Myford gear selection

[Cornish bodgerParticipant @cornishbodger]

Hi I'm in the process of making the Eric Whittle aero V8 and and at some point in the future I'll need to make a camshaft.

So my question is there a gear configuraion the Myford ml7 that makes the lead screw go the same speed as the main spindle so I can make a pattern lobe that runs of the leadscrew and then make a jig to make a pentograph setup so then the bar stock can be machined wiith some sort of replication.

I'm still a novice at this so any poor terminology I apologize. Here's a pic of the crankcases for the engine,

[Cornish bodgerParticipant @cornishbodger]

Getting a 1:1 ratio

[Howard LewisParticipant @howardlewis46836]

Have to admire your courage at undertaking such a complicated model!

All that you need is to ensure that the gears on the Leadscrew and the one driven by the Tumbler Reverse have the same number of teeth. 60T comes to mind

There should only be one idler between them, if you wish the Leadscrew to rotate in the same direction as the mandrel.

Howard

[Cornish bodgerParticipant @cornishbodger]

Posted by Howard Lewis on 18/02/2019 13:07:37:

Have to admire your courage at undertaking such a complicated model!

All that you need is to ensure that the gears on the Leadscrew and the one driven by the Tumbler Reverse have the same number of teeth. 60T comes to mind

There should only be one idler between them, if you wish the Leadscrew to rotate in the same direction as the mandrel.

Howard

Thanks I like the challenge I find it's mainly patients and remeasuring all the time. That's good info I'll rummage in my gear box and see what I've got but i reckon I'll be asking on the forum for another gear.

[Clive Brown 1Participant @clivebrown1]

AFAIK, the standard Myford 7 change gear set comes with two 20T gears. They would be needed to set up 8 tpi. which is what you are effectively proposing to do

Edited By Clive Brown 1 on 18/02/2019 13:51:54

[Neil WyattModerator @neilwyatt]

Not quite!

It's the gear on the back end of the spindle not the one after the tumbler reverse you have to match. If using all idlers is impractical, make sure any pair of reduction gears is mirrored by an equivalent pair stepping the ratio up.

Neil

[Chris TriceParticipant @christrice43267]

Use the 8 TPI gears quoted on the Myford gear cutting chart that should be on the lathe and/or in the manual that comes with it. The chart is also widely available online.

[Cornish bodgerParticipant @cornishbodger]

Thank you all 8 TPI it is.

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