[metalworkz]

Yeah, I have the MultiMachine plans and was impressed with the capacity that could be gained by using the engine block but I have not done anything with the plans other than look through them. I was contemplating that build or perhaps a modified version but have not seen the need for pursuing it. It is all really relative to what you want to accomplish in the end and what you feel is going to get you there with the least resistance. The Gingery series of DIY machines will teach you a lot if you work through it, but you will most likely learn things with the multimachine build too. Myself, I have used pattern making, sand molding, and casting aluminum a lot since I finished working on the machines and it enables doing things that are very difficult if not impossible to do with other fabrication techniques.

[AxelFoley]

Yeah, I have the MultiMachine plans and was impressed with the capacity that could be gained by using the engine block but I have not done anything with the plans other than look through them. I was contemplating that build or perhaps a modified version but have not seen the need for pursuing it. It is all really relative to what you want to accomplish in the end and what you feel is going to get you there with the least resistance. The Gingery series of DIY machines will teach you a lot if you work through it, but you will most likely learn things with the multimachine build too. Myself, I have used pattern making, sand molding, and casting aluminum a lot since I finished working on the machines and it enables doing things that are very difficult if not impossible to do with other fabrication techniques.

Oh, It is on my to-do list. However, for the sake of goal accomplishment I am sticking with and completing this project before moving on to the next one.

Old cast Iron blocks can be found for pretty cheap, as can the engine stand. You could build a pretty large machine with a relatively small amount of money.

I must say, Medium Density Fiberboard is SUPERIOR for pattern making. I just discovered that, so I thought I would share.

I'm busy working on tapping those holes and making patterns. Looks like the wrench included with the harbor freight kit isn't up to the task. I bought their more expensive one, but it's chuck broke. Took it back and got refund. Might get something better somewhere else. (This looks pretty good: Amazon.com: Lisle LI70500 Tap Socket Set: Automotive )

I did happen to find some free solid polished granite off craigslist.
2 pieces, both 3/4 inch thick. one is 17x13.5", the other is 17x15". I'm wondering if I could use those in some way that would be beneficial.

[aarggh]

I've lost count of how many times I've watched that shaper video, so cool.

MDF is the bee's knee's for machining, but be careful of the dust, it's full of chemicals and is extremely hazardous for your health. Loads of cases of illness and long term respiratory problems with people machining it, partly also as the dust is amazingly fine at times and really gets in everywhere.

cheers, Ian

[AxelFoley]

Ok, well I just did my carriage casting. looks like i was just a tad short on the total amount of metal needed.

I'm thinking that instead of redoing this, i might just melt some pennies down or fill in the gaps with some epoxy and just roll with it.

[AxelFoley]

Alrighty, well that only cost me 12 cents. Cheaper than the fuel to try to do another casting.

Let's hope that holds up well.

[AxelFoley]

More work and grinding revealed more defects with the casting. At this point I think it would be less work just to cast again and not make the mistakes i made previously.

[alan_3301]

what is your casting process?
Something is very wrong, either your sand is too wet, or you have way too much dross mixed in with the melt.

Are you using green sand mix? and are you skimming the dross off?
Or maybe you are not packing the mold tight enough?

[AxelFoley]

what is your casting process?
Something is very wrong, either your sand is too wet, or you have way too much dross mixed in with the melt.

Are you using green sand mix? and are you skimming the dross off?
Or maybe you are not packing the mold tight enough?

A little of both, really. My sand was too wet, It had dried out and I overdid the remoistening part. I was hoping it wouldn't affect it that much. I didn't skim prior to pouring (it had been previously melted though), and I also made the sprue a bit larger than necessary.

My greensand is a mixture of bentonite clay, and medium sand. (the finest I could find at Home Depo).t

[alan_3301]

Ok, as long as you know how to fix it, I wasn't trying to insult, just wanted to make sure you knew you should expect much better than that.

If you haven't heard of the lost foam process, check it out.
It is very easy to get good quality castings, the only downside is you have to make another pattern each time you cast.

[AxelFoley]

Ok, as long as you know how to fix it, I wasn't trying to insult, just wanted to make sure you knew you should expect much better than that.

If you haven't heard of the lost foam process, check it out.
It is very easy to get good quality castings, the only downside is you have to make another pattern each time you cast.

No offense taken. I was eager to see things moving along and my hands were already dried/chapped from other work and i wasn't keen on kneading sand endlessly. I have seen the castings of others and knew this was pretty gnarly in comparison. There is a business local to me which has a bunch of foam they are getting rid of, I intend to pick some up. today.

I cleaned it up with a die grinder somewhat in my attempt to salvage it. However, now I realize my time would be better spent just recasting vs polishing a turd.

[metalworkz]

Another thing that helped a lot with molding and casting is Petrobond molding sand. It is an oil base sand and is very fine. It allows me to mold any time without tempering the sand and the main downside is a little bit of the sand is lost with each cast. It can be saved and remixed with the oil, so I just keep it separate from the unburned sand. It will yield very fine details in the cast parts as well. It probably costs a bit more than green sand mix but the convenience made it worth it to me. If the voids do not affect the main working part of the casting you may be able to utilize it even though it cosmetically looks bad. I did not see the core area on the top of the carriage, did you opt to make it without that?

[aarggh]

That result is very similar to a sign I did a while back, not realising the finer details required I just used some "moist" sand I had around, and found the moisture in sand blows back when the aluminium is poured in, and causes all sorts of bubbles and pits. probably lucky it didn't just explode on me when it hit the wet sand really.

How big is your crucible? Will you fit the whole block in or you need to cut it up?

cheers, Ian

[jgro]

If you're interested, I built a Gingery lathe also. You can see it documented here: Jgro's Shop Pages: Gingery Lathe . My inspiration came from Lionel's build here: Building my Gingery style lathe . If you want help/inspiration, come on over to Alloy Avenue: Alloy Avenue . It's filled my some very knowledgeable people when it comes to hobby casting.

jgro

[AxelFoley]

That result is very similar to a sign I did a while back, not realising the finer details required I just used some "moist" sand I had around, and found the moisture in sand blows back when the aluminium is poured in, and causes all sorts of bubbles and pits. probably lucky it didn't just explode on me when it hit the wet sand really.

How big is your crucible? Will you fit the whole block in or you need to cut it up?

cheers, Ian

I made my foundry out of a 16 gallon pail, and used a 5 gallon bucket to form the cavity inside. I have been using steel pots on sale at goodwill. I do have a #6 silicon carbide crucible, however I do not think it would hold enough pure molten aluminum to fill the mold.

Since all this came from a melted down trans am engine, I am thinking of possibly trying to just cut the shape of some of my parts out of my larger melts. I melted it down and poured in some roughly drawn ingot shapes on the ground to get the oil burned off and steel separated.

I have a set of cutoff wheels for my die grinder, and this bit will be in friday: Amazon.com: TEMO SC-5 Aluminum Cut CARBIDE BURR 1/4" SHANK 1/2" HEAD Cylinder Ball Nose: Home Improvement

At this point I know I've strayed waaay far from Gingery's progression/plans. I'm not sure how casting everything in aluminum seemed economical when the book was first written. That is quite a lot of aluminum to find, and fuel to burn. All that running around and you could by steel bar from the hardware store. In the end you still have to buy some CRS from the shop.

[AxelFoley]

Another thing that helped a lot with molding and casting is Petrobond molding sand. It is an oil base sand and is very fine. It allows me to mold any time without tempering the sand and the main downside is a little bit of the sand is lost with each cast. It can be saved and remixed with the oil, so I just keep it separate from the unburned sand. It will yield very fine details in the cast parts as well. It probably costs a bit more than green sand mix but the convenience made it worth it to me. If the voids do not affect the main working part of the casting you may be able to utilize it even though it cosmetically looks bad. I did not see the core area on the top of the carriage, did you opt to make it without that?

Actually I was just lazy and didn't do my false cope when ramming, nor did i introduce enough draft.

There was another particularly large void right outside my wear pad in one corner, but i filled it in with zinc and silver solder for the most part. I was thinking I would try to clean it up and get everything within spec and fill in where it is important with AlumAlloy rods or something else. I have considered using epoxy as well.

This is my pattern as it is right now, I plan on hitting the edges with a rasp. It will be a few days before I can cast again, as we are in our No Burn days here in Phoenix.

[AxelFoley]

Where do you get your petrobond molding sand?

[AxelFoley]

I have some granite tile laying around. I'm wondering it it might be worthwhile to make some of the parts out of it, in order to add more weight/stiffness.
Perhaps I will just use it as the surface to which the entire lathe mounts. Attach it to a sturdy wooden table like in your build, jgro

[AxelFoley]

Wow, my cheapo harbor freight tap made it through two of those crankcase mounts. The Irwin brand tap from home depot didn't make it past one hole.

[metalworkz]

I got my Petrobond from a foundry supply in Oakland, CA because I lived in the east S.F. bay area at the time. You should be able to find a source near you with a search and it has been years since I got mine but I am fairly certain they are still in business. I can't remember the name of the place, but a search should yield suppliers to choose from when you are ready to buy it.

[AxelFoley]

This casting turned out better. still had some bubbles but no large voids. i should have let the mold sit overnight.