Penrhos Junctions

[martin_wynne]

19 hours ago, Penrhos1920 said:

I can't decide between buying the one Martin recommends (Geeetech Alkaid at £91 in P&P)

 

I'm not actually recommending it as such, if you prefer something bigger and better. Just reporting that it can produce perfectly acceptable results at very low cost. James Walters is very pleased with it:

 

 

 

Martin.

 

[Penrhos1920]

Lord lead me not into temptation…..

 

I don’t need another Victory tank, I don’t need another Victory tank, I don’t need another Victory tank….

 

 

[Penrhos1920]

Has it really been 7 weeks since I posted!  Well it's taken all of that time to get sorted with my own 3d resin printer so that I can print my railchairs to go with the printer sleepers.  I've bought a Mars 4 9k funded by selling some of my post privatization rolling stock on eBay.  Then I've had to purchase several other things that I hadn't thought about: screen protector, cover to keep out the light, z-axis grease, heater and a full face mask.  They're on top of the items I had thought about: a plant sprayer to wash off resin, a roll of UV leds and a little rotating stand to make my own curing station.

 

The 'wash station' consists of a bucket of water and a plant sprayer.  I'm only using water washable resin so the cleaning is a couple of dunks in the bucket of water followed by a spray into the finer details to remove the last of the resin.  In theory the bucket of water, when left in the sun, should evaporate leaving behind waste resin, but so far this summer the bucket has filled with rain more than its evaporated. 
 

I then dry the prints with a hair drier,  put the build plate on the rotating stand and cover with the homemade curing station:

 

 - a 10" plant pot covered inside with silver foil and a roll of UV leds.

 

The first railchairs I printed would not take the code 75 rail I've have had for a while.  I concluded that it was a combination of over exposure and the rail web being over scale.  I posted a photo on the Templot forum and Martin suggested that the rail head and bottom were also over scale.  So I printed some printer calibration models with different exposures to hone in on the best expsoure time.  Then I printed a series of test print railchairs with different rail dimensions.  The 5th print below shows I could slide the rail into all 10 chairs which I thought was a bit loose.  For the 6th print I reduced the rail web by 0.06mm and then could only slide the rail into the first 4 chairs; so thats the rail dimensions I going to us moving forward.

 

I've now printed of the rail chairs for a whole turnout, but this time they are loose jaw, meaning that the outer jaw(s) with a key are printed separately.  Loose jaw chairs allow the chairs to be inserted into all of the sleepers, then the rail is dropped in vertically and then the loose jaws are slotted in to hold the rail in place.

 

 

 I’m going to label every raft of rail chairs that I print with the location on the trap plan they are for.  Just to make sure I don’t get mixed up once they come off the printer. Look who’s found my secret stash of wagon kits. 

 

Edited June 25 by Penrhos1920
Images added

[martin_wynne]

1 hour ago, Penrhos1920 said:

In theory the bucket of water when left in the sun should evapourate leaving behind waste resin, but so far this summer the bucket has filled with rain more than its evapourated. 

 

Hi Richard,

 

It's not likely that a whole bucket of water will evaporate anytime soon, even in today's heat.

 

The idea is that the UV in daylight cures the resin which is dissolved in the water. Which then falls to the bottom of the bowl or bucket. This takes only a day or two, even in winter. You can then pour off the clear water, leaving a layer of sticky residue in the bottom of the bowl. This can then be left in the sun to dry out, leaving a solid layer of cured resin which will shrink away from the bowl as a solid disc and is easily removed. And can be discarded, or put to some clever use. Anyone?

 

cheers,

 

Martin.