Any tips for honing?

[Garwood]

I have a "best effort" job to bore a blind 4.000" hole 18" deep. It's a hydraulic cylinder that is currently 3.5" with a ballooned bore.

I don't think the boring will be too bad. I have never used a rigid hone before though. Just berry honed engine cylinders, master cylinders and such.

A friend just gave me a new Sunnen AN-112 hand hone and I have an Ammco model 500. Both seem able to do the job, but the Ammco is pretty cheezy.

I found a shop about an hour away that can do the honing if I can't. Figured I'd better have a contingency plan if I can't pull it off.

I want to try this honing thing. It was very hard to find the other shop that can do it. Seems like it wouldn't be a bad capability to add to the arsenal here.

How much stock would you leave for honing? I was thinking about .005" if I can get a nice finish with the boring tooling. If it's not pretty than maybe .01" Does that sound in the ballpark? I asked the honing shop what they wanted, but they wouldn't give me a number. Just "The more you leave, the longer it takes and the more it'll cost".

Should I buy or borrow honing fluid for this? I was going visit my local engine builder friends and see if I could borrow a gallon of used honing fluid, catch it and bring it back when I'm done.

Any thoughts?

 

[Dualkit]

I have used a Sunnen honing machine, but it was decades ago and the parts were the size of a brake cylinder. I think .005 sounds like too much. If it was me I think I would base my attempt on what the pros quoted you and what you promised for lead time.

 

[Garwood]

I've never used them myself, but have spent plenty of time around sunnen engine cylinder hones. With coarse stones those things will take 30 thou out in a reasonable time. But that's cast iron. Maybe totally different from steel.

 

[Mud]

I understand using the correct oil is critical. Oil meant to lubricate will keep the stones from cutting. Sunnen oil is said to be the best. I'm an amateur at honing, have never done it on a production level, just passing along what I've been told.
I have a Superior hone, use it maybe 6X/year, hoping to learn something here.
I'd think more than .005 will take forever to hone out.

 

[Vancbiker]

Have not done much with the hand held Sunnen hone beyond dusting cylinders for a ring job. As with any honing op, starting with trued stone/mandrel assemblies is a big help and keeping adequate pressure on the hone. The Sunnen stationary machines have an indicator that helps you set and maintain pressure. The hand held needs the “touch”. You can get coarse stones for stock removal and fine ones for finish. If you are leaving .005”, get a set of each.

 

[Barbter]

I've only ever used a small horizontal Sunnen machine - hand held parts with a max bore of less than an inch.
Oil yes and 1/2 a thou took a lonnnnggggg time....5 thou on 4" dia seems like forever to my thinking.
Also mostly thru but I have done blind, but the bottom wasn't critical.
I think the hand hones are more for de-glazing type work?
If you're currently 3.5", I would play with your DOC and S+F and set your finished size to 3.6" and see how close and good you can get.
Then 3.7, then 3.8 if need etc - and when you're happy with your process go for gold and if you do use the hone, it's just to cross hatch the finish.
And you can have tested the hone on the previous "test" sizes to see what you get and how long it takes....

 

[Mud]

How straight does the bore need to be? I remember helping to hone race engines with a hand hone in the 70s and there was a lot of effort and measuring to get the cylinders cylindrical enough to suit the builder before he got a CK.

 

[Herding Cats]

With coarse stones those things will take 30 thou out in a reasonable time.

Good way to end up with an off location, tipped and cocked cylinder on an engine. I usually leave .002-.0025 on the diameter but it will likely be very difficult to to get a good enough finish to do that on such a high aspect ratio hole.

I would be very suspect of a honing shop that won't work with you in giving you a finishing stock spec. The answer they gave you sounds BS to me and like they are priming you for a big bill or oversize bore.

 

[Garwood]

Good way to end up with an off location, tipped and cocked cylinder on an engine. I usually leave .002-.0025 on the diameter but it will likely be very difficult to to get a good enough finish to do that on such a high aspect ratio hole.

I would be very suspect of a honing shop that won't work with you in giving you a finishing stock spec. The answer they gave you sounds BS to me and like they are priming you for a big bill or oversize bore.

I think they were trying to capitalize. There was a huge honing shop in portland that was around forever, knew thier shit and affordable. They closed up in 2020 and this one shop is the only one offering honing in this area now.

Reason I'm thinking I should try it.

 

[Garwood]

How straight does the bore need to be?

These are gripper cylinders for log processor grapples. They destroy them when they log old growth big stuff. The cylinders are $5k each and there are two sizes, 3.5 and 4" bore.

What they tell me is as long as the seals last until they break it again we're winning.

 

[Mud]

Around here the Amish hydraulic shop just welds a new tube on the old ends. I think you can purchase the honed tubing from a specialty steel supplier.
Found this -

honed tubing - Google Search

Otherwise, it sounds like it just needs to be smooth enough to not destroy the seals before the rest of it gets torn up, right? I'd bore it .003-.004 under and go at it with the hand hone

 

[Garwood]

Around here the Amish hydraulic shop just welds a new tube on the old ends. I think you can purchase the honed tubing from a specialty steel supplier.

There's a ton of machinework in the barrel of these and the barrel is 1.5" wall thickness.

I've bought honed tubing from Scot industries. They can make the barrel, but if I can bore and hone it that would be simplest I think.

If I can do it, this is a repeat job. All the new cylinders are 3.5 bore so they can be bored to 4" and take the same gland, rod and a $150 piston kit from the oem.

 

[Mud]

I'm sure you've seen a line hone machine, with the drill motor fixture to hold the drill motor aligned with the bores. I'm picturing a rig like that made from linear rails to support the drill motor and make the job easier.

 

[atex57]

There's a ton of machinework in the barrel of these and the barrel is 1.5" wall thickness.

I've bought honed tubing from Scot industries. They can make the barrel, but if I can bore and hone it that would be simplest I think.

If I can do it, this is a repeat job. All the new cylinders are 3.5 bore so they can be bored to 4" and take the same gland, rod and a $150 piston kit from the oem.

1.5" wall? I would be boring that for a honed tube insert. Maybe O rings on the ends to finish the seal.

Ed.

 

[Garwood]

1.5" wall? I would be boring that for a honed tube insert. Maybe O rings on the ends to finish the seal.

Ed.

What kind of wall thickness? Where do you get one?

 

[atex57]

What kind of wall thickness? Where do you get one?

Wall thickness depends on pressure. 1/4" generally will take 2500PSI at that diameter. Do you know if there is much back pressure? Does it get a reverse impulse? Nothing harder on machinery than a logger, oof.

Many hydraulics shops can get tube and it can always be ordered in. Scot Industries I think will cut and ship. SteelSupply.com has it.

Ed.

 

[Garwood]

Wall thickness depends on pressure. 1/4" generally will take 2500PSI at that diameter. Do you know if there is much back pressure? Does it get a reverse impulse? Nothing harder on machinery than a logger, oof.

Many hydraulics shops can get tube and it can always be ordered in. Scot Industries I think will cut and ship. SteelSupply.com has it.

Ed.

That's what I was thinking, no way that would fit with the way the gland attaches. I could do .060" wall probably.

I believe these run at 5500 PSI and I don't know what is meant by reverse impulse.

What they do to fuck these up is when they're logging the big stuff, they have to get the grapple near the center of mass of the tree to pick it. On trees that are bigger than the machine is supposed to pick, they open the grapple all the way, with the boom/stick most of the way out and they use the swing momentum of the rotation of the whole machine to slam the grapple as far down the tree as they can get it. You can imagine what kind of forces you could generate doing that.

They are so hard on shit. The loggers love Kobelcos because they run 1000 PSI or such more pressure and have more horseponies than everyone else. The Kobelcos flat book it. Well, there's a price to pay for that, especially with a rough operator. One outfit has a few of these things and the new ones come with 11 liter Hino diesels. The Hinos are pile of shit. They don't last 3000 hours. Rebuilds don't hold up. Bad engine design. Only option is a new engine for $80k. So we said fuck that. I set a windowed Hino on the ground next to a $3000 M11 Cummins out of a semi and I made all the parts to make the Cummins look exactly like the Hino. They love it, Can't hurt the Cummins, but the Cummins has a bit more oomph and now they're blowing the plastic pump drive couplers every few thousand hours.

You wonder why a 2x4 is so expensive lol.

 

[atex57]

Reverse impulse is when they give it all its got then they twist it with another joint in the boom. But no one would do that. Oh, wait, loggers.

Ed.

 

[Doug]

I recall reading on a heavy equipment forum, how Cat had problems keeping D-5's in the woods, so they took a D-6, turned the pump down, and re-badged it as a D-5.....

 

[AARONT]

I would shoot for leaving .002"-.003" total to finish. That's what the grind shop we work with likes. More than that and the cost goes up real quick.