Tuesday, August 28, 2012

Do as I say not as I do

A while back I told of a short circuit on a friends layout that could have caused a fire (actually it did cause a 1cm round fire that went out when I called for the layout to be shut down immediately). The short was caused by placing two track spikes on the same PCB sleeper, one with copper on top and bottom. The top of course had been gapped to stop short circuits but the bottom hadn't and possibly due to expansion and contraction, both track spikes came into contact with the bottom layer of copper completing the circuit from one rail to the other.
Well, I had the Ramblers over recently for an impromtu operating session and when I turned the layout on at 7:05pm I found that it had a short circuit that shut down the DCC, it wasn't there the night before!
The boys started arriving around 7:45pm to find me trying to track down the short. I had worked out that it was in the new Cassilis branch terminus station.
A careful examination found three rail gaps at points that had closed up, these were cleared but the short remained. The Rambler with the previous 'fire' short asked if I had removed one of the track spikes from the two on sleepers of the hand built points as I said I was going to do after reporting his shortcircuit 'fire'.
By now you know the answer!
Five minutes later with a number of track spikes laying on the Cassilis baseboard the short was gone.
The moral of course is don't put off something that you know that you should do and do as I say not as I do (or don't do as the case maybe).

Sunday, August 12, 2012

Mini Sand Blaster Fine Grit Supply

Earlier this week I received an email from Scott Hamilton with information about where to get supplies of the fine sand blasting grit for the mini sand blaster in my last post.

Scott sent the following information and links:

"I have found that Micro-Mark in the US sell the blasting medium in 5 lb to suit your sand blasting tool. The gun that you have seems to be based on the Passhe model which Micro-Mark also sell."

"Hobbytools Australia also stocks the abrasive medium for these 'air erasers'."
 Just a short post this time but I will post again soon.