This was found many years ago when BMC nitrided the en40 mini cranks - they grew!
- Thread starter Pete.
- Start date
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Its alive!
I managed to assemble the gearbox, then i put it back to the frame. It was not an easy job!
@Pete. , If the time arrives when you put your machine together, an advice for the gearbox installment:
There is a ~15 mm hole in the center of the casting against the speed selector. If you put a bar into it, it gives an exellent grip to tilt the assembly in place. I did it all by myself, but if you can, invite someone for two extra hand.
Conclusion:
The gears are OK-ish, the tooth gap should be bigger. As all the errors sum up, there is a point when the gears slightly jam up, then free again.
I did a dry testrun to get all the dirt from the surfaces scraped off. Then I filled the space up with oil. The jamming can not be felt with hand, but the new gears can be heard:
I managed to assemble the gearbox, then i put it back to the frame. It was not an easy job!
@Pete. , If the time arrives when you put your machine together, an advice for the gearbox installment:
There is a ~15 mm hole in the center of the casting against the speed selector. If you put a bar into it, it gives an exellent grip to tilt the assembly in place. I did it all by myself, but if you can, invite someone for two extra hand.
Conclusion:
The gears are OK-ish, the tooth gap should be bigger. As all the errors sum up, there is a point when the gears slightly jam up, then free again.
I did a dry testrun to get all the dirt from the surfaces scraped off. Then I filled the space up with oil. The jamming can not be felt with hand, but the new gears can be heard:
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Thanks, it had a worse voice back then, you can imagine.
I'm happy how it turned out.
Yes, i have one, with the reversing gearset on the back. Right now the belt is not installed for the feed gearbox.
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
By the way, i took some photos about the replaced X nut..Thanks, it had a worse voice back then, you can imagine.
I'm happy how it turned out.
Yes, i have one, with the reversing gearset on the back. Right now the belt is not installed for the feed gearbox.
I will tap an M36x1,5 thread through the whole nut, then glue a bronze bushing into it, to save a lot of that precious metal.
The adjusting part will be bronze aswell, as in the original design.
pressbrake1
Forum Supporter
- Messages
- 5,707
- Location
- Essex
Heat treatment makes thing get thicker
Sensible way to ht gears is to use induction on just the teeth
Sensible way to ht gears is to use induction on just the teeth
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Yep, as I experienced now..
The base technology that I followed said that the dimensions will not be affected by the heat threatment.
I used 42CrMo4+Qt base material, because it is available at my favourite store at a bearable price. This material has good mechanical properties, and can be machined really good. This only needs a nitride coating on top, fo fullfil all the requirements I need.
Other solution would be a C45 material with induction hardenig, or use 16MnCr5, then carbonize the furface, then quenching and tempering. Due to quenching, the dimensions woud be affected, and the tooth would need to be grinded to final dimension.
The main problem, that I have no contact to a tooth grinding factory, so it would be more money to grind them, than start the whole process from the beginning, and mill the tooth with bigger tolerances.
Pete.
Member
- Messages
- 14,732
- Location
- Kent, UK
What do you mean, reversing gearset? Does your feed gearbox have a rod with a round knob coming out the rear? I have seen photos of them but mine is not like that.
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Yes, thats what I mentioned.
There is an extra gearbox under the pulley. With the knob, I can reverse the feed direction if i need.
I plan to clean that gearbox also and machine a new rod because mine is quite bent and damaged. If you need pictures of this gearbox, I can make some next weekend.
Pete.
Member
- Messages
- 14,732
- Location
- Kent, UK
I have the gearbox which is in good condition apart from a couple of leaking seals, but it is non-reversing although it does seem to have and extra 'lump' behind the pulley. I'm pretty sure that the machine doesn't feed when the main motor is in reverse, so I guess that is why the gearbox has a reverser.
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Yes, that lump is where the reversing gear is in the setup.
The kinematics of the machine contains a kind of ratchet mechanism, as you saw, at the direction selectors on each axis. If you need to rotate the spindle the opposite direction as usual, (eg. boring head operations) the directions off the feeds will be reversed too. In that case, your feeds will not functional, as the ratchet mechanism will push back the selector lever to neutral.
Thats why there is a reverser on the feed gearbox also, as the reversed spindle needs reversed feed too. The spindle reversed electrically, but because the gearbox is "hardwired" to the main motor, it needs a reverser gearset, to change its direction back to the "normal".
Oh, how strange. Is the Deckel like this too does anyone know?
My Aciera has a separate motor for feeds so is independent of the direction of the main spindle.
Is there room for you to fit a separate motor @Pete. ?
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
The "ratchet" mechanism looks like this in all axis:
The power can be only delivered through in one direction, otherwise the center piece lifted back to neutral.
Pete.
Member
- Messages
- 14,732
- Location
- Kent, UK
I could fit a separate motor but first I want to look at this gearbox just in case there's something I've missed. Using a separate motor would carry the benefit that the main motor need not be running when using the high speed head just so you can have powered feeds.
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
I started to manufacture the new parts for the mill. The Z nut is finished, the screw needs the thread, and the milling of the keys.
Last edited:
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
How can I send you PM through this forum, so we can discuss the details about the electrical components, you mentioned?
It"s not urgent, I ain't finish the mechanical part in the next month..
paradipiro
Member
- Messages
- 100
- Location
- Budapest, Hungary
Probably because you are a new member...
