My Last Post of 2015

2015 is drawing to a close and I have been spending some time this week catching up on some of my projects over the Christmas break. So this week’s post is simply to remind you about Shapeways 15 days of deals which will be running until the end of the year and to wish you all the best for the New Year.

The start of the New Year will bring the completion of some long awaited projects and the introduction of some new ones, I think it’s going to be a good year.


New Gears for an O Scale Rivarossi F9 Revisited

Back in February of 2015 I shared with you my 3D printed replacement gears for the Rivarossi O Gauge F9, you can read the post here.  Since producing the gears we have picked up a few anomalies in the different Rivarossi locomotives, mainly caused by a large manufacturing tolerance, that causes an issue with the gears.  In this post I will be showing you the new updated gears.

Although the 3D printed gears are vertically identical to the original Rivarossi ones they have been coming out at about 0.3mm to 0.5mm larger in diameter than anticipated.  For the majority of the Rivarossi O Gauge F9s that were fitted with the new gears, this had no impact as there was room for this.  But a few seemed to bind up.  The problem was traced to the 3D printed gear teeth hitting the corresponding gears root.  The root is the bottom of the gap between the gear teeth.

To solve this the 3D printed gears teeth where reduced in length by a fraction each reducing the overall diameter of the gear.

Below is an image with all three gears.  On the left is one of the first run of 3D print gears, in the middle is the original injection molded gear and on the right is the new 3D printed gear.

Rivarossi o Scale Gears 1

Although it is hard to see, as the difference is small, the teeth on the new gear are slightly shorter than on the first run.  This will make the new gears mesh perfectly with all the existing Rivarossi gears even if the drive gear position is a bit out of tolerance thus eliminating the problem that arose with a few models.

All the gear pack in my shop have been updated to the new versions and you can get them here.

Mike Dobson is the fellow modeler who first asked me to 3D print the gears to repair his locomotives and below you can see the new gears fitted to a chassis under a Great Northern GP7 shell.

Rivarossi F9 (O Scale Gears 6 (Mike Dobson)

As you can see below Mike has several sets of axles already repaired with the new gears ready to be fitted to his locos.

Rivarossi F9 (O Scale Gears 7 (Mike Dobson)

Rivarossi F9 (O Scale Gears 8 (Mike Dobson)

With the locomotive reassembled, it was time for a test run.  Mike storage yard is above his layout in the roof and there is a fair climb up to it.  This is a great test for the gears.

Rivarossi F9 (O Scale Gears 9 (Mike Dobson)

And finally we have a video of his repaired GN GP7 running on Mike’s layout.

And that ‘wraps up’ my last post before Christmas, but not wanting to leave you with out a gift, the nice people at Shapeways are having 15 days of deals to close out 2015, and today’s deal is $10 off all Frosted Detail Plastic orders of $30 or more!  As all the gears and my locomotive shells and detail parts are printed in Frosted Detail Plastics this could be useful.  Simply enter the code FROSTY2015 at the checkout.  This offer ends at 11:59PM Pacific Time on the 21 December 2015.

Happy Christmas

Completing My N Scale DD35 Set

This week’s post is about completing my set of Union Pacific EMD DD35 locomotives and making one of them look like it’s about ready for the scrap man’s torch.

My N Scale DD35 kit comes with 3D printed handrails and although they are strong and fit well, they are a bit on the thick side, as you can see in the image below.  This is one of my early DD35 dummy locomotives.

UP DD35 With 3D Printed Handrails

When running a DD35 along with a Con-Cor U50, as shown in the next image, this is less of a problem as the U50 also has oversized handrails so they work well together.

DD35s and U50

To further improve the DD35 I released an Additions kit of brass handrails and as you can see below they greatly improve the locomotive.

UP DD35 With Brass Handrails

The DD35 above has been painted as if it was a new locomotive and is ideal for running with a pair of GP35s as shown in the following image.

UP DD35 with GP35s Brass Handrails

Ideally another DD35 is needed to complete the set but as you can see from the image below the 3D printed handrails tend to stand out.

UP DD35s with GP35s Plasic & Brass Handrails

Weathering a locomotive always improves the appearance, even if it’s a little soot around the exhaust stack and grills, but to really make a DD35 look like it’s had a hard life you need to go a step further.

The DD35 shell used for the locomotive below was actually a damaged shell.  It had suffered damage which had left the surface very rough and some of the detail had been obliterated.  This made the shell perfect for a heavy weather.

UP DD35 With Brass Handrails & Heavy Weather 1 UP DD35 With Brass Handrails & Heavy Weather 2

Not only has the paint been darkened and discolored but rust streaks have been added along the sides; this has been done with decals.

UP DD35 With Brass Handrails & Heavy Weather 3

Very close up you can still see the roughness of the shell but you have to look for it.  Overall the effect of all the rust and corrosion blends in with the roughness to create a great-looking loco.

UP DD35 With Brass Handrails & Heavy Weather 4

Putting all three DD35s together you can see the differences.

All UP DD35s

I am planning on running both the heavily weathered and clean DD35s together as if one has been refurbished.

UP DD35s Brass Handrails Heavy Weather & New

Although it’s difficult to see, my GP35s are not actually the same.  One is a Phase 2 and a later model so I have one new and old GP35 and one new and old DD35 to complete my set.

UP DD35s & GP35s Brass Handrails Heavy Weather & New 1

My older GP35 Phase 1, on the left, will get some heavy weathering too.  This line up would have produced 15,0000 horse power at the draw bar and even for the long trains we run on our N Scale layout, Solent Summit, that’s a lot.  So only the weathered DD35 is powered and the refurbished one is a dummy locomotive.

All the painting and weathering on these DD35 locomotives was done by Bob Norris who has also painted and decaled Southern Pacific DD35 locomotives.

SP DD35 9902 8

In fact we can offer DD35 locomotives in SP, UP & EMD Demonstrator liveries.

DD35 UP SP Demonstrator

If you wish to read more about my DD35 kit for powered and un-powered models here is a link to their page in the shop and here is a link to their gallery page.  If you are interested in getting a ready-to-run model in any livery, in new or weathered condition, please contact me though the contact page.

Adding N Scale Wheelset Resistors for Circuit Detection

As well as 3D printed models I do a lot with DCC and model railroad wiring.  Recently I have been building computer controlled DCC layout and this adds a whole new level of requirements to the layout such as circuit detection.  In this post I will share with you how I get rolling stock ready for circuit detection on an N Scale DCC layout.

Circuit detection is fundamental to computer control as it tells the computer where trains are on the layout.  It is also useful if you have hidden sidings and you want to know where your trains are.  There are several companies that produce circuit boards for circuit detection and on this layout I have used Digitrax’s BDL168 boards.  The boards work by measuring a resistance across the track; this can be anything from an LED to a DCC chipped locomotive.  So if you have a locomotive in a section connected to a BDL168, even though it’s not moving, the board will detect a resistance and turn on the output for the section.  The output could be connected to a display panel or a computer could pick it up through the Digitrax Loconet system.

This is fine for locomotives and rolling stock with illumination but what about basic freight cars or wagons?  The computer controlled layout I’m building is a British outline model railway and has a lot of coaches that will all need to be modified so the circuit detection can pick them up.  A lot of the coaches, as shown below, are made by Graham Farish and luckily have metal wheels, obviously plastic wheels sets are no good for circuit detection..

Wheel Set Resistor 1

If you do have rolling stock with plastic wheels you can get replacement wheel sets for just about all ready-to-run stock.  Although metal wheels usually run better you don’t have to change all the wheel sets for metal ones, only the ones you intend to modify.  In fact you only need to modify one wheel set per item of rolling stock.  Because of the length of the coach I am going to modify one wheel set in each truck.  If it was a short wagon I would only do one.  Ideally I would like to modify the two outer wheel sets but as the axle is so close to the coupling box there would be no room.

Wheel Set Resistor 2

Adding lighting to the coach would be one way of creating a resistance across the coach but by far the simplest way is to add a resistor to a wheel set.

Wheel Set Resistor 13

As you can see from the images above with N Scale, and OO/HO, a standard resistor is a bit big and would be very impractical.

To overcome this, tiny resistors called ‘Chip Resistors’ are available, and are also very cheap to buy.

The best size of resistor for this job is a 10K Ohm.  The Ohm rating is the measurement of resistance and it is important to get this correct as the wrong resistor may cause heat which might warm up the wheel set and melt your train.  The chip resistors are usually supplied in strips as shown below.

Wheel Set Resistor 3

Close up you can see the tiny chip resistor, each one is in a pocket in the strip and covered by plastic film.

Wheel Set Resistor 4

Below is a comparison of the strip with an N Scale 3 axle tender truck.

Wheel Set Resistor 5

Once the chip resistor is popped out of the strip you can see just how small it is.

Wheel Set Resistor 6

And immediately you can see the advantage over the traditional resistor.

Wheel Set Resistor 7

The next issue is how to fix the resistor to the wheel set.  If you attempt to solder it on I guarantee it will go wrong.  The heat from the iron will heat up the wheel set and melt the plastic spacer between the wheel and the axle.  This will cause the wheel to become out of line and wobbly.  It may even cause a direct short across the wheel set.  The other option is to glue the chip into place.  This also has a few problems because if you get glue between the metal contact of the chip and the wheel or axle, the chip will not be able to conduct electricity.  To overcome this I have used Wire Glue made by Anders Products.

Wheel Set Resistor 8 Wheel Set Resistor 9

This is glue that has been designed so once it sets it will conduct electricity.

Unlike superglue or CA the wire glue needs time to dry, normally overnight, and that means it needs to be left where it won’t be knocked or moved.  Sitting one of those tiny chips on an axle that rotates is not very practical so I pop out the wheel sets and gently hold one of the wheels so the set can’t roll over.  Make sure what you are using to clamp the wheel set is not too strong as you don’t what to damage the wheel.  I would also recommend checking the wheel centers are correct before gluing the chip in as you won’t be able to move it once the glue has set.

Wheel Set Resistor 10

Once you are ready, and have stirred the wire glue, use a tooth pick to put a tiny amount on the axle and the inner face of wheel making sure you don’t bridge the plastic spacer with the glue.  Then using a pair of tweezers position the chip so one end touches the axle and the other touches the inside of the wheel.Wheel Set Resistor 11Once it has dried a little I put a bit more glue over the top to ensure everything makes contact.

Wheel Set Resistor 12

If, like this particular wheel set, both wheels have a plastic spacer you will also need to bridge the other side.  I have done this simply by spreading some of the glue across the spacer from the wheel to the axle.

Once dry you can check the resistance across the wheel set with a multi-meter.

This glue generates a fair amount of resistance itself so it would not be good for main DCC wires etc but for this purpose it does the job nicely.  I also don’t think it’s as strong as most glues so to make sure the chip won’t come off you could also put some superglue or CA over the top once you know it works okay.

Then it is a simple matter of fitting the wheel set back into the truck and the coach is ready for use on any layout and will trigger track detection on layouts with circuit detection.