentially going to the dogs as there is almost zero independent Government investment in infrastructure for our children's future as the Governments lurch from one election to the next buying votes. Anyway, rant over, but as a late starter to a couple of young children, I can't help but think they will look back on our generation when they're my age and say "You ba#$ards!"

Can't see the problem, I've cut some down with an angle grinder (well, bandsaw actually). So has variant22. In fact I have a number of castings I'm going to cut in half and make matched sets of parallels from them.

The point was the OP stated that one of the reasons for buying the tool was to preserve a piece of Australian history. Not a lot of point in that if you're then going to chop it up into little pieces with an angle grinder

I've never really understood why people cut straight edges down to make smaller ones, but whatever floats your boat if you pardon the pun Peter. The proportions for the straight edge will be wrong for its size (ie it will be unnecessarily high vs length). The other thing is short straight edges are relatively easy to come by, longer ones are not so easy to find. The price follows availability. So it would be far more logical to sell a longer straight edge and use that money to buy a shorter one(s) than to start bodging up a shorter one with a hacksaw!

Originally Posted by Pete F

I've never really understood why people cut straight edges down to make smaller ones, but whatever floats your boat if you pardon the pun Peter. The proportions for the straight edge will be wrong for its size (ie it will be unnecessarily high vs length). The other thing is short straight edges are relatively easy to come by, longer ones are not so easy to find. The price follows availability. So it would be far more logical to sell a longer straight edge and use that money to buy a shorter one(s) than to start bodging up a shorter one with a hacksaw!

I've got 5 castings for parallel beam straight edges 1m long and another 4 or 5 of the 640mm long parallel beam ones so cutting one down isn't really an issue if it's more convenient. I can always (as long as the foundry is open) get more done. Still, I take your point, which is why I'm getting a batch of smaller dovetail straight edge castings done.

PDW

Well I got it home after spending much of the afternoon at a trampolene play centre with my daughter, shes got a damn curriculum day!

Turns out I'm not very good at judging length (my wife has told me that on a few occasions) at this thing is actually 1800mm! It's bloody heavy but I can lift it realatively easily from the ground to a height of maybe 400mm (like a dead lift) so could use it unaided if the part was sitting close to the ground.

It looks in reasonable good nic apart from those scratches. For what I can tell, there is not a lot in those rust marks. Running my fingers over the surface, I can feel the scrapeing pattern but not the staining. I gave it a bit of a clean up with some turps and a silicon carbide stone and took some pics. With a bit of luck, most of those blemishes will come out after maybe 1/2 dozen scrape cycles.

The middle pic is of the top. It has some letters, a wing insignia and what appears to be a date, 1952.

20171103_141339.jpg20171103_142421.jpg20171103_140709.jpg

WRT PDW claim to cutting SE, these are parallel SE and cast by himself. So don't see why that's an issue. Certainly a separate issue to me cutting up a perfectly good camelbak type.

In a perfect world a 900mm long SE would be ideal for me and do all I need but at least I have something for now. I don't think I will loose any money on it.

Simon

Peter I can't say I blame you for cutting them up, I'd probably do the same in that situation, but with all due respect I don't think they constitute part of Australian history

Simon the issue with cutting up longer SE is that the height of the SE won't be appropriate for the length. To take it to the extreme, imagine a bridge that happened to also be a SE, the bridge is 100 metres long and 30 metres high. Now you only need a 300 mm long straight edge so you decide to cut your bridge up and ....

Clearly that's an extreme, but if you were to compare a 300 mm parallel SE and one that's 1200 mm long you'll see they're very different heights. The difference can be enough to that it could be difficult to use one that's bodged from a longer one.

Yes, understand what you are saying and I also follow your logic at the extremes. Sometimes the best way to work something out or work out a problem is to look at the extremes or "boundary conditions" they call it in mathematics. Same principle.

Yep, PDW, I think one of those 900mm SE will do me nicely. Won't really be ready to purchase til next year, not that I expect you to put one on hold or wait for my phone call but when the time is right, I'd be keen to see what you have.

Simon

Originally Posted by simonl

Yes, understand what you are saying and I also follow your logic at the extremes. Sometimes the best way to work something out or work out a problem is to look at the extremes or "boundary conditions" they call it in mathematics. Same principle.

Yep, PDW, I think one of those 900mm SE will do me nicely. Won't really be ready to purchase til next year, not that I expect you to put one on hold or wait for my phone call but when the time is right, I'd be keen to see what you have.

Simon

The big ones aren't wasting away so there'll still be some there next year. I can't plane them ATM anyway as the reversing mechanism is not playing nicely and I won't get to work on that until I get some room.

So first the boat has to go but the good news for me is, that event isn't very far away now. It remains to be seen if there really is life after boat building, though. Maybe - we splashed the 20m, 43 tonne one today.

PDW

No worries. PDW. 43 tonnes, is that heavy for a 20M craft or standard? My dad built a 40ft in steel and it was about 17 tonne and I thought that was heavy for it's size as dad had a habit over over-engineering just about everything!

Simon

At 800mm longer than the plate I reckon you might have some strife getting it flat Simon.
Or do you have a devious plan?

cheers, shed