Gas Powered Blender of DOOM

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Introduction: Gas Powered Blender of DOOM

About: I like to do electronics, metalworking, woodworking, fixing things and all sort of cool and stupid things :)

I really like making cool machines.
One time I was trying to blend some almonds into almond butter. I put them into my cheap 30$ blender and started it. Almonds were blended into pieces, but after about 10 seconds, as the almonds started to thicken, my blender just stopped. And I was without my almonds.

I told myself into making a very powerful blender. But I did not have an appropriate electric motor for it, so I came across the idea to make a gas powered one. It will be strong, portable and it could be used off grid to make pancake mix :D

Watch this video to see how it works(feel free to hit the LIKE button):

And here is a video describing the build process:

In this instructable, I will further describe the details of the build.

Step 1: The Principle of Operation

I was looking for specifications of 1k$+ industrial blenders to see what makes them great and I found out the following:

- strong-ass motor

- strong-ass blades

- big-ass bowl

- metal coupler gear between the mixing cup and the motor (cheap ones use rubber ones)

- high blade rpm speed (18k-25k rpm) for blending everything into a smooth smoothie

I wanted to use a 2 stroke grass trimmer engine for this build:

- the engine needs to be powerful enough - so higher displacement is better

- the typical engine rpm shaft output i in the range of 6-8k rpm. So I will need to make a gearing system that will spin the cutting blades faster than the engine shaft, otherwise blending performance will be compromised

- I need to make a metal chassis that will hold everything together

- i need to find a big bowl

- i need to find good cutting blades

- I need to find gears for the transmission

Step 2: The Tools Needed

There are many ways you can make this machine, I have used an angle grinder, a drill, lathe, stick welder, CNC router, 3D printer and a woodworking router.

But would say that the lathe, CNC router and 3D printer and woodworking router are not strictly necessary, since you can make the required parts with simpler tools, it will only take a bit more time.

Step 3: The Engine

As you could see in the video in the beginning, I got an old grass trimmer engine for free.

It ran badly, and it was not possible to tune it properly. I suspected that the carburettor could be the problem as the engine smoked a lot and did not reach high rpm. This indicated fuel mixture that was too rich.

I ordered cheap Chinese clone of the original carb for 14$ from Aliexpress and bolted it on. And the engine now runs as new!

The engine was 40cc which is powerful enough. 50cc would be better, but I used what I got.

Step 4: The Bowl

The bowl was a critical part.

I didn't want to use typical blender bowl, as it doesn't look cool enough for a build like this.

The bowl needs to be tall and not too wide, so the ingredients don't run away as easily.So I searched the internet for the appropriate bowl for ages.

I didn't want to use glass one, since the gasoline engine produces a lot of vibration and I didn't want the bow to break if I drop it. And drilling into glass for mounting the blades is difficult.

So I decided to go with stainless steel.

I got an used kitchen robot - dough mixer bowl for 20$. The bowl is tall enough, it has 4.5liter/1.2gal capacity and is perfect for the project.

Step 5: The Bowl Lid

Dough mixer bowls do not have lids, so I needed to make one.

I wanted a transparent lid, so I could see what is going on inside the bowl.

I used 1cm thick acrylic sheet (plexiglass) and with a handheld router I carved the outer shape and the notch for the bowl. From a friend I borrowed a simple jig for making round cut-outs with a router

I used self-adhering foam tape to make a simple seal inside the notch so the insides stay (mostly) inside the bowl.

Step 6: The Cutter Blades

I searched the Aliexpress for good and affordable blades and I found these:

https://www.aliexpress.com/item/33052081909.html

and the coupler:

https://www.aliexpress.com/item/32868069523.html

I like them because they are:

- big and they have cutting teeth on the blades (good for ice)

- made from metal and are quite robust

- nice an big bearing
- it also has a metal coupler which will be able to transfer high power without problems.

Step 7: Modifying the Bowl

I needed to cut a hole in a bottom of the bowl in order to fit the cuter blades.

The bowl had a double bottom, and I needed to cut out the lower bottom out for the blades to fit.

First I tried it with a holesaw, but it was unable to cut stainless steel.

So I cut a few dozen holes around the perimeter and use a dremel to cut it out. After some grinding it came out good enough.

Step 8: The Gears

I needed to find gears that will multiply the engine rpm to around 20 - 25k rpm on the blades.


And I needed a 90 degree transmission, since the engine shaft is horizontal.

I came to an idea of using replacement hears for an angle grinder.

I found these:

https://www.aliexpress.com/item/32857720778.html

I like them because:

- are made from hard metal which doesn't wear out quickly

- are to be mounted to the 15mm and 8mm shafts which are easy to find

- i get 90 degree angle

- helical gears are quieter

- are cheap (6$)

EDIT:
When I tested the machine, I measured 41k rpm on the blades which is way too much :) I underestimated the speed this little engine is running at :) If I would do it again, I would use an engine which works with less rpm, or I would reduce the gear ration to 1:2 approximately.
With having so many RPMs on the blades, the engine is a little bit underpowered for running them when mixing thick mixtures.

Step 9: The Shafts and Bearings

Step 10: The Shaft Notches

I needed to cut the notches in the shaft. In these notches, the pins that will hold the gears are inserted.

Step 11: The Horizontal Shaft

Horizontal shaft attaches to the engine clutch. I used the old grass trimmer flexible shaft as a flexible coupler for the horizontal shaft.

You need the flexible coupler else the slightest misalignment of the shafts will cause catastrophic breakdown.

This shaft holds the big gear which is secured with a pin I also needed to make from a sheet of stainless steel.

Step 12: The Vertical Shaft

The vertical shaft holds the bowl coupler element and it is driven by a small gear. I cut a small notch on top of the small gear which slides across the pin inserted in the shaft hole. This ensures the power delivery to the shaft.


The gear is fixed with a pin and a retaining ring (circlip) which prevents it from sliding on the shaft.

Step 13: The Completed Transmission

The transmission is now complete.

Step 14: 3D Printed Bowl Holder

I needed to print a custom bowl holding bracket, so the bowl can be locked in place so it does not fly away when mixing.

If anyone wants the 3D model:

https://www.thingiverse.com/thing:4598619

Step 15: Painting the Frame

Used some nice orange color which matches my youtube channel logo :)

Step 16: Fuel Tank

For the tank I used a random plastic flask. I made a custom brass fuel inlet on a lathe for connecting the fuel line, since I was not willing to wait for few weeks for an inlet from ebay :)

Step 17: The Exhaust Deflector

I had a problem - the exhaust of the engine was pointed directly to the mxing bowl. This meant the stuff I will mix will be splashed with the unburned oil and smelly gasses from the engine.

I used a piece of pre-bent steel tube for deflecting the exhaust gasses away from the mixing bowl. I welded a nut on it and it was screwed in the frame.

It works quite well!

Step 18: Adding the Kill Switch

I added a kill switch, which is used to shut down the engine. The engine has only one wire sticking out of it and if you connect this wire to the engine frame the ignition spark is disabled and engine shuts down.

Step 19: Throttle

I installed a simple ball on the throttle cable to manually add the throttle input. Nothing fancy.

Initially I wanted to make a throttle lever (as seen on boats) but It was too much work and it would prevent me from being to rev it up unnecessarily :D

Step 20: The Bowl Lid Holder Bracket

I also made a simple wooden swing arm which holds the lid pressed down with a help of a spring. Otherwise the contents of the bowl would leave the bowl with great speed :)

Step 21: The Finished Blender of DOOM

Here is the finished beast!

Don't forget to watch the PART 2 video where I made some blending of different stuff!

I hope you enjoyed my Instructable! Please vote for it in the make a tool contest!


Thank you!

You can subscribe to my YouTube channel:

http://www.youtube.com/c/JTMakesIt

You can also follow me on Facebook and Instagram

https://www.facebook.com/JTMakesIt

https://www.instagram.com/jt_makes_it

for spoilers on what I am currently working on, behind the scenes and other extras!

PS:., if you REALLY, REALLY liked it, you can also buy me a coffee here, so I will have more energy for future projects :)

https://www.buymeacoffee.com/JTMakesIt

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    59 Comments

    0
    Nikita Maree
    Nikita Maree

    9 months ago

    Everyone needs one of these on their kitchen counter. That grass clipping cocktail and apple core sauce were quality recipes that can't be matched 👍

    Great videos, very entertaining
    (just subscribed).

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thanks! You are awesome!

    0
    Irishintx
    Irishintx

    9 months ago on Step 21

    as Tim the Tool Man would say...😱🤨😍

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thanks! :D

    0
    _kamini
    _kamini

    9 months ago

    Brilliant job and very nicely explained. Congratulations :)

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thanks!

    0
    markk9119
    markk9119

    9 months ago

    Nice use of keys&keyed shafts -- a rarity in DIY'd anything.

    One comment regarding structural design: the Biolomix rotor is a nice choice, I have a blender by this manufacturer and it is by far my favorite of all time, IMHO humiliates over-designed gadgetry for flagrant displays of wealth (but lacking even a fraction of the mighty Bilomix blender's utility). That said, you have a great rotor, but, A-Hmm, dude!? You forgot the stator! Every blender ever made, considers the physics of shear forces and what happens when you initiate and sustain a rotational motion along 2 axes of symmetry, in a parabolic shaped vessel. Well, you will make a vortex. quite a nice one probably. but not much else.
    "What are you talking about? Been guzzling piña coladas for weeks! These ARE blended!"
    My reply grants you that blending happens, but it only happens at the accelleration regime, when the items at rest in the vessel are moving much slower than the blades. However, everything will accelerate quickly and move at speeds much closer to the rotor in motion. The high speed is what saves the stator-free design from more obvious symptoms in the product, like large chunks which persist after long mixing cycles, but I imagine yours does OK, and the high speed causes enough turbulence to achieve blending.

    My suggestion to design-in a stator is an easy fix, which can even be tested before committing to it. Using the lid as anchor points, install 2 or 4 baffles along the outer wall of the jar. Your photo of the underneath coupling of blade assembly, the hole with steps along the perimeter, with teeth pointing inward, now imagine only 4 teeth 90º apart, or even a single rib, like a screen-printing squeegie, a surfboard keel, half an oar paddle (chase your lover around the house with the other).

    THeory: when you invite the liquid to visit Mr. Scissorhands far more often than your don't-inconvenience-the-liquid design, you will be rewarded with otherwise unattainable textures and cell-wall rupturing shear forces.

    You will bring some sport into pureeing. "honey? come here and check this out!" vuh-rooooM!...

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thank you for a massive comment :)
    Yes this was the first time I did keyed shafts - or any kind of project with gears. It came out better than expected.
    The rotor is a Chinese copy o Biolomix, but it is very good quality, especially for the price.
    Thanks for the detailed explanation of the stator thingy :) Yes, I didn't study the blending technology much and now I believe the blender would benefit by having them. I could even mount them to the lid. Maybe I will do some tests. Thanks for the info!

    0
    markk9119
    markk9119

    Reply 9 months ago

    Thanks for the reply! If you want any design suggestions on stators, impellers, or fluid dynamics or powder science. Powder science is a thing? Yes, an unusually boring thing, but comes with top-of-the-line jargon: critical rathole diameter is a hands down winner, tied with glassblowing glory-holes. Powders are more complex to blend than liquids, and require lots of formulation and sometimes a hopper needs a good slap to encourage normal function. This is a good conceptual test of your design, visualize the beast 1/3'rd full of powders needing lump-breaking and blending. now turn it on (in your mind, in slow motion) can you visualize the spiral, as it rotates, transferring force by contact so the whole mass is involved? If yes, then part 2 is visualizing arrows [or cows walking as a classmate always did] dues the outer hull "corral the herd" in a nice roundabout path, involving visits to the center? I found some examples to help you out. The variety of impellers seems daunting, but there are only a handful that see wide usage. The rushton, as unimposing and illogical looking as it seems, surprisingly is probably the no. 1 choice. It has a good amount of shear and lots of tangential flow [away from the shaft, axial flow is up down, tangential is off to the sides, ideally a good mix of both]. How can you tell what's what by looking at it? If it looks like it could fly a plane or make a boat go fast, axial, if it pushes a big flat surface like the front of a huge truck (we all know those things have bad aerodynamic properties. So think of a truck driving fast and all that air holding it back, and look again at the rushton, as it spins fast, it's like a truck. Tangential, and lots of shear. What is shear? It is the violent ripping action of very fast flow next to no flow, the contact of the 2 is the violent negotiations of forces colliding. This BTW is great blending, you want as much shear as you can design in. Google homogenizer, or high shear mixer disperser. Lightnin mixers offer a lot of learning materials related to mixing. https://store.lightninmixers.com/

    I hope that helps. Take a deep breath, congratulate yourself on progress made, then psych yourself up for takining if a few levels further, the rewards await you.

    hydrodynamic flow and impellers.jpgvariety impellers no sawblade.jpgrushton impeller.jpgcowles impeller agitator.jpg3-bladed axial flow alt.jpgnice design high shear and tangential flow.jpg
    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Whoa, you surely know a heck of a lot more than me about fluids and "powder" science :D
    Thanks for the extensive reply :) If I will ever need someone who knows stuff about fluids, you are THE man to call! Maybe I will upgrade my blender one day.

    BTW, you have a great style of writing, you should write a book, it would be a blast to read!

    0
    john3850
    john3850

    9 months ago

    I never seen any gas engine or race engine run at 41k in my 70 yrs
    I spent 3 years at quarter mile tracks even the The Isle of Man bikes stay below 20k
    Very cool or nice build through.

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    As @etriker explained, the 41k rpm is after the gear multiplier.
    Thanks for liking the build!

    0
    etriker
    etriker

    Reply 9 months ago

    Well at least you prove that point that just because one is old doesn't mean you're either smart nor wise. See 'step 13' for the transmission detail to understand how to multiply or reduce engine output RPM to almost whatever you want. Counting the teeth in that picture tells me a ratio of about 4:1. (BTW, I'm older than you... ;~) According to Google avg chainsaw RPM is:
    ""Depending on your saw, the reading should be between 10,000 and 14,000 rpm.
    That's a wide variation, and so it's important to look up the maximum
    speed of your saw before conducting this test.""


    0
    john3850
    john3850

    Reply 9 months ago

    Thanks and understud

    0
    AdrianJ10
    AdrianJ10

    9 months ago

    Maybe where you got your idea from / or not :D

    If geared up it would be 41000rpm - however, if you have a V8 you could blend bricks. Great build.

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Too bad I can't get a V8 engine here easily :D

    0
    osterac
    osterac

    9 months ago

    Delightfully ridiculous. And well engineered! Although the lid made me a bit nervous at times. In any case, I've subscribed to you on YouTube and look forward to your next design.

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thank you very much!

    0
    throbscottle
    throbscottle

    9 months ago

    This is completely bonkers!
    The Sanity Police will be watching you...
    But I love it!

    0
    JT_Makes_It
    JT_Makes_It

    Reply 9 months ago

    Thanks!