Need a pinion gear

Hi Guys,
This is my first post on this site. Hope to post many more.
That said, I have a slight problem. I am rebuilding an old Strands gear head drill press. Beautiful machine.
The table adjust pinion gear is damaged. Not much but I would like to replace it. The gear itself seems to be pretty standard except that I cannot find one with the same bore. The specs are as follows.
Spur gear module 2.
17 teeth OD 38mm
Width 20mm
Bore diameter 17mm.
I can find this gear with 12 or 15mm bore diameter.
Does anyone know where to aquire this gear otherwise I guess I will have to get one with smaller diameter and just drill it to 17mm. It may be to hard to drill but I can always make a plan.
Thanks
Chris

Generally stock gears are not hardened ,but are made of hardenable steel (SAE1045)....so you should have no difficulty drilling it.......but better to bore it on a lathe to get an accurate result.

Thank You John.

I just assumed a new gear will be hard as I tried a file on the existing gear and it seemed quite hard. If I replace it I will have it modified on a lathe.

Post a picture of the existing gear, if it's just a little damaged it could be cleaned up. It's just for elevating the table?
I once cleaned up a ring and pinion gear on a 6' King boring machine after one of the grade 8 bolts holding the ring gear had fallen out and passed through the massive 7" wide gears! The damage was considerable but where are you going to find a new ring and pinion gear set without spending multitudes of what the machine was worth. A lot of grinding later with a 4 1/2" angle grinder to remove metal from several bent gear teeth and it was back up and running.
I was called in when the machine just suddenly lurched to a halt! It could still run but it sure was noisy, after checking the gearbox I pulled the table and found the issue. The remains of the 3/4" grade 8 bolt were bent like a pretzel.

Mr Bridgeport

Sorry for the late reply.
Here are some photos.
All the teeth are in a similar condition.
There was no noticeable problem with the rack and pinion before I stripped the machine.
It is only to lift and lower the table.
I was thinking that maybe I should just use the gear as is.
Any ideas?

Thank You

Chris

That looks like a pinion which is worn from being driven
by an ill fitting worm.

You might try turning it over and wearing on the other side
of the teeth for a while.

I needed couple of change gears for my lathe. The gears had hardened teeth but were soft elsewhere. It was no problem boring them to the size I needed.

Chrisboon said:

Sorry for the late reply.
Here are some photos.
All the teeth are in a similar condition.
There was no noticeable problem with the rack and pinion before I stripped the machine.
It is only to lift and lower the table.
I was thinking that maybe I should just use the gear as is.
Any ideas?

Thank You

Chris

Click to expand...

I'd run it as is, grease it up good and it will last longer than you. My strands D P is great, I bet it is stiff as some knee mills.

Boston Gear

Boston Gear may have what you are looking for. They carry both 14 1/2 degree and 20 degree pressure angles. Good Luck!


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