No, usually what I'm setting the resin in is a solid box or block of some sort, I guess if the mould box was thin and flexible it might distort but it doesn't generally seem to be a problem.Originally Posted by Drew
Forum whore
No, usually what I'm setting the resin in is a solid box or block of some sort, I guess if the mould box was thin and flexible it might distort but it doesn't generally seem to be a problem.
Bogeyman
Neals Foundry 2016 Ltd.
Has changed hands again?
Go soothingly on the grease mud, as there lurks the skid demon
Forum whore
A bit of a story it seems, the owner went broke but was bought out by one of his customers (boat builder maybe?) but the old owner now just works there as the floor manager. I don't know? we will see, at least the clutch case is simple. It may or may not be a good foundry but I want to find out. I'm using Skellerns in Auckland at the moment for all my Aviation gearbox castings, they finally produce a nice product but very expensive! I'd like to just have a backup option. There are not many options in NZ now.
Bogeyman
I used to use Neals quite a bit, mostly for bronze boat fittings. Been around for yonks, picked up a lot of Cables work when they died. It's changed hands quite a bit since then but over at least three owners they usually managed to get my stuff right.
Not using green sand nowadays, someone said. Newfangled stuff will never take off...
Go soothingly on the grease mud, as there lurks the skid demon
Forum whore
Said they were using Fenotec, chemical with a hardener, mixed with the sand and delivered to the mold by a machine. Time set, ram the mold and leave for ten minutes, then remove the pattern. Like I said, we will see.
I'm getting braver with the 3D drawing program I have a little stack of Aluminium off cuts, all paid for from a job, so the next case might well be CNC cut? Just when I think I'm on to it (3D program) I find a new brick wall and my worker, who knows all about the program, but I'm too proud (stupid) to ask anyway, has gone on holiday to Europe for ten weeks. Keep hammering away I guess.
Bogeyman
Another local old timer is Borren Metals: http://borrenmetal.co.nz/
Investment casting specialists. Might be a bit pricey for one-offs but a dozen or more would probably be competitive. I used to get them to shell mould delicate wee stainless bits, I've never had them do alloy but I'd be surprised if they didn't do it.
No draught requirements, (in fact negative draught is fine) effectively no allowance for surface discrepancies, better resolution, less porosity. All means tighter tolerances with thinner wall castings and the ability to cast finer gussets and tighter radius fillets.
And I'd be surprised of they couldn't print wax cores direct from your CAD files...
Go soothingly on the grease mud, as there lurks the skid demon
Forum whore
CAD files, you mock,
But good to know, thankyou.
Bogeyman
OK, send me the wooden bits and I'll get them scanned, import them to Rhino, tweak it for shrinkage and spit it out as an stl. Done.CAD files, you mock,
Go soothingly on the grease mud, as there lurks the skid demon
Hardcore Biker
Well, we had a delivery, a beautifully plated sliding cylinder from kiwiland. Next thing is to get a piston for it.
Turns out there is a place right near us that does these, so will put the word on them.
Now I can do the cylinder head to suit the bore size plus the ring and O ring grooves can be machined all in the one setup.
Forum whore
NICE, now you stay in that workshop until it makes noise out the exhaust! OK. Tell the wife you have strippers at work and can't come home or something, anything, just make it go. We can't wait.
Forum whore
Epicycloid crank, missing one of the crank webs. This is a fully supported crank system.
Forum whore
While we are at it, the beam crank system.
still basking in the glory..
which of these cranks do you feel would take the most abuse / rpm level?
still basking in the glory..
ken, what are your expectations with regard to this design?Well, we had a delivery, a beautifully plated sliding cylinder from kiwiland. Next thing is to get a piston for it.
Turns out there is a place right near us that does these, so will put the word on them.
Now I can do the cylinder head to suit the bore size plus the ring and O ring grooves can be machined all in the one setup.
Forum whore
That's the problem, I don't know which one to pursue? I expect the epicycloid would be best for rpm, it has the lightest oscillating components but it also has a bushing in between the the cranks that is turning at double speed. This could be a problem. I have a specific cylinder in mind for these (one of these) bottom ends. It's an FOS / Ryger (or should I say just a high pressure bottom end rather than ryger) it has three high pressure ports at quite a high angle up into the combustion chamber and three more leading in under these, being straight from atmosphere, no crankcase pump. All at 60 degrees to each other, alternative. The three transfers from atmosphere also act as piston port to fill the high pressure crank case, double jobs. Fueling will be via standard EFI injection into these ports but only the crank case will see fuel as when these ports are flowing straight into the cylinder they will flow only air as the injectors will be off at this point. Perhaps at high speed they will also flow fuel but I don't know about that yet.
I had thought (and am leaving enough sleeve length in the casting) to fit the HCCI top end. This will allow me to regulate this engine fuel only with a full air charge each cycle. Alternatively if I ran this new cylinder on the beam bottom end I could just vary the compression to achieve HCCI with perhaps some control? Knock sensor attached to a servo to adjust the compression eccentric and maybe an exhaust valve, on the fly. Too many ideas at once I think
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