PM Research #4 Build Log

[abowie]

Today I drilled the central holes for the shafts.

I decided against using the reamer, and set the crank up in my 3 jaw and bored the hole to 0.624".

I turned one side and skimmed the edges so it's all square with the centre bore, then cut it off in the bandsaw.

It is too hot in my shed to do any more today. I will do the other side and make the shafts when we get a cool change.

 

[Richard Hed]

Today I drilled the central holes for the shafts.

I decided against using the reamer, and set the crank up in my 3 jaw and bored the hole to 0.624".

I turned one side and skimmed the edges so it's all square with the centre bore, then cut it off in the bandsaw.

It is too hot in my shed to do any more today. I will do the other side and make the shafts when we get a cool change.

View attachment 122440
View attachment 122441

Just curious. Do you live in city? Do you have access to lots of cheap water? If you have lots of cheap water, you can build yourself an "air conditioner" useing several techniques. If the water is cold out of the faucet, you simply run it to a radiator like a car radiator, use a fan to blow it around, and put the warmed water on your lawn or trees. Another method is more difficult but uses less water. It's the evaporative method in which you circulate water in a radiator but the water goes to a set of pipes which are wrapped with cotton cloth. A fan is necessary to evaporate waater dript on the cotton. The cooled water circulates to your radiator and you put your fan behind it. Where I live there is lots of water, but it comes out of the ground luke warm in the summer when you needs it. 42Deg is time for a couch and a beer.

 

[stanstocker]

Funny, it's expected to hit a high around 40 here too, just in F rather than C. Getting old enough to dislike cold... We rarely get over 35C in the summer here, but it's usually with very high humidity just to make sure you really get the full effect. Looks like you're making good progress, that is one large engine in my book! I'm looking forward to getting to the smaller model version PM sells, hopefully this spring during our wet season.

 

[Richard Hed]

Funny, it's expected to hit a high around 40 here too, just in F rather than C. Getting old enough to dislike cold... We rarely get over 35C in the summer here, but it's usually with very high humidity just to make sure you really get the full effect. Looks like you're making good progress, that is one large engine in my book! I'm looking forward to getting to the smaller model version PM sells, hopefully this spring during our wet season.

Generally I live in the Philippines during the winter months. I am not making that engine at this time but looks interesting.

 

[larryg]

In the above picture you can see how I modified the union in the valve linkage. I threaded the rod from the valve and threaded the union to receive it, 10-32. This worked out very well for me to tune the valve position while the engine is running. You have to add a bit of length to each piece to allow adjustment.
I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.

https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
Build thread, Larrys PM Research #4

lg
no neat sig line

 

[Richard Hed]

View attachment 122461

In the above picture you can see how I modified the union in the valve linkage. I threaded the rod from the valve and threaded the union to receive it, 10-32. This worked out very well for me to tune the valve position while the engine is running. You have to add a bit of length to each piece to allow adjustment.
I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.

https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
lg
no neat sig line

Nice log. Luv ur setups. Where in Oregon r u? I live in Moses Lake.

 

[larryg]

Nice log. Luv ur setups. Where in Oregon r u? I live in Moses Lake.

Thank you. I'm just south of Salem, just over the hill from the Enchanted Forrest.

 

[Richard Hed]

Thank you. I'm just south of Salem, just over the hill from the Enchanted Forrest.

Enchanting.

 

[abowie]

View attachment 122461

In the above picture you can see how I modified the union in the valve linkage. I threaded the rod from the valve and threaded the union to receive it, 10-32. This worked out very well for me to tune the valve position while the engine is running. You have to add a bit of length to each piece to allow adjustment.
I also have a build thread here and an album of pictures that have languished for a year as other life events have consumed me.

https://www.homemodelenginemachinist.com/media/albums/pm-research-4-build.257/
Build thread, Larrys PM Research #4

lg
no neat sig line

That's how they did it on the smaller PM1 kit I built, and I was a bit surprised to see the roll pin setup.

 

[abowie]

Just curious. Do you live in city? Do you have access to lots of cheap water? If you have lots of cheap water, you can build yourself an "air conditioner" useing several techniques. If the water is cold out of the faucet, you simply run it to a radiator like a car radiator, use a fan to blow it around, and put the warmed water on your lawn or trees. Another method is more difficult but uses less water. It's the evaporative method in which you circulate water in a radiator but the water goes to a set of pipes which are wrapped with cotton cloth. A fan is necessary to evaporate waater dript on the cotton. The cooled water circulates to your radiator and you put your fan behind it. Where I live there is lots of water, but it comes out of the ground luke warm in the summer when you needs it. 42Deg is time for a couch and a beer.

Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.

Yesterday is not the first time I've considered fitting one to my shed.

 

[Richard Hed]

Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.

Yesterday is not the first time I've considered fitting one to my shed.

Where I live it is very dry, summer and winter. Those evaporative coolers are prevalent here, howeveer, they are not the type I am talking about. People swear by them but I know enough about thermodynamics that I thimpfk it must be mostly psychological with a tiny bit of reality. When water evaporates, it sucks out the heat from what ever it is evaporating from. (boiling water may be viewed that the steam is removing heat). But then the wagter vapor is blown into your home or whatever--that means that heat that is taken out of the absorbing material is blown right into yuour home. The water has such a high heat of transition from water to vapor that it actually DOES cool a bit but the major place that is actually cooled is in th eabsorbing medium. What I am proposing is to take advantage of that mechanism, that is, putting pipes inside the absorbing medium which cools th ewater inside the pipes and is circulated into a radiator in your room then heat exchanged by means of a fan. Much more efficient but a pain in arse to make--not terrible but definitely a day or two's work. Why this idea is not commercially available, I can only guess that the setup wojuld require some kkind of hole in your house (or an krackt open window for two hoses), the hoses being traipsed around, the radiator and it's setup.

There is a third option involving a regular airconditioner--that is, an improved one using the same method of evaporation. As you know, airconditioners take water out of the air and drip it outside==well this is a terrible ineficiency. If hyou capture that water and spray in on th e cooling coills on the outside of your window (or whatever), the cooling coils cool MUCH faster thus saving yuour airconditioner the work of compressing ghe internal gasses to a higher pressure (which releases the heat from your house to the outside). In horribly hot places this would be a great alternative to letting the water drip out on the ground. If one doesn't have enough moisture in the air, use distilled water.

I have a friend in Tamworth.

 

[Nikhil Bhale]

We use the below type of evaporative coolers in my part of India. We have dry hot summers with temperature going up to 48C. These work best in low humidity conditions. We call them desert coolers.

Three sides covers are made of two layers of mesh with dry grass filled in between. This cooler is kept in a big tub of water. Water is circulated from bottom to top by a pump. The top water collector has holes from which it drips on the grass. Fan sucks in air through this grass and helps in evaporation.

Regards
Nikhil

 

[Richard Hed]

We use the below type of evaporative coolers in my part of India. We have dry hot summers with temperature going up to 48C. These work best in low humidity conditions. We call them desert coolers.

View attachment 122474

Three sides covers are made of two layers of mesh with dry grass filled in between. This cooler is kept in a big tub of water. Water is circulated from bottom to top by a pump. The top water collector has holes from which it drips on the grass. Fan sucks in air through this grass and helps in evaporation.

Regards
Nikhil

We call them "swamp coolers".

 

[abowie]

Weather has now returned to sensible.

I finished the build by making the oiler cups and completing the centre section for my replacement crank.

The oilers are huge in comparison to the ones on the PM1 kit

 

[TubeTech]

Because South Australia is so dry (similar climate to Northern California) you can actually buy commercially made evaporative air cooling systems. They're essentially a big plastic box packed with water absorbing material and a big fan.

Yesterday is not the first time I've considered fitting one to my shed.

Rusting lathe ways and other tooling is the consequence of evaporative cooling - Beware.

 

[Anatol]

Rusting lathe ways and other tooling is the consequence of evaporative cooling - Beware.

evaporative cooling will increase humidity - which is usually pleasant in very dry hot climes. May experience is that evaporative cooling will not work in humid air. So how can ambient moisture from evap cooling be more than, say normal humidity in, say, southern England?

 

[Richard Hed]

evaporative cooling will increase humidity - which is usually pleasant in very dry hot climes. May experience is that evaporative cooling will not work in humid air. So how can ambient moisture from evap cooling be more than, say normal humidity in, say, southern England?

Yes, particularly in a moist area, the evaporative cooling wojuld not work very well.

 

[abowie]

So you may recall that I made a mess of the conrod, with one end being about 35 thou off centre. With this error the cross slide keeps jamming when I assemble the model and it won't spin freely.

I ordered a new casting from PMR and it arrived last week.

I made short work of it this time.

I decided to turn it between centres until I had some nice straight parallel sides to register from. Once that was done, it was a piece of cake.

This one is correct to within 2 thou alignment.

 

[abowie]

Oh dear.

A cautionary tale.

So right at the beginning of the build you may recall that I stood the frame up in my mill to drill the 4 mounting holes in the feet.

Then, when I couldn't fit the frame in my lathe I made up a plate with some studs to bolt the frame to, then bolted that plate onto the backplate on the BIG lathe.

As the casting was pretty rough I used a mandrel to get an approximate centre for boring the cross slide bore. And bore it I did.

BUT.

The bore was not centred realtive to the mounting holes. But the crankshaft pillar mounting holes on the base are located in relation to the mounting holes for the frame.

Which is off centre. SO THAT'S WHY IT DOESN'T WORK.

 

[abowie]

All of this has a happy ending, however.

I have fixed the problem.

I haven't fixed the model, although I will over drill the mounting holes and that ought to fix the misalignment.

But I have fixed the problem with my lathe being too small.

I have bought this:

50mm spindle bore, 380mm swing over, 1000mm bed. 2 axis DRO plus 3rd DRO on compound. Built in coolant. Foot brake. Power X and Y axis. Cam lock chucks. Thread cutting gearbox up the wazoo. AU$3300 at auction from the local trade school.

It weighs 980kg. Installation is going to be fun. Watch this space!