Metal bashing

oldbilbo

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The top end of my 1" rudder post is formed into a 'male square taper'....

IMG_3621.jpg


Onto it fits a block of s/s which has a 'female square taper', mating with that above. The nut is to retain this in place.

IMG_3385.jpg


Welded onto the rear/side of this block is a short horizontal tube which takes a through-bolt, permitting the end of the tiller to secure to the above assembly.

I'd like to have the above s/s block reproduced, using the original as a template. How involved, please, would be the cutting of the 'female square taper'....? What sort of gear is necessary?
 
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Reverse engineering of that item would be pretty simple for any engineer

There are a number of ways it could be made, but probably the simplest solution would be to get it wire cut
 

Hypocacculus

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It almost is like a cheese wire. Its a form of edm which is a way of cutting through metal by electrically eroding it away. It's neat, can make the most amazing things.... and is pretty expensive, but one-offs always are. Look up "edm wire cutting" on youtube for videos of it in action.
 

rogerthebodger

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To cut any square hole that kind of size would need a shaping machine or heavy duty internal vertical key way cutter.

I did some thing similar but not tapered for the emergency tiller on my boat by making 4 plates clamped on the sides of the square shaft and welding the plates together. I had a 1mm thick packing plate to give me clearance and to allow the removal of the welded plated.

I then split the end of a tube with an angle grinder to insert the fabricated square into the end of the tube.

As yours is tapered the shape of the plates must be tapered to allow a close weld of the edges. I used 6 mm stainless plate and stick welded the whole together.

Don't know if I have any pics will have a look of post if I find any.
 
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Another (also expensive route) would be 3D printing, there are a number of suppliers in the UK that could do this for you, but you'd need someone to knock up a CAD file

If you give them enough time so it can be made with something else you may get a reasonable price

CDRM could scan the original to create the CAD them make a part, might be worth a call
http://crdm.co.uk/

 
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Hypocacculus

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Isn't 3D printing rather in the early stages of development for that? I wouldn't like to rely on a lump of sintered metal for something so critical. I'd want a nice, fat forging.
 

FullCircle

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Why does it need to be tapered? Could it not be a square hole with a square shaft, with radii on edges? You wouldn't get the snug fit of a taper, but you can get a pretty good fit with a good machinist - far cheaper.
 

rogerthebodger

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Why does it need to be tapered? Could it not be a square hole with a square shaft, with radii on edges? You wouldn't get the snug fit of a taper, but you can get a pretty good fit with a good machinist - far cheaper.

It is much easer to locate the emergency tiller onto a tapered square than a parallel square. Mine is a parallel square and it can take me a minute or 2 to locate the emergency tiller on to the top of my rudder post in dock. Never tried it and any kind of seaway but it would be more difficult.

I need to modify my emergency tiller to make it easer to locate in the correct position.
 

john_morris_uk

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I would be very tempted to start with the drilling and hand filing. With some engineers blue and some care you could end up with a good fit. Make sure the files are sharp!

Stainless is only difficult to work if its work hardened. Its actually very easy to file if you are careful and use sharp files.
 

Heckler

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I would be very tempted to start with the drilling and hand filing. With some engineers blue and some care you could end up with a good fit. Make sure the files are sharp!

Stainless is only difficult to work if its work hardened. Its actually very easy to file if you are careful and use sharp files.
At last! Some common sense! Patience is all that is required.
Stu
 

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I stand corrected although when it comes my boat, the word "prototype" scares me; what a pity they chose to make guns though.... :(

There's a lot more than guns being made, aerospace are flying parts, even in engines
F1 teams are using it for structural items such as roll hoops which have to pass a 10 ton static load test
Replacment hips and dental structures are now common
 
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pmagowan

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Couldn't it be cast? Another thought, simply drill a hole large enough to take the tapered rod, rough up the inside, put releasing compound in the rod and, with the part in place, pour epoxy in. It will mould to the right shape. Alternatively again, make it in 4 pieces and machine screw them together. All the above could be DIY. To avoid DIY simply take the part to local fabricator and say "I want another one like this", come back in a week and you will pay your money and have your part.
 

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I would be very tempted to start with the drilling and hand filing. With some engineers blue and some care you could end up with a good fit. Make sure the files are sharp!

Stainless is only difficult to work if its work hardened. Its actually very easy to file if you are careful and use sharp files.


That depends very much on the grade of stainless selected and deep hole drilling in stainless can be a real pain if you're not set-up for it

It's all basic apprentice skill test stuff and relatively simple in a good workshop, however you’d probably want to make an exact copy of the male as a gauge.
I don’t think I’d want to be doing the final shape on a boat
 
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