Wall thickness/Thread advice

Hi Everyone,

I am planning to add some adjustable machine feet to my CNC but I could do with some advise.

My machine has four 50x3mm steel box section legs. I was thinking that I could just weld a 50x50x5mm piece of steel to the bottom of the leg and drill/tap it to accept the machine foot.

The machine feet are m12 with a 1.75 thread so my question is would the tapped 5mm plate thick enough??

The total weight of the cnc is about 150kg

Cheers,

Jim

Quote:

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Originally Posted by cncJim

The machine feet are m12 with a 1.75 thread so my question is would the tapped 5mm plate thick enough??

The total weight of the cnc is about 150kg

Cheers,

Jim

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I think it would be fine as you would have 2.8 threads in the plate, also the machine foot would have a lock nut on it and therefor the weight of the machine would also rest on the nut. You could of course weld a nut onto the plate.

I made up plates and then welded nuts to them. Seems to have worked fine, and saves a bit of tapping! I set the plates into the legs a short distance so that the nut is on the "outside" but more-or-less flush with the bottom of the leg; this way it does not rely on the weld to hold the machine weight.

Quote:

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Originally Posted by Clive S

I think it would be fine as you would have 2.8 threads in the plate, also the machine foot would have a lock nut on it and therefor the weight of the machine would also rest on the nut. You could of course weld a nut onto the plate.

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Quote:

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Originally Posted by Neale

I made up plates and then welded nuts to them. Seems to have worked fine, and saves a bit of tapping! I set the plates into the legs a short distance so that the nut is on the "outside" but more-or-less flush with the bottom of the leg; this way it does not rely on the weld to hold the machine weight.

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Thanks guys - I hadn't even thought about the lock nut on the foot. I think I will just go for it and weld a nut on if I feel its needed.

Cheers,
Jim

Quote:

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Originally Posted by Neale

I made up plates and then welded nuts to them. Seems to have worked fine, and saves a bit of tapping! I set the plates into the legs a short distance so that the nut is on the "outside" but more-or-less flush with the bottom of the leg; this way it does not rely on the weld to hold the machine weight.

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I did a similar thing but mine rely on the weld to support the weight. Pic below shows the nuts tacked in, I welded on all sides of the nut in the end.

Attachment 16226

At the moment they've got machine feet in them but ultimately will be used to secure the machine to the inclined frame...

Wouldn't mess about with tapping etc Just weld Nut on it's simple and easy.!!