DIY Universal Testing Machine

[JohnCoker]

This looks like a way to get a material testing machine on the cheap:
https://www.instructables.com/id/TestrBot-The-300-Universal-Test-Machine/

I'm going to look into more options. (Ideally something that could also do a lap-shear test.)

 

[Chad]

that would be huge! i've read your epoxy comparison page a bunch of times. It would be awesome to have data on more materials like cardboard to plywood, cardboard to fiberglass, bluetube to plywood, etc. Also, data on structural fillets would put a lot of questions to rest like fillet radius, epoxy + various fillers and on and on.

 

[Chad]

This looks like a way to get a material testing machine on the cheap:
https://www.instructables.com/id/TestrBot-The-300-Universal-Test-Machine/

I'm going to look into more options. (Ideally something that could also do a lap-shear test.)

Do you have any ideas on measuring the strength of a fin to body tube joint with respect to the forces encountered during a flight?

 

[JohnCoker]

Do you have any ideas on measuring the strength of a fin to body tube joint with respect to the forces encountered during a flight?

Not particularly during flight, because those are dynamic. Clearly we could measure static shear or tension force on the joint though.

 

[JohnCoker]

Has anyone built one of these, or have an idea how to do it? I now feel like I need one and I'm guessing the commercial ones are insanely expensive. (I requested a quote from Instron, but I'm guessing it'll be ludicrous for hobby use.)

 

[0011001100]

Has anyone built one of these, or have an idea how to do it? I now feel like I need one and I'm guessing the commercial ones are insanely expensive. (I requested a quote from Instron, but I'm guessing it'll be ludicrous for hobby use.)

Having used an Instron at school. It was ~$70k for their smallest machine

 

[RCBrust]

John,

Don't know if you're familiar with this guy, but do a search on YouTube for "CNC Kitchen". He's a 3D printing guy who does a lot of material testing using a home made test rig. Actually, start with this video.

May not be exactly what you're after but you may get some ideas.

Randy