There is something wrong with my head. It just isnt right.

[Cactus Jack]

HANG ON A MINUTE.... just had a read of that quote from Cactus Jack...

sorry mate but that is not how spark erroders work, they actually use a copper or graphite electrode which is positively charged and never touches the part being erroded, there is a minute gap and when the spark fires (hundreds of sparks per second) it basically creates a cavity in the part and the excess material is washed away.

also its submerged in a dieletric fluid (similar in properties to kero), not water.

just wanted to clear that up, not having a shot at anyone..

It's all good ... I haven't used a spark eroder for over 30 years now so they've more than likely changed things now ...

My main aim was to make people aware of the existence of spark eroders and give a brief explanation of how they work (off the top of my head) ... NOT get into a debate over the specifics of what's right and what's wrong ...

I put links up for anyone interested in getting into the scientific specifics of how it's done ...

I actually meant to say "liquid" because I know that several types of dielectric fluids can be used ...

BUT ... Deionized water is also used as a dielectric ...

In this link ~ Spark erosion or Spark eroding or electro disintegration on site mobile service
~ they state : Under the new REACH requirements, the only dielectric used is water.

Deionized water ~ Water that does not contain any dissolved solids. Deionized water is used as a dielectric fluid for wire EDM machines.

Micro electrical discharge milling using deionized water as a dielectric fluid

In electrical discharge machining, dielectric fluid is an important factor affecting machining characteristics. Generally, kerosene and deionized water have been used as dielectric fluids. In micro electrical discharge milling, which uses a micro electrode as a tool, the wear of the tool electrode decreases the machining accuracy. However, the use of deionized water instead of kerosene can reduce the tool wear and increase the machining speed. This paper investigates micro electrical discharge milling using deionized water. Deionized water with high resistivity was used to minimize the machining gap. Machining characteristics such as the tool wear, machining gap and machining rate were investigated according to resistivity of deionized water. As the resistivity of deionized water decreased, the tool wear was reduced, but the machining gap increased due to electrochemical dissolution. Micro hemispheres were machined for the purpose of investigating machining efficiency between dielectric fluids, kerosene and deionized water.



What is the definition of dielectric fluid?

 

[logicquests]

Looks to be the small-valve mid block head, common as crabs. If you don't find a satisfactory solution, cover postage ($45) and I'll donate a good one from the absurdly overstocked spares shelves here at GDFP World Headquarters. Your problem (that one, any how) will be solved, I'll have less crap to move about in, and I'll get another drop in my karma bucket. Thing's either got a hole in it or it evaporates too fast. Confirm displacement and/or stud pattern, but I've got a dozen or so of either type from new take-offs to fragged and sawed in half.

Thanks for the offer Mate.

There are a few damaged motors up for sale in a lot not too far from me. Hopefully they will be ignored due to their condition. I will see how this goes and let you know.

I should find out in the next 36 hrs.

If they do become mine I will end up being in a similar position to you. More bits and pieces to deal with.

Logic

 

[motodevo]

Years ago my mates old man fixed up an old z50 motor for me that had the same problem(before i started tinkering and bodging things myself), what he did was drilled down the centre of the snapped stud with a tiny bit and kept moving on to bigger bits until it was all gone, then because i had chewed out some material off to one side aswell he kept going up in size until we just had a clean hole(around8 or 9 mm). Then we tapped it and he found a 100mm long bolt to suit, and applied red loctite to the thread and tightened it into the new hole with a nut on the bolt tightened down to act as a lock nut. Let the loctite set for a while(few beers) then we cut the head off the bolt and took off the nut. Reamed out the manifold hole to suit and used the bolt as a stud. We ended up putting a stud in the other side to make it look uniform and then finally trimmed them down so the studs were about 5mm longer than they needed to be to hold on the manifold. Had that motor for 10 years and never had a problem again.