saving a 1980 KZ750 twin

doc_rot said:
The foundry I have access to is operated by the sculpture department at my college. As a grad student I get a pass to do pretty much anything I want; interlope into other programs and departments. Its awesome. That being said, this foundry pours metal maybe 6 times a year for the sculpture students so there is a VERY loose/crude process established here. Typically sculpture doesn't need to "work" so a lot of things that would make castings unacceptable for industry use are widely tolerated here. I blew their minds when I showed them how to do a "face coat" with chopped fiberglass in the investment. That should inform you to the caliber of work they are turning out. I asked for their advice on gating and started talking details and got blank stares in return; its something I know little about, them as well. I did one cover per investment to keep the investments physically smaller. I have only done the plaster/silica investment once before, the other times I had access to ceramic slurry investment which is much better IMHO. The castings moved around a bit and there is porosity throughout. Its not too noticeable unless you inspect close up. I would not expect them to hold oil but its for the ignition cover so its good enough.

The expense to run a foundry class has limited the ability to teach it and much of the knowledge has been lost as a result, save for what people can find online. For the most part, schools have shuttered programs, so to find a functioning foundry at a university at all is an achievement. In major cities or areas where there is access to commercial foundries, the process stops at wax positives in the studio and a professional foundry casts the work. I taught it for years, but we shuttered the metal foundry at Temple University in 2009 when we moved Tyler School of Art from Elkins Park to the main campus in N Philly. We didn't include a metal foundry in the Sculpture program in the new facility and instead, all casting shifted to the Glass and Ceramics programs where I taught. One exception is in Metals/CAD/CAM (Jewelry) programs, but that type of metal casting typically occurs in kilns or with torches. It's unfortunate.
 
Very cool. I have been contemplating doing some cast covers for the 360 using 3D printed masters. Definitely some good motivation here.


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doc_rot said:
The castings moved around a bit and there is porosity throughout. Its not too noticeable unless you inspect close up. I would not expect them to hold oil but its for the ignition cover so its good enough.
Did you use flux and degassing tablets?
 
You have about a 3 minute window to pour aluminum before hydrogen forms. Drossing flux and de-gassing tablets are pretty important when you don't have the equipment to de-gas.

http://www.ebay.com/itm/N406-Sodium-Free-Dross-Cover-Aluminum-Flux-1350-1470F-/250663652557?_trksid=p2141725.m3641.l6368

http://www.budgetcastingsupply.com/product-p/2011-010.htm
 
I was so mesmerized by the castings, I forgot to ask you what silicone rubber(s) you used and I gather, did a vacuum debulk on the rubber before you made the moulds?
Pat
 
irk miller said:
You have about a 3 minute window to pour aluminum before hydrogen forms. Drossing flux and de-gassing tablets are pretty important when you don't have the equipment to de-gas.

http://www.ebay.com/itm/N406-Sodium-Free-Dross-Cover-Aluminum-Flux-1350-1470F-/250663652557?_trksid=p2141725.m3641.l6368

http://www.budgetcastingsupply.com/product-p/2011-010.htm
very interesting


pacomotorstuff said:
I was so mesmerized by the castings, I forgot to ask you what silicone rubber(s) you used and I gather, did a vacuum debulk on the rubber before you made the moulds?
Pat

The rubber was leftover from another casting project, hence the two colors. I used Smooth-On's PMC line, I chucked the containers and don't remember which ones specifically. I did not use a vacuum.
 
I got the calipers mounts fitted. Should I do pocketing or holes? holes will be faster, but pocketing will be stronger. both will look cool.
 

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Shoot Doc, that's a Brembo P08 if I'm not mistaken. One of the very few calipers that was around in 72 and still good enough to be used today. Or a Grimeca copy at least. I can't read the cast in name.
 
Good eye, indeed it is the P08, I like the old school flavor and you can get them brand new for $130. You may already know this, but it's a semi replica of the lockheed brakes that were common on 70s racers. In fact the lockheeds were standard on the venerable Kawasaki S1. A simular Lockheed design came stock on some triumphs as well but they were cast iron bodies and pistons. I actually have two of those OEM calipers and they weigh a 3 times as much. I have the Grimeca replicas on my kz1000, and the Brembos are definitely nicer
 

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I have a P08 that I was going to use on a TZ350 project to replace the heavy cast iron stock RD caliper. The original Lockheeds are (or were last time I checked) available again. I don't recall if they are 3 rib or 4 rib. Good calipers for the time and still work well.

Good choice
 
doc_rot said:
Good eye, indeed it is the P08, I like the old school flavor and you can get them brand new for $130. You may already know this, but it's a semi replica of the lockheed brakes that were common on 70s racers. In fact the lockheeds were standard on the venerable Kawasaki S1. A simular Lockheed design came stock on some triumphs as well but they were cast iron bodies and pistons. I actually have two of those OEM calipers and they weigh a 3 times as much. I have the Grimeca replicas on my kz1000, and the Brembos are definitely nicer


Where did you find the new ones?
 
teazer said:
I have a P08 that I was going to use on a TZ350 project to replace the heavy cast iron stock RD caliper. The original Lockheeds are (or were last time I checked) available again. I don't recall if they are 3 rib or 4 rib. Good calipers for the time and still work well.

Good choice

That would be the perfect brake for that bike, very cool. do you have a build thread? I think the Lockheeds made by AP look cooler as they are pretty much replicas of the originals with the ribs and all, but they are significantly more expensive. Last I checked they were $250 each, but that was before the GBP tanked.

canyoncarver said:
Where did you find the new ones?

I got mine from Bevel Heaven, but any Brembo dealer can get them.
 
need some new bolts
 

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First off - thanx to CC for pointing me in this direction!

Second ......... Nice work, good to see other Lonesome Twin owner's projects - I'm now a follower.
 
thanks guys. small update but the brakes are plumbed and cables shortened and routed.
 

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