3 leg hone

Before I part with my cash, are those three leg spring loaded hone things any use? I'm only trying to improve surface finish in a cast iron cylinder, it's already parallel and a pretty good turned finish. Otherwise I'll set to and make an expanding lap

hone thing

YES, I have 2 and 3 legged ones. Yes they work well with careful use on a slow speed drill, use parafin as a lube/ flushing agent. Noel

Take care that you don't bell-mouth both ends. Go slow and take measurements often.

Edited By Pete Rimmer on 29/12/2020 00:15:46

I agree with Noel, they are very useful. The finish they leave is better for rings to bed onto than a lapped or bored finish. Bell mouthing should not be a problem since you should not be trying to remove a significant amount of material. Move the hone up and down the cylinder as it works, taking care not to come out either end.

John

Millions of automotive brake cylinders are honed with these things worldwide every year. They work. Peoples lives depend on them.

The linked one looks ok. The cheaper Chinese ones held together with a rubber O ring instead of a proper spring tend to fly apart unless used with scrupulous care and you hold your mouth just right.

The cast iron cylinder for my traction engine was bored for a running fit with the piston but after a shrink fit with the engine block (heating in my BBQ for an hour), the ends had shrunk and was too tight for the piston. Although it did provide a good seal and did not leak when tested to 250 psi.

I uses a cheap 3-leg cylinder hone to enlarge the bore at the ends, checking the diameter at different places with a dial bore gauge to ensure a constant diameter thruout.

Paul.

Edited By Paul Lousick on 29/12/2020 06:02:53

My largest one easily hones a bore of 110mm but I don't have one small enough for brake slave cylinders.

I prefer a Flex Hone for this type of job. Often referred to as a 'bog brush' for its similarity with the household item. They are more size specific (probably with a range of 5mm of bore size in medium sizes) but also available in small sizes. I have a 12 bore one (0.73" ) and a 16 bore one (0.663" ) for shotgun bores which work very well.

Edited By Oily Rag on 29/12/2020 09:51:39

The trouble with three leg hones is you need to avoid the temptation to withdraw them too far, thats when they bell mouth.

They will not correct any ovality in a bore like a true Delapena type hone would, being spring loaded they just follow what is already there.

Phil

Flex hones are splendid things, capable of reproducing the cross hatch finish of a machine honed bore, in depth and surface finish. But being silicon carbide, the bore needs to be cleaned extremely carefully after use. Otherwise the components will continue to lap themselves for the remainder of their short life!

Flex hones tend not to be cheap, and how to get the best from their use needs to be learned.

Howard.

I have never used one but a place where I worked years ago did. With the hone fitted to a thing like a very large two handled electric drill the fitter would hone a bored cast iron cylinder to take a cast iron piston that I had ground for him. Pistons varied in size up to 7" diameter and 8" long. The point I would like to make though is that of all the fitters, only one of them had the knack of getting it REALLY right. A hot sweaty job in the summer, Pete certainly earned his wages doing that job.

Rik

I bought the Kennedy version from Zoro (from ebay) about £16 it has two and three legs and covers a lerger range of diameters. It was fine in use and gave a nice finish to the CI bore for my Economy Engine using oily diesel..

Link