3" Burrell Traction Engine build.

 Where Are We Now? We are now seven years into this build. Over that time, many parts have been started — including some of the larger components — and if you’ve been following this blog, you’ll already know it’s been a slow process. Recently the weather has also not helped being so hot in the workshop!! Looking ahead, the task can feel daunting. Even imagining the engine finished, there are still countless hours of workshop time needed to complete it. It’s easy to admit that the engine may never actually be finished, but for me that has never really been the point. The interest has always been the same: Use my father’s machines. Make use of as much of the mild steel lying around the work shop as possible. Learn new skills - such as welding, and screw-cutting, and improve machining standard. Involve my son, who incidentally is a fabricator/welder. Keep busy every Monday night, trying to make the next part. And these, more than anything, is what keeps the project mo...

  Cutting The Square Brake Rod Nut   (Final Part, Honest!).  Right, this really is the last post on this part! It’s been a long and slightly risky job, but I’m genuinely pleased with how it’s turned out. Learned a lot along the way—especially with screw cutting and case hardening mild steel—and it’s another part ticked off for the engine. Photos show the plug tap I made (top left) , the nut in progress (top right), and then the nut fitted on the brake shaft. Happy to say it all works spot on. The square thread runs really smoothly, with no slack or backlash at all, and very little friction. With the amount of thread engagement, it should be more than strong enough in use. Feel free to leave a comment !!      stephen.meredith1@gmail.com If you have any questions while reading these blog updates—I'm always happy to reply. Until Next month, stay safe, make swarf and be the best you can be.

   Cutting The Modified Square Thread-Brake (Part 4).  Me aged: 53 Software Engineer Machinist, with zero tolerance to mistakes.. Simple Idea: Making a Tap from a Threaded Rod Hello everyone—just sharing a simple idea I’ve been trying. Instead of scrapping a brake rod, I decided to practice screw cutting and then use the best threaded piece to make a tap. The goal is to create a matching internal thread for a nut. The brake rod has been completed (As above) but this has taken a few practice goes before committing to this. The results of which I am very pleased with and the square threads look the part as compared to just cutting a metric thread of say 8mm.  What I did Cut an external thread on the rod Used a 4 mm ball-end cutter to make three flutes Offset the cutter slightly to give a bit of rake Cleaned up the edges with a file Case hardened the tool The idea behind it If the external thread is correct, turning it into a tap should produce a matching internal threa...

  Screw Cutting The Square Thread-Brake rod (Part 3). Hello again. (To put a face to the Blog)   The brake rod threading is still very much in the practice stage—we’re now on part 3. Screw cutting is proving to be a real skill to master, especially when it comes to achieving the correct thread form and overall appearance. The latest attempt (shown above) still isn’t quite right, but it will be used as the basis for making a tap. The plan is to produce a clean, symmetrical thread, then mill flutes into it and case harden it. This tap will then be used to cut the bronze nut so it matches the thread that will be machined onto the brake shaft. The current issue is with the pitch-to-width ratio. I used a 1.5 mm cutter for this test, but in hindsight it really needs to be closer to 1.25 mm to achieve a proper 50/50 tooth-to-gap ratio, which I wasn’t able to get here. The drawing specifies 10 TPI (2.5 mm pitch), and while I’m close at 2.55 mm, the groove width of 1.6 mm is too larg...

Screw Cutting The Square Thread-Brake rod (Part 2). Hello again, this time I intend tackling the screw cutting problem, head on. Previously I eluded to the thought of cutting an acme thread but through some useful feedback, I've learnt that a square thread is, as the name suggests (square) and not acme form. The 2nd thing I have found out is my previous thinking of a pitch 0.108" is also incorrect. 1. Why the first lathe change gear setup didn’t work I selected from the longitudinal feed section of the chart instead of the threading (metric pitch) section. These feed settings are designed for fine carriage movement per spindle revolution , not for synchronizing the carriage with the spindle to cut a thread. So the gear train I spent hours installing: 24T stud 72–18T compound 80T 60T screw was creating a very small feed ratio , which explains why: ten turns of the chuck certainly wasn’t giving 1" of carriage movement That’s expected — feed rates are ...

  Screw cutting Acme Thread - Brake rod (Part 1). Welcome to this month’s traction engine build update. With the weather not helping motivation, I decided to tackle some straightforward lathe work — the brake rod. The drawing specifies a 3/8" × 10 TPI left-hand square thread. While anticlockwise operation to apply the brake would justify a left-hand thread (as seen on some full-size engines such as those by Aveling & Porter and Burrell ), cutting an internal LH square thread at this size would be challenging. A right-hand thread will be perfectly adequate for the model. My plan is to screw cut a trial thread in silver steel, mill flutes to create a tap, harden it, and use it to thread the bronze nut. I’ll then cut the matching screw so both parts mesh correctly. Since the nut is bronze, machining should be manageable. Although the Boxford metric lathe is the easiest machine to set up for screw cutting, producing true 10 TPI would require imperial conversion gearing. Instea...