Tell me about - CASTING

[ToolsnTrack]

Casting, whats the chat?

I have been trying to source a shifter shaft for an LT77 box, and frankly they are hens teeth at the moment. I can get a loan of one which will be useful for aligning my box during the build, but it isnt a permanent solution.

I have toyed with the idea of taking a mould and casting an aluminium replacement for the shaft, and maybe knocking out a few of them if it is successful and punting them on to recoup costs. Once i've done a few I may even do a few other things in cast for sh1ts and giggles. However, I have never done this before and could use some insight...

Has anyone done homebrew casting before? Would a sand cast be sufficient to replicate a ball and shaft as below:


and would I be able to heat the metal at home to a temperature needed to melt it? Can I build a furnace that will be hot enough at home and what methods and parts can I use to do this with?

Also, would recycling the metal from obvious sources of aluminium (cans and old ally castings from junk) be a good idea or should I source an ingot from scratch?

Thanks in advance for any tips!

Incidently i did try googling "amatuer casting" for advice, but its brought up something quite altogether different.

[purplevanman]

There are loads of sites that mention casting
look under hobby machine sites, I have read about people casting new bits for obsolete lathes etc.
If it the gear stick shaft and the swivel ball then I would say that ally would be a bit soft and fragile?
Ally engine/gearbox parts would be a good source, cans wouldn't be worth it as you would need loads
A forge is fairly simple, fire + air = heat the actual casting process is gonna take some learning
PICS

[ToolsnTrack]

Thast was my only concern that the ball section would be liable to wear. I also considered that the shaft would be easily bent but i worked out i could just make the ball and lever a short stub which had boltholes to attach a steel shaft to, a la Hurst style:



Looking at info i need 800degC to melt aluminium. I presume mild steel will be well out of the reach of a home furnaces temperature capabilities?

[pauldaf44]

If you do do it any chance of persuading you to make me a filling from hens teeth made of poor quality wobbly children's play pony poo subframe mount bracket

[ToolsnTrack]

If it works i cant see why not... Sure you want a subframe bracket in aluminium?

[composimmonite]

Just remmember to make pattern oversize as the cast item shrinks when cooled. That means you strictly cann't use an original item as a pattern. Cast iron shrinks less than cast alloy but I cann't remmember exact amounts.
Basically I'd say either carry on trying to source "hens teeth" or develope your own fabricated version (best idea) but forget casting and definaltey casting for resale (unless you have the apprioriate liabilty insurance etc). Also sand casting isn't really good enough. I'm not sure how they are manufactuered but the finish isn't from a sand casting - maybe die cast (gets my vote).

Paul H

[IDY]

This guy has documented his metal casting experiments including casting iron, its an interesting read

www.backyardmetalcasting.com/

[pauldaf44]

Nov 18, 2010 7:44:42 GMT ToolsnTrack said:

If it works I cant see why not... Sure you want a subframe bracket in aluminium?

That is a worry but without one at all the car is unusable. its been proving fun to find. This is the part I need.

[optima21]

personally I'd be looking at either fabricating it or machining it from solid. even if you cast it, wouldnt the ball need machining anyway to fit the socket properly? in the past I've fabricated things out of steel and brass by silver soldering them, which can be done with a decent blowtorch, like a Sievert or bullfinch one (silver solder melting between 600 and 850c depending on grade). or you could just weld sections together. If you want a cast part, I'd make the wooden master (allowing for shrinkage) and take that to a local foundry. it would be alot cheaper than the outlay of getting the equipment to make a handful of parts.

John Winter are a company that supply euipment for doing foundry work

www.johnwinter.co.uk/

[ToolsnTrack]

Well that gives me something to think about.

So no one actually done it on here?

[Dez]

its not really worth the time and effort it involves, especially considering the hit and miss end results. its far easier, simpler, stronger, and safer to just fabricate an alternative, be it out of ally or steel.

for what youre doing, id look to get a shifter ball and socket setup out of another car (nearly all cars have a remote setup with similar parts these days) and adapt it to fit. much easier than fabricating something from scratch that already more-or-less exists.

[steveo3002]

www.clubgti.com/forum/showthread.php?t=225073&highlight=casting

this fella on cgti has started doing small items , and he did a thread on "how to " he might do you some bits if the ££ is right?

[rangerbob]

There is another way. These guys are just up from me and prototype for F1 and Bentley etc.
May be a little more expensive but worth giving them a call.

www.mtt-group.com/metal-part-casting.html

[composimmonite]

Nov 18, 2010 9:59:06 GMT steveo3002 said:

www.clubgti.com/forum/showthread.php?t=225073&highlight=casting

this fella on cgti has started doing small items , and he did a thread on "how to " he might do you some bits if the ££ is right?

I notice how he states "For reasons of liability, all parts are sold on a non-road use basis."
Also 10 years experience of DIY casting and a cabinet maker by trade so the skills to make patterns.
Add lathe and skills to operate to mix.
I simply cann't see how even paying "an arm and a leg" for a LT77 remote is going to cost anything like the time (years of learning curve and not weeks) or money in casting to an acceptable standard yourself.

Paul H

[kevfromwales]

don't sherpas have this part?? - or am I getting my lt77's mixed up again??

- kfw
ps - frank at karma kustoms pretty good with the old casting, we're going to be needing him to knock up some unobtanium studebaker tailight housings at some point

[v8ian]

I have has a few things cast for my cortina, I speak from experience as a ex foundry engineer, The LT77 remote looks as if it is pressure die cast, so it has to have very little machining, get it sand cast 1, it will be 3% smaller if you use the original a pattern, 2, material quality control is also a problem, with blow holes and voids, also it will probably be too soft to offer any wear resistance but use thw right material and it can be heat treated to gain hardness, 3,getting the right sand for casting may be a problem if you don't want a couple of ton of green sand, moisture is a real problem with a closed mould, which you probably need to use, I have seen the result of moisture explosions is sand where when moisture boils in the mould and then expels the molten metal from the mould, with a real possibility of severe injury to yourself.
When I get bits cast, I do the pattern making myself, but entrust the casting to professionals
Have you asked on here for a remote, www.v8forum.co.uk/forum/index.php?sid=7e49b063e97946492f44c3da41c2ab63

Ian

[MrSpeedy]

AFAIK they are the same LT77 in the TR7, SD1, Sherpa and even a variant of them in the Landrover Discovery !!
These gearboxes pop up fairly often on the bay for around the £100 mark. I can't see it being that difficult to find one

[ToolsnTrack]

Thats answered a lot guys! Thanks for the insight.

The logic for doing it myself was not just to make the part, but also to know how to do it. It seems like a handy thing to have a crack at and know how to do. Understandably though for an integrated part i think quality control may be the issue.

Was not aware that sherpas and discos share the remote, will have a look there too!

As for a whole box, i already have a LT77 box, just missing the wand so i cant see the point in buying another, although i may just do that and keep a box spare at this rate...

Nothing ventured nothing gained, i guess it may not be as simple as it looked. Might be better off getting a lathe instead with the moneys saved and going back to the ol turning roots!

Cheers for the advice though folks!

[Steve]

Nov 18, 2010 14:16:53 GMT ToolsnTrack said:

Was not aware that sherpas and discos share the remote, will have a look there too!

Sherpa's possibly are the same(aint seen one so cant be sure) but the 4x4 LT77 remotes(Defender&Discovery) will NOT be the same as the RWD LT77's

Steve

[v8ian]

LT77s, The 4x4 gearboxes may well be another gearbox type with the amount of differences to the 2wd box,
There are 3 different remotes fitted to the 2wd box
The one shown in the picture is a Sdi, TR7, Morgan, TVR style, the Sherpa type remote is a cast iron shorter version total length about 5" long, and TBH is fooking horrid as most of them have been driven to the moon and back, and the gear lever 18" long and canted over to the driver, the 3rd is Rockin horse Poo, series 3 XJ6, its about the same overall length as the sherpa, but is alloy, mounted square to the box, and much better engineered than both the others,
There is a different gearbox fitted to the MGRV8 and some Morgans, the R380, its looks identical, stronger than the LT77, but reverse is on the other side to the LT77, so the remote wont work correctly on a LT77