The first stage of fitting 3D printed brake blocks is the hangers. Sadly the nice cast brass hanger are far too thick for the replacement block so it was either make some new from nickel sheet or try to mill off the shoes from the etches supplied in the kit. with the make new ones as a back up plan I decided I had nothing to lose in trying to mill of the shoes and use the existing brake hanger etches.
So far so good. I now need to trim off the remains of the shoes, solder the fronts and backs together and then probably file a little more off to make the shoes fit.
I have had a Hobby Holidays Chassis Jig for a good number of years and I am really pleased with it.
It came with additional components to make it into a rolling road. I do use this but I have never really been happy with it. The rollers are set at 32mm apart to suit Peco track but as with the inherent slop in Peco track I find that the loco being tested tends to hunt from side to side never really giving a true reflection of how it’s actually running. I tried once a few years ago to reduce the distance by adding washers behind the roller bearings but my washers were too wide and all it did was seize up the rollers so I took them back out. When I bought my mill I had the bright idea to mill of 0.5mm from each spacer to reduce the slop but never got around to it until yesterday. I was about to dismantle the roller sets to mill them when I remembered that a former guild member had given me a collection of various nuts, screws and washers so I had a look through them and found some 0.5mm thick washers that were also very thin in terms of the washer area which while acting as a spacer to take off 0.5mm didn’t inhibit the movement of the bearings.
Hopefully this photo will show what I am struggling to describe.
This cured the hunting immediately, so I can’t recommend it enough to anyone else experiencing the same issue.
If you are connecting power directly the the motor the HH rolling road units are fine but if you actually want to test pickups then that’s a bit more interesting because the unit really isn’t designed for it. For years I have used a bit of a lash up of some lengths of copper wire and some crocodile clips to transfer power to each of the wheel cradles.
After doing a recent repair job for a fellow member which required testing pickups I thought it about time I did something a bit better. I found in my stash of “it will come in useful some day” materials a strip of aluminium which when cut into two pieces was perfect to create two bus bars. I milled some slots in them to allow adjustment to cover all my rolling road cradles (mine is a 5 axle jig).
As luck would have it in the front of the rolling road units is a hole to allow you to fit a hex key to get at some cap screws on the rear. These were just the right size to tap M4 while still allowing the hex key passage. There are also a set of holes already tapped M4 on top of the adjusters which will pass the current to the other side.
This is the bus bars in place. All that’s left for me to do is shorten a few cap screws to make them fit better. The end tabs allow me to connect via crocodile clip either DC or DCC
To prove it all works I took a shot video but instead of there being a boring video of a loco on the Rolling Road I played with the video editor to to turn it into a cartoon.
Recently while attempting to finish off all the little details of the J6 I had a bit of a conundrum. While I had fitted the front buffers previously to check that they went through the holes okay (I have had them in the past that haven’t and the hole had needed easing) I hadn’t actually tried to fit them with the body on.
What I found was that the 8BA nuts fouled the strengthening plates on the chassis and that the threads on the actual buffer heads hadn’t quite been threaded deep enough to pull the thicker part of the ram into the buffer stock. I recalled that David Hill of Gladiator had built one of these kits so I emailed David to ask how he had overcome the problem of the nuts fouling the chassis and I also mentioned about the threads not being deep enough. At this point although I could turn some replacements, the easier route would be to just run a die down them to make the thread a little deeper. What I was struggling with was working out the eternal problem of how to hold it securely to thread it.
As I have always found when emailing David, he responded very promptly and advised that he had filed flats on the nuts to clear the strengthening plates and he apologised about the threads and offered to replace the buffer heads. Now by this time I had my thinking head on and had worked out how to hold the existing buffer heads to add a few more threads.
Last night I decided to have a go. I had short stub of 16mm aluminium bar which I drilled 4mm x 5mm deep. Then I parted off a 5mm length and made a slit down one side to allow the centre hole to be squeezed to grip the buffer head.
Sadly, the buffer ram behind the head was 3.8mm and having drilled it 4mm (the nearest sized bit that I had) I found that the aluminium wasn’t quite flexible enough to tighten and grip the ram. I quickly sawed the rest of the way through making two halves these then gripped the ram and a few more threads were quickly added to both of them.
Next was what to do about the 8BA nuts fouling the chassis. I decide to see if I could drill out a 10BA nut and tap it 8BA. The 1.8mm drill bit was either two big or two small to be gripped tightly in the myriad of pin vices that I have so in the end I gripped the drill bit in a spare Jacobs chuck and used that to ease out the hole in the nut. I used my 10BA nut spinner to hold the nut while drilling and tapping to save faffing about trying to hold it squarely in a vice.
The next small issue was that the tail of the buffer was visible beyond the valence. To overcome this, I took 5mm of each of them and they became a snug fit behind the buffer plank (while still retaining some movement against the spring) and invisible once the body is on the chassis.
It was pointed out over on Western Thunder that the inset in the base should have the profile all the way around which I agree it should but I couldn’t work out how to do it. As always the minute that I started to reply to the gent who raised it I thought of how I might achieve it.
Next I drew a couple of upright lines on the first sketch to determine the width of the base of the fluted section. Which was 8mm on my overscale drawing. Then I created another offset plane this time at the top of the column/base of the fluted section.
Then I created a sketch on that plane and drew a circle 8mm in diameter on the edge of that circle I drew another circle 0.6mm in diameter using these as a best guess for the size of the flute. I then used the circular pattern tool to create circle all around the inner circle. this ended up being 42.
Then on the first sketch I drew the profile of the flute.
I extruded this again symmetrically 0.3mm either way, to give me the 0.6mm thickness that I had determined (best guess!!!) was the flute size. Then I filleted the front edges to give me the round flute
Lastly I used the circular pattern tool again to create the circle of 42.
I even managed to get the render tool to work this morning last night I think that my machine was doing an update in the background and it was running like a dog.
Over on one of the other forums, I was asked for help in the form of how to go about drawing up an NSR lamp post
On the basis of the drawing I had a few ideas of who I might go about it and once I had it cracked I was asked for an explanation of how I had gone about it. I thought I would share it wider as it might help someone at some point. You will have to excuse some of the wording that relates to answering the initial question. I haven’t the time at the moment to go through and re write it.
This was the drawing attached to the request for help.
First I downloaded Andy’s drawing and imported it into Fusion on the front plane. Then as I said previously, but repeated here for completeness. Because the drawing had no dimensions, I best guessed that the main part of the post would be around 10 feet tall. I was way out as it’s only around 6ft when taken right to the ground.
However using the 10ft as the basis, I created my self a User parameter of 1ft/7mm which allowed me to quickly scale the drawing to 7mm to the foot.
Next I did pretty much as Mossy had done in his test example and drew a profile of the lamp base and revolved it.
Then I worked out the middle of the column height wise and created an offset plane.
Then I created a sketch on that offset plane and drew the shape for my cut out
I nloy drew one of the shapes then used the ‘create circular pattern’ tool to create the other five. As it tuned out initially I had the outer circle slightly under the column sized so when I extruded as a cut it was actually inside the body. I then extruded using the symmetrical function and cut command so I was going both up and down to get the cut outs in place all around the column.
The wind dropped enough for a couple of short bursts of painting outside. This enabled me to get the chassis primed and then top coated. I also did all the other little bits that I missed when doing the body and tender, fall plate, doors etc.
Before risking gumming up the motion I asked Warren Haywood and Tony Geary how they painted inside motion. Tony hand paints his and Warren sprays it. Warren did suggest that since the brief for this is weathered black rather than red to metal black it. Thinking this a good idea I had a go. I gave the chassis a liberal dose of acetone to hopefully remove all the oil then a liberal dose of Birchwood Casey Brass black. It kind of worked, the motion itself looked fine but the insides of the frames and motion plates etc. were quite patchy.
In the end I bit the bullet and lightly sprayed it with black etch primer. Thankfully it all still moves as it should but I did mask it before putting the final coat of the rest of the frames.
Contrary to my last post I decided to see if I could make the motor mount removable. It proved not too difficult to add a screw and retaining nut to the adjacent frame spacer.
The motor mount also made a convenient place to mount a piece of Vero board which means that I can now remove both the motor and mount together without having to unsolder any wires which I count as an unexpected win.
The hole in the tender plate which supports the bottom end of the pivot pin was much bigger than the screw itself (8BA) and after fiddling around for about 10 minutes trying to get the screw to engage in the nut I decided to turn a small bush to centre it.
I am getting dangerously near to painting the chassis.