Kozo A3 in 1.5" scale - new project
Moderator: Harold_V
Re: Kozo A3 in 1.5" scale - new project
Machined the mounting ring for the steam dome. It will be TIG welded to the boiler, then drilled and tapped. Show in position:
Re: Kozo A3 in 1.5" scale - new project
Kirk, Looks like a much better design. I can't tell from the photo, but will you be able to remove the elbows should the need arise?
Vic
Vic
For Duty and Humanity
Re: Kozo A3 in 1.5" scale - new project
The ring fits under the one elbow, so the two will be able to be removed together. I may need to machine a small relief on the ring to clear the elbow that screws into the boiler, depending on where it ends up after welding.
I will be using 10-24 screws for this plus the cap rather than the 10-32 used previously. A bit stronger.
I will be using 10-24 screws for this plus the cap rather than the 10-32 used previously. A bit stronger.
Re: Kozo A3 in 1.5" scale - new project
Got three main pieces cut and ready for welding.
Re: Kozo A3 in 1.5" scale - new project
Got the welding done by a buddy. Here's the base ring welded to the boiler, drilled and tapped:
A view of the bottom ring of the dome body, drilled to match the base plate. The notch is to clear the elbow.
An interior view:
Mounted on the boiler with the lid; safeties and fill plug installed.
Next is to fabricate and weld the mount for the throttle tube.
A view of the bottom ring of the dome body, drilled to match the base plate. The notch is to clear the elbow.
An interior view:
Mounted on the boiler with the lid; safeties and fill plug installed.
Next is to fabricate and weld the mount for the throttle tube.
Re: Kozo A3 in 1.5" scale - new project
Short shop sessions today. First, measured and drilled the hole in the dome through which the throttle rod will pass. It's 1/2", but could be enlarged is needed.
Then setup on CNC mill to smooth welds where the mounting flange will be welded later.
Then setup on CNC mill to smooth welds where the mounting flange will be welded later.
Re: Kozo A3 in 1.5" scale - new project
Made the mounting flange for attaching the throttle tube to the steam dome.
The 1/2" drill bit will align the two parts together for welding.
The 1/2" drill bit will align the two parts together for welding.
Re: Kozo A3 in 1.5" scale - new project
A friend welded the mounting flange to the dome body, so it was time for some fit checking:
With a little fettling I got the dome cover and base to fit, although I need to install the boiler jacket to be sure. When I installed the throttle rod mechanism onto the rear of the tube I found that the crank for the valve stem is now too short since the valve sits slightly higher now. I had made the hole in the dome smaller this time (.5" vs .65"), so enlarging the hole may work vs. making a new crank.
Since I'm going to redo the piping and since the Superscale injectors are lifting, I will position them inside the cab rather than underneath the running boards. Test fit of the cab looks fine for this by eyeball inspection.
With a little fettling I got the dome cover and base to fit, although I need to install the boiler jacket to be sure. When I installed the throttle rod mechanism onto the rear of the tube I found that the crank for the valve stem is now too short since the valve sits slightly higher now. I had made the hole in the dome smaller this time (.5" vs .65"), so enlarging the hole may work vs. making a new crank.
Since I'm going to redo the piping and since the Superscale injectors are lifting, I will position them inside the cab rather than underneath the running boards. Test fit of the cab looks fine for this by eyeball inspection.
Re: Kozo A3 in 1.5" scale - new project
Only 6 months since the last post; the engine has been sitting with boiler parts sitting around untended. But now with Cabin Fever past I don't have any shows for a while to get models ready for. So I made new gaskets for the steam dome and buttoned it up. Planning to take the boiler/throttle assembly to the RR tomorrow to do a hydro and see if the throttle leak has been cured.
I needed more 1/8 NPT plugs for the boiler than I had on hand, so I decided to make a batch. Needed 6, made 10. Here are the leftovers:
First time using a NPT thread mill in anger.
I needed more 1/8 NPT plugs for the boiler than I had on hand, so I decided to make a batch. Needed 6, made 10. Here are the leftovers:
First time using a NPT thread mill in anger.
Re: Kozo A3 in 1.5" scale - new project
Hydro was a meaningfull success as there was no leakage through the throttle @100 psi. A couple of seeps from tapped connections, but I intend to rebuilt the turret head anyway as well as redoing 90% of the piping.
Re: Kozo A3 in 1.5" scale - new project
Good to see you back at it Kirk.
Ken
Ken
Re: Kozo A3 in 1.5" scale - new project
Assessing the reassembly and piping project. Club member said copper tube in the smoke box is liable to corrode away, so I just ordered some SS tube and fittings from McMaster. Painted the boiler jacket again. Also ordered some elbows and brass pipe from PMR. I have remade the turret as well without the crappy solder joints. My plan is to get the jacket installed before mounting the boiler back on the chassis, as it was a PITA to do when on. Then sort the smokebox piping.