I have just purchased a Boxford Lathe

[123hotchef]

I presume the change gear swaps with the bottom right gear does it.

 

[123hotchef]

I am new to this.

 

[Agroshield]

As the gear you show is two joined together, there are two places it cannot go: on the output from the spindle or the input to the gearbox. It has to go in the middle somewhere so that one of the gears is driven from higher up in the chain and the other is the drives something lower in the chain. That is how it does the imperial-metric or metric-imperial conversion.

I think it is pages 74/75 (80/81 of the pdf) here: http://www.pulse-jets.com/boxford/boxford_know_your_lathe.pdf

 

[Seadog]

 

[123hotchef]

Ok got it it goes in the middle in the sliding part. Why are there 2 gears stuck together. For different threads i presume.

 

[Guineafowl]

You normally mesh the smaller (100t) of the double gear with the screw gear (on the right). Pic above is not converting to metric.

 

[Agroshield]

OK got it it goes in the middle in the sliding part. Why are there 2 gears stuck together?

Mr Seadog's photo is probably a 'stock' photo showing the general principle, not one specific to your current need. In his photo, since only one of the gears is in use, it is only acting as an idler - not changing the ratio in anyway whatsoever.

As Mr Guineafowl says, for converting from one set of units to the other, both gears need to be used.

 

[123hotchef]

You normally mesh the smaller (100t) of the double gear with the screw gear (on the right). Pic above is not converting to metric.

ok I see so you flip the double gear over

 

[Guineafowl]

ok I see so you flip the double gear over

No, leave the double gear as in the photo, but mesh the screw gear with the smaller of the two. I’ll try to find a pic.

 

[Kram]

I cant really help other than try https://ridethegeartrain.com when you get some spare time to set it up, which takes a while. It greatly simplifies choosing the gears and which to go where, including for obscure/uncommon pitches that are not in your lathes diagram.

 

[Seadog]

Mr Seadog's photo is probably a 'stock' photo showing the general principle, not one specific to your current need. In his photo, since only one of the gears is in use, it is only acting as an idler - not changing the ratio in anyway whatsoever.

As Mr Guineafowl says, for converting from one set of units to the other, both gears need to be used.

Mr Seadog's photo is Mr Seadog's lathe, if you don't mind

 

[Guineafowl]

Like this:
You see you’ll have to swap the screw gears around so the 56t screw gear meshes with the inner gear.

Then use this chart for threads:

 

[Seadog]

ok I see so you flip the double gear over

No

 

[Seadog]

I'm in the pub. You flip the two gears around on the gearbox shaft.

 

[Agroshield]

Mr Seadog's photo is Mr Seadog's lathe

Sorry, I meant it was a photo you already had in your computer ('in stock') that happened to show the translation gear in the correct place, but not being used as a translation gear. You had not gone out to the shed specially to take one in answer to his specific question about how to set up for cutting metric threads.

 

[Guineafowl]

I'm in the pub. You flip the two gears around on the gearbox shaft.

I’m not in the pub, but am drinking homebrew. Together, we can explain it

 

[RichardM]

and don't forget the spacing collar under the gear ( not in the pub and not drinking homebrew or any other alcohol - unfortunately )!

 

[123hotchef]

hum ok I need to have a play

 

[addjunkie]

And do t forget….once you get your gears set upright. If cutting metric on an imperial lathe the thread dial indicator is no use, and vice versa. So you need to keep the lead screw engaged and reverse the machine.

 

[123hotchef]

oh boy, this is getting more complicated!