DIY shop hone

[bruce]

I know this has been discussed in the past on some other threads, but I had to hone another block this past weekend by hand and gave some more thought to building a small engine hone based on the larger commercial hones. My need is for small engines so I don't need anything large.

I have most of it designed in my head but still have a few questions . . . one would be what spindle speed would I need? I have a motor (1725 rpm) attached to a gear reduction unit that outputs 48 rpm's. I can speed up or slow this down thru a variable speed pulley setup I have.

I plan on having a footprint of no more than 24" deep x 18-24" wide, again keep in mind small engines not V8's. For right now my plan is for it to be manually operated with the motor/gearbox counter balancing the head/spindle. Sometime down the road adding air stroke to it maybe, probably have all the parts needed to do this laying around in the shop (I don't do alot of engine work, thats why this is a later project).

I currently have an Ammco 500 style hone which I plan on making an adaptor to use in the spindle. Since I will only be doing single cylinder engines I don't need the head to slide sideways. The spindle will be adjustable up and down to set my hone height relative to the block. This will probably be slip-fit mechanical tubing of some sorts or rectangular drive shaft material avaliable at the local farm/hardware store which would then be drilled for height adjustment holes/pin

With that being said, any thoughts?

Keep in mind my desire to keep it simple and as compact as possible. I'm not machining anything larger than a small tractor engine.

[gofaster]

I believe the spindle speed and stroke speed are figured in relation to the size of the bore. I think my Sunnen materials may have some info about it. I'll try to check tomorrow, otherwise it'll be next week, as I need to go out of town for a few days.

[gofaster]

Bruce,
these are the suggested "spindle speeds" and "strokes per minute" from the charts inside my Sunnen power stroke hone:

Spindle rpm/Bore Size
200 rpm / Greater than 3.250", Greater than 83mm
250 rpm / 2.500" to 3.250", 64mm to 83mm
320 rpm / 2.000" to 2.500", 51mm to 64mm
400 rpm / 1.625" to 2.000" / 41mm to 51mm

Length of stroke / Strokes per minute
3" to 6" / 80
1 1/2" to 3" / 110
3/4" to 1 1/2" /160

It goes on to list smaller bores and strokes, but I felt that they weren't pertinent to what you are trying to do. If you need the rest of them, let me know and I'll post them next week.

[bruce]

Jim, THANKS!!

Most of my bore work will be in the 3.5 to 4" range.

I'll post pics as I progress with yet another project!! LOL

[1960flh]

[color=#000000]Bruce;

I am very interested in your project as I too just use an old

[bruce]

I'm trying to do away with my hand drill/hone setup so for right now it's going be all manual except for the spindle. Probably add in a manual spindle brake to stop the hone when its at the top of the stroke to make size changes.

I can add the bells and whistles later, I don't do alot of block work. But, everytime I have to do it manually I HATE it even more, I have most everything already in my shop to build this rig just need to work it out to use what I have on hand to build something that will work for me. I would like to use what I have on hand and not buy alot of new parts, it's not in the budget right now. Not like I have a budget anyways!! LOL

If down the road I need something better I can always rework what I am using and make it better. I do plan on adding in an amp gage as you suggest, this was in my plans from the start.

[Greg]

Bruce, I started on my hone last weekend finally. Not having to have the head slide across saves an awful lot of work.

I'm making mine to run at 140-150rpm. I just spent the afternoon looking through planetary gear sets in an auto trans shop for a nicely sized set to make the friction feed for the hone head. A new sunnen friction head here is AU$5500 so I can justify doing some fiddling!

My last hone was hand stroking. I used a gas bonnet strut which was enough to give it positive lift if you let the head go. To take .030" out of single cylinder didn't take too long roughing to within .005" with an100 stones.

I made a telescopic drive shaft which adjusted about 6" to suit different height blocks with a grub screw to lock it in place. It meant you could keep the handle to stroke it with at a comfortable height with different block heights.

You should be able to make a nice cabinet style machine pretty cheaply, I did the same, just stacked stuff away until i had what I need to make it, hopefully will be running next week to test it before I send the parts to be powdercoated.

[wing64k]

I too am geing parts togeather to build hone,could you post or send me pic's of what you have done so far.

Thanks Dean

[Greg]

I got the top part of my hone finished off this weekend. I'll post up some photos over the next few days. I found a really simple way to do the spindles in the machine using trailer hubs. I bought them for around $50 each including the hub and stub axle. I machined the axle to take the pulleys I'm using and shimmed the tapered bearings to provide almost no axial movement. The axles have a 3/4 unf thread on the end which I have cut into the uni joint at the top of the honing spindle so I can just screw it on.

The spindle is engaged by a tensioner wheel on a lever arm which tensions the drive belt when you pull on a lever. I am going to add a spindle brake which stops rotation once the lever is released.

The motor runs at 1370rpm which is reduced through two lots of 2" to 9" pulleys which gives me 9:1, so a 152rpm spindle speed. The motor is 1.3kW, my last one was .75kW and was a tad underpowered when I really wanted to rip some metal out so this should fix that problem.

I have a pneumatic ram, 80mm bore by 80mm stroke. with 100psi air pressure, this should lift around 350kg. The ram is pushing 270mm from the pivot and the spindle is 515mm from the spindle so it should lift or push 180kg at the spindle which is heaps considering you can do it quite easily by hand. It should use around 1cfm at 60 strokes per minute.

The ram is connected to a 2 position, 5 port, push/pull dcv which is fed from a pressure regulated on/off type of valve. I'm adding a dwell setup once I have it up and going but this will do for now. The dcv will be switched by adjustable stops on a shaft connected to the head of the machine.

Next up is the rollover fixture for the blocks to sit on. I'm thinking of making it height adjustable, maybe on ballscrews or acme threads. This is mainly so that if I set up a line hone drive on the side of the machine later on I'll be able to lift the blocks out the top of the machine to hone them. It will also save having to have an adjustable bottom stop for the stroking as you can move the block to suit the postion of the hone rather than the other way.

Hopefully tomorrow night I'll have the ram fitted and see how it works. I should have some photos by then.

[gofaster]

1960flh posted:

"... the serviquip hone I used to use had a nice amp gauge on the motor circuit to keep track of stone load"

For those unfamiliar with having an ammeter on their hone, it is a great way to detect taper. If you dwell at the higher amperage position a few times while you are stroking, you will see the amperage even out, and then your taper is gone and you'll have a nice straight bore! It would be a slick accessory to add to your DIY stroking hones.

[Greg]

I got a fair bit done over the last week on my new hone, photos hopefully below:



















It's running a little behind as I accidentally did some extra angle grinding on my wrist and arm but hopefully I should have the majority of it finished so I can give it a dry run and get it off to the powdercoaters next week.

[bruce]

Thanks for the pics! Looks good!

[Greg]

Here's a few more photos, it's getting pretty close to done now. Still not as quickly as i would have liked though!

[Greg]

and a few more...

[gofaster]

It looks like you're well on your way to having a first rate hone! Looks terriffic!