worn out steering gears

[DavidBarkey]

I won't bother with pic.s you all have seen destroyed steering gears . The center section of the steering selector (half round gear) are done and the pinion has been adjusted already . The pinion is the easy one , it's on order and will have it first of next week . Now that brings me to the selector gear . Have any of you tried to rebuild the teeth , if so how did you and was it successful ? I have one old style and one new style . The old style is cast iron as far as I can tell and the new one is steel plate . The iron I can build up with brass and the steel I can build up with mig. Now come to machining . Spur gear cutters are expressive and I would need to make an arbour to put it on . Close inspection of the selector gear at the end "good " teeth I found them to be straight angle cut . So I am thinking that if I rough in shape with small grinder and template then use a carbide dovetail cutter to finish . I have a small indexing head and router bits .
Sounds simple enough , that what makes me think I am missing something.
Thoughts

Dave

[Harry]

I won't bother with pic.s you all have seen destroyed steering gears . The center section of the steering selector (half round gear) are done and the pinion has been adjusted already . The pinion is the easy one , it's on order and will have it first of next week . Now that brings me to the selector gear . Have any of you tried to rebuild the teeth , if so how did you and was it successful ? I have one old style and one new style . The old style is cast iron as far as I can tell and the new one is steel plate . The iron I can build up with brass and the steel I can build up with mig. Now come to machining . Spur gear cutters are expressive and I would need to make an arbour to put it on . Close inspection of the selector gear at the end "good " teeth I found them to be straight angle cut . So I am thinking that if I rough in shape with small grinder and template then use a carbide dovetail cutter to finish . I have a small indexing head and router bits .
Sounds simple enough , that what makes me think I am missing something.
Thoughts

Dave

Your the machining magician Dave! I think you have already got it figure out!

Keep the Peace
Harry

[Eugen]

Dave, wouldn't it be easier to cut the teeth on a 1/2 inch piece of steel plate, than building it up with MIG? Marked well according to one that's in good shape, and cut with thin disks on the angle grinder. Then just welded on the old rod? Unless you're set on fixing the old one, and in that case building it up with MIG makes sense. I'm sure you'll make that work just fine, either way.

[Spike188]

Dave,

I have been thinking about trying to build up and rough in with a drimel zip disk.

Spike

[Gordy]

With the number of casting being cast steel, I would test that cast piece to see what it is. I use a 1/8'' drill bit in an out of the way spot to drill about an 1/8" in. You know steel will curl and be shiny, cast iron will be small chips /powder and grayish in color. If cast iron, high nickel / stainless steel will stick nicely. If you have a TIG you could build the teeth up closer to the final shape to save some machining. Stick welding will be more work in the machining end. You probably would not use it enough to justify the roll of wire and another tank for your MIG. Found this for the shielding gas for stainless.

For MIG welding stainless steel, a shielding gas mixture that's 90 percent helium, 7.5 percent argon and 2.5 percent carbon dioxide is generally ideal.

For cutting the teeth I am limited to a die grinder with cut off wheel and a file


Gordy

[thebuildist]

That sector gear is based on a 50 tooth 10 DP (diametral pitch) gear.

To cut the gear slots perfectly, you need a 10DP #6 involute gear cutter.

Like this:

https://www.ebay.com/itm/274708008050?h ... SwVQhgQgGP

build it up, either by weld or brazing, depending on steel or cast iron, then mount the sector gear in a spindexer and the involute cutter in your mill spindle, and Bob's your uncle.

Run the cutter through a slot, rotate the gear 7.2 degrees, and run it through again. Wash rinse repeat.

Bob

[DavidBarkey]

That sector gear is based on a 50 tooth 10 DP (diametral pitch) gear.

To cut the gear slots perfectly, you need a 10DP #6 involute gear cutter.

Like this:

https://www.ebay.com/itm/274708008050?h ... SwVQhgQgGP

build it up, either by weld or brazing, depending on steel or cast iron, then mount the sector gear in a spindexer and the involute cutter in your mill spindle, and Bob's your uncle.

Run the cutter through a slot, rotate the gear 7.2 degrees, and run it through again. Wash rinse repeat.

Bob

Thanks Bob , I Knew it was a number 10dp but had not figured out the number of teeth / cutter number yet . This will help save some of this . It was going to take some math I have not done in a long time , Since I worked at Toronto Gear over 30 years ago . Thanks for finding that cutter . It is on order but won't be hear until after the new year , I hadn't found one that cheap . So I think I am going to try doing the steel one by hand and finishing with the dovetail cutter . Ya I know it means doing one side then flipping the set up and doing the other side of the teeth. And wait for the cutter comes in to do the cast one . Both should make interesting threads.


Dave

[DavidBarkey]

With the number of casting being cast steel, I would test that cast piece to see what it is. I use a 1/8'' drill bit in an out of the way spot to drill about an 1/8" in. You know steel will curl and be shiny, cast iron will be small chips /powder and grayish in color. If cast iron, high nickel / stainless steel will stick nicely. If you have a TIG you could build the teeth up closer to the final shape to save some machining. Stick welding will be more work in the machining end. You probably would not use it enough to justify the roll of wire and another tank for your MIG. Found this for the shielding gas for stainless.

For MIG welding stainless steel, a shielding gas mixture that's 90 percent helium, 7.5 percent argon and 2.5 percent carbon dioxide is generally ideal.

For cutting the teeth I am limited to a die grinder with cut off wheel and a file


Gordy

Good point , I made the assumption that it was iron because of the ware factor , but if they had all the rest out of cast steel. It would make sense that it may have been cast at the same time to save money . As for the bottle , the only bottles in my shop are Act. Oxy. and occasional malt based Co. containers.

Dave

[DavidBarkey]

I won't bother with pic.s you all have seen destroyed steering gears . The center section of the steering selector (half round gear) are done and the pinion has been adjusted already . The pinion is the easy one , it's on order and will have it first of next week . Now that brings me to the selector gear . Have any of you tried to rebuild the teeth , if so how did you and was it successful ? I have one old style and one new style . The old style is cast iron as far as I can tell and the new one is steel plate . The iron I can build up with brass and the steel I can build up with mig. Now come to machining . Spur gear cutters are expressive and I would need to make an arbour to put it on . Close inspection of the selector gear at the end "good " teeth I found them to be straight angle cut . So I am thinking that if I rough in shape with small grinder and template then use a carbide dovetail cutter to finish . I have a small indexing head and router bits .
Sounds simple enough , that what makes me think I am missing something.
Thoughts

Dave

Your the machining magician Dave! I think you have already got it figure out!

Keep the Peace
Harry

Thanks Harry , but as you see buy the others comments I there was some things I had not though of . Many minds with different perspectives help you see a clearer picture .

Dave

[thebuildist]

If you don't already have an arbor to drive that cutter, they're not too difficult to make if you use a "built-up" approach. I could have increased the "perfection" of mine by turning it from blank stock, but I couldn't resist the lure of using an off-the-shelf bolt and nut. Fast, easy, cheap. And it works great.

To make the large taper to fit the R8 spindle, I skimmed a section of the bolt just until it was true and then mounted a sleeve there using Loctite 680. The Loctite is not as tough as silver solder, but faster/easier/cheaper and it is very strong and permanent. Then I turned the r8 taper onto that sleeve. The other end that goes way up inside the spindle is the bolt head turned down to the exact dimension. 1 inch if I remember correctly. But I looked it up, whatever it is. Then drilled and tapped for the tightening bolt.

For the section where the cutter will be attached I just milled a keyway in the bolt threads, turned a collar for a tight fit (out of standard black "iron" pipe) and faced and counterbored the nut so that it can telescope over the od of the top of the key. The counterbore approach means that your key extends across the full width of the mounted cutter, no matter how thick the cutter is. The key is just soft steel that I ground/sanded to a tight fit.

The only thing to note is that I faced/counterbored the nut while it was threaded onto the bolt threads, to ensure that the face of the nut that bears onto the cutter is perfectly square with the threads and centerline of this precise bolt. That makes sure that the mounted cutter runs square/true with no wobbling.

Bob