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Cast Iron Straight Edge

Retailer of cast Iron straight edge

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Peter F21/01/2019 00:38:15
21 forum posts
5 photos

Hi, does anyone know where you can buy cast straight edges, for the purpose of printing dye on to ways for scraping?

I found some companies selling them in India and China, but no retailers in the UK whatsoever.cast-iron-straight-edges-500x500.jpg

Pete Rimmer21/01/2019 01:21:37
243 forum posts
2 photos

Don't know of any new finished ones in the UK. There's a guy in the South West sells the odd casting for 12" dovetail straight edges and they are nice to scrape in but you'll have to machine all the working faces first.

Kblast straight edge

Other than that you can buy King castings off eBay but they also need machining, perhaps stress-relieving and then scraping to finish before you can call them good to use. You're looking at 400 quid for an un-machined casting, plus import and vat most likely.

Used ones are very thin on the ground.

Speedy Builder521/01/2019 08:12:23
1646 forum posts
111 photos

I don't know how accurate these would be ??
**LINK**

Brian Oldford21/01/2019 08:24:37
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453 forum posts
4 photos

PMed

Ketan Swali21/01/2019 09:12:52
1060 forum posts
87 photos

Try Ian at Rotagrip.

Ketan at ARC

Nigel McBurney 121/01/2019 10:03:21
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539 forum posts
3 photos

Better to get an old English made straight ,where the castings were allowed to "weather" to relieve the internal stress and were often rough machined and then left to stand for some time before final finishing,Using new "green" castings is not a good idea,Try the second hand tool dealers.

Pete Cordell21/01/2019 11:41:29
8 forum posts

If you have deep pockets and long arms this guy has them

Edited By Pete Cordell on 21/01/2019 11:41:54

SillyOldDuffer21/01/2019 12:43:49
3753 forum posts
746 photos
Posted by Nigel McBurney 1 on 21/01/2019 10:03:21:

Better to get an old English made straight ,where the castings were allowed to "weather" to relieve the internal stress and were often rough machined and then left to stand for some time before final finishing,Using new "green" castings is not a good idea,Try the second hand tool dealers.

The need to weather cast-iron castings means the maker is using the wrong type of cast-iron! Cast-irons that don't need to be allowed to de-stress were developed in the USA during the 1920s and were widely used in Europe before WW2. (Meehanite etc).

Craftsmen often see weathering as a sign of care and quality; on the other hand it gives accountants and shareholders apoplexy! A hundred years ago it was costly to store items for months before they could be finished and sold. These days it's disproportionally even more expensive. I think a Production Manager would look carefully before agreeing to any process that made untoward weathering essential.

Of course, a big advantage of buying an old tool in good condition is that you know it isn't going to warp! Quite a lot of cast-iron is carp and for things like weights and street furniture it doesn't matter. With new cast-iron there's always the possibility of buying from a cowboy. A small foundry making small tools as a sideline might not bother with using the right alloy or weathering.

Dave

Barrie Lever21/01/2019 16:38:09
104 forum posts
23 photos

SillyOldDuffer

BMW used aged crankcase castings in their first Formula 1 turbo engine in the early 80's and a mighty powerful engine it was as well.

The aging was acheived by using crankcases from road car engines that had completed at least 100,000 Km, these were then modified to the specification required for the F1 engine.

To be clear these were cast iron crankcases.

Regards

Barrie

SillyOldDuffer21/01/2019 17:10:05
3753 forum posts
746 photos
Posted by Barrie Lever on 21/01/2019 16:38:09:

SillyOldDuffer

BMW used aged crankcase castings in their first Formula 1 turbo engine in the early 80's and a mighty powerful engine it was as well.

The aging was acheived by using crankcases from road car engines that had completed at least 100,000 Km, these were then modified to the specification required for the F1 engine.

To be clear these were cast iron crankcases.

Regards

Barrie

Hi Barrie,

That's interesting. Do you happen to know why they did that? It seems an extreme way of eliminating warping. Presumably the advantage was that old crankcases have been put through a huge number of heat cycles between ambient and hot over a long time. Racing being extreme perhaps the idea was to select crankcases with absolutely no tendency to warp in an extra hot engine run flat out.

However, I stand by my comments about Production Managers - what's done to a Formula 1 engine isn't typical value engineering!

By the by, I'm not familiar with the reasoning behind Formula 1 engine design especially as it's changed over the years. Mostly I expect them to be using exotic materials for triple-extra go-faster performance and then discover the rules don't allow it! Can anyone explain what the state of the art for high-performance engines is, and what's allowed on the track?

Dave

Nicholas Wheeler 121/01/2019 17:48:06
196 forum posts
9 photos
Posted by Barrie Lever on 21/01/2019 16:38:09:

BMW used aged crankcase castings in their first Formula 1 turbo engine in the early 80's and a mighty powerful engine it was as well.

The aging was acheived by using crankcases from road car engines that had completed at least 100,000 Km, these were then modified to the specification required for the F1 engine.

To be clear these were cast iron crankcases.

They were using a very old design of engine!

Martin Harris 921/01/2019 18:02:01
13 forum posts

I recall being told that good blocks from high mileage van engines were much sought after for building Top Fuel and Funny Car drag racing engines.

Michael Gilligan21/01/2019 18:07:56
avatar
12544 forum posts
544 photos

A reasonably lucid account of the BMW story, here: **LINK**

https://f30.bimmerpost.com/forums/showthread.php?t=1350137

MichaelG.

Edited By Michael Gilligan on 21/01/2019 18:08:50

Barrie Lever21/01/2019 18:31:35
104 forum posts
23 photos
Posted by SillyOldDuffer on 21/01/2019 17:10:05:
Posted by Barrie Lever on 21/01/2019 16:38:09:

SillyOldDuffer

BMW used aged crankcase castings in their first Formula 1 turbo engine in the early 80's and a mighty powerful engine it was as well.

The aging was acheived by using crankcases from road car engines that had completed at least 100,000 Km, these were then modified to the specification required for the F1 engine.

To be clear these were cast iron crankcases.

Regards

Barrie

Hi Barrie,

That's interesting. Do you happen to know why they did that? It seems an extreme way of eliminating warping. Presumably the advantage was that old crankcases have been put through a huge number of heat cycles between ambient and hot over a long time. Racing being extreme perhaps the idea was to select crankcases with absolutely no tendency to warp in an extra hot engine run flat out.

However, I stand by my comments about Production Managers - what's done to a Formula 1 engine isn't typical value engineering!

By the by, I'm not familiar with the reasoning behind Formula 1 engine design especially as it's changed over the years. Mostly I expect them to be using exotic materials for triple-extra go-faster performance and then discover the rules don't allow it! Can anyone explain what the state of the art for high-performance engines is, and what's allowed on the track?

Dave

Dave

I think the reasoning was that the crankcases had been through so many heat cycles that they were about as stable as could be.

The crankcase design was very old, I think it was a mid 60's design which was right for their turbo project.

The current state of the art Formula 1 engine is the Mercedes (made in England) it is a total engineering marvel, where do we start ?

The engine is turbo charged and with hybrid power as well, there are two sources for recharge energy for the hybrid battery pack, one is braking effect through the MGU-K (kinetic energy) this is a motor generator on the engines crankshaft, the other regeneration source is MGU-H (heat energy) this is a motor generator on the turbo charger shaft, so instead of using a waste gate to dump turbo over pressure, the turbine is held back by the generating load.

The real jewel in the crown of the Mercedes engine is that the turbo charger is split, so the compressor is on the front of the main engine V and the turbine is on the back and the two are connected by a relatively long shaft and also some where in this little lot is the MGU-H. The split turbo gets the compressor up near the front of the engine and close to the air intake and probably minimises latent heat soak from the turbine.

The motor generator on the turbo MGU-H can also put power onto the turbo to reduce turbo lag.

The hybrid power is 160Kw but that cannot be deployed permantly, as the MGU's have to recharge the battery through the course of a lap

The engine is also a stressed member in the car, effectively the back end of the car (gearbox, drive train and suspension) is mounted off the back of the engine.

The last F1 engines that I got up close to where turn of the century time and they were very light and compact, the current generation will be mind blowing if you could get close to them.

By the way the Mercedes on the dyno can acheive over 50% efficiancy which is pretty good for an IC engine.

I am sure I have missed loads but that gives you a flavour.

Regards

Barrie

Martin Connelly21/01/2019 18:58:00
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799 forum posts
90 photos

There are a couple of scraping straight edges on ebay at the moment.

Martin C

Neil Wyatt21/01/2019 20:01:00
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Moderator
15459 forum posts
651 photos
72 articles
Posted by SillyOldDuffer on 21/01/2019 17:10:05:
Posted by Barrie Lever on 21/01/2019 16:38:09:

BMW used aged crankcase castings in their first Formula 1 turbo engine in the early 80's and a mighty powerful engine it was as well.

Do you happen to know why they did that?

Maybe BMW engine castings are of poor quality

Neil

Pete Rimmer21/01/2019 20:48:13
243 forum posts
2 photos

Raw straight edge castings need stress relieving. The HKA-x ones you see on ebay are King design and the finished ones they used to sell were stress relieved, rough-machined, stress relieved, machined then scraped, sometimes with a third round of stress relief thrown in. The ebay ones have one round of stress relief and are said to require no more but it's still possible they would move during machining.

Even old, previously-finished straight edges can develop a twist over time. I bought a 36" one which looked pretty good but had about half a thou of twist in it.

Brian Oldford21/01/2019 21:42:26
avatar
453 forum posts
4 photos
Deleted
 

Edited By Brian Oldford on 21/01/2019 21:44:06

Peter F22/01/2019 00:31:42
21 forum posts
5 photos
Posted by Pete Rimmer on 21/01/2019 01:21:37:

Don't know of any new finished ones in the UK. There's a guy in the South West sells the odd casting for 12" dovetail straight edges and they are nice to scrape in but you'll have to machine all the working faces first.

Kblast straight edge

Other than that you can buy King castings off eBay but they also need machining, perhaps stress-relieving and then scraping to finish before you can call them good to use. You're looking at 400 quid for an un-machined casting, plus import and vat most likely.

Used ones are very thin on the ground.

Thanks, the one in that link looks like what I'm after, do you know this seller?

Peter F22/01/2019 00:45:32
21 forum posts
5 photos
Posted by Pete Rimmer on 21/01/2019 20:48:13:

Raw straight edge castings need stress relieving. The HKA-x ones you see on ebay are King design and the finished ones they used to sell were stress relieved, rough-machined, stress relieved, machined then scraped, sometimes with a third round of stress relief thrown in. The ebay ones have one round of stress relief and are said to require no more but it's still possible they would move during machining.

Even old, previously-finished straight edges can develop a twist over time. I bought a 36" one which looked pretty good but had about half a thou of twist in it.

So what is the process of 'stress relieving'? I was under the impression it was the casting being left for a period of time? you mention several rounds of stress relieving? what is involved in this?

Cheers.

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