Bottle engine

[dnalot]

As I near the end of my first motor build I have begone to make parts for my second. I built myself a furnace two years ago and started making simple parts. This time I wanted to do something a little more difficult so I decided on building a Bottle Engine. I have made up my design and have rendered the parts to be cast in 3-d. The bottle is first and it is my first attempt at a two piece pattern with only one half pattern to work with. And its my first go at making a hollow with a sand core. I was very happy with the results, the two sides lined up perfectly and I have no voids or sand pits. The walls are .25 inches thick and the top and bottom collars are about .5 inches thick. The area to be cut out is .06 or less inches. I plan to sand it smooth and polish it.

What works well for gluing cores together?

Mark T

 

[stevehuckss396]

Holy smokes that is awesome!

 

[wildun]

There were many occasions when I had to make some patterns and coreboxes for iron castings and found it really very interesting, so I can say that this is a fine achievement for you - also being the first time!
Wooden patterns in themselves look like works of art when they are finished and I guess you'll have them all on your mantelpiece when you're finished with them - I can't see you throwing them away.
Keep up the good work.

 

[idahoan]

Wow that's nice! I really admire folks who do great pattern work and them pour their own castings.

I have been working on a Pacific Vapor engine for the last year or so that has a nice bottle frame; IMHO a very nice shape for an engine steam or gas.

Dave

 

[metalmad]

WOW, now thats a keeper!
Pete

 

[Septic]

Respect to anyone who casts their own larger parts.... Having seen enough failed castings to last me out, the last thing I'd want to do is try something that even the pros don't always get right...

 

[moya034]

Nice work!

The best part about casting is when you make a mistake you can melt down the part and repour it with little loss of metal.

 

[Wizard69]

Most impressive!


The quality of the woodworking is excellent, it must be stressful just pounding sand onto it. I have to ask was the pattern done on a CNC machine?

 

[dnalot]

Yes, the patterns were cut with a cnc router using a tapered bit round nose bit.

I am still trying to get a perfect casting. I am having a little issue with gases venting from the core creating a small bubble on the inside of the top flange. Today I will make two more tries at making it right.

That's two sided sticky tape holding the part to the table. The kind they use to mount golf club grips.

 

[100model]

I use roof/gutter sealant to glue my cores together.

How big is the casting?

 

[dnalot]

Thanks for the tip on the gutter sealant, I will give that a try. I have tried a caulk for gluing in the rope seal on wood stoves and it is working OK.

The bottle will finish at 8 inches tall by 4 inches in diameter. There is 40 oz. of aluminum in the part before machining.

 

[LSEW]

dnalot, very nice work. I really like the shape. Is it for a steam or gas engine? This is the kind of work I will be doing a lot of in the near future for a project I'm just beginning. Is that maple wood you are using?

About the core gasses, are you venting the mold? When I mold I use pokers made from 1/16 & 1/8 drill rod sharpened like an ice pick. Have them on file handles.
For a casting that size I'd vent 1/8 holes clear through the cope, 1 on each end in the core print, and at least 3 along center where the core touches the cope.

maury

 

[dnalot]

The bottle will be for a steam engine. bore 1.75" stroke 2.5". I am just completing a two cylinder marine engine of the same bore and stroke and I want to use the same tools and jigs that I have for it on the new project.

The wood is clear pine and I used Elmer's latex wood filler and coated it all with wipe on pollycoat. The polycoat makes the surface hard and durable and with very limited production the pine works great. My cnc can cut through it quickly and its easy to sand to final finish. "do not use much of the polycoat as it can warp the pattern when it cures"

I have been trying to vent out the side of the bottle through the area that will be removed "the key hole". I need to add vents at the ends, especially the small end as that is where I am getting a bubble. I am reworking the patterns gate system to allow better venting of the ends and I am making a new form for making the core one piece instead of the 2 piece design I have now.

This is a learning experience that I hope will make it possible for me to make more complicated shapes.

Right now it takes me 1 hour and 15 minuets to make the core, ram the drag, start the furnace from a cold start, ram the cope, assemble the forms and pour.

Mark T

 

[LSEW]

dnalot, you are off to an excellent start. I was wondering, since it's a steam engine, have you thought of casting the cross slide guides into the bottle?
ALso, not sure how you planned to do the mains?

I just got my CNC mill up and running recently, made a few brackets and some cams for my Holt kits I'm building. Just trying to get up the learning curve a bit. I think I'll try a 3D part using wood just for an experiment, see how it works.

maury

 

[dnalot]

I plan on casting a bronze bushing with a wide flange on the top end to use as the cross slide bearing. It will drop down through the hole at the top of the bottle and be secured by the head bolts.

For the shaft support there are shelves cast into the lower half of the bottle that will be milled flat and will support the bearing blocks.

I do about 90 percent of my cnc work in 2.5D. Its fast and most parts can be made that way. But some parts like the bottle are only possible with 3D. Its actually easier to program the G-code for 3D parts but it takes a long time to cut the part.

For experimenting with 3D use the foam you can buy cheaply at most building center in the insulation department. Cutting foam you can skip the roughing process and do finish cuts at high speed.

Mark T

 

[dnalot]

Tip of the hat to LSEW

Using your poker idea and making my core one piece I was able to make a perfect casting this morning. I used a long drill and penetrated the core to its center where there is a 1/4" vent channel that runs the length of the core. Gas escaped at a good clip for 5 minuets. Tomorrow I will make two more. We have 4 months of good weather Here in the Pacific Northwest so I plan to do my castings now and put them away till fall.

I am adding another layer of insulation to my furnace and making a blower attachment so I can cast the 6" flywheel in cast iron.

Mark T

 

[gus]

Have done gravity casting aluminium in the plant with DIY C.I. Mold and Gas fired Crucible way back in the 90s. Now living in a walk-up flat and casting aluminium is but a dream.I am limited
to casting my own fishing sinkers.:rant:

Your aluminium casting is very good.th_wav