This channel is going to be about different projects I like to work on. From 3d printing, foundry and patternmaking and maybe some videos about my offgrid house as it's being built.
And maybe some videos about my many other hobbies.
My main emphasis will be on patternmaking. Reason for this is having spent 2 months laying in bed just watching videos on backyard casting, I realized something is missing, patternmaking. And a lot of backyard foundry seems to stop after a few castings. Within a year or two anyway. I'd like to change that. I'm a journeyman patternmaker, served an apprenticeship from 1973 to 1978. I'm 72 now and would like to share what little I know with those that are interested. I do my own castings. I have two small furnaces for melting non ferrous metals.
My name in the shops was Roscoe, we had two Dave's as apprentices, that just didn't work. But for me Roscoe apparently did.
contact me at [email protected]
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It looks like the half cylinder that was supposed to be filled up by a hanging greensand core formed by the cavity on the cope side of the matchplate somehow filled up with metal anyhow. What happened? Or was that just a thin skin of metal that got in between the half round positive and negative?
It was just flashing. About .032 thick, clean up was easy.
@@roscoepatternworks3471 that makes sense, just couldn't see the other side of the castings in the vid. Thanks for the quick reply! 👍
If you don't mind me picking your brain a bit. When you were working as a pattern maker, what was a typical tolerance required of a final casting? And what was a really hard tolerance to hit consistently that you still could manage?
Typically the required tolerance is on the drawing or defined in a cad model. That said, for small parts .015" - .030" can be achieved for castings under 12" inch in size. I've made a few ship patterns where the tolerance was as much as .25". That was for a propeller strut for a 600 foot tanker. It all depends on engineering requirements. Other things come into play as well, such as type of sand used in the mold, type and hardness of any core used. And experience of the foundry with similar castings. Probably not much help because there are a lot of factors to achieve consistent results on a casting. But in all cases you need a dimensionally accurate pattern.
@@roscoepatternworks3471 indeed! And I appreciate a ballpark answer even though I know it varies from job to job. I'm trying to learn foundry practice and pattern making on the side of my career as a machinist, and simple details like that are surprisingly hard to come by. Engineering handbooks list tolerances that are "possible" for various casting methods, but there's nothing about what a typical, reasonable, and achievable spec looks like.
@DerrangedGadgeteer the problem is there is "no rule of thumb" on casting tolerance. It all comes down to the engineering requirement. So an assumption, you're going to be built patterns for you and friends. Home foundry size? If you design the part or trying to duplicate an existing part, you need to determine what is acceptable. If you build the pattern at net size, you'll get a casting that works. If you're referring to surface quality and accuracy you should be able to polish the part and not lose any dimensional integrity. I'm thinking I may need to do a video along this line.
Thanks for the video. I find that knowing why someone does something is more interesting than just seeing how they did something. Sometimes it is for very good reasons. Sometimes it is personal preference or just habit. Often it is choosing the least undesirable option. The best compromise. And then there are some people that don't give much thought to their approach. And you can learn how not to do something.
Very well thought out, explained and nice results👍
When i built my first worm gear and drive, I was surprised how easy it was. I was a 3 year apprentice at the time. Hardest part was the accuracy of the layout. For core sand, co2 or airset cores. Green sand wouldn't work, too soft to handle.
I'm subscribing to learn a thing or two about patterns. I'd really like to see the gear tooth core box in use. My intuition tells me it would be super fiddly and failure prone, but since it worked, that's obviously not the case. And what would be the binder used for sand in a detailed core box like that? Would it just be packed with greensand? Or would it have to be something more stout? Thank you for sharing your experience!
Serendipity. Just this last week I was thinking about casting a walking stick handle from scrap brass (I've never cast anything before), since I imagine a walking stick will come in handy for me in the next ten years. I was trying to think of a style (pistol grip? Zeppelin?), and I really like your mini ice axe. Don't know why I hadn't thought of that before as I used to do a lot of mountaineering and still have a classic ash-shaft Italian ice axe from the 1970s.
Did you cast those flasks?
Yes, split pattern with one core box. Used green sand for the cores.
@@roscoepatternworks3471 That looks like a nice second or third project, making a pair of flasks.
Sub'd ya eh. Stop by for some silver pouring if you like.
👍
I was wondering if the outside core would have had to be so thick in the way they did it. It seemed to me that it could have been much smaller on the od which would have made the required flask smaller and lighter. If the thinner cores would have been too fragile, I would think you could put some steel rods in it to reinforce it.
That is why a discussion with the foundry is important. You need to know their capabilities and what would work best for them.
What I was surprised at with the capstan mold up was that gaggers (nails/gagger?) to give strength to the sand. I think I remember where the cope separated. It seemed to me that the project was bigger than they could effectively handle. The size and the weight involved.
What about "cire perdu" ... "cera persa" ...
Lost wax is actually a time-consuming process for this size and type of part. The actual part is far bigger than my example.
@@roscoepatternworks3471 Way to big to do a lost wax process. The oven alone is a lot bigger than anything I know of. It really would be a nice piece with little finishing and machining though.
When I do split patterns like that, I usually drill holes in one side, then use dowel centers to transfer the holes to the other side of the pattern so it leaves you with blind holes, that way you can turn it without worrying about trying to cut the end grain from the dowels or the holes, and usually put the screws off to the ends in a waste section, that way they get removed when you cut the ends off.
I'm going to do a video soon on how to use these centers. But pin holes are drilled after cope and drag halves are all put together with the centers attached.
A short video but great information.
I Like it! Any chance you'd be able to share the files so others can make their own?
I'll see if I can add th files to either KZread or setup something to email the files directly to those interested 🤔.
@@roscoepatternworks3471thanks!
@@roscoepatternworks3471 Thanks!
Now I *really* want to make one. But first I need a bigger disc sander than the 6"er on the side of my belt sander...😂
Hey! I finally got my 12" sander but it's a different model. I wonder if you could explain a little more about how you decided on the distance from the main pivot to the curved slot, the length of that slot, the distance and angle of the arm where it curves beyond the slot, etc. My untrained instinct is to get out some scissors and cereal box cardboard to put on the sander table and just play around to see what dimensions would let me spin the widest boss at the tallest usable part of the disc. But I'm here to learn - how did a real patternmaker approach this?
You're making me go back a long ways😢. My 12" sander has a table 7" wide. So I decided that was about my biggest circle I would use. From point to casting is about 3.5". From arm rotation center to adjust pin is 2.5". Slot is about 2.25". The arm has about a 13⁰ bend. Center to center on the arm is about 6.875". I say about on everything because I didn't use dimensions when I built it. I just made a layout and said that's about right. Hope this helps.
What is the tool you showed at 5:25 for? You mentioned something about Dymo labels right before you showed it, but I'm not sure what the tool is for. Very interesting stuff!
It's a hand router. I used it to cut a recess in patterns for lettering. Worked well for dymo label tape so only the raised lettering showed on the castings.
@@roscoepatternworks3471 aha! Makes sense, thanks
My entry level 3D printer allowed me to pull off the biggest run of parts I've ever taken on (77 castings), without having the space or budget yet to set up the bandsaw and bigger disc sander that I very much plan on adding to my shop one day. There's nothing I hate more after my day job (programming) than sitting at a computer for even more hours trying to make CAD behave, unless it's F'ing with a 3D printer that *Just. Won't. Stick.* prints to the build plate. But it'a a necessary evil for now. I've had some success working around the limitations of the flimsy plastic patterns by casting aluminum patterns from them before they can get too roughed up. The widget came out great by the way. What's it for?
The widget is just that, a widget. I was using it to show the design time on a computer and print time will take longer than just building a wood pattern.
@@roscoepatternworks3471 wow, a lot of work for a show and tell piece. Thanks for taking the time!
That spinner gadget for the sander looks like a fun project, and a useful tool. I may try to make one myself. 😀👍
Absolutely, yes. kzread.info/dash/bejne/o598zNmEd7Xdhqw.htmlsi=2szk9Erq804WOQCT Here's a link to the build.
Wow, I'm late to the party! Just found your channel and about to do a deep dive. Looking forward to learning a few things and stepping up my patternmaking game!
If you have any questions or comments, feel free to post. Welcome
It looks fantastic! Very crisp design too
I think it's awesome! Good job man!
I like practical 3D printing.
I'm really interested in the worm gear speed reduction project. It is something that I have wanted to tackle. That layout pattern example part interests me. I like the complex arrangement and the suitability for casting. (rather than machining from stock)
Speed reduction is straightforward. For every one revolution of the worm the gear will advance one tooth. So on my case a 60 tooth will make 1 revolution for every 60 revolutions of the work. Hope this helps.
In 1980 I was 20 years old. I lost my job so I was collecting Unemployment Insurance. (Canada) I had to go through an assessment program to guide me into a profession based on my aptitude and the current job market. I remember the main recommendation. Sewing machine mechanic. Seriously. Well I had other plans. I couldn't get into the two year Electronic Technology course I wanted until the next year. E.I. sponsored through a one year Domestic Electronics course, that I took in the meantime. I graduated from the electronic technology course in 1983. We still were in a recession so it took more than a year before I could get a decent job working at Northern Telecom in their production testing department. Laid off a year later. Got a job at a tiny electronic manufacturer doing production, testing, design. After 12 years I was hired as the head 'engineer' at a 25 employee electronic manufacturing company. I did design of new products and support of our legacy industrial products. I retired last year. I feel that my decision to peruse electronics as a career path was a better than as a sewing machine mechanic. Now being retired I can pursue hobbies, including metal casting.
Congratulations on retirement. I always thought I'd have lots of time, for hobbies, when I retired. Sometimes, I think I had more time when I was working.
Hey rosco, it's cae2100 from alloyavenue, but Ive really fallen down the rabbit hole of patternmaking over the last year, and I really appreciate videos like this showing the tools and techniques used. Ive been building up my toolbox for a while now and Im more of a hand plane user if I can help it due to allergies to the sawdust, and I can be much more accurate with the hand planes and work faster than I can with the power tools really. Also, the riving knife and all of that, most of my woodworking tools is more cast iron than anything else and made during the early 1950s or earlier, so none of that stuff was even invented yet I dont think, lol. Thanks for the video and cant wait to see more of the tips and tricks videos like this.
Thanks for the comment.
Nice use of 3D printed "training aids" to demonstrate the molding process
Two perfectly functional parts. I have been debating making an angle block similar to yours. Looks good.
Thank you for showing your process
A nice look at you moulding process, could you show us how you prepare/recycle the sand ?
Got a couple more castings to make, I'll add that to the next video.
great information
A lot of information in your Videos, i am assuming the the 3D printed parts are painted on the sand contacting surfaces, what paint do you use ? what computer modeling software are you using ?
Thank you. The models are painted with rust-oleum auto filler primer. Software is rhino 3d, solidworks and a few others i have access to. Fortunately I spent too much on software when I was younger. It's all 10 to 20 years old now, but it works.
Great information about the fingers. So simple but so useful.
Thank you , and a bonus to see the pattern
At 7:39 ,Can you show us more of the "spinner" you made, is this your own idea or a version of a commercially made tool ?
I'll work on getting a video out. It's not my idea, but this one is my design. The shop i served in had one. Custom made. Depends on sanders rotation and size. The shop had a 24" reversing sander. Mine is a 12" double ender.
Thank you for showing the layout process
The old tradesmen at work referred to this as the "sticky pin method"
Cheers Good explanation and demonstration, thanks for using Metric units
When I took cad classes, the instructor told me to look at all dimensions as units of measure. There is no conversion. I do the same when building patterns. For any pattern or machine work I use the appropriate rule. This saves a lot on conversion errors.
Do you know if ductile iron shrinks the same as grey iron or no?
Yes, shink is 1/10" to 1/12" per foot. If you know your properties of the ductile iron and need exact measurements. Cast a test bar 1"×1"×12" using a common rule. Then measure the exact amount of shrink. The foundry we dealt with used 1/10" shrink.
I love you models. 👍 That small flask makes me want to make a small real one, a bit bigger than that one, but still small. Just for quicky small items. I'm still setting thing up in my workshop. Trying to make it so that doing anything isn't such a chore. I really want to do some casting soon. Hopefully next week. Thanks for the video.
Seeing the completed casting (with gating) I now understand the core you made for the casting. I was not able to visualize it earlier.
Thank you , very kind of you and they look great . I will finish them up this winter when the wood working room is set up again. Classic hot water tank pop and upset the balance of the basement while it dried. I will send a Pic when they are done . Thanks again
Hoped you liked them. Needed to do something for your help and encouragement.
I talked to you before about casting a tractor head. The top of the head has a cavity and it all has draft so I poured epoxy into it to make a male cast of it. Now I am going to saw it at each cylinder and stretch it out to allow for shrinkage. Then repair all the stretched out saw cuts and Then I want to pour a cast of this to use as a pattern. What do they usually use for material to pour a plastic pattern and where could I buy it? I seen another guy using it and I believe it was polyurathane but not sure.
James look up Freeman supply. They have a fast cast polyurethane. As far as a mold to cast the polyurethane in, we used ultracal plaster. After you get the master out, while the plaster is still warm. We'd brush really thinned shellac until the plaster started to look glossy. This gave the plaster a hard shell that can be sanded and any imperfections taken care of.
@@roscoepatternworks3471 I sprayed silicon spray on the cavity inside the top of the head and then filled with epoxy but I couldn't get it out. What do you use for mold release like when you made the widget core box
@@TheJohndeere466 I use 2 one is called honey wax mold release. Made by specialty products company. For a cheap release for bonds or body filler, I use Johnson paste wax for wood floors. I used the Johnsons for my corebox. Forgot to add, after you applied the paste wax. If you're really concerned about the part sticking, wipe a thin layer of grease on the part. And make sure the part is very smooth an no back draft areas. Good luck and post pictures.
@@roscoepatternworks3471 Thanks for the reply I sprayed the head with silicon spray and then I brushed on a coat of lucas oil aditive that was thinned down with mineral spirits. It definitely did not work. I had to break it all up to get it out. I am thinking about just making a wooden pattern and just cnc machining the shape in the top On the outside of the head there are some recesses where the injectors go back in. I coated this with car paste wax and then sprayed it with silicon spray. I did get it off but I had to warm up the head with a torch to get it to release. Now this cast was made of fiberglass resin with fiberglass cloth and some smaller areas I mixed sawdust with the resin. The big cavitys I put blocks of wood in. I attached a flat board to the back to make it stiff. Basically I need to make a core the shape of this cast to form the one side of the head. So I need to smooth this up a little and then cast a core box around this. I will try your mold release and see if it works better. I also saw a guy melting bees wax and using that for a release.
While I like the potential in 3D printing I feel that using the printed part, without filling the layer lines, would cause problems. Or less than desirable results. And if the part were so simple that layer lines were not an issue for pattern removal the the part probably could have easily been made out of wood. Thanks for showing your process and the explanation.
Looks good.👍
Thanks for the video. I just found your channel---Windy Hill sent me here. It's so great to have a few grown-ups on the internet teaching out of experience.
That CO2 device is great. I had wanted to try making cores like this but wasn't sure how I would handle the CO2. That looks like a good option.
For small cores, for me it's perfect. I do have a co2 tank from my paintball days. If needed I can covert that to do the same thing.
I like the size of that flask.
I'm glad you are going to continue. I was disappointed then your videos disappeared. Videos can take a lot of work to produce. I one in the works but have decided to put all the project stuff off until winter sets in. I have too much that I need to do before winter.
Got the same issue here, lots of work to do.