Check your bolts

[Tweedledee]

I'm so glad Tom (Teslar) alerted me to this.

He suggested an upgrade on the dovetail and bolts for my relatively heavy 10" Schmidt Newt.

I was very surprised and concerned when I took out the bolts attaching the dovetail to the tube rings. There are just two of them M6, only 16mm long, and worst of all, less than 3 turns of the hex key and they fell out! So I had nearly 16kg of ota (even heavier when I've finished loading it up) hanging on about 3mm of thread on 2 small bolts.

This morning I went to my local bolt supplier and got two high tensile bolts 25mm long and two 30mm long. I thought the 30mm might be a millimetre or so too long and pinch the tube. They were 50 pence for cash!

The alternative could have easily been a major calamity if the threads had sheared under the weight and the ota had fallen to the ground .

Whatever tackle you have, it could be worth just checking those bolts and changing them if necessary, before it's too late.

Cheers,

Pete.

[andyboy1970]

From an engineering point of view a Nut and Bolt is in safety if you get 3 threads clear of the nut.

But as you say you can't trust the monkey metal supplied.

[Teslar]

Glad to help spread the news. I can't believe Skywatcher thought my Quattto was safe on the two bolts and vixen they supplied. After I replaced them I tested one and the head twisted off so easily seems they are made of cheese

Edited June 30, 2012 by Teslar

[+Graham]

Good old quality Chinese metal.

I know margins are tight these days but you would have thought for the price of that scope they would supply you with quality Stainless Steel bolts.

I supose that is the big company mentality, so long as it does the job as cheaply as possible then great and sod the customer.

A timely warning there Pete with everyone getting set ups ready for the longer nights.