Pattern Making for the Foundry - The Basics you NEED to Know!

Some of the basics you need to know if you are going to make a pattern to have cast in metal at a foundry along with examples of patterns that I have in my collection made both by myself as well as professional pattern makers. Patterns need:
1 - Draft
2 - No sharp Corners - radiuses and fillets
3 - Scaled up in size to account for Shrink
4 - Be extremely smooth
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[@horatiohornblower868]

I remember from my youth that mould makers were among the best paid workers in the engineering works near by. One of them had his own work shop isolated from the main hall. This was long before 3D-printing and CNC. Professors from the university discussed with him the plans they had designed. More than once the mould maker got the last word. One day my mother asked him to make a table for us. The result was a genuine work of art which became a heirloom.

[@MrArtVendelay]

When I took pattermanking in HS in 1968 we used wax with a heated ball tool to press the fillet into the pattern.

[@davidstreeter9426]

My former employment was at the Dodge foundry where they had thousands of patterns along with core boxes, molding machines and core machines. We used oil sand for cores which required baking and chemically bonded sand which set up by chemical reaction along with so2 catalyzed core sand. Our melting capacity for iron was 150 or so tons per day. Keeping track of patterns and core boxes involved several individuals. Everything which you said was spot on.

[@aiseatohi3375]

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[@aiseatohi3375]

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[@mrzon9344]

Always good to speak to the foundry or machine shop who you intend to use as different machine capabilities can change the way the part is/can be made dramatically and sometimes just adding a hole to help holding the piece or small flats on a round flange can make the world of difference to the machine shop ... and in turn cut your costs.

[@jamesstanlake4064]

Excellent information. WHILE IN HIGH SCHOOL OUR SHOP CLASS MADE ALUMINUM SAND CASTINGS AS A WAY TO RAISE MONEY FOR GENERAL SHOP MATERIALS AND REPAIRS. I got hired by the local foundry to work part time during the school year and ful time in the summer and enjoyed the foundry process a great deal.

[@matthewmarkle1839]

When I graduated high school in 1993 i worked as a Pattern Making Apprentice for at Dussault Foundry in Lockport NY for a year and a half until they closed. I learned a ton about wood working that I still use today. I stil have a couple of shrink rules in my toolbox, havent had a use for them in near 30 years.

[@raselforhad]

I've been doing this for ten years, working in a government literary institution, currently I don't have a job, due to the closure of the government institute, now I'm unemployed, if my job is benefited somewhere, of course I want to do it,

[@normmcrae1140]

I bet Clark is REALLY going to appreciate you making this!

[@Oh-ou4lp]

I feel like I just took a useful course, its School how it use to be were, you know you LEARN something Thank you very much.

[@karlgoebeler1500]

Newbie in the house The hidden info I need Thanks for the presentation

[@mdouglaswray]

GOOD STUFF! The old skills take TIME and DISCIPLINE. Thanks for helping keep them alive!

[@nicksayajirao1730]

Great run through the basics. Took me back. My first job out of University was as a design engineer for automotive brake rotors and drums. Back then we cast them in house, so i had to prepare designs for both finished parts and rough castings. The foundry mainly did high volume but simple castings for flywheels, bearing caps, rotors, drums and similar and used a modern vertical flaskless moulding line to do it. But they also had a traditional green sand line and used it to make all sorts of special castings - everything from repairing older machine tools to casting brake blocks for the company’s switching locomotives. Even in the mid eighties pattern making was a dying art. As you say, casting cylinder blocks was a different order of complexity, great video thoroughly enjoyed being transported back 40 years.

[@anusficker-hw2xe]

i am a foundry pattern maker apprentice in germany, and i can say, it's the best job ever. i really want to gain the opportunity to become a master of that craft!

[@velumaniengg1102]

Hi Anusficker, I am too foundry pattern maker

[@alstonofalltrades3142]

If I ever get to make a pattern I'll comeback and refresh on this video. That last one was a patern and a half!

[@tomthumb3085]

I’ve watched this video several times since it was uploaded a couple of years ago and still find the content really interesting. You explain everything so well that, apart from being so informative, it’s really fascinating to watch. I wish there were more people making such detailed and interesting video content. Thanks for a great video.

[@maggs131]

I remember a few years ago I saw a big wooden gear at an antique shop. It was about 20" in diameter and about 8" thick and I was perplexed at what it could possibly be used for and a quick Google search told me it was a foundry pattern. I immediately loved the age and craftsmanship in the wood work and when I went back to get it, someone else had already got it. I was so disappointed 😥

[@garyrhodes7089]

olfoundryman has a very good channel on casting and patterns

[@Dudleymiddleton]

14:30 'lil helper!

[@ROBRENZ]

Very good stuff Keith! ATB, Robin

[@artszabo1015]

I worked at Union Malleable (foundry) in Ashland, Ohio in 1971-72. Everything you said was spot on target. Excellent job of cramming so much knowledge in such a short video and still easily grasped. Wonderful job Keith!! Art

[@farmalltomf]

Keith, well presented and spot on content. Kudos on the work you do to keep the knowledge flowing.

[@lonnywilcox445]

Keith, I think everyone would be in agreement that you need to take that amazing pattern up to Clark and have him pour it so we can see what it looks like finished. And clearly the missing core box is the perfect place to put the "Vintage Machinery" logo so it can hang proudly on the wall.

[@dennisleadbetter7721]

Hi Keith, Great video on a very skilled process. Thanks for that. I've been watching a series on the rebuilding of a 120 year old gaff rigged sailing boat, the Tally Ho and they have been making the patterns and casting the floors and other braces in bronze. They are quite large casings and odd shapes. That was a very interesting process, and Leo, the shipwright, did considerable explanations on the process, including shrinkage, draft, radiused corners, the pour hole locations, and the relief openings so you get a full casting, and also showed the casting boxes being filled and rammed, split apart and then the actual pour.

[@d.mushroomhunter3528]

Hey Keith great video I actually watched it twice.!! I worked for 5 years on the pouring line at Cadillac casting in northwest Michigan..(if you look on their website I was one of the spacemen in the silver suit with the green mask) we made and used lots of patterns, mostly to make pig molds.. (molds to put extra iron not used in production) but every year we made horseshoes for the summertime. And huge 20 in iron skillets for deer camp season (in our downtime of course) we made patterns for both and used resin sand to cast them and you had to take them home and clean them up yourself.. we also used a spray on very slick graphite type pattern release. And by the way just because I thought it was funny the second time I watched the video I counted every time you said pattern... 150 times in 50 minutes 😜 thanks for spreading the knowledge I love your videos I really wish I had some machinery to play on!

[@ericnightmare2695]

I work in a steel foundry doing many jobs. Now I'm back in the pattern shop. Lol

[@anricedeybat]

Keith, I just want to say well done on this video. I used to work as an assistant pattern maker in an iron foundry and you gave a lot of good information here that should be very useful to anybody needing to make a pattern. I especially thought your explanation of cores was very good. I have tried to explain cores and core prints to people and sometimes the concept of how they work just confuses people. "What do you mean you have to add a piece to make a hole? That doesn't make any sense!" Well, yeah it does. Thanks again. DCN

[@fredwild190]

As Foghorn Leghorn said, "Two half-nothins is a whole nothin."

[@garthbutton699]

I appreciate you taking the time to explain the pattern making process, last time I did this was in my high school shop class circa 1963 where we cast aluminum projects.Thanks for all the time you invest in making this videos😀😀😀

[@larrymills8527]

we did the cast name plates for the top of mail boxs in shop class 65

[@gilbertreeves24]

Awesome video as usual! I relate to this one especially due to my father being a pattern maker on nuclear submarine tenders in the navy. I am blessed to have all his specialized tools and his Gerstner and sons machinist box. I learned woodworking from him and it has served me well over the years, mostly the meticulous care and precision he demanded in every thing we did.

[@andyZ3500s]

This was a outstanding video Keith. You covered the basics very clearly.

[@dhaynes4515]

Great info video, good to see Ginger doing well.

[@StreuB1]

Amazing Video, Keith!! Few things I have learned casting as well as a design engineer. For fillets, epoxy over clay works well. Form in the fillets with modelers clay and then brush several coats of 2-part epoxy, letting the coats dry between applications, makes for a nice way to make fillets. Especially fillets that are of variable radius. I like to put some filler material in my epoxy to help shore it up. I use fumed silica (West Systems 404) to add rigidity and sand-ability to the epoxy. Remember, the clay below the epoxy IS soft so your epoxy is creating a shell. Another thing that I use when the surface finish is not great on the pattern OR the 3D print material leaves fuzz. Before I even sand the pattern, I spray several coats of high build automotive primer. This has LOADS of filler in it and will fill in the surface irregularities and allow you to sand the filler instead of the base material that might be a pain to sand in the first place. Another thing, draft is a function of your parts L/D ratio. Tall and skinny parts will require higher draft angle so an area where 1-2° works, might require 4° to not break the sand out. It depends a lot on adjacent geometry as well and the sand type; how much it "hangs onto" the sand. Last but not least, WORK WITH YOUR CASTING HOUSE!!! Send them a picture of what you want done and talk about it. Sketch up a pattern map to show the shop how you envisioned the pattern layup to go. Send them this BEFORE hand so they can give you feedback on what works for them and their processes. Not all casting houses are the same so what works for one, might not be good for another. Its a give and take relationship so work with them, that is about the most critical thing I could tell someone.

[@jeffwilliams4964]

Oh man. I could have saved at least 1000 hours with just the clay/epoxy aspect.

[@elsdp-4560]

THANK YOU...for sharing. Very much enjoyed.

[@bobvines00]

Keith, this was a very clear & educational into to pattern-making! Thank you for making it. I'm sure this will reduce the number of bad/flawed patterns sent to the different Foundries around the world.

[@bobbytriplett6443]

Thank For All You Do 5 Star Bobby

[@bradthayer6782]

Great video. I love Windy Hills, but your video was frankly far clearer.

[@stevespra1]

Very interesting, instructional and well done video Keith. Back in my much younger days, I worked in a fiberglass mold shop. The molds are opposites of patterns but the same principles apply.

[@a.bakker64]

Never heard about the shrink rulers. Thanks.

[@mikehubert4539]

Great video Keith. I've been building and running cupolas for for the general public for a couple decades and have my basic pattern making speech memorized. If you ever do a part 2 could you touch on sprues, runners, gates and vents. Also Cold Draws. People seem to struggle on those concepts. I will argue that foam makes a fine pattern for one off parts. Lost foam gives you some options that you don't have with a traditional pattern.

[@BonnieKay13]

I worked in biggest shop in Minneapolis, mostly Navy castings, this in the 60's when there were still big foundries, big pattern shops. It all went o China ~~~

[@Music_Musica-Sounds_Sonidos]

Awesome. Thank You. Thank You so much... Mind expanded 💡 I feel empowered, and am grateful for your knowledge, sharing. BEST to You. Thank You

[@gardenman3]

Thanks for the great video. I learned a lot.

[@redluck01]

Nice, Keith. I needed this. i am melting aluminum into sand models. pattern making is an art in itself.

[@millomweb]

Back around the late 1970s in school, before removing a pattern from the sand, usually some pointy tool was poked into a hole in the pattern and the tool tapped on the sides to move the pattern a little bit. OK, so it made the casting a little bigger than the pattern but it helped tapping the sand away from the sides of the patern so it'd come out cleanly.

[@silasmarner7586]

@@millomweb myfordboy on youtube uses that technique or a variation thereof. His stuff is quite nice.

[@TroyeWelch]

@@millomweb “some pointy tool”... it’s called a rapping bar.

[@millomweb]

@@TroyeWelch Now I thought I was doing really well remembering back to the late 70s 'cope' & 'drag'. Now you mention it, a rapping bar (never used one) sounds about right and that has been precisely confirmed. I'd suspect to today's youngsters, it'd have a completely different meaning ;)

[@fredohnemus7685]

I'm not a woodworker or pattern maker, but I have been in a pattern shop many times. It is an amazing conglomeration of size and shaped patterns. I have seen them being made and assembled, many with multiple cores that are very complex. To me, if there is a little piece of heaven on earth, it is the smell of a pattern shop. Truly wonderful.

[@brucecapron9344]

Ideal woods for patterns have a thermo coefficient near 1. Pattern mahogany and bass wood have best characteristic.

[@joypaul1976]

Great discussion

[@lecnac855]

Great tech talk as usual.well done.

[@raselforhad]

I've been doing this for ten years, working in a government literary institution, currently I don't have a job, due to the closure of the government institute, now I'm unemployed, if my job is benefited somewhere, of course I want to do it,

[@oldschool1993]

CLARK- " keith since you did that video over here, I'm getting 10 patterns a day and none of them are any good- then I spend an hour on each one explaining why"

[@bulletproofpepper2]

Very useful! Thanks for sharing.

[@eddalexander9005]

Back in the day when we were buying lots of patterns for ductile iron castings, our rough rule of thumb was that, if we were gonna make less than 100 parts, use a wood pattern. Any more than that, go to aluminum. The aluminum patterns were a quantum leap in cost over the wood patterns.

[@chemcody5119]

Went over to Windy Hill like you suggested. Pretty interesting. I subscribed. Thanks Keith.

[@thomasstone1363]

superb video, thank you!

[@AdrianHiggins83]

Interesting video Keith thanks.

[@CraigLYoung]

Thanks for sharing!

[@mrnate19]

Hardly anyone wants to pay for quality patterns anymore in the UK, which is a shame. Most of the work that gets brought into us to mould are architectural pieces that have been sitting in all weather conditions for years. Using “CO2 sand” gets over a multitude of problems when dealing with terrible patterns. Great video.

[@SuperAWaC]

The point of "Check with the foundry to see if your pattern is ok" also should be repeated for people sending blueprints to machinists.

[@johnmcdonnell6109]

Well done! Have seen Clark, via KZbin, struggle with some of the patterns. Most appear to be a lack of draft but I will also bet that they didn’t factor in the shrinkage.

[@WayneT51]

As usual very interesting Keith. I've been watching Leo casting the floors etc for Tally Ho, it's so interesting.

[@TomChame]

Very interesting, thanks.

[@StreuB1]

One other thing. Small tidbit of info that reaffirms your statement at the end; the idea that the old ways and methods are still relevant. Many parts of the Merlin and Raptor rocket engines produced by SpaceX use traditional casting as its the only viable way to make them; not even 3D printing will yield a suitable product. The inert atmosphere vacuum casting process as well as inert atmosphere direct pour method is used to produce liquid oxygen, RP1 and liquid methane distribution manifolds, high pressure ducts, powerhead main body, injector body, turbopump turbine housings, and many other parts out of Inconel.

[@whathasxgottodowithit3919.]

Keith, very interesting as always, Leo at the Sampson Boat Co has been casting the Bronze Knees & Floors on recent episodes, these showed the complex process involved from making patterns through to casting and finishing, including failures too.

[@spentacle]

@@jnimitzch4738 No. I think that was someone else (Not Acorn to Arabella either) but I can't find the reference just now. edited to avoid offense :)

[@markthompson4885]

@@spentacle No not Acorn to Arabella ether. the guy that did the fake injury is building a junk steel boat in Tulsa Okla.

[@spentacle]

@@markthompson4885 Ooops. Should have looked back on the Abom videos. No offence intended :)

[@LightAndSportyGuy]

@@jnimitzch4738 I believe that you are referring to Doug at S.V. Seeker - he has faked a couple accidents - I have unsubscribed as a result. Leo at Sampson Boat (restoring the Tally Ho) does not pull that sort of nonsense that I am aware of.

[@notnowhoney1663]

Sampson Boat Co. is the youtube channel for molding bronze parts.

[@thomasnewton9818]

Thank you.

[@bigun447]

Automotive-style engine castings have what are commonly called freeze plugs on the outside. Those are not for freezing, they are where they use their processes to remove the interior core parts of the molds.

[@ksingleton101]

Thank You, I love learning something new every day. I had to replace a plug in a 1968 Ford Galaxie 500 I had in 1977.

[@rennkafer13]

Which is why I've heard older guys than me (at 59) call them "core plugs".

[@bigun447]

@@rennkafer13 Yes, we older guys knew the truth. In fact, the myth that those plugs would pop out and save a block from freezing was not the actual fact as the block would usually be cracked by then. A pushed out cup or welsh plug was just an indicator that you had big $$$ trouble.

[@mattymcsplatty5440]

great videos. great channel. oh, did anyone else see the sneaky kitten? haha

[@jamesmcalarney2991]

Thanks for videos girl

[@benjaminalliger7416]

As a Pattern maker/ hobby machinist I wars lucking foreword to this Video Mister Rucker. Funny to see the American color scheme, the German is almost the other way around, yellow would be Bras/Bronze and the Core- marks are black. The old Core box looks to miss a "loos piece", out of wood with that prism shape and tow (like ears) on either side that make the transition from the other half, a corner radius and the wall thickness. Over all great work Kieth, keep up the spirit.

[@jayslong]

The core box with the area that is painted yellow with black stripes is what told the core maker that a loose piece was to be placed there. This loose piece was used because it had an area that that would not let the core be removed from the box if it were not loose. These cores were pasted together afterwards to make the entire core. The black stripping told the coremaker this area was a seat for a loose piece that belonged there. For Ferrous castings ( iron, steel etc.)the pattern would be painted black to indicate where metal is versus yellow for core prints and red areas indicating machined surfaces. For non-ferrous castings ( aluminum, brass, etc. ) metal was represented by yellow with black core prints and red stripping for loose pieces seats and machined surfaces again in red. These colors were industry standards. J.

[@geniibuntu]

Photocopying a regular 12" rule with the photocopier enlargement at the percentage you need for a particular material works, I've done this then cut out the oversized one with scissors and put clear packing tape on both sides to keep it from getting soggy or greasy long enough to finish using it for a specific job ( in this case aluminum).

[@millomweb]

Re draught/draft on patterns - not entirely necessary as prior to removal from the sand, the pattern can be tapped sideways to loosen it before extracting it. It results in the casting being slightly larger but if that's an issue, it's much easier to remove excess than add bits on ;)

[@CathyInBlue]

Keith: Have you investigated acetone vapour/fume finishing for 3D printed parts? It's useful for making 3D printed objects assume a silky smooth surface finish by using heated acetone or similar solvent in the gaseous phase in a chamber with the part for a set period of time. It's kinda like a solder reflow process, softening the outer skin of the plastic and causing it to self-level. Works really well.

[@billmorris2613]

Good morning from St John Parish, Louisiana 19 Oct 20.

[@frankkuchenbecker]

Keith, I don't believe that you miss a part of that big three piece pattern. The part with the black stripes on the inner yellow circle is for removing the sand from the core. This would end up in a core with a hole and finally a reinforcement or fixture for the whole thing from side to side in the final cast piece. Just a thought...

[@TheJohndeere466]

Ive found that fiberglass resin works well covering wood to make it nonporous and smooth so it comes out of the mold easier. It also makes a nice small radius in a corner if you need the radius small.

[@raselforhad]

I've been doing this for ten years, working in a government literary institution, currently I don't have a job, due to the closure of the government institute, now I'm unemployed, if my job is benefited somewhere, of course I want to do it,

[@jamesoates1334]

Keith, could you please do a video covering the why and the how to put chills into a mould .

[@royreynolds108]

I bet that would be a subject for Clarke to do.

[@diamondpressco2673]

I have to say I was thinking about getting a foundry because of windy hill

[@royreynolds108]

If you do get or build a foundry, it will help you to be able to know the temperature of the metal to pour. Pouring too "cold" will tend to cause holes in the castings and runners. There is a person who does aluminum casting for live steam modeling and would entertain selling the foundry for about $100K.

[@jayslong]

An addendum to the previous post should also state that the loose piece seats for non-ferrous casting patterns are painted aluminum with red stripping. J.

[@josephkrug8579]

Would you put finish on the wood patterns or leave it raw? Fun video :)

[@wayneriedlinger]

Just watched this video again. the last pattern you showed which you said you have no idea what its for,. well it looks like the jaw clutch from a draw works (big winch basically) on a drilling rig to connect and disconnect the water brake called a Hydromatec later ones were called an Elmago and were electric. they were used to run pipe in the hole and give resistance so the big band brake on the draw works didn't get hot.

[@ksingleton101]

When I was young 10 or maybe 12 I was lucky enough to go on a class field trip to Body By Fisher (Fisher Body) and watched Car Bodies being made. Not poured/cast as Mr. Rucker is explaining but stamped. I can only remember some of it now (50 years ago) I remember the steal sheets being stamped and I think they made the engine but again it was a long time ago. I was amazed at how noisy and how every piece was moved from one station to the next and how they all fit as it was moved along. There was no Robotics at that time, every station was manned by 1 sometimes 2-3 men. I don't remember ever seeing how the blanks were made but I can imagine much like Mr. Rucker is explaining. Thank You Sir for sharing your knowledge of how things work and even those that worked years ago. It's sad that today it's a robot that does most of the work and it only takes a few (maybe more than a few) men to make an automobile but nothing like it used to be. What an awesome country we live in! I pray we don't erase everything we have done and achieved.

[@royreynolds108]

If you went to the Buick plant in Flint, MI they did cast and machine their own engines until about 1981 or 82 when the engine casting was sent to Saginaw Grey Iron in Saginaw, MI. At that time the Fisher Body Plant was about 1.5 miles south of the Buick Plant and the car bodies were trucked from the body plant to the assembly plant in groups of 6 on a trailer so the bodies were inserted into the line on a frame that carried the body. The carrier frames were trucked back to the body plant for reuse.

[@ksingleton101]

@@royreynolds108 The Body by Fisher plant I went to was in Hamilton/Fairfield, Ohio. I have read there were 3 or 4 plants, Body by Fisher. I may be wrong about the number of plants but I have heard of the one in Michigan. I was really sad to see them close the one in Hamilton down I had a lot of friends who's fathers worked there. I think a few got transferred to somewhere in Kentucky? The building still stands but has been refurbished into a warehouse. I heard China purchased the tooling and presses. Most likely for scrap. Give China a chance and they will buy used toilet paper if they can get it cheap and sell it back to us. Maybe some day the USA will wean itself from China?

[@michaelrice500]

36:00 That looks like a hydraulic cylinder end cap with a trunion. I recall some older D7s or D8s may have something like that for lift cylinders?

[@dansvec5411]

A really good foundry channel is oldfoundryman on KZbin. I believe he's from Australia, and his information is solid

[@johnopalko5223]

14:30 Kitten alert!!

[@WilliamTMusil]

Hiya Keith

[@jamessheets9205]

So I have a question about shrinkage calculations on a complex part like an engine block. Say for example you are casting a block with a bore spacing (center of one cylinder to the next cylinder) of 10.000 inches. Would you keep your crank case, cylinder, and water jacket cores at 10.000 inches or spread them out at the precentage of shrink? Or would the shrinkage factor only apply to your wall thicknesses?

[@dlfabrications]

Great video!!! need info can you help? The lead screw on my lathe is 5 TPI ( is this a common lead screw). SO with the lock nut engaged at any position, I can only make 5,10, 15 TPI threads? My lathe doesn't have a threading dial. These values ring metric to me. Is there any method to make threads (engage lock nut) without threading dial like with a dial indicator or marked tape? I want to make internal threads in a blind hole without crashing the lathe in the hole. If i disengage the the lock nut and pull out, how do I find the position to lock the nut again?

[@larryschweitzer4904]

Excellent presentation. I do aluminum casting as a hobby. The one important thing you didn't cover was shrinkage of thick sections. It is a lot and will distort the end result. A flat area will endup concave where the metal is thick behind the flat. Thin sections will cool/solidify before the thick ones introducing all sorts of bad results. Olfoundryman has some excellent videos of making castings on a small scale. Cores introduce an entirely different problem. My patterns are always wood & Bondo, cores are fine sand and sodium silicate, set with CO2. Lost wax or foam is another option. Fun/frustrating hobby. But along with machining allows many different things to be made. Recommended.

[@walter2990]

30:32 Looks like a stator core for a large engine to make electrical energy.

[@henryD9363]

Very interesting and informative as always. In the case of the crushed core example of your chart, would that cause the cast iron to break when it tried to shrink around the sand and compress it. Sort of the opposite of putting water in a cast iron bottle and freezing it. The iron bottle shatters. I guess I'm asking when you have to have that hollow cast can you put something in the sand that allows it to compress? You can see I have no experience with this but I enjoy finding out

[@siggyincr7447]

As far as I understand it, you generally want to use a coarse grained sand for the core that allows for a fairly porous structure to the core. That way it's strong enough to handle the casting process but will yield and compact when the casting cools.

[@TroyeWelch]

Organic material in the sand is usually used. Sugar in sodium silicate and sawdust in others. Amounts vary according to the class of work. The organics hold the shape of the core sand when cool, but burn upon application of hot metal and allow the sand in the core to compress and crush without tearing the metal as it contracts. Coarse grained sand is used more for permeability reasons, and in some cases (eg, iron) to aid in resisting fusing of the sand to the metal. Mold washes do that too though. Permeability is a big issue if you don’t vent or vent properly.

[@afnDavid]

14:30 Cat! Meow!

[@samuraidriver4x4]

I said shop cat when I saw the cat pass by. My dog started to bark and growl immediately after because she hates cats.....

[@Mike-pr8hx]

Ginger!

[@markoantesic4362]

Hey Keith, you can try 3d printing with ASA(its like ABSv2) or ABS and then doing aceton smoothing. If you made a dedicated aceton smoothing box you could probably cut down the post print work by 90%. There are plenty of aceton smoothing boxes on the net, but its basically an air tight box that you heat up aceton in and you part rotates on a rotary table. Then you get a nice uniform smooth finish. And as you are printing larger peaces, you would have practically 0 warping.

[@MF175mp]

It's probably better to buy a sla printer if you need good quality, not to try polishing turds

[@markoantesic4362]

@@MF175mp What he shows that he cast, looks like its on the large side for a FDM printer. But sure you can buy a 300x300 mm sla machine like formlab form 3bl for 10 k Or a big HP polly yet of 100k No need to polish turds there

[@MF175mp]

Chinesium 300x300 sla would probably be south of 500 american pesos and deliver outstanding quality

[@markoantesic4362]

@@MF175mp And which one is that? Getting a SLA printer for as cheep as a fdm that size, thats fantastic!

[@guy_b]

Safe dial would be great to see...

[@brianevans1946]

14.31 Your cat is gorgeous....

[@oliverwade8066]

I now know 100% more about pattern making than before, I am now at the "dangerous" level.

[@coconutpie333]

anything going on with the lathe rebuilds ? i have a monarch addiction

[@daffyf6829]

Another great video. Acouple of questions: In plastic injection molds, you can have a rougher surface as long as you increased the draft an appropriate amount. Could you do the same with a 3d printed pattern, using maybe a 5 or 7 degree draft? Second question, I noticed a lot of inconsistent thicknesses in some of your patterns. It seems metal casting is more forgiving than plastic in that regard, but there must be a limit to what you can get away with. I was wondering what the rules around that were.

[@aceroadholder2185]

Wouldn't help. The rough surface would still cause tear-out in the sand no matter the draft. Think of the rough pattern surface acting like velcro.

[@dlfabrications]

If I 3d print a threading dial, and the lead screw is 5 TPI, this means that if I double the number of teeth on the gear, I can only get a dial with two divisions and still have whole numbers instead of 4, 8 and 12 subdivisions? Should I go with 20 teeth on the gear so i could go 4 whole number divisions? I Wish it was an even number of TPI.

[@mgmoody42]

A 24" wood jointer you say? I'd love to see that running!

[@andyZ3500s]

About thirty years ago My boss and I needed a long beam that nobody stocked. We found a place right on the harbor in San Diego that delt with this kinda thing. They milled it on sight. The jointer that they had was probably 25 feet long if not longer. Every machine that they had was enormous.

[@dennisleadbetter7721]

I've seen one that would have been at least 36" wide, was in a joinery works making doors and windows, and they put complete doors and windows over it to flush everything up. Would have been made maybe around 1920's, and like machines of that era, no guards, very heavy, noisy, but solid and produced a perfect finish with sharp blades.

[@andyZ3500s]

@@dennisleadbetter7721 that's the way all of these machines were. The place was probably there since the 20's when San Diego was starting to grow in population. Before that I thought a 12" jointer was huge. It was definitely interesting to see.

[@cyrilhudak4568]

Hey Matt pretty much everybody on this site would too. But Mr Keith doesn't think it's worth his time.

[@mgmoody42]

@@cyrilhudak4568 I think that’s unfair, he can’t control what the museum will provide.

[@Dudleymiddleton]

Sawdust mixed with pva wood glue always was and still is the best wood filler!

[@matthewkantar5583]

@ 14:30, Ginger cameo.

[@canocano5480]

Question How does one become an apprentice?

[@peterchristensen4860]

Great video as usual ! But as a typical old man I’m legally deaf . I rely on CC to help me follow along . Many times your videos don’t have them available is this utube or you ? Again great videos just need help !

[@williampugh6699]

What is happening with the Stoker engine?