Replicating Bruce Satra's M-1 and M-5 engine

[Dragondark]

Hi all. I have a complete casting set for Satra's M-1, and all but the cylinder castings for a M-5. I've searched, asked, bugged, and harried everyone since Bruce passed to get the cylinders all to no avail. I have several pages of notes from emailing back and forth with Bruce before he passed and am in the process of making new molds for the cylinders, and have already made molds for the slave connecting rods in the M-5. I plan on eventually making all new molds for all the cast parts of both engines because I usually screw up machining something on a casting and need spares if I'm going to get one finished. I plan on documenting the molds, waxes, and castings in this thread. I have original Satra castings to compare to, so I have reference parts to compare to.

 

[Dragondark]

Didnt want too many days to go by without an update. Have some fresh con rod waxes to sprue up and a 22lb ingot of A356.2 alloy that was delivered today. Need to get the waxes sprued up and ready for the flask.

 

[stevehuckss396]

I have always had a soft spot for the morton m5. Making wax, I assume investment casting. I will be looking in at your progress.

 

[Richard Carlstedt]

Me Too, always liked the Morton M5
Assume you have Bruce's SIC articles ?
Rich

 

[Dragondark]

Sorry it took a week for me to reply. I'm moving out of my house after 22 years and into my shop up in the hills. The shop has a loft area and it's going to be interesting for the next few months while I figure out where to put everything.

Steve, yes they will be investment cast and properly heat treated. I have made some test casts with junk melt aluminum and they turned out good for the material used. Mostly wanted to make sure that the flow was good and I didn't get any voids.

Richard, I have the SIC articles as well as the Model Engine Builder articles and emails with Bruce. I will be trying traditional wax from molds since I'm familiar with it, and will also be trying some of the specialty 'casting' resins in my sla printer. If I can get a good burn out with the 3d printer parts, it would make certain parts faster to produce.

I'm still moving equipment out of the house garage up to the shop, so it will likely be at least another week before I can attempt a trial burn out with the 3d resins.

 

[Shopgeezer]

I am interested to see how the casting resins work. I have a resin printer and washer/curing unit in my Amazon cart ready to push the “Submit Order” button but am holding off a bit to see if I can find info on actual experience with casting resins.

 

[Richard Carlstedt]

I took a 3 D Printer class at the local Tech college and am blown away with the detail possible on Resin Printers. That was right when Covid hit so have not cast the parts I made yet-
Still have to get the temp controller and burnout oven working . There is a many step burn out procedure and i don't want to mess that up
Rich

 

[Dragondark]

Geezer, I have used some of the castable resins before but they didn't want to print well. I have made a couple changes to my printer and settings and can get a good print out of one of the three resins I purchased. I will keep playing with the setup and try to get the makers wax castable working. They claim it is the closest to working with regular wax. Don't buy into the 'just buy and print' with castable resins, I haven't found one yet that has worked that way. Once I get a good clean burn out and cast I will post my findings.

Rich - I have an old Paragon kiln I use for porcelain/enamel/silver work/burn out/ect. I also have a large pottery kiln I picked up and plan on using for similar stuff. My Paragon is small and from the 1960's, so no controller. I ended up making a controller for it using a pic microchip I programmed and a few other components. Last year I built an upgraded controller using an Arduino and SD card reader to load custom burn out and enameling schedules on. It's nice to be able to set as many temps and holds as I want to get a really good curve for what I am doing. The temp control is good enough I plan on doing heat treat in the Paragon too.

 

[Shopgeezer]

Dragon where did you get the plans for your Arduino based controller? I’ve cobbled together Telescope controllers from plans on Sourceforge. I’d like to make a burnout controller like you describe.

 

[Dragondark]

Geezer - I based mine on this project from the Ardu forum Electric Kiln Controller - Arduino Project Hub

I have made commercial electronics and microcontroller stuff since the early 90's, so I modded the project to fit my needs. Overall, I used probabaly 90% of what is in the article.

 

[Shopgeezer]

I checked that link and found the project. He doesn’t have an actual schematic of the circuits, just a diagram of the layout of components. I suspect that if you followed the diagram closely you could work out the wiring connections, although he has a flag saying no guarantee on accuracy and a caution on 120v. Did you find the info on this page sufficient to actually build the controller?

 

[Dragondark]

Geezer - I based my project on his, but I'm familiar with Arduino programming and electronics. I did a long look over the project on the page before I used it, and found everything pretty much lined up correctly. If you decide to go with the project and have any issues, just PM me through HMEM and I will help you out all I can. You might not need 3 heat zones like he has in his project, or you may decide that you don't like the display layout as the project uses it. I can help with that kind of stuff too.

This weekend is the final moving days from my house to the shop, so I may not reply or post until early next week.

 

[Shopgeezer]

Good luck with the move. We may be facing the same thing and I don’t look forward to moving the shop. Serves me right for accumulating all this junk. Thanks for your offer of help.

 

[Dragondark]

I'm still questioning my sanity on the move. I built a shop with a big 16'x50' loft upstairs with nice views in the middle of nowhere ranch land, and thats what I'm going to live in for a bit. Machines and toys downstairs, basic apartment style upstairs. I've always wanted to try it, but at 50 I may have waited a tad bit long. lol.

I'm going to be smart and hire regular machinery movers to move the vertical mill and the big lathe. I last moved that stuff 20+ years ago when I healed quicker.

 

[propclock]

50 is prime

 

[Shopgeezer]

You young folk have lots of time yet to mess around with setting up the situation that you want. As fossilization sets in the options start to close. Not sure if the rest home would let me sneak in a Taig or not.

 

[dnalot]

Geezer, I have used some of the castable resins before but they didn't want to print well

I agree castable resins are difficult to print. I have been printing with Siraya Tech Cast, one of the affordable casting resins. It requires large supports and is very brittle. But once I found the best settings for my printers and how to best position patterns on the build plate I have been getting good results. It burns out cleanly but requires a bit more time at the highest temperature. Using an investment powder made for resien patterns is a must. Thermal expansion in larger patterns is still a challenge but I am now getting that figured out.

By affordable I am saying "cheaper", nothing affordable about investment casting.

I have found it best to print the patterns and cast soon after to avoid shrinkage of the patterns.

This site reviews castable resins and posts a ranked list that is very handy. Castable Resin Ranked List

Mark T

 

[Dragondark]

I have found it best to print the patterns and cast soon after to avoid shrinkage of the patterns.

Thank you for the heads up on this. I wasn't aware of a shrinkage issue. I have some prints done in iFun 3122 that I was waiting to invest after I figure out the mess I made of my shop moving everything. I even started piling stuff in the bed of my '41 ford pickup project.

I will have to measure them and see what kind of shrink I get. They will still be useable to figure a burn out schedule even if they are undersized. I haven't tried Siraya but have heard from several people that it's good stuff. I also didn't know that there was 'resin' investment. I guess I was just so comfortable with my good ol tried and true investment I never thought to look and see if there was something better suited to the job. Almost makes me want to just stick with the good old wax stuff that I know. Almost.....

I'm waiting on a quote from a local company on the cost to move the mill. Once it's up on the hill I can get back to finishing the cylinder molds.

 

[Shopgeezer]

Mark

Wow some of those resins weigh in at $300/bottle. I notice that washing in ethanol is still recommended. Do you post cure these resins in UV as well? I am thinking of getting the wash cure machine offered by Anycubic when I buy the printer. I see that the Anycubic Mono 4K resin printer has fallen to $280 on Amazon. If I wait a bit longer maybe it will be free!

 

[dnalot]

Do you post cure these resins in UV as well?

Yes, I do as the resins instructions recommend and post cure under uv light for an hour. The prints are sticky until post curing. After post curing the parts are less brittle. For the Siraya Tech cast I place the print in a jar of vegetable glycerin during the post curing as recommended. I use the Anycubic wash and cure machine for curing but not for cleaning as the Siraya Tech cast resin can not be submerged in alcohol for more than a few seconds. I have the anycubic Mono printer and the larger Elegoo Saturn. Both give excellent print quality. The Elegoo is a sturdier unit being made of mostly metal compared to the Anycubic made from mostly plastic.

My printers live in a heated cabinet with a thermostat heat control. Siraya Tech resins like many others need to be used at around 85 degrees F for best results.

These printers are like inkjet printers, they cost about as much as the ink.

Mark T