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sprayhead
Sat 28 August 2010, 03:19
HI guys

When mounting the whole motor assembly to the gantry, how do we guarantee we get zero play with the screws and washers?

Do we need a screw that fits the gantry and motor mount hole with a very small amount of play? .05mm to each side or something similar?

Because If I can picture it right, we don't want to tighten the screws too much otherwise the motor bracket will be "hard" and pretty much ignore the spring... How tight have you guys tightened them screws?

thanks,
Francis

AuS MaDDoG
Sat 28 August 2010, 04:40
Hi,

The bolts can be tightened fairly tight and the size of the bolts is called up in the drawings. The use of teflon washers on these bolts allows movement and for the spring to work.
Hope that helps.

Cheers
Tony.

sprayhead
Sat 28 August 2010, 06:46
thanks tony,

I was just having a look at the drawings... and,

The holes are .1 mm bigger then the nominal screw diameter. So, in theory, we would have a .05 backlash.?
But I suppose if we tighten the 2 screws enough, she'll be stiff and playless.

btw, the long hole is for a M8 screw and the Pivot hole is for a M10.

F.

Gerald D
Sat 28 August 2010, 07:30
Francis, in theory we have backlash at that point, but in practice we don't see it.

We tighten the hinge screw until the motor stays up under its own weight. The other smaller screw at the slot is tightened only lightly.

sprayhead
Sat 28 August 2010, 08:19
Thanks Gerald,
good to see you are still active up here.

Francis