The Steamboating Forum

Tubular dowels are not uncommon for those sort of places. No need for anything special, you can make your own. Plenty oil about so steel is fine.

The ones on my antique engine just use the screws, but dowels would work fine. If anyone ever need to remachine the straps due to wear, they'll want to remove the dowels, so I'd make 'em a slip fit in both sides of the strap.

One of the interesting things about working on old machinery is thinking about the fellow who machined the parts 120 years ago. I work in the computer industry, where if a piece of code lives for 20 years it's ancient; steam engines and old tools are a nice contrast.

- Bart

Quote: "When I split the strap does there need to be any thing that will keep the 2 halves in alignment other than the bolt itself?"

Keeping the clearance holes .25" should be sufficient and use grade 5 or 8 bolts so they don't stretch. Grade 2, 1/4-20 bolts can stretch very easily. The only time this is going to be a concern is during machining. Installed on the eccentric, the "key" and the OD's on the eccentric will align them automatically.

These need to run with zero clearance, or they will clack. I machined these a few thou under on the bores and then ran them in over time. Slowly adjusting them up while keeping them greased well.

Of course put mating numbers on each pair for proper re-mating and orientation.

-Ron

I got around to doing a bit of machining this past week. Decided to try and use a router bit designed for wood on some steel. As long as you go slow with small cuts it worked fine. This was more cosmetic than functional but it makes the edged look finished.



Frank

Also this week is the debut of my new Kurt vise. It is holding the valve slide. I did not get many photos but I did end up with 2 machined valves. All that is left is the hole for the rod(waiting for a longer 3/8 end mill)





Until next time
Frank

Hi Frank,

Looks good. That's a dandy vise you have, they make a nice dent in the checking account, but worth every penny.

On those D-valves, they show a deep .375 slot going all the way through - it's not necessary. Just mill a .375+ slot all the way across the part. Like a dado slot. That is how most other slide valves are made and they work just fine, had I known at the time, I would've done as I'm suggesting here. Not sure why they drew it like that, it serves no purpose.

-Ron

DetroiTug wrote:Hi Frank,

Looks good. That's a dandy vise you have, they make a nice dent in the checking account, but worth every penny.

On those D-valves, they show a deep .375 slot going all the way through - it's not necessary. Just mill a .375+ slot all the way across the part. Like a dado slot. That is how most other slide valves are made and they work just fine, had I known at the time, I would've done as I'm suggesting here. Not sure why they drew it like that, it serves no purpose.

-Ron

So instead of the elongated hole, I could put the valve face down and mill a slot from the top down? I'm assuming to the same "depth" of the bottom of the elongated hole? it makes sense I guess, once the shaft is in and adjusting nuts top and bottom, it can't go anywhere.

like this


Frank

Exactly. Does anyone else here see a problem with doing that? Maybe they were afraid it would warp with heat etc, but every other slide valve I've seen isn't how they have it drawn.

-Ron

DetroiTug wrote:Exactly. Does anyone else here see a problem with doing that? Maybe they were afraid it would warp with heat etc, but every other slide valve I've seen isn't how they have it drawn.

-Ron

A slot is fine; I've seen plenty of valves done that way. Double jam nuts on each side so it can just float on the valve stem, and you're set.

- Bart

Its not much but I received a package with some tooling from MSC. Last night I milled the slot for the valve rod in the valves and hit all the drilled and drilled and taped holes with a 90 deg countersink.

I am debating running the valve rod up through the top of the steam chest into a second bushing . The plans don't call for it but I have seen a few engines done like that PRO"S -----CON"S???




Hope to get more done tonight.

Frank