MIT Ventilator Plans - Sizing and Conversion - Covid-19

MIT has put their Ventilator plans online. They can be found here:

You have to register but they dont seem concerned with who you are seeing them. I also attached them.

The Unit 02 Pre-Production Model looks to be a plan that an X-Carve easily could do however Im not familiar with STEP files. - MIT E Vent Pre Production Model.step

I also have DXF files but when importing them they dont seem to scale to the correct size. There must be an easier way to convert the CAD files to scaled SVG / GCODE files we can all use.

This would likely be a great contribution from our community if our X-Carves could help produce parts even if its just converting the cad files to something compatible for our use. (43.3 KB) (1.4 MB)

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This part are SVG and the rightly scaled.

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That awesome need to add a few of the finger tips they sandwich together to squeeze the air bladder gently. Hmm wonder if its best to put the finger tips on a separate cut so you can switch to thicker material so you don’t have to cut so many of them.

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for the finger tips they can be cut 1.75"

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Hi, B.F.,
Thank You for Your help converting files.
Can You please convert to dxf or svg this aluminum pre-production model.
Thank You. (1.4 MB)

I cant open step files, but I think that this is not for aluminum pre production model, but by ambubag holders, for plexiglasss model

Hi guys, I am trying to get proper cutouts for the parts. But I do have a problem with the gearing. I am getting tooth overlapping. It tried both to extract the outlines by my self, and then tried the DXF’s provided by MichaelMitchell. In both cases I get similar overlappng in the teeth, please check the attached picture and DXF file.
Units of the drawing are mm.

crude (60.0 KB) (41.2 KB) (197.4 KB) motor.dxf (3.9 MB)

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Thank you, but I have trouble opening these files. As I don’t have Illustrator I use Inkscape. It supports SVG, but can not open this particular one.

Can I please ask you to provide an export to DXF? Also saving in an older Iluustrator format would be useful too. *.ai for “Illustrator 9 and above” should be readable by Inkscape.

If you can provide the drawing in those two formats that would be very helpful. By the way, that is a very neat design for a full sheet metal assembly, what is the thickness of the material?

the thickness of the material IS 0.25

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Wired appears to show an even easier design but no plans. Im thinking that is using a windshield wiper motor.


Martin what if you cut on line/inside would that provide enough space to work instead of cut outside?

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I did not design this file, I copied the link that B.F. provided and converted it so I could open it in Easel.
Stay safe everyone



Can someone please explain to me what pressure transducer they used for this, as well as what the MIT team means by the following note: “Note: The shafts on the gear-driven fingers need to be keyed. This detail is missing from the CAD below. We’re in the process of updating our designs; an improved model will be shared here soon.”

Also, is there something wrong with the CAD files that the team has posted on their website, that causes you guys to upload these files on the forum instead?

I am new to CAD, sorry if I’m mistaken. Please advise.

Thanks in advance! :slight_smile:

Keyed likely means the gears have an indicator that you can use as a reference point to align them. Without proper alignment of the gears it may over rotate, uncouple, crash into itself etc. It basically a starting reference point for everything. I see the two fingers have a little notch its likely they should point down when putting the machine together and the first teeth connect with one another. But the motor gear also should probably have a notch so say when you put it together and it begins to move it doenst run in the opposite direction. Its kind of why I like the other design thats circular in motion but thats a bare basic model vs the MIT design which is more precise.

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To answer your second question Inventables is a hobbyist community and the X-Carve CNC machine sold here is a low cost entry level CNC machine that’s quite a capable device. It puts a CNC in the hands of the hobbyist and experienced CNC machinist for their home use and home business. The files MIT is offering is great if you can afford the software they use but most of us use free software called EASEL which is quite capable but not compatible with the files provided. Our machines can easily do the job but the files need conversion.scaled thats compatible with the free software most of us run. I also noticed a few other people experiencing the same issue with the files provided by MIT. Not everyone is an engineer and the file conversion helps cast a wider net to the hobbyist community. B.F and Russel Crawford have been kind enough to lend their expertise to converting the format so that more people can produce these much like the 3D printer community has helped provide shields and valves. I’m technically just the messenger and someone who can help print parts. B.F and Russel Crawford deserve the recognition for helping others do what I cannot. Thanks to them many other people are now capable of being contributors.


Has anyone sourced the parts for this project?

Have those of you considering making a ventilator been in contact with a hospital?
I think there are plenty of ways to squeeze a bag, but there’s a lot more to a ventilator than just the mechanical action.
If someone has a contact that has a need that could be filled by this community, it’d be great if you shared that. I’d be concerned that a MacGyver’d ventilator might be a liability.

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Hello Michael,

Thanks so much for the super detailed response.

So I am using this this motor as the motor for the MIT E-Vent. This is the exact motor that they specify on their website as having used for their own prototype. I see that this motor does not have a keyed shaft, but instead has a hex shaft. Will I have to find another motor, and if so, could you please advise as to which motor I can use?

Please let me know.

Thanks in advance,

Hi Michael,

Thanks, I get it now. I was under the false impression that they had made their own adjustments or something to the files.

Thanks B.F. and Russel Crawford for all your selfless help!

  • Shudhant
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