Seadog
Save the planet. It's the only one with rum!
- Messages
- 12,927
- Location
- NE London - UK
I see what you mean, Pete.
- Thread starter Pete.
- Start date
Seadog
Save the planet. It's the only one with rum!
- Messages
- 12,927
- Location
- NE London - UK
Low Budget Skills on Instagram: "Incredible Manufacturing Process of Double Helical Gear with 100yrs Old Technology"
59K likes, 166 comments - lowbudgetskills on October 16, 2023: "Incredible Manufacturing Process of Double Helical Gear with 100yrs Old Technology"
www.instagram.com
Back in school in the 1960's we each had a light blue book of tables of all the trig functions, log, log / log, and anti log (Godfrey and Siddons iirc) - there must have been gazillions of them printed so surely they'll still be around in book shops?
Yes here you go:
Yes here you go:
Godfrey and Siddons - AbeBooks
Four Figure Tables by The Late C. Godfrey and A.W. Siddons and a great selection of related books, art and collectibles available now at AbeBooks.co.uk.
www.abebooks.co.uk
Windy Miller
Semi-Professional Potterer!
- Messages
- 3,672
- Location
- North Kent, UK
I still have mine. Used daily when I was at school before calculators!
Brad93
Member
- Messages
- 19,085
- Location
- Essex, United Kingdom
I think we were shown excerpts of these types of books and it was quickly brushed aside.
Shame really, tremendous mathematical calculations used to be made with books like the aforementioned and slide rules.
Pete.
Member
- Messages
- 14,893
- Location
- Kent, UK
Big thanks to @Dcal for coming round and helping me put this back together yesterday. Earlier in the day I had stripped out the oil pump and du-gunged the sump. There was no metal in it just the heavier elements of the ol cutting oil had settled out over 30+ years and formed a tar in the base.
With that all cleaned out I turned to the pump. I re-greased the grease caps after digging out all the old grease. I put some light oil in first to ttry to soften what was left of the dried out stuff then fresh grease. Stripped and cleaned the impellor housing and set the terminal box for 240v delta. Then I found a 8uf cap and a 4uf cap, cobbled up a steinmetz connection and tested it out.
That was pumping great (even going backwards) so I re-wired it to turn the other way and it pumped even greater.
By now Dcal was here so he set about re-assembling the gear trains whilst I wired in the VFD. The drive fitted on the back of the button plate after removing the old contactor and shifting a few wires so apart from losing the start and stop buttons in favour of an Estop switch and speed control pot, it all fits inside without spoiling the look of the machine.
So things left to do are:
Button up the electrical cover after fitting the speed pot
Re-fit the guards and covers
Re-make the arbor drawbar for the hob arbor, the original buckled under 4 tons of hydraulic press getting the arbor out
Make some other arbors for different bore hobs
Fit a light, and a magnifier on the hob head scale, coz I can't read it easily where it is.
Re-make a couple of bushes for the gear train which are the wrong type
Re-make the 5/16"BSF nuts for adjusting the hob angle, with intenal hex instead of nut flats, as they are the devil to use so tight against the housing (and you use them a lot)
See why thwheel is wobbling when it turns, and sort it out.
Find if there's a method of simplifying the index geartrain setting. I did this on my old hobber by making some new gears and fitting them so that setting the train was a simple matter of putting the same tooth count in the train as the gear you want to cut.
Finally, Find a permanent spot for it, coz it's a keeper.
With that all cleaned out I turned to the pump. I re-greased the grease caps after digging out all the old grease. I put some light oil in first to ttry to soften what was left of the dried out stuff then fresh grease. Stripped and cleaned the impellor housing and set the terminal box for 240v delta. Then I found a 8uf cap and a 4uf cap, cobbled up a steinmetz connection and tested it out.
That was pumping great (even going backwards) so I re-wired it to turn the other way and it pumped even greater.
By now Dcal was here so he set about re-assembling the gear trains whilst I wired in the VFD. The drive fitted on the back of the button plate after removing the old contactor and shifting a few wires so apart from losing the start and stop buttons in favour of an Estop switch and speed control pot, it all fits inside without spoiling the look of the machine.
So things left to do are:
Button up the electrical cover after fitting the speed pot
Re-fit the guards and covers
Re-make the arbor drawbar for the hob arbor, the original buckled under 4 tons of hydraulic press getting the arbor out
Make some other arbors for different bore hobs
Fit a light, and a magnifier on the hob head scale, coz I can't read it easily where it is.
Re-make a couple of bushes for the gear train which are the wrong type
Re-make the 5/16"BSF nuts for adjusting the hob angle, with intenal hex instead of nut flats, as they are the devil to use so tight against the housing (and you use them a lot)
See why thwheel is wobbling when it turns, and sort it out.
Find if there's a method of simplifying the index geartrain setting. I did this on my old hobber by making some new gears and fitting them so that setting the train was a simple matter of putting the same tooth count in the train as the gear you want to cut.
Finally, Find a permanent spot for it, coz it's a keeper.
Seadog
Save the planet. It's the only one with rum!
- Messages
- 12,927
- Location
- NE London - UK
I still have mine somewhere.
Seadog
Save the planet. It's the only one with rum!
- Messages
- 12,927
- Location
- NE London - UK
That looks like the makings of a good Christmas pudding
Agroshield
Member
- Messages
- 6,147
Looking for something else, I found these:
They are an old series of booklets on gearing by the Association of Engineering and Shipbuilding Draftsmen.
It is good to see them preserved in electronic form.
They are an old series of booklets on gearing by the Association of Engineering and Shipbuilding Draftsmen.
It is good to see them preserved in electronic form.
Martin Hocking
Member
- Messages
- 475
- Location
- Norfolk
Can someone tell me whether gear helix angles are that unique to their application?
Sorry I can’t think of a better word to explain. The gear in Pete’s example using the calculator he has found has a helix angle of 15.15 degrees. Would this be something you’d encounter commonly? Why would this not just be 15 degrees? Pressure angles seem to be set to standard angles what does the extra .15 gain?
My naive first impression was that there would be the fixed gear sets for whole degrees (which I think is what it says in manual) and bobs your uncle helix away my friend.
(Apologies in advance for expressing an angular measurement in decimal hail Mary’s have been said)
Sorry I can’t think of a better word to explain. The gear in Pete’s example using the calculator he has found has a helix angle of 15.15 degrees. Would this be something you’d encounter commonly? Why would this not just be 15 degrees? Pressure angles seem to be set to standard angles what does the extra .15 gain?
My naive first impression was that there would be the fixed gear sets for whole degrees (which I think is what it says in manual) and bobs your uncle helix away my friend.
(Apologies in advance for expressing an angular measurement in decimal hail Mary’s have been said)
Pete.
Member
- Messages
- 14,893
- Location
- Kent, UK
The pitch diameter of a helical gear increases slightly with the helix angle. So if you have two gears at fixed centres (perhaps on a common shaft as in a gearbox) you can fine-tune the mesh/backlash of the gears by increasing or decreasing the helix angle which will bring the gears closer or further into mesh.Can someone tell me whether gear helix angles are that unique to their application?
Sorry I can’t think of a better word to explain. The gear in Pete’s example using the calculator he has found has a helix angle of 15.15 degrees. Would this be something you’d encounter commonly? Why would this not just be 15 degrees? Pressure angles seem to be set to standard angles what does the extra .15 gain?
My naive first impression was that there would be the fixed gear sets for whole degrees (which I think is what it says in manual) and bobs your uncle helix away my friend.
(Apologies in advance for expressing an angular measurement in decimal hail Mary’s have been said)
Also you can cut gears deeper or less so to ensure pairs of gears on a common shaft mesh, whilst using the tooth number needed for a particular ratio.
But the answer generally is that you can have any helix angle - for example original mini gearboxes were helical (no idea what angle, even if they were all the same), then came straight cut, which in theory are weaker, but lose less energy, and then someone came up with semi-helical, essentially a low number helix.
But the answer generally is that you can have any helix angle - for example original mini gearboxes were helical (no idea what angle, even if they were all the same), then came straight cut, which in theory are weaker, but lose less energy, and then someone came up with semi-helical, essentially a low number helix.
Martin Hocking
Member
- Messages
- 475
- Location
- Norfolk
Thanks chaps,
Plenty of food for thought there. I’ve spent most of today staring at tractor tyre tread trying to get my head around how the helix angle changes where the gears meet.
This thread has been a very helpful incentive to try and relearn some of the maths I used to know, and the Greek alphabet for that matter!
Plenty of food for thought there. I’ve spent most of today staring at tractor tyre tread trying to get my head around how the helix angle changes where the gears meet.
This thread has been a very helpful incentive to try and relearn some of the maths I used to know, and the Greek alphabet for that matter!
julianthegypsy
Member
- Messages
- 4,330
- Location
- Cirencester
Off topic slightly, but I used to work on industrial centrifugal separators. They were driven by a worm gear running backwards. Typically driven off a 10kw or more motor driving a big bronze gear through a centrifugal clutch to the shaft that held the bowl with the worm gear on it. The bowl would weigh about 250kgs and spin at about 8000rpm. There was a lot of force on that worm gear! It took 3 minutes to get up to speed and eight to stop using the brake, or about half an hour if the operator forgot the brake...
westfalia or Alfa-laval?
julianthegypsy
Member
- Messages
- 4,330
- Location
- Cirencester
Westfalia. I spent four years as service manager for their local subsidiary in North Sumatra.
julianthegypsy
Member
- Messages
- 4,330
- Location
- Cirencester
Yep. You can dial in how much fat you want left in the milk, but usually they take all the cream out then add whatever amount back to the skimmed milk to make semi skimmed. We had a heap of machines doing raw palm oil, latex, some doing marine diesel plus assorted oddballs doing wine, recycling lube oil in a steel rolling mill etc etc. Oh and a couple cleaning viscose fibre out of caustic solution. They are a rabbit hole when you get into all the different types and uses.
