Depends what you are casting, in what and how big, I do centrifical tin casting using a Centricast machine in rubber moulds, very safe and easy process. The machine is a very easy project to make in a SHED. But you need to make a few identical bits to be worthwhile. Moulds are 10" or 7" diameter.

Alloy casting is now a low cost deal, there are several good furnace designs made from cement and cat litter on the web. Some people do lost plastic using plastic foam bits stuck together to produce oversize castings that can be machined down e.g. http://www.buildyouridea.com. Often the plastic foam is shaped with a hot wire cutter, all very suitable for real model engineers at home in their SHEDS. Mike Cox has some very well written projects on his excellent web site **LINK**. There is also the very good video series by "Myfordboy" on the tube that covers home casting.

Billy,

For the centrifugal casting technique, there is a safer approach using a spring loaded rotary arm with the mould on the end. I've seen it done commercially by a dental laboratory, complete with guards around the whole affair. Not impossible to build one at home. Another technique uses a vacuum pump to suck the air out through the porous bottom of the mould. The flask is just a piece of metal tube with the refractory mould cast into it, the metal is poured into the top and the vacuum is applied to the bottom…much nicer than messing around with water near molten metal.

My own thinking on 3D printers is that I would be better to take my 3D model file to someone that has the right gear and get them to print it. This is the approach that I have taken with colour printing too, having found that whenever you want to use it, the jets are clogged and the cartridge goes dry while you try to clean it. It is much cheaper to let someone else do the prints, and because of economies of scale they will have better gear than I can afford. I suspect this will also apply with 3D printing.

John

Sadly I can't afford to service an Audi, let alone to buy one in the first place.

John

Having fixed many a strange problem on Audis for co-workers over the years, I certainly would not want to own one. Never seen such odd bits of electronic gadgetry for simple things like door locks and windshield wiper delays. One such wiper control unit had 6 individual circuit boards packed in a metal enclosure on a base like a relay. A new replacement was out of the question for the owner as it was well over $2000 from the dealer, about 3 weeks' take home pay for the guy at the time. We ended up making a new delay wipe control based on the well known 555 timer IC and a few discrete components to replace the old one – total cost $8 including a heavy duty relay. Drilled a hole and mounted the pot shaft for adjusting the delay period under the lower lip of the instrument panel. He took the controller unit out when he sold the car and has fitted the unit in several cars since.

Another Audi had a really odd seal design between the fuel filler cap and the fill neck. We just could not get it to seal, and the car would not run unless the tank could have about a half a psi pressure built up in the fuel tank, so a seal was mandatory. The replacement was over $300 from the dealer and not guaranteed if there was any rust at all in the filler neck. We ended up adapting a seal off a small engine for a large portable concrete mixer that fit almost perfectly with a minor od trim and it sealed with no trouble, total cost $1.75.

We won't talk about the 24 ga headlight wiring that caught fire regularly on one lady's Audi, until we replaced it with normal 12 gauge wire as used for most headlight wiring on other cars of the time. Or the gearshift reverse interlock switch on one guy's Audi that was so close to the pivot it had to be set within about .0015" to work (until we modified it with some real world +/-.125" engineering)

Lovely memories of fixing some dismal but very expensive status symbol cars in cold Canadian parking lots usually in February. Just pretend you are in a garage made of ice blocks at the end of an aircraft wind tunnel. At the time you think you will never be warm again.

JD

Dangerous to generalise but anyway. Generally the Japanese and Korean companies are the top tier, followed by the Germans/GM/Ford in the middle and the likes of Renault, PSA, Fiat, Chrysler (and remember Rover?) etc at the bottom. Funny thing is that VW got away with making out they were very reliable yet were only ever average and more recently very poor (the power of marketing). Another funny thing is that Skoda (also part of the VAG group) made very much the same vehicles as VW but their vehicles were/are noticeably more reliable. I worry about Nissan, as they are co-owned by the same company that owns Renault.

Quality is a cultural thing that is very hard to change, much like a personality. Hondas are often referred to as the engineer's car! Yes, I have owned a long string of them, as well as a range of outliers for reference….

Merry

It will only be accepted when the media use size phrases like "its as big as xx double decker busses, football pitches or swimming pools.

I had a GM-era Saab 9000 for less than a year. Lovely car, very comfortable and solid, lots of comforts. But after the engine grenaded a couple of times we found ourselves leaving the Saab at home when we had to go any distance and instead packing into a miserable Citroen diesel we'd been given. Eventually I saw sense, sold both and went back to Hondas. Paid my dad 2 grand for it, spent 2 grand on it, sold it for 2 grand and did less than 2000 miles. Would have been cheaper taking taxis. Never had a confidence problem since.

The guy who forced the sale of Rover to BMW was the same idiot who oversaw the demise of Lord Weinstock's GEC. Rover was only a few years into a long journey to change their quality culture. Honda was never interested in owning them, just being a cross shareholder as is common with Japanese companies. Funny thing is that a Rover often cost more than its Honda equivalent. Used to make my toes curl when we were told to buy British. Said idiot was made a Baron for his services…..

Absolutely disgusting the way Towers and his buddies sold off Rover assets for their personal gain and left the employees on their own. The final chapter of a shameful story.

Edited By Muzzer on 19/02/2014 18:53:41

Here is a very good (In my opinion) video of the full lost PLA casting process.

Les.

Hello all,

For those into these things, try this as a master class in 3D printing

**LINK**

Regards

Brian

Moved from Garage door thread by JasonB

Edited By JasonB on 04/03/2014 12:37:02