Made a gear cutter arbor

[DavidR8]

I'd be right proud if I made that!
Well done Jeff.

 

[Janderso]

That looks really good Jeff. Does the gear go to anything?

It sits in my reject pile

 

[brino]

It sits in my reject pile

For me it would be on a trophy shelf!
Even if not perfect over 99% of people would not be able to tell.
Just say it was not up to "your personal standards".

What moved?
Were you locking the RT between passes?
Would a tailstock have helped?

Thanks,
Brian

 

[ErichKeane]

Nice! I've cut gears on a few occasions and have a few learnings:

1- The rotary table needs to be locked, otherwise the gear can take up the backlash and screw you over.
2- The only 'good' arbor I've ever had for those is a home-made mandrel that uses whatever interior fixture on your gear holds it (like a set screw, key/etc), PLUS a bolt off the end compressing it.
3- Because of #2, grab a 4 jaw and indicate in the mandrel!
4- Cut as close as you can to the chuck, but no closer( or your chuck gets gear teeth ).

I've NEVER had the tailstock help at all FWIW. I'd rather use a center bolt to help hold on the mandrel. The side load on the gear blank is pretty minimal anyway, most of the force is rotational or towards the chuck.

 

[Janderso]

Nice work Jeff.

Interesting that individuals have some things that are easy for them and just do them, but others would hesitate. For me, having flubbed up an arbor, I'd hesitate making this. Guess we all come from different backgrounds. I'm just barely developing machining talents, whereas it seems you can just do things like this as a quick project.

Keep at it, you are an inspiration.

Those are very kind words. I appreciate it very much.
When you are just having fun and you don’t have a boss or schedule to satisfy, it’s just quality time in the shop.
Stretch yourself. That’s the only way to learn.

 

[Janderso]

For me it would be on a trophy shelf!
Even if not perfect over 99% of people would not be able to tell.
Just say it was not up to "your personal standards".

What moved?
Were you locking the RT between passes?
Would a tailstock have helped?

Thanks,
Brian

The gear slipped in the mandrel. I trued to keep the forces light by being patient.
Maybe a tapered mandrel and a tailstock.
I watched a video where they put a 1.5 degree taper in the mandrel. That’s easy enough.
I won’t use an expanding arbor next time I can assure you. I haven’t been too impressed with these cheapos.

 

[Winegrower]

I had good luck with the type of expanding mandrel that is two tapered wedges pressed together so they expand evenly and without a taper. The kind that expand with a screw in the end, I have little confidence in.

 

[Janderso]

I had good luck with the type of expanding mandrel that is two tapered wedges pressed together so they expand evenly and without a taper. The kind that expand with a screw in the end, I have little confidence in.

I have a couple of those. Haven’t used them yet. Good to hear they worked for you.

 

[WobblyHand]

I had good luck with the type of expanding mandrel that is two tapered wedges pressed together so they expand evenly and without a taper. The kind that expand with a screw in the end, I have little confidence in.

Is this the style you have no confidence in?

Used it to turn the outer edge of an 8" aluminum disc. 30mm OD. Uses a tapered 5/16-18 SHCS. 1045 steel, shop made. Guessing I was lucky that day.

Can you show a picture of the dual wedge type mandrel? I'd like to try making gears sometime, so having a good mandrel seems like a good idea.

 

[Winegrower]

Yes, that is the single end expanding mandrel I have, let’s say, little confidence in. I have used them for some work successfully. But this type below is far better, since you can use an arbor press to tighten the part on the mandrel.

The set below from eBay is particularly well made, seems to me.