Wichendon Machine Shop (restart)

[swisstrain]

Continuing to follow your build.  You are really going "all out" on that machine shop.

Excellent work!

[deemery]

I swapped emails with Deluxe Materials on the belt attachment.  They suggested epoxy.  That's a very interesting idea.  It certainly has good initial tack.  I ordered some long cure epoxy (all I had was 5 minutes, but I wanted more working time.) 

dave

[Philip]

   Hope the new epoxy works out. 

[nycjeff]

Hello Dave, the interior details look great, nice job. I hope that you work out your belt attachment problems.

[deemery]

My primary accomplishment this afternoon was practicing soldering really fine wire for LEDs.  My soldering skills tend to be quite perishable...

add:  and I realized I can test a string of LEDs with my LED tester, by testing 2 or even 3 at a time.  That's A Good Thing, when soldering together a longer string of LEDs without having to fiddle with resistors, etc. 

another add:  The lights are soldered together, i just need to confirm my calculations and add the appropriate resistor.  Then I can glue those onto the machine shop joists.  Those are Warm White LEDs with Tamiya Clear Yellow painted over top.  That gives a good old-timey color, I think.  The bottom right LED is the smaller LED for the office area, the other 3 go over the machine shop itself.


dave

[deemery]

Here's the position for the LEDs:


The little office LED goes where the arrow points.  Once these have been fully checked out, they'll be glued underneath the ceiling joists in those positions.

dave

[nycjeff]

Hello Dave, you're moving right along with the lights. Can't wait to see them all working inside the shop.

[ACL1504]

Dave,

This kit sure seems to have it own challenges and you are doing a great job at solving the issues.

I came very close to buying this kit when I saw the pilot model at one of the Expos. Just didn't think I needed it at that time.

Looking forward to your completed model and following along on this journey.

Tom

[deemery]

It's a nice kit.  They did include lighting, but those were big bulky things and I thought I could do better.  The big effort is in doing the machine shop interior.  They offered an interior kit of tools, etc, but I don't think that really included the full set of belt drive stuff.  Plus I think it was a woodworking shop, rather than metalworking shop.  The instructions are OK, they really do require experience to fill in the gaps. 

I'm sorry they got out of the kit business.  They had a nice niche for large prototype kits, but the market for those was probably limited.  Not many people have room for full-size coal dealers, like their first kit.  They still do custom models for architects, etc. 

dave

[deemery]

My resistor set arrived last night.  The 1k resistor is hooked up, I cranked up the amperage, and the lights remain lit (no magic smoke.)  I'll let them burn for the rest of the day, just to be sure.  

There's a hole in the floor (behind a closet I built) to run the wires down underneath the floor.  But the 1w resistor is too big to fit through the original hole.  I drilled a larger hole.  I'm sure a 1w is overkill, but another thing I'll check during the burn-in is how hot that resistor gets.  It would be A Bad Thing for a hot resistor underneath the model to cause a fire...

In the meantime, I painted some BESTTrains workbench tops and built some legs for them.  Right now the A&I over top of the paint is drying, I've learned to let that dry thoroughly because it softens the acrylic underneath.  Then I'll glue the legs onto the benchtops.  


dave

[PRR Modeler]

Nice job on the details Dave.

[Jerry]

Details look great Dave!!

Jerry

[jbvb]

The power dissipated is is current squared times voltage across the resistor. In your circuit, that's the voltage left after the 4 LEDs.

The resistor will try to dissipate the same amount of heat whether it's 1W or 1/4 W. The 1W resistor has more surface area to transfer heat into the air around it, though. You could leave your test rig on for a while, then check the surface temperature of the resistor - easiest if you have a remote-reading IR thermometer (you could borrow mine). If the resistor in free air is much above the air temperature, you could leave it outside the building. Maybe hanging under the foundation/baseboard?

[deemery]

The power dissipated is is current squared times voltage across the resistor. In your circuit, that's the voltage left after the 4 LEDs.

The resistor will try to dissipate the same amount of heat whether it's 1W or 1/4 W. The 1W resistor has more surface area to transfer heat into the air around it, though. You could leave your test rig on for a while, then check the surface temperature of the resistor - easiest if you have a remote-reading IR thermometer (you could borrow mine). If the resistor in free air is much above the air temperature, you could leave it outside the building. Maybe hanging under the foundation/baseboard?

I think it's less than 1v of 'excess' voltage from the 4 LEDs, and current is about 0.012a or less.  The resistor was on most of the day and doesn't feel warm to the touch (feels about room temperature,) so I think I'm OK. 

dave

[deemery]

I wanted a 'safe' glue to attach the LEDs to the underside of the ceiling joists.  I tested Deluxe Materials Tacky Glue, and this should work quite well.  Here's the test:
1.  Glue a small part of a long piece of styrene to a piece of wood:


Then suspend this so the length of styrene places torque on the joint:


After an hour to cure, the joint is quite strong. 

add:  Well, it took a couple of curses, but I have the 4 LEDs glued to the ceiling joists.  The problem is getting them placed squarely, when there's no space for your fingers...   Tomorrow, after the glue is cured, I'll do another lighting test, then add a bit of CA to lock them into position.  That's just in case there's a bad glue joint with the Tacky Glue.

dave