Heavy Duty Machining 1000HP Tree Grinder Shaft | Part 1

Hey viewers Happy New Year! Our first video for 2021 is part 1 of machining a new shaft for a 1000hp tree grinder. This did not go as expected and we had some serious issues with the material. Hope you enjoy the video 😎👍 Subscribe and hit the bell icon to turn on notifications so you don't miss our weekly uploads. 👇 🤳 Follow us online here: Instagram www.instagram.com/cutting_edge_engineering Facebook www.facebook.com/cuttingedgeengineeringaustralia/ Official CEE Merch shop: www.ceeshop.com.au/

As Woodworker we bump into Problems with stress and bowing quite often. So we use heat treating as well. We heat the wood up to about 1000°C in the stove and this solves any Problem. :-)

Enjoyed the video about the bent shaft that kept throwing out. I worked on a copper mine in the 70's in Africa and we often made shafts. I remember shaft turning carbon steel pump shafts and larger shafts for the mining operations. With long shafts with a ratio of diameter to length over 1:13 one had to keep turning end for end and between centres. There was no heat treatment, we just kept turning end-for-end with light cuts until the stresses eased out of the shaft. Later in life running my own company similar to yours we found alloy steel shafts needed heat treatment. Not annealing, but stress relieving treatment. There is a British Standard available I believe, forget the reference number now. We would rough out to plus 10mm on diameters stress relieve 1. then further rough out to plus three mm on diameters and stress relieve 2. and then rough to plus 1mm all over. We would not finish important diameters leaving them to the very last. Where large keyways or drilling operation were involved axially we left bearing diameter's until the keyways had been cut. If a shaft is absolutely critical sometimes it is best to let it rest for a week in the roughed out state in addition to stress relieving. I found a company in Saudi in the 80's that had spent a lot of work on a large shaft 6" diameter x 6ft long and ground all over which had moved after grinding and the throw was 4/10 thou. That is 0.0004". The shaft had been rejected. To the comment someone made about cheapskate customers supplying poor quality steel, I would say no billet or bar is always perfect. I have had to reject stainless steel bars with cracks in the core. It's part of life I guess. I'm not familiar with the steel designations given in the video I only remember the British EN series. From memory the most stable steel available for shaft turning, steel that did not move, was EN14. It's tensile strength is little better than 20 carbon steel i.e. 20 tons tensile, but it is stable and easy to cut, also resistant to cracking. Customers often choose better quality steel for a job, but it is not always better, the steel has to suit the application. I remember a customer coming to me in desperation, he had used every type of alloy steel for a railway application where there was heavy vibration. We eventually tried structural steel grade 43A and it lasted 20 years. No cracking and the welds held. I think you could save a lot of time by buying a small horizonal milling machine for boring out gussets and beating. The Cincinnati 2E is ideal for such things and bigger millers for the larger work. I am very impressed however with the automatic welding device for line boring. I've been retired now 20 years, and I suppose I miss the old machine shop work. But better to watch your videos. Best wishes, your videos are fascinating and I have earned a lot from watching.

Just came across your channel and enjoy the content. I’m a manual machinist and make these shafts often and can keep them running within .001” the whole way but they can be very temperamental .Couple things I have found/been taught. Number 1: 4 jaw Number 2: face up the ends of the shaft and have it banked against something solid in chuck Number 3: rough in the big OD the length of the shaft before turning the ends. For one it gets all the stress out from the beginning that’s in that top layer. It also reduces the size of the square shoulder which will warp the shaft Number 4: step in your radius while roughing so it looks like a staircase. This will help with the large square shoulder and help keep it from moving. Radius will always fit under a 45% angle. Say you are taking 0.100” perside when you get to the end of your cut stop 0.100” sooner the next pass until then go step it down some more when done roughing before finish passes. With a radius that big on a shaft of that length you want the radius on both ends roughed in before finishing either side or you will risk bending it. Number 5: gotta be careful with the steady rest can bend them with that also. Number 6: I scraped one the other week because I got some unexpected taper on my last pass. Besides that nice work and I envy your lathe. I make them on a 1940s 20” American. That rapid traverse on the carriage, DRO and the chuck for the tail stock make me drool.

I just retired from a machine shop in Philadelphia. After rough machining we always send in out to be stress relieved , before final machining.

9 and a half banana's... spot on !

Interesting to see how different shops use different ideas to do the same type of job and I enjoyed seeing how you got it done. I used to do large commutator shafts of a similar size, and we had a few rules.... 1. No steady rest adjacent to the live centre. 2. Kept looking for another steady rest. 3. Span of less than 2 metres between Chuck/Live centre and steady rests, adding a second steady rest as required. 4. Opposing interrupted cuts for the two steady rests meant that we could send the material back. That interrupted cut behind the steady rest along the unsupported centre section had my teeth on edge...some evidence of sagging at the 12:00 mark. Building up heat in the work piece could explain some of your later run out issues as due to the thickness it likely wasn't heat treated fully before hand. Thanks again for an enjoyable video.

I remember the first machine shop I worked at and one of the things they made were impeller shafts about 10 feet long and about 3 inches in diameter made out of 4140. They would always warp .050-.100 once rough machined and left over night due to the fact the steel isn't stress relieved.

Hey mate, I’m an Aussie, not a machinist. But I have recently found your channel and have watched them all in a couple days. Love your work and genuine skills. If only I could turn back time, I’d love to do what you do and the skills you have. Thankyou!

The way this year has gone.... This is about what id expect.

Interesting method. Put 10 tradies in a room and everyone will have their style of machining.👍

Enjoy your videos . Your explaining each step of the job is great. My grandpa was a machinist for the Pennsylvania Railroad in 1937 to 1960. He was excellent at his trade. Had his own lathe & tools , unheard of in those days. No one but he could use it. He was that good. He would have loved to see you work. Love your pup...your wife is great behind the camera, you’re a good team. God Bless

That was just insane. The amount of work that goes into thinning that rod and turning the whole thing is crazy. You are amazing!

.... nothing more beautiful than a freshly machined piece of quality steel! I guess I'm just wired a little differently? I just can't help it. Some people go nuts over fresh baked bread (I've got that bug too) but, for me, it's fresh cut steel! :)

Really enjoyable to watch Curtis go about his work. A real craftsman!

15:55 One thing I've learned over the years, don't ever slide the end with a run-out into the 3-jaw chuck. First of all there's no way to check the end of the shaft and second, the 3-jaws will try to move the run-out in different direction. As someone mentioned before 4-jaw chuck and working between centers is your best bet. But if it turns out that it's some shitty material, then there isn't much you can do.

Mate, having turned hundreds or more shafts like that, the only way to ensure it stays straight is to run between centres in a 4 jaw (or a bored 3 jaw), rough it out, let it sit overnight, then finish it. Heat treatment is sometimes needed, but only usually once in a thousand. If you rough it with 10mm green on each end, or maybe you can get away with 5, then let it rest, even for a couple of days, then face off the green and re centre it and run it between centres again, it’ll run true, because you’re not gonna be removing heaps of material in the finishing cuts to put heat in and stress it out. If it was 4140, it would be much less susceptible, and 1045 much less again. But 4340, you have to look after it.

You two put a great video together. I always wondered how these giant machines worked and how they get repaired in a shop, etc. From Detroit, thanks for the look into the how to's.

Hello from Northern Ireland, I’m a machinist in a heavy engineering shop and we do lots of screen shafts for the quarry’s! We would normally use a 4 jaw Chuck when machining them and we don’t get a lot of runout maybe 0.2mm

Thank you for showing us the issues that are acquainted with doing such a job look forward to seeing how this would be handled