Wades extruder and M8 bolt heads...

Hi to all,

Does anyone know the if the dimensions of an M8 nut are different to the dimenions of an M8 bolt head? i have printed off a wades big gear from the prusa iteration 2 files and i tried to fit a M8 nut into the centre hole after it printed. The hole was too small. I have cleaned up the plastic and it still wont fit.

The dimensions of the nut are 12.86mm flat to flat, 14.75mm point to point.

Are the dimensions of a bolt head smaller? i have checked the size of the print against the STL file and its within .2mm of the stated sizes.

Thanks,

Raj

They should be identical. Do you actually have an SAE 5/16 bolt instead? I've done that before. :p

AFAIK all metric hex heads are the same diameter as the nut, but thinner.

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Hi,

The extruder wheel was taken from the metric lm8uu prusa folder. I will double check this thougthankRaj

This is a useful page for standard sizes: http://www.numberfactory.com/nf metric screws and bolts.htm

Hi,

I got the m8 nut in the hole. All it took was a big hammer...not the most precise solution so I will compare wades stls across a number of sources to check for differences in nut hole sizes. I will update tomorrow.

Thanks

Raj

I've designed them at 14.5 point to point and when cold they are too tight. Imerse the PLA part in a cup of near boiling water for about 10 seconds and press the bolt head into the recess of the gear. Make sure you don't distort the gear while you press it. Run it under cold water and its back to full stiffness. I use 5/16" bolts.

you can use a power drill, just drill into the plastic in reverse. that way instead of tearing the part, you melt through with the bit. then turn the drill to forward when out of the part and clean out excess debris by going in and out of the part 6-7 times.I also use 5/16 bolts