some work pictures

[dirty4fun]

You sure do some very excellent work, Tom. Thanks so much for sharing I sure enjoying seeing what you are repairing.

 

[Mink]

Hello . Its my first post on this great forum. Its cool because a member dont keep info. It interesting to see many information possible to find. My queation is:A cat interferance fit its .001 per inchs,anybody know a how many thousand of fit need for komatsu excavator? Its possible .003 inch per inches?

 

[ETER]

Hi Mink, That's an interesting question you have posted...Are you talking about a specific bushing to bore or pin to hole fit on the machine? I have never heard of a 3 thou per inch interference before...not to say that there isn't. A thou per inch is a good rule of thumb for a class 8 "heavy force" or "shrink fit". I would think that 3 thou an inch is beyond the elastic limits of any ferrous metal, especially cast iron. I would like to hear more on this too.
Regards, Bob

 

[Mink]

Thanks Eter for your answer. Its for bushing in bore. Whats "class 8 heavy force". Im agree with you for 3 thou. It s very high and its a shoulder bushing with seal housing . With 3 thou probably broken bushing.

 

[Wes J]

I own a machine shop. We use .001/inch for almost every press fit. For example, if I was using a 3/8 dowel pin, I would ream the press fit to .3745. It's a little tighter than .001/inch, but it works well and that size reamer is readily available.

 

[Mink]

I use 1 thou to but when i repair a cast iron electric motor cover housing, i use 1/2 thou per inch. Is more easyer to enter cast iron inner sleeve. I freeze it in co2 and push it in housing with hand. Not necessery use jack or other.

 

[RayF]

3 thou/inch is common on Hitachi diggers.

 

[Mink]

The last job i made is a komatsu excavator. Pin is 70 mm (2.756). Internal bushing is 70.36 (2.770) and external bushing is 85.12 (3.351). Logicaly,boring hole at 85mm (3.346) witch give .005 of thigthness. 2.770 - 0.005= 2.665 dia. of internal bushing after pressed. It remains 0.009 of space between pin ans internal bushing. I think it is much?

 

[Mink]

Thank you Ray!

 

[ETER]

3 thou per inch +/- (looseness) would allow for grease penetration...tighter fit, less grease...and according to my old machinists' handbook, this would be a "class 1" loose fit. I would think too that much of the "bushing to bore" interference decision would be based on the length of the bushing. I know that when I used liquid nitrogen to bring down a 9" diameter ring gear about 9-10 thou to go into a final drive housing...I was very glad that the gear was only about 2" thick because the temp equalization between the gear and housing happened very quickly! That's good to know on the Hitachis Ray
Regards, Bob

 

[NCHeavyDiesel]

Been a lurker on this forum for a while and just joined today. The quality of this mans work is impeccable! I consider myself to be a pretty competent mechanic but if i had just half of the knowledge that Tom had forgotten in his career then i would be untouchable!! Hats off to you sir!

 

[CM1995]

Welcome to the Forums NCHeavyDiesel!

 

[TOM V]

Mink, on the press fits I usually use .001-.0015 per inch, NC thanks and welcome to the forum.
Here are some pics from yesterday.

 

[Wes J]

Looks like you need a new bucket

 

[BPMfore]

With his talent, the bucket will be good as new when he is done.

 

[Wes J]

He probably has a plastic welder somewhere on that truck. Maybe he can hard face it with nylon.

 

[ETER]

Just stack another bucket in that one...soon you will have about a hundred of them...just like rabbits!
Regards, Bob

 

[kshansen]

He probably has a plastic welder somewhere on that truck. Maybe he can hard face it with nylon.

Never work dissimilar materials would need to use polyethylene.

 

[NCHeavyDiesel]

Tom i see you are doing some fairly good size cylinder packings....what do you do for the stubborn or large piston nuts?

 

[TOM V]

Tom i see you are doing some fairly good size cylinder packings....what do you do for the stubborn or large piston nuts?

1 1/2" drive impact wrench, excavator pushing on a homemade wrench,and if that does not crack em loose I'll send send it out.