Tuesday, 30 September 2014

Bits and pieces

Well i've done another etch which worked ok. I used ammonium persulphate as the etching solution. I feel this worked better than the other solution i used. The only down side is that i have to heat and keep it at about 70 degrees. Something i will have to work out. I'm thinking of having the solution siting in a small contaner of hot water to keep it warm.  I'm still going to have to make a small spray tank for etching. The dip method just doest cut it for what i want to do.

Got another shapways order, which once again prove to be a miss print again. I'm working with shapeways now to sort out what went wrong. You can see in the photos below that the ones on left are good which i had done earlier this year and the parts on the right are the bad prints. Notice the blur along the straight lines and over print on the parts.

Here some photos of the semaphore signals ive been working one. These are nearly ready for realese. I'm still having problems with the bend in the mast. I think this is been caused by the ladder pulling down on the mast when it is cured in the oven at shapways. Some more testing to be done.

In the ment time still working on other projects as well. I'm about to start on a second Y class diesel.  I've got a new chassis design from Spirit design which will place the loco at the correct height. Now just need to work on my light holder design and put it all together.

Friday, 19 September 2014

Etching away

Well after a few busy weeks leading up to hosting the boys from VNSC over the weekend I finally got around to getting some more etching done. This was the first time I got to use the new brass sheet I bought. I'm using a 1/2 hard sheet. I have a feeling the other brass sheets I was trying to use in other etching were not 1/2 hard, hence the funny results I was getting. I used the same process as before. The end result I was fairly happy with, close to been perfect. I had made a few changes to the design of the plates to make them better. I expanded the gap between the two spike heads so the rail could sit in better and I also made the plates a little bit narrower. In making them narrower I had to delete the small square hole in the design that's next to the spike head.

I'm still not 100% sold on a etching solution yet. The one I used was ok, but does take a while to etch and I believe because of that it rounds of the square edges more. I'm going to give Ammonium persulphate another go. They only draw back is that the solution has to be heated but it may be a small price to pay for a better etch. Sorry no pics this time our camera has gone missing in action.