Hawk

Very, very sad news. I had the fortune of visiting Roy and seeing Retford a few years back, and feel priviliged to have met Roy and seen his fanastic layout. The model railway hobby has lost one of its giants, but today my thoughts go out to his family and friends.

I have used this index a lot, and it has been a very useful tool. Unfortunately, It seems like it is getting more and more behind on the updates. So why not make a call for volunteers to bring the index up to date? I would guess that there is enough fans of the MRJ on this forum that would be happy to lend a hand. I certainly would.

I would love to hear some suggestions for speed/feed combinations for milling brass. I have been puckering around with a similiar CNC-router, but I have never really worked out the feeds and speed combination for the different sizes of cutters. I also wonder how deep cuts your machine is able to handle.

Snatched from a post on Narraow Gauge Modelling Online ( http://ngrm-online.com/forums/index.php ): -- Issue 116 has been sent to the printers with despatch due in the next week or two. The contents are as follows: Fen End Pit - The Rebuild - David Barham describes improvements to his 16mm layout The Other Way Around… - More on the Road-Rail system from Jonathan Palterman 7mm Scale Trees - Robin Edwards show you how to build deciduous trees Die Adlershorst Waldbahn - Part 1 - Making the forest by Roy C Link Kalka-Simla Articulated Locomotives - Archive material Kalka-Simla Rly in Postcards - Colour postcards from the past Equipment for Huffkins Mine - Modelling excellence from Stuart McPherson in 1:24 scale Compressed Air Mining Locomotive - Archive material Surviving the heat - Long term layout ownership with John Clutterbuck  Please login here to check your subscription status or take one out: https://narrowgaugeandindustrial.co.uk/ -- Really looking forward to it!

Both Shapeways and iMaterialize can do this with rather excellent results. Price and quality is almost identical. Here is a picture of an 0-scale center (outer diameter around 20 mm): All prescision surfaces needs machining, of course. Just like the real thing. The touch surface looks quite like the sand cast surface of the prototype, me thinks. A truly parametric Fusion360 model for drivers would be the holy grail of small series production of wheels. Combined with CNC machined tyres It will be possible to produce wheels in series of one. What a time to be a modeller!

I would go for 3D-printed centers and machined tyres. Finding someone to do custom wheel tyres should be easier and cheaper than the full wheels. The 3D-printed centers could be plastic or brass. For wagon wheels plastic would probably be OK. I have seen 3D printed plastic centers for steam engines in 0-scale (american 1/48) and it seemed to work rather well. I used Shapeways and iMaterialise to make me some brass wheel centers for some 0-scale wheels, and they look quite nice. For more info, you could take a look on this thread: http://www.rmweb.co.uk/community/index.php?/topic/130238-scratchbuilding-locomotive-drivers/ Best of luck with your project!

I am not quite ready to label the time spent with my lathe as a "pure joy". The learning curve has at times been so steep that I almost gave up. But I am more optimistic than ever. Maybe I in a couple of months will reach the pure joy stage! I fully agree that the journey is a destination in itself. But It is extremely pleasing to have completed at least two scratch built engines and a handful of wagons.

Long time no post, but I have not given up on my machining ambitions. Quite the contrary. I have long been thinking about taking some machining classes, but as no such classes are available in my area I had to find an alternative. So I posted a wanted ad on a local Facebook group for a private tutor. And to my surprise I got a positive reply. So a few nights ago I got my first machining lesson. It was almost a revelation to get the basics sorted out by a pro. What I learned this night will hopefully make a big difference on my future postings in this thread. I have also changed the way I think about my lathe and machining. When I first bought the lathe I greatly underestimated the time it would take to acquire the skills to make parts with the quality I want. But quite recently it struck me that buying a lathe is like buying a musical instrument like a guitar. You can not except to play beautiful melodies right after picking it up. You have to practice a lot, and taking lessons will speed up the learning process. Before, I felt a little stupid after spending a couple of hours at the lathe and not having anything to show wifey but a brass disk with a pressed on steel rim. If I had been practicing guitar for the same time, I would not have dreamt about making a recording of the session and let people listen to it! But enough with the metaphors. If you are not prepared to spend a lot of time learning new skills, you should probably not buy a lathe. Spend the money on custom built parts instead. And If you are, find a way to try out a lathe for some hours. Don’t expect to produce something useful, the point is to find out if you enjoyed the time spent on the machine. By the way, the going rate for a machining tutor in my area seems to be a bottle of decent red wine and a vinyl Frank Sinatra record!

I have now for the first time tried to add a tyre to a casting. The insulation is a thin-walled tube of delrin acetat. This type of plastic machines remarkably well, and it is easy to machine a tube with 0.3mm walls. While the tube was still in the chuck, I pressed the casting into the tube. I made a rather tight bore, so it was possible to skim the outside of the tube before pressing on the tyre. The fit was slightly loose, so I fixed the tyre with super glue. After the glue had dried, I placed the wheel in freshly machined soft jaws. With soft jaws I have been able to rechuck the wheel with a runout of 0,02mm sideways runout measured on the tyre. Axial runout measured on the tyre is very close to zero. When you machine the soft jaws it is necessary to tighten the jaws on a steel ring or similar: Finally, the axle hole is bored: I was a bit concerned that the forces from the machining would break the tyre loose from the casting, but it worked out OK.

Obviously, there are many ways to skin a cat! But I am glad I don´t have to mill all my spoked wheels on manual machines.

I appreciate the input! Is the crankpin press-fitted? And how did you hold the casting while machining? As I am looking for a contract casting company, do you know if the Birmingham caster you used are still in business?

Thank you for an informative reply! If you have some pictures of your wheel projects, I would be very interested in seeing them.

Thanks to all for the feedback! It is important to remember that this "print" from Shapeways is not really a print at all. Shapeways prints a wax master and makes a regular lost-wax casting from it. So it´s properties should be like any other brass casting. That said, I have other castings that has machined better with carbide insert tools. But as I would really like to get as much tool grinding experience as possible, I will try to use HSS as much as possible for my lathe work.

I will go along with "interesting", but how clever it all is remains to be seen... But hopefully there will be some pieces of useful information among all the noise!

You are right, I should have given the equation a bit more consideration. Another matter while I am at the keyboard: I tried to machine the castings last night, and a carbide insert tool gave the absolutely worst surface I have ever managed to achive in my career as an amateur machinist. A home ground HSS toolbit worked far better. Is the poor finish to be expected using a carbide insert tool on cast brass, or is it a feed/speed issue?

I focused on the sentence "Scaling up your model by 1% will make your design closer to your desired size.". I thought that meant that shrinkage was 1%. It seems a bit counterintuitive that you should increase the size of the digital model 1% to compensate for a 1,5% shrinkage.

As mentioned in the last post, the plan is to have the wheel centers cast in brass. I need only castings for two engines, and it is almost as cheap to have them all printed by Shapeways instead of having them cast by a casting service. (The cost for one wheel centre excluding postage was € 13.45) But I have a small hope of getting some other modellers interested in modeling my favorite railway, and then it would be nice to be able to offer some castings for sale. I have made the digital master for the 3D-print in Fusion360, and even if all the fillets and the form of the spokes is not perfect, I think no one will notice on a wheel less than an inch in diameter (22mm to be precise): A test was printed with Shapeways, and even if the surface is quite rough, I think it is passable for cast iron. But I think I will try and send the pictures to a casting service to hear if they can achieve a somewhat smoother surface: What do you think? Is the surface finish good enough? More troubling than the surface is the shrinkage of the part. The digital model has an outer diameter of 20.18mm, while the finished brass part is 19.8mm. Shapeways claim a shrinkage of around 1%, somewhat less than the almost 2% shrinkage I encountered. I also suspect that the part has been somewhat polished, even if I ordered a part in "raw brass". The 5mm diameter stub on the back is for mounting the casting in a collet on the lathe. It will be interesting to see how well the cast brass will machine. Suggestions for type of tool, feed and speed are welcome!

Some very fine models you have got there, David! May I ask where you put the insulation on your wheels? And what do you use for the insulation?

I am in the process of learning myself to scratchbuild locomotive drivers in 0-scale, and hopefully this is a subject that might be of interest to others. But at the time of writing I have not finished a single wheelset, so it is going to be quite a lot of trial and error in this thread! The concept is modelling wheel centers n Fusion360, 3D printing masters and finally having them cast in brass. Tyres will be machined in mild steel. What I have achived so far is machining tyres for two electric engines of this type: Here is a little photo-essay on how I made the tyres. My lathe is a Wabeco D4000, a machine that despite its quite hefty price tag has gotten somewhat mixed reviews. My impression is that the machine is more than adequate for work in 0-scale, and the troubles I have encountered is certainly more due to my experience than the qualities of the machine. But enough with the disclaimers, here is how I did it. 1. A piece of mild steel with a diameter around 1mm larger than the larges diameter on the finished tire is chucked firmly into a regular 3 jaw chuck. As all operations is done without re-chucking, a ordinary chuck is good enough. Purists will probably shake their heads already, the bolt extrudes far more than recommended. But I am a lazy bum, so I wanted to see if I could machine 8 rims in one setting. reducing this to 4 is probably wise: 2. The end is faced off: 3. The bolt is bored with a center drill: 4. The live center is placed firmly in the hole: 5. The carbide tool is set exactly to centre height. This is critical for a good result. I am measuring against the live centre in the tailstock: 6. Turning the bolt to a diameter slightly larger than the finished wheel: 7. With a parting tool slots are machined into the bolt. This defines the width of the tires, and are also an important relief for the profile tool used in the next step. Extreme care is neccesary for this and the next operations. Steady, slow feed and low rpm (around 50-100RPM) is essential. I lubricate with WD-40, wich probably is not the best lubricant, but it seems to help: 8. With a form tool from Protocraft in the US the final profile is machined. Now even more care is needed, i run my lathe as slow as possible. (50 RPM). Again, steady feed is a must. I lock all slides except the cross_slide. Note that the overhang of the tool is as small as possible. I did also add custom-made packings for critical spots on the tool holder: 9. For the next operation, the live center is removed, and the inner hole drilled with successively larger drills. If you look closely you can see that I ruined my largest drill: 10. The final size of an inner bore should always be made with a boring tool and not a drill. My $ 8 boring bar from eBay was just fine for the job: 11. Chamfering the edge of the tires: 12. The moment of truth. Parting off the tires. Easy does it! 13. At last, success! 14. Dial caliper beside the tires to show the size of the wheels. The outer diameter is 22mm. 14. All the different lathe tools used. A quick change tool holder is a must in my opinion: Well, thats all for now. In a not too distant future I will sho how I machine cast brass centers and assemble the wheel sets. Thanks for reading this far, and keep the comments coming! All suggestions and criticism is welcome. Best regards, Håvard H

A little postscript on the wagon project. As the wagons was going to be published in the narrow gauge and industrial railway modelling review, I held back on my best pictures until the piece had been published. (It ran in issue 112) So here are the images for those who did not see them in the Review. In addition, I added a couple of images with the wagons fitted with brake hoses. Got some nice glad-hands castings from a German modeller who was kind enough to sell me some. They are fitted with tiny magnets. Thanks for looking!

Does anyone know if Tony Reynalds is still in business? I have without success tried to get in touch with him. An email or snailmail adress would be perfect. Best regards, Håvard Houen

As I mentioned in another thread, I have just began using Fusion360, As an architect I am quite familiar with software like Revit, Archicad, VectorWorks and SketchUp. But Fusion is strikingly different from all these programs. So it takes some time to get used to it, especially the concept of parametric modeling. Still, after using the software for about 15-20 hrs, I have been able to model a engine driving wheel that is almost complete: Only a few features of the prototype wheel needs to be incorporated in the design. I will also remove the tyre, as the digital model shall be used as a 3D-printed master for brass castings. A very nice feature of F360 is that export to .stl (the format used by most 3D-printers) is painless. I will probably use F360 for making 8-10 casting masters for my current engine project. The wheel centers have by far the most complex geometry, so the rest of the masters will be plain sailing. An very interesting feature just added to F360 is Sheet Metal. I think this is a feature that can prove extremely helpful in designing complex etched models. I look forward to hear from anyone that has looked into this feature.

I looked for a thread on Fusion360 before starting my own. But I missed this one; The Great Fusion 360 Thread. My ego is pretty big, but I still feel I do not need my own thread on this topic. So I suggest that this thread is left alone in favor of the The Great Fusion 360 Thread. See you there!

I have never been an active Autocad user, so I am not the right man to answer your question in detail. But Autocad and Fusion360 are VERY different animals, so my half-educated guess is that FS360 uses few of the SC commands. But I urge you to take Fusion for a test run, and please share your experiences !

It is my guess that more and more railway modellers will look into Autodesk Fusion 360 as this is very likely the most advanced 3D modelling software available for free. I have just started to look into the program, but only after a couple of evenings I have reached the point were I am able to model a quite complex driver for a engine project: The mesh shows the stl version. One of the great things with F360 is that it outputs clean stl files that at least Shapeways accepts without any postprocessing. F360 also have CAM features for preparing models for CNC machining A recent feature added to F360 is sheet metal. I have just made a very brief test, but I think this can be a very efficient tool for designing complex etched models. So I have startet this thread in the hope that It can be a place to ask questions and share experinces with this software. Feel free to join the fun!