How it's Made: Propeller Pattern 

Lots of sand casting experts here....it's a pattern that will be put in a box & have sand rammed around it. The pattern has to be strong enough to be reused many times and withstand that abuse. As for balance, note the pattern's hub extended past the centreline, and note the hole. The pattern is indexed off that hole and rotated into position in the sand to create a pattern for each blade. It ensures accuracy and balance because every blade is identical.And as for table saw safety, no need for a riving knofe or a push stick when freehand cutting wide boards, your hands are nowhere near the blade. You can tell the internet experts as they have no idea as to what is safe of not.Finally, if it was cheaper and easier to do this on a CNC mill, I doubt people would be paying Shapeandform money to do the excellent job he does.Why do the curent generations despise manual labour so much and have to put it down as inferior, just because they don't know the sharp end of a plane from a chanisaw? There are still PLENTY of industries where it is cheaper, faster and just makes more sense to do things the traditional way.

Before WW-3 starts.. someone needs to make sure all the how-to videos are safely archived!

I had a question about how both halves are made identical. It seems like you would be off by a small amount, or is this something you have to spend a lot of time to check. First I thought you made one and they cast two parts, but at the end there were two forms.

Nice job and not so really out of date or inaccurate as some indicated, there are props still made this way in the US. I own a Pattern shop and we do 90% of our work CNC because the talent to do this kind of work accurately and efficiently isn't out there anymore.... and as eluded mostly we receive files and not prints so the cad is there anyway so you just cut it. However having built on the bench and still dabbling from time to time I am confident this job was built in a 50- 60 hrs (I know I could do it in that or less) and accuracy is enough that it does what is needed.Look at the investment in materials and equipment. $6500.00 - $10,000 pattern 1 -1/2 weeks work and all the money goes in the pocket..... VS cost of a cam system a big CNC and cost of foam or model board.... Money goes to the bankerYeah I know ok Grampa

BONDO. It covers a multitude of sins.

Mauritor - In Brazil 40 years ago, patterns were made of red cedar wood, for good stability, ease of working and goog for glueing. The painting colour is a code indicating the metal to be used in foundry, and enamel used is special preventing sand adherence to pattern in foundry. For more pieces, aluminium copies of patterns were used. Great skilled caftsmanship is required in this job. Good video!

Great job, wish had something to put one on, I would build it. but then again, not being able to see it would be the bummer... or is this just for show? BTW, kill the music.. don't need it

There is much more to these patterns than just the shape. These are 'tools' used by the foundry and must be made as such. If stored and maintained correctly, these patterns will last indefinitely.

Im not sure why there's all the harping on using a CNC machine, I mean the man is using power tools so the time saving is moot. The CNC is only as fast as its gantry system and you have the added risk if something goes wrong it goes REALLY wrong. There's nothing like a lost investment when a CNC just plows its tool into the material snapping it off and having recoup the costs of damage to the machine and loss of materials. This is just a pattern it doesn't have to be accurate it just has to have the general shape ;)

I always listen to Wagner's "Ride of the Valkyries," when I use my tablesaw.

"I love the smell of Bondo in the morning" (sorry,couldn't resist)

In my youth , I designed and made propellers a few times, using hand tools to make the pattern and they were all pretty accurate and the latest one, about 25 years ago was a 17 inches Dia. by 17 inches Pitch. Since young I always felt that the tips of propellers were not right and there were other issues I was concerned about. All I did was to look at evolution of birds and fish which operate at different speeds and studied what nature had made over the last few million years and here was my final design incorporating the following points. In wings of birds and fins of fish I had noticed a few issues which made a lot of sense and so I incorporated them in the design. Also may I say that wing tips of aircraft wings were wrong as the small Tiger cub and also the Spitfire and other planes. Well here goes. I feel the propeller in this video could do with a few modifications, * Nature always makes fish propulsion tail fins and feathers in birds wings with the trailing edge at the tip always trailing back or swept back , ( not forward as in the Spitfire wing) so any vortex formed will be thrown out at the tip rather than travel back along the trailing edge into the boss which could erode it. This was incorporated in my propeller. The American P51 compromises but does not have its trailing edge swept back , but it is better than the Spitfire wing) * The leading edge of the fins in fish and fast birds is always trailing back or swept back even the last part of long range birds as the albatross and the seagull. Well since the upper surface has a low pressure and the lower surface has a high pressure, the air or water will try to escape from the high pressure zone under the wing in to the low pressure zone above the wing forming a heavy tip vortex . Well the swept back leading edge will see to it that if starting from the leading edge some air is going to escape from the high pressure zone under the wing , then all one needs to do is to extend the wing the further back one goes to form a barrier to the vortex , hence the swept back principle was also also incorporated in my propeller. * Now with both the leading edge and the trailing edge of the propeller being swept back there was no possibility of the vortex going into the boss, but only outward to the extended tip where an inner vortex at the trailing edge would cancel an outer vortex from the leading edge........... the beauty of nature saw to this thousands of years before man ever did!!!! * Well, when a propeller starts from rest, because of the twist in the angle of attack, the outer part of the blade , may work rather efficiently even tolerate the high slip but the blade nearest the boss with a higher angle of attack will probably stall as it behaves more like a paddle wheel rather than a propeller. So knowing this and the fact that the inner part of the propeller does not contribute that much, well all I did was to work out the top speed of the boat and at the Boss provide a different pitch such that at top speed I would not get any push from the first third of the blade, but the pitch was reduced to that where the propeller at top speed would simply go through the water without producing any drive, but I would have gained the benefit of having a lower pitch hence a lower angle of attack at the boss at starting from rest ,reducing the paddle wheel effect ( which can stall) and the start would be better but this part will be inactive at top speed. This was incorporated in my propeller where effectively the pitch of the propeller was reduced in the part nearer the boss. It was not exactly a variable pitch propeller, but in a way my propeller had a variable pitch, smaller nearer the boss to soften the paddle wheel effect at start condition, which does count on occasion. Also as any propeller would slip I felt that this reduction of pitch towards the boss will reduce having the higher angle of attack near the boss contribute to cavitation. * Since propellers operate in zones of different pressures especially when they meet air pockets and break the surface I incorporated an ever increasing radius in the leading edge which acted as a scimitar as it re- entered the water and not as a straight sword which can give too great impulses and break a blade. A scimitar shaped leading edge would soften the entry in to the water after the blades break the surface. Note I did not want a surface propeller. * Since the boat I was dealing with was rather heavy , I went for four blades and with a high blade area to reduce the possibility of cavitation due extra low pressure on the upper surface. * With the leading and trailing edge swept back I did not apply any wash out at the wing tips as I thought this was not necessary, but the thickness of the section followed a natural one depending on the chord joining the leading and trailing edge at any radius. Well those were the basic inclusions and I must say that the two engines were Cumins running at 3200 direct drive as my colleague for whom I designed them said that he could not afford two expensive gearboxes!!!!! Well, to be honest I was rather excited when we tried the boat , well all I can say that it did one knot for every 100 revs per minute and she was happy at 32 knots. The boat made Pantalleria to Malta in less than five hours, a distance of 150 miles or there about. I published all this in one Yacht Magazine including photographs and all I can say is that it seems to have been appreciated as most propellers these days have my propeller tips , and swept leading and trailing edges and I would like to check whether the variation in the pitch nearer the boss was incorporated in propellers used in boats competing from a standing start!! I feel that this would produce a silent propeller for super yachts for owners who look for such details. Well that is one of my contribution to boating, as I do come from a boat building ancestry.

This right there sir, is proper fucking craftsmanship. Oh the skills people are forgetting and taking for granted these days !

So fucking amazing welll done ! Crafter!

Thanks for your comment Dave. There are many reasons the patterns are made this way and the method of manufacture is often decided on a case by case basis. While some propeller patterns are done on the cnc router, the set up - glue up process is the same. A skilled patternmaker can be just as fast as a cnc router.

Is this music playing in the shop all day long?

Turn on closed captioning. Just do it.

I am also a Patternmaker, and ours are made with solid timber, such as yellow pine and very little filler, all hand carved. The largest propeller I have built to date was 20 foot diameter cast in Stainless steel by the loom and strickle method.

When i open video - i read it's name as "Peperoni Pattern" and thought about gigant pizza. First half of video i was like "WTF?", and then i read title again/////_o

Ride of the Valkyries? It's beautiful music, but lends an epic feel to the video which doesn't match the content. Very odd.

I liked it. I started my pattermaking apprenticeship before CNC machines. That is how we did things.

How about a commentary to explain what is going on?

be better if narrated. beat is annoying

first turn off the volume then watch :-)

Hi Jeffery, While that may be a faster way of achieving the desired shape, the foundry would likely break them as soon as they tried molding with them. These patterns are more or less tools, so they must be made to withstand use in a foundry.

Beautiful music.

Pattern maker required

أحسنت عملا فنيا سيدي الفاضل هل يمكن معرفة كيفية عمل هذا العمل الرائع بالقوانين العلميه فنحن صناع نماذج مثل هذا الموضوع لاكن لا نجيد تنفيذ النماذج الرفاص البحري تحياتنا إليكم بالتوفيق الدائم اخي العزيز من الاسكندريه مصر

It would take days to print something that large. I would expect them to CNC mill layers of foam and then glue and coat it with a hard epoxy.

cool vid, dispite the music, interesting watching it take form, thanks for postin

Cant believe something like this is first made by hand... awesome

Just wondering how many idiots have asked if you could 3d print this - what a magnificent piece of work great job.

Very impressive! I thought something like this would be done on a big cnc machine nowadays, glad to see proper craftmanship!

Propeller may be purely axial flow and having shroud . Hub may be 50 percent dia of blade tip to avoid re entry from pressure zone . Length of hub may be 50 percent of blade diameter to hold and transfer maximum energy . During testing of propeller the re entry of warer from pressure zone at about 4 kg pressure

You're correct about the push stick, but a riving knife is still handy because it helps prevent kickbacks. A riving knife is not in the way for any regular tablesaw operation, so there is no reason to remove it. The only time it would get in the way is during a cove cut.

能請教一個問題嗎? 希望知道的解惑.螺旋槳是高速運作能量的物件 為什麼會用木材製作 日曬雨淋容易變質彎曲龜裂 安全堪慮.重量 強度 平衡 都不成比例 why?

A push stick and riving knife are completely unnecessary when cutting sections that big

Well, since there is only one "blade" when the foundry molds and casts it, they make the other blades out of the same template to insure that they are identical.

Amazing craftsmanship (craftspersonship?). I watched the whole video before realizing I should have turned the captions on.

Don't get me wrong this is very cool, but with all the props that have been designed and made over the decades by now isn't there already just a stock collection of standard designs that ship builders can make use of as is or slightly modify? This would exclude custom racing props and other specialties I'm not aware of.

The video was great but a voice over explanation of the process would have been AMAZING!!! Good work at any rate.

Dislike button abuse is becoming rampant.

this is the first video i have ever watched in my life that i did not skip threw a part that was not exciting . your view duration on this vid is gonna make you rich wne your 80 years old bro , this thing is still gonna be cranken out views

Hard to understand how this process requiring highly skilled workers has survived with the advent of CAD/CAM and CNC milling.

I wonder if there are advantages of this old school art. I tend to believe there are things that a human can do that a cnc mill wouldn't on a design like this. Anyone with experience knows a propellor is a bitch to deal with if it ever gets slightly deformed. The tolerances on these things are so critical. A minuscule dimension change near the hub could throw the tips of the blades way, way off.

Actually they're cast in stainless steel at a foundry. This is just the "Pattern" (notice the title and description).

⚓️ After all this time, I didn't know they made of wood and just painted! ⚓️

Would I be right in thinking that these halves are two different propellers, the foundry will use the same half pattern to create two identical cavities in each case?

Why is all of this hand crafted and not simply made with a 3D router. It is not THAT big.

How do propeller makers make propellers without gluing wood? They cant. Get it?

I thought, marine propellers were being hot forge, instead of being molded? This means that a molten metal will be poured into mould.

Wow... I thought these things would be CNC-made, like with a robot and lots of plastic foam...

WHAT CLOSED CAPTIONS ??? Video is probably very interesting and informative , if only I knew what was happening . Scrap the Valkerie and add some commentary .

Very poor music background, quite annoying !

May I ask how you made the calculations for the measurements? Also, what is the goal when designing a propeller?

Or let a sculptor make one out of soft stone - at least no need to build one up from small pieces., cover it with glass fiber and u have a mold.

STOP THE DAMN MUSIC... IT MAKES ANY AND ALL VIDEOS ANNOYING... IF THIS IS NOT A MUSIC VIDEO, THEN DON'T TRY TO MAKE IT ONE!

It's a shame to cover up the wood grains just to make a mold.. Put some stain on that sucker and use it as a display..

I thought propellers are made of metal!

it's a mold that will be covered in sand/silica and injected with steel/bronze

No explanations, just an annoying sound track... :-(

what is that grew putty your using ? any body no if that is bondo ?

looped music is an evil plot to drive us all insane.

Just how difficult is the math for doing this?

Theres an easier way to do this that cuts building and finishing time by 80% plus one can add + or - rake to the pattern. NO need to check specs because it's a natural curve. This can also be used for Air Craft props too. 30 yrs ago we built steel pitch blocks for propeller repair.

Learn how to use a table saw safely guys. No push broom, no riving knife?

Instead of the unnecessary call of the valkyrie song playing in the foreground, a narration of what we're watching would have been much more inviting.

How it's made by one guy with tools and materials from Home Depot.

"cast the finished propellers in stainless steel". Um, isn't in bronze?

The final piece would probably be milled; this is just for the casting.

If this were made in Bangladesh I would understand the lack of accuracy and admire the fact that people make the best of whatever little they have. But in Canada ??

Very impressive , but how do you keep the datums ? You ' ve cut by eye & pencil from ply blanks and then taken it back to the base face with a grinderette ..... and then you go on with a power plane , how do you ensure the face is to the design calc ?

i am foundry engineer and i just say buy a cnc router then do it simply.

But who buys wooden props these days???

iki kanatlı gemi pervanesi dökümünde kullanılmak üzere kum kalıp hazırlamak için ahşaptan hazılanan pervane modeli... güzel işçilik...🖒🖒🖒

Very creative always keep our mind busy for better life lovely

I made it myself thanks to woodprix website.

This is all done by hand! How do you ensure proper balance?

looks like a funn game but what ever will i do with a prop that big!

Es un buen desarrollo de trabajo. Excelente.

Question don't get me wrong that looks like fun , buut if I was trying to make money at this why not use a 3D router to make a plug from foam or wood , or do you forsee purchasing a 3D Printer in the future ? Thanks !

Always a pleasure to watch something new being created :-).

The question is: will it fly?

So that's how they do it! Punch random numbers into a calculator, draw lines on boards, cut the boards into random shapes, glue them up and sand to shape. Always wanted to know how to do that...

great video

Well I m not that handy I guess!!!

A lot of beauty work

awesome ..real craftsman at work .

I would if thought a 4 axis cnc would of done this!

I feel like this seems very imprecise? Really awesome hand craftsmanship but should this process not be computer aided by now? The only reason I say this is because I would think that the propellor would have a lot of aerodynamic testing done on the computer model and you would want to variance in the real model right? I'm not saying what was done here was wrong, it was just screaming CNC to me the whole time.

I love the smell of wood shavings in the morning

High School level difficulty. Pi is used in calculations, as well as in finding angles, radii etc. Also machining, shrinkage and contraction allowances are made in the measurements and added to the pattern.

Interesting... I wonder if this is common, or if there are portions of the industry that has moved onto more accurate technology like large-scale 3d printing. This seems like a perfect candidate for an extremely large 3d printer as you'd waste so much material milling from a single piece.

How big a boat would a propeller like this go on?

Do they check the wood molds to make sure that the finished product will be balanced prior to casting?

Really interesting, thank you. It's nice to watch a pattern make at work on such a huge scale. Also nice to see how the shapes are formed. Great video

Start again, there was suppose to be three blades not two. oops

what is that gray substance you are are usin?

I've seen lathes big enough to turn the shafts for large props and generators. I assumed there was a giant 4 axis CNC machine as well. I guess the old way of doing it is still the best.