Building Rudy Kouhoupt's Fore and Aft Compound

[gerritv]

A bit of a delay in progress, medical appt on Thursday and a significant birthday for my wife intervened.

But, holey steamchests baby, here is the result of a bunch of match drilling and a pocket job. Very pleased with how everything lines up. I forgot to take photos of the setups but they were nothing out of the ordinary.

I have the cylinder block all squared up and to size. I bought some CI pipe fittings to use as liners but the small one is too large. The larger one might bore out a bit oversize as well but should be close. The pistons will be made to measure of course.

DRO is on the way, should be here this Friday according to UPS but that usually means the following Monday.

gerrit

[crueby]

Great looking collection of steam chest bits! 

[wagnmkr]

That is a lot of holes Gerrit! Looking good!

 

[gerritv]

After a detour into "installing a 4 axis DRO on my milling machine" it's back to the engine.

I made a vise stop to make flipping operations more consistent, That resulted in adding the last holes to the steam chests. Then made the glands and bearings for same.
Last, made the clevis'. I had kept a .130" wide cutter from my horizontal mill, which conveniently was the exact width needed.

Gerrit

[gerritv]

I also roughed out the cylinder liners. Rudy calls for bronze but based on a hint from a fellow HMEC member years ago, I used some cast iron pipe unions instead. They still need honing/lapping but the outside is good to go into the cylinder block once that is bored out.

(I won't be running this on steam so not worried about expansion factors etc.)

gerrit

[gerritv]

Some more progress today:
Based on advice from @creuby I made the valves out of one piece instead of two. I had appropriate sized bronze, that should mate/slide well over the O1 steel I used for the port faces.

I kept the block as large as possible for as long as I could to simplify holding. Also the depths were consistent when flipped resulting in lower risk of whoopsies. All dimensions are within the tolerances that Rudy stipulates so very pleased. Only 1 end mill sacrificed, a 0.090" HSS of unknown heritage. Still getting used to how hard bronze is.

Still to do on these, cutting the recesses for the valve faces.

gerrit

[MJM460]

Hi Gerrit, nice work on those valves.  You are making good progress on this engine.

Always good to see the new steps each day.

MJM460

[Roger B]

Good progress on the valves   

Is that a carbide tipped milling cutter you are using to slot the forks?

[Admiral_dk]

Great progress Gerrit 

Your Ruler eludes that you work in Electronics and maybe even PCB Layout (CAD).

Per   

[gerritv]

Thank you, yes progress is always good. I have had some detours into clock repair, happy to be back at the engine.

The main slot I used a 5mm carbide end mill (AliExpress), worked great. .125" doc, it was like cutting butter. There is a smaller cross slot (0.097" wide) that is where the other cutter broke. I switch to a 1.5mm carbide and finished them. It could easily have been chips getting in the way, they are like needles in this material.

gerrit

[gerritv]

Great progress Gerrit 

Your Ruler eludes that you work in Electronics and maybe even PCB Layout (CAD).

Per   

Thank you,
yes, I make to occasional PCB layout. Most recently for an ESP32 controlled MQL for my shop made CNC router/mill. I find that the ruler is a greater reminder of what my minimum part size is as I tend to use surface mount parts often to keep within the hole limits of the free version of DipTrace.

gerrit

[Admiral_dk]

I truely prefer SMD components as long as they don't get under a size that is posssible to repair with either a soldering iron or a 'heated air reflow Pen'.

I really like to do PCB Layout in CAD - so much so that I from time to time do it just to relaxe and get stimulated   
Though to be honnest I'm proudest of some of the big Internationa sellers I have done for others - either ( @ previous employments) or as an Consultant (there are also one I'm not so proud off - but it was supposed to be a Prototype (and not sold in thousands), so not checked for all eventualities).
My own projects do often not end in completion (assembled) - more to satisfy a Proof of Concept 

Do you write your own Firmware too ?  - If so, I'm impressed that you completed the CNC on that account too 

Per       

[gerritv]

Per, I've done a lot of sw design and implementation over the years. Mostly under Unix for medical imaging (implementing DICOM standard for CT, MR and US).

Firmware off and on, my one and only FOSS implementation was GrblPanel, still available on GitHub.

HW, my first real pcb in 1982 we sold >500, my last commercial one was in 1984, it sold >250k. That last was a Uniscope synchronous interface for IBM and similar pc's. OEM to Unisys as well as direct sales. It is only the past 8 years or so that I do my own layouts using DipTrace. I haven't tried milling or otherwise making my own boards, At prices from Asia it is not worth learning for me.
I'll try to post a thread in OddBall about my CNC, it runs Tormach PathPilot, no coding required.

gerrit

[Admiral_dk]

Impressive stats - I think my best is around 50K.

I would like to see your CNC system too 

Per     

[gerritv]

More progress. I completed the high pressure valve face, that went much quicker the the first one. Practice makes for less stress. I used 1.5 and 2mm cutters, centered on the openings. After the cut was all the way through I measured the width. Then did an offset on both sides to get the correct width. Within 0.003" so within tolerance.

I cut the valve faces, 3mm end mill using the DRO. I am used to watching the DRO during cutting on the lathe, that is coming in handy on the mill as well. The only thing I change my gaze for is to blow out swarf. MQL for lubrication and air is on the schedule.

Next up is the start of opening up the bores for the cylinder sleeves. I drilled out to 7/8", then using a Sherline boring head with MT1 adapter to a R8 3/4" collet began the process of getting to 1.25". Created some aluminum art along the way.

To make my life a bit easier I made a simple vise jaw clamp as a repeatalbe stop. And some 3D printing to create t-slot fillers. The latter makes for easy cleanup at the end of each day, just sweep into a dustpan.

gerrit