K1 Garratt Project (12) - Running test ....

Today I've been tinkering with the setup of weights on the loco for traction.

Initially I removed the pick ups from the front motor-less motion to allow the wheels to move 'free and easy', thus obviating the need for any weights in the front tank.

To get enough traction for the rear driving motion, I needed to add some extra weight, this was done by positioning it in the cab roof...

Then it was play time, the loco pulls 4 coaches or 8 or 9 wagons; the Radius1 curves on my layout slow the rolling stock down as there isn't much play in the Accucraft wagons' wheels (really should run these on Radius 2+ curves).  Anyway what the loco can pull is my typical train anyway, so success.

Run test with goods train .... (youTube)

I am going to look into the option of powering the front motion again, although I may need a new controller with more oomph to drive the two motors.

Also bought some loco crew (from Modelu).. primed but not painted yet...

K1 Garratt Project (11) - Rivets & Weight holders

I wanted some river detail on the edge of the tanks; found some strips of rivets from Zinge Industries ( https://www.zinge.co.uk/collections/flexible-resin ); tricky to get off the backing - had to stick the strips on user super glue.. 

Made up some weight holder compartments in the tanks....

I had a quick run test with the front motion motor removed, playing around with weights. It does run OK, but the rear motion slips a bit with 5 coaches. I will have to experiment some more to get the weight balance right with enough at the front for the non-powered motion to move and the rear powered one to get enough purchase on the track. 

K1 Garratt Project (10) - Couplings, weights and run test ....

Couplings added ....

Finished the coal bunker as well...

For weights for running adhesion I cut down those from the donor locos so they fitted in the end tanks...

Out to the garage layout for a run test ....

Run test with coaches ...  (YouTube link, may take some time load)

the run test picked up some problems - one being my controller kept cutting out - it has only enough output to drive one loco chassis not two. I could have one loco with no motor - will have to try that out.

K1 Garratt Project (9) - The water tanks/coal bunker

 Turning my attention to the water tanks and coal bunker...

The tanks made and the tops trial fitted (will fix them in place once suitable traction weights are added)....

top view of the rear tank, front part will be the coal bunker ... 

tanks are currently held in place with a screw into the chassis (may need to add extra fixings later)

K1 Garratt Project (8) - Footplate, boiler & cab ......

Making good progress on the build ...

Underside of plastikard footplate showing weight for adhesion ( I may need to add more later...)

The two 0-4-0 motions get a bit of padding on top to provide some support ...

bolier and cab fixed in place (whole thing is no quite rigid...)

Handrails to get from steps to cab ...

and of course the steps...

the main structural centre part of the loco build is now completed ...

 

K1 Garratt Project (7) - Safety Valve...

The shiny dome rather showed up my improvised safety valve made of plastic bits

so a suitable one fitted - a Ramsbottom Safety Valve,  plus a whistle...

The boiler and back-head assembly mostly done...

My order of Plastikard arrived from Slaters this morning so I've cut and marked up the footplate

K1 Garratt Project (6) - Rear Tank and Cab...

While waiting for delivery of some plastikard I've ordered for the build, I made a neat'ish drawing of the pieces for the front tank...

I wanted to use the same tank construction for the rear tank as well, so I sketched out a scheme for the rear tank (and coal store) to fit inside the back of the cab as per the real engine,

I spent a good half hour 'carefully' removing the bottom part of the back of the cab...

using my mock-up cardboard tank I fixed a profile of the coal bunker to it (slightly narrower than the tank); fits just right into the rear of the cab...

going round a curve the loco will pivot; a check on the worst-case cornering position the coal bunker doesn't touch the cab side - super 😀

The coal bunker will work as an add-on to the rear tank, although I need to take a bit out of the tank edge facing the cab for the coal to sit in.  The final coal bunker will be best designed once I get to the build stage.