Highland Railway 7 ton timber wagon - Type L

Found M, on most software Q = quit.

Noticed The fusion 360 server has been down a lot over the last 48 hours.

Not had chance to look at the model today, hopefully tomorrow.

Paul

 

Time to extract the finger

First up the floor

I created a sketch of a 6" plank 1mm wider than the internal distance of the underframe.
Extruded the plank to 1.5mm thick



I then applied a 0.2mm fillet to the upper face to provide the planking effect when each plank is added together



This was then copied and moved to produce a second plank - when the spacing was correct (a slight over lap) the two parts were combined together.



This process was repeated to for a 4 plank then an 8 plank unit.
I only needed 31 planks so 4 x 8 plank units were assembled with the final units were overlapped with one plank to give the 31 planks



Then moved into position



Next up holes for the grab handle, and lugs for the ropes plus bolt heads for the W irons were added



And finally for today the holes in the headstocks for the buffers (3mm) and coupling hook (1.2 x 2.5mm).



Next up the buffers, and coupling reinforcing plates.

Paul

 

cheers - we'll see how it turns out at print time.
I've been a good boy and refrained from doing a test print, but boy has it been difficult not to

Paul

 

Buffer first

I have done this as a separate Head and Shank, with a 1.6mm hole through the both for a 1.6 mm brass rod to be inserted into the head and passes through the shank.

I'll show this backwards, here is the final result



The shank



and head



Up untill now I've being doing all my Fusion 360 body creations from sketches, this time I did it more like the way I did it on 123D application.

Using the buffer beam sketch



I selected the sketch for the buffer recess, and extruded it 3mm to form the shank.



Then from the create menu I selected cylinder, clicked on the front edge of the buffer shank to select the plane to build on, then clicked on the center point of the shank face to set the new cylinder center point, draged the pointer out slightly to bring up a dimention box and typed in the diameter, press enter, then enter the length.



Repeat a few more times to create the rough profile of the buffer shank



Now for the bore hole through the center, same process as above for adding a cylinder, but when it comes to setting the distance, just drag the arrow the opposite way, it will turn red, but cuts the hole through the shank



Same again for the counterbore for the buffer head to fit in, I set this to 3.3mm diameter, the buffer heat will be 3.0 mm diameter.

I then added fillets to the corners to give the final result



Paul

 

The bufferhead was created in a similar method

I selected create cylinder, selected the outerface of the buffer body to build on, defined the diameter as 3.0 mm, and length as 6mm. The buffer head has 3.5mm of shaft exposed, the other 2.5 mm will be witin the body in normal position and can be pushed in a further 2.5mm.



Next the cylinder was bored out 1.6mm for the brass rod to fit in



Another cylinder added for the buffer head



and finally some fillets added



Now I know this is a flat surface, whereas it should be domed, but I can live with it.

Paul

 

And the coupling strengthening plate



Now this was a total fudge, which I will try and reproduce using the time line

Looking at the photo's they were no so much of an elipse as a diamond with rounded corners

Using the bufferbeam sketch as a guide, and clicking on the bufferbeam face I drew a triangle the approximate size of the plate.



I then extruded the shape 0.5mm



Mirrored and joined the shape



Applied a fillet to the top and bottom edges



And now the left and right corners



To reduce the size of the center hole I offset the faces by 0.2mm per face - if this is too tight for the hook I can open it up with a scalple



Now I tried all sorts of ways to produce the edge rib - and I've seen it done on many a video on how to do it, but murphy seems to have removed them from my internet access.

So I fudged it

I copied the body, and moved out of the way by 5mm. Increased the copy to 1mm thick, then used the shell command to create the edge



Then moved the original back into position, and used the extrude command to make the inner surfaces then same.



I then used the fillet command to round off the edges

 

The bolts were added next

A cylinder added



Filleted and moved in to the correct depth



I tried to copy and move the the bolt head, but would only let select the whole item, so another fudge, I copied the whole body, rotated it through 180 degrees, re-aligned them over each other and combined them into the final model



Mirrored the body on the rear face, and then aligned them into place on each end, finally merging the plate with each end.



Just the stanchions to do and then I can look at a test print.

Paul

 

Cheers guys, I'll have a look into lofting.

Think I've cracked the Stantion, just a combination of all the other techniques upto now.

Here's the result





And the wagon



It's tempting to start a print tonight, but I'll do the supports in the morning.

And with the drawing in place

Looks close to me



Paul

 

I used the auto support feature to apply light supports at 30% density, then manually added additional heavy supports to the underside of the body and buffer beams.



I had to reduce the raft size from 101% to 90% as the raft was beyond the build plate as shown in the red areas above.

Estimated print time is 3.5 hours, so should be back in 4 hours, if the boss hasn't found more gainful employment for me.

I'm going to try a test print of the buffers on the Photon with the Craftsman resin.

16 x buffer heads and bodies (12 needed for 3 wagon bodies plus a few spares)



Estimated 2h30m

Paul

 

OK disaster struck

After about and 1 hour and a half, I spotted the two outer prints appeared missing, a closer look at the center print and it didn't appear to be getting any bigger than the supports only. It'd very difficult to see the print progress as it takes a while before the print appears above the resin vat.

Now not sure what happened, the bases were definately well stuck to the build plate, so the cure time for the first layers are good.
As the delamination is about the same point 1.6 to 1.7 mm into the build and the surface is sooooo smooth.
As far as I'm aware, that leaves me with three possibilities.

1. Something happened to cause a non-standard exposure for a layer or two - Murphy strikes again
2. A slicing / file creation error
3. Exposure is too short

I can't do a lot about number 1 bar hope it's not a regular event, but as I was in the room there was no evidence of a power glitch, and no unusual noises from the printer.

To try and eliminate 2 or 3, I changed resin to Anycubic Green (I didn't have enough Standard grey to do the print), and didn't want to use the Eco resin.

Three hours 41 mins later

Prints look good

In the mean time, the Photon had completed the buffer head and body print - after cleaning

Note three prints are missing - one was in the wash tank

But no sign of the others - time to strain the resin in the vat and check the FEP - yep two failed print artifacts stuck to the FEP.
It's always best to check the build plate for missing items, and if there are some missing, get the Deer Stalker out and do the Sherlock bit to find them. If you don't then you've a chance of getting a punctured FEP, or evn a cracked LCD screen.

After removal from the build plate, they were given a 2 min cure, they will get longer but I want to drill out the holes before fully hardening them up.

Back to the wagon body

The prints were removed from the build plate, and washed in the wash n cure.

 

And the supports removed

The stanchions have printed well, including the hole, for wooden risers to be inserted - I will try a suitably stained and shaped match stick.

No errors in the print, so looks like an exposure issue for the Craftsman Grey resin.

The detail has printed very well with the green resin. In the manual - yes I have looked at it - well I did have nearly 4 hours to waste - twice, it suggests that the Green resin should be printed with a power setting of 50%, whereas the Grey, Black, White etc resins are printed at 80%. Now I have only ever used 50%, as there are many Youtube video's warning of premature burnout of the LCD by raising the UV power output. I simply increased the exposure. I probably will need to increase the exposure by between 20% & 30% for the normal layers.

I should really do the exposure tests to get it right.

Paul