photos of MOHO

[Angel Rodriguez]

Hi

Google might not have uploaded my photos.  so here is a link

https://drive.google.com/drive/folders/1c_iM1FlyOufE-dIJZCAggVhL1GYMRGiX?usp=sharing

Cheers,

Angel

[Jonathan]

Hi Angel,

Very nice work on this! Is this intended to replace the HammerHead or an alternative? 

I’m still in the process of building my HammerHead. I was able to get some good 3D prints. 

Jonathan

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[Angel Rodriguez]

Hi Jonathan,

MOHO is not a replacement for HammerHead.  HammerHead is a very inexpensive very good sensor.  MOHO is much more expensive.  Not sure how much but you can see that there are six PCB boards, one of which is quite large.  There is also a heat-treated flat spring, it requires a pressure case.  

I would say that HammerHead is the best passive hobby sensor you can make and that MOHO is the best active sensor you can make.  A properly setup MOHO is as good as many professional sensors.  They both use the same Baby Shark digitizer and RPi zero.

MOHO was only possible because of Dave's previous sensors NAPA, YUMA, and YOLO.

As a hobbyist, there is no better seismometer that you can make from the point of view of building ease and cost.  MOHO has no machined parts.  The magnet keepers have six holes each that you can make with a hand drill.  The flat spring is difficult only because of the heat treatment.  Once setup you can see all sorts of seismic waves.  You will be able to see a 5.5mb event anywhere in the world.  

I hope to make a kit that has all the non-3d printed parts and one that has all of the parts.

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[Brian K]

Hi Angel,

Reviving this old thread.  

Just wanted to ask if you are willing to share the drawings and schematics for MOHO.  I'd think I'd be interested in building one.  I have two Yuma's operating currently and I'm looking for a new project :)

From the photos it looks like it uses a PCB linear motor coil, instead of a voice-coil type actuator, is that right?

I can probably fabricate all of the mechanical parts myself, but bare PCBs (or the gerbers) would be ideal.  I have some 4 mil and 6 mil 17-7 shim stock and the ability to heat treat to CH900.

Cheers,

Brian