Test Bed

[Captain Jerry]

This what I am planning.  I call it a test bed because it may or may not become an engine.  I depends on the success of the tests. If it looks like something I have already done, looks are deceiving.  It is very different.  If I seem like a one trick pony, I can see why but you can't count the trick until you get it right.  So I am going to keep at it until I get it right.

This one is bigger.  The block is 3" long, 2.12" tall, and 1.8" thick.  All steam and exhaust passages are milled internally with no external plugs. All valve faces are oriented in the direction of steam flow and are at the bottom of the valve bore for proper condensate drainage.  It will look more like a casting without bolt on top and bottom plate. 

The attachment is a 3-D PDF.  It can be rotated.

More to come.

Jerry

[Captain Jerry]

Here is a little more development of the idea. The only way that I can think of to mill the passages from the inside so that no external cover plates have to be bolted on, is to make the block in two halves and glue them together.  I say "glue" because the block will be aluminum.  Some might think that aluminum is not the best choice but it is cheap and I have it on hand.  The cylinder will have a cast iron sleeve.  I had originally thought that the valve bores would just be bored and reamed in the aluminum but I am now leaning toward using cast iron sleeves there as well.

I am still working on the order of operations but I think that I will mill the passages, join the two halves using alignment pins and some kind of glue, and then bore the cylinder and valves in the joined halves. What Kind of "glue."  I am not as concerned about operational failure as I am about failure due to stresses from machining the bores.  Once the bores are done, the sleeves will also be glued in, adding to the overall strength of the assembly.  I'm not concerned about operational heat since it will never be run on steam.

So what kind of glue?  JB-Weld, epoxy, other?

Thanks

Jerry

PS:  Pardon the use of attachments.  I am having problems with my on-line photo storage account but I am working on it.

[Ian S C]

Jerry, I would use a liquid gasket of the Loctite type, then you can if needed pull the assembly to bits.
                                              Ian S C

[lohring]

Cynoacrylate (super glue) works well if things don't get hot.  The glue line is very thin and a little heat followed by acetone cleans it up.  That tip came from my uncle who needed to grind aluminum and hold it in a magnetic chuck.  He used Eastman 910 to attach the aluminum to a steel plate.  That was at Hanford in the 1950s.

Lohring Miller

PS  I love your axial engines.

[Captain Jerry]

Thanks for your input, Ian and Lohring.  Disassemble at that level won't happen.  If I have to get back inside after putting it together, I'll treat it like a casting and use a hammer.

How is the shrinkage on those products?  I would like the seam across the top to be invisible but I guess some high build primer and paint will take care of that.

Jerry

[Captain Jerry]

I made some chips yesterday.  Starting with a bar of aluminum from the scrap yard that was 7" long, 2.15" wide and 1.12" thick I squared it up on all faces using flycutter.  This is very nice stuff to cut.  I could swing the cutter the full width of the bar and take cuts of up to .010" deep.  The chips were like feathers.



I have decided to use the valve bores for alignment.  After locating the positions, I drilled them through at 3/16" (.313).  I dont expect that the alignment will be good enough for use as the finished valve surface so the are drilled undersized.  I will use brass tubing for alignment while gluing them together.  The holes through the tubing will let me pass screws through for clamping and for mechanical support during the cylinder boring.  The brass will get some glue on it and will be stuck in the block but will be easy to drill out for the finished valve bore when it is opened to full diameter.





After that, I milled the steam and exhaust passages,  1/8" wide and .200" deep for the manifolds.  The vertical slots for the valve opening are 1/16" wide and .200" deep.  I milled all of the 1/8" slots in two passes and all of the 1/16" slots in single passes.  Like I said, this is very nice aluminum to work with.





That will be all of the work for a week.  Tomorrow I will be a mile high and two days later I will be nearly two miles high in the Rocky Mountains. 

Jerry

[Captain Jerry]

This is the view from my sons cabin at 10,600 ft altitude.  The valley floor is about 2000 ft lower.  Weather is moving in.  I'll be home and back to the shop tomorrow.





Jerry                                                                                                                                                                              359

[Captain Jerry]

Back in the shop and relearning some of the techniques that I need to use to overcome a lack of equipment.  One thing that I haven't relearned is the ability to document with photo and post.

Yesterdays problem was to produce some thin slices of cast iron for some small parts to be milled.  The slices need to be .085 to .090 thick and flat.



Parting slices from the end of a 5/8" bar produced slices from .088 to .096 but they were not dead flat.  Slightly domed and with a pip in the center.  They need to be dead flat because they will be super glued together two at a time and stuck on the end of a sacrificial bar for milling. Two at a time because I want identical parts.  They will be milled with a .063" end mill that has a  maximum cutting depth of .1825" so two of them can't be more than .090" each.

A surface grinder would be great for this, I think, but I don't have one so I had to work something out.





I super glued them to a block of steel and had at them with a file.  I glued down six of them with the two thinnest in the middle.  I should only need 4 of them  but there is a good chance I will need more to feed the scrap monster.




Keeping the file flat on six faces over an 1.5" x 2.5" surface is much easier than doing them one at a time.  Laying the block on the bench made it too easy to apply uneven pressure on the file.  Holding the block in one hand and stroking the file with the other hand made it fairly easy to float the file on all six disk fairly evenly. 

I thought about running the group under a fly cutter on the mill but I didn't think the glue would survive the impact of the fly cutter.  The 1/16" end mill that I will use to profile the parts will not impart that much impact so I think it will hold fine for that.

Cast iron is dirty stuff to file but I have some good hand cleaner.  When these are good and flat, they will be flipped over and filed on  the other face to remove marks from the parting tool.

I hope I can complete the four parts with the six blanks but if not, I may have to do this again.  There may be an easier way to do this so post it here to help me next time and to prevent someone else doing it this way.  My way or the right way!

Jerry

[Mosey]

Back in the shop and relearning some of the techniques that I need to use to overcome a lack of equipment.  One thing that I haven't relearned is the ability to document with photo and post.

Yesterdays problem was to produce some thin slices of cast iron for some small parts to be milled.  The slices need to be .085 to .090 thick and flat.



Parting slices from the end of a 5/8" bar produced slices from .088 to .096 but they were not dead flat.  Slightly domed and with a pip in the center.  They need to be dead flat because they will be super glued together two at a time and stuck on the end of a sacrificial bar for milling. Two at a time because I want identical parts.  They will be milled with a .063" end mill that has a  maximum cutting depth of .1825" so two of them can't be more than .090" each.

A surface grinder would be great for this, I think, but I don't have one so I had to work something out.





I super glued them to a block of steel and had at them with a file.  I glued down six of them with the two thinnest in the middle.  I should only need 4 of them  but there is a good chance I will need more to feed the scrap monster.




Keeping the file flat on six faces over an 1.5" x 2.5" surface is much easier than doing them one at a time.  Laying the block on the bench made it too easy to apply uneven pressure on the file.  Holding the block in one hand and stroking the file with the other hand made it fairly easy to float the file on all six disk fairly evenly. 

I thought about running the group under a fly cutter on the mill but I didn't think the glue would survive the impact of the fly cutter.  The 1/16" end mill that I will use to profile the parts will not impart that much impact so I think it will hold fine for that.

Cast iron is dirty stuff to file but I have some good hand cleaner.  When these are good and flat, they will be flipped over and filed on  the other face to remove marks from the parting tool.

I hope I can complete the four parts with the six blanks but if not, I may have to do this again.  There may be an easier way to do this so post it here to help me next time and to prevent someone else doing it this way.  My way or the right way!

Jerry

If they won't survive the impact of the fly-cutter, could you flatten them close to final thickness with an end cutting mill? That would minimize the hand filing work and give you precise thickness.
Mosey

[Captain Jerry]

Thanks, Mosey.  I might try that on the next batch, (different part), but what size endmill?  A big one, 1/2", would be fast.  Three passes would do it but it might put to much side force.  A small one, 1/16", would not stress the glue joint to much but would take about 20 passes.

The filing wasn't too bad, less than an hour for both sides.  I wound up with six disks within .010" and if I discarded the outliers, I had four disks within .004" at .083"- .087" which is plenty good for this.  Here are two of them mounted on a sacrificial post and chucked on the Rotab.



Getting this in position took almost as much time as the filing.  Last night, I sat with the drawing in front of me and wrote out the 24 steps in the machining process.  If I don't do that, I tend to get careless and make dumb moves.  Cast iron is wonderful stuff to mill.  I was able to take full depth (3/16") with the tiny 1/16" end mill with no problems.  An occasional puff of air to keep the swarf from clogging the cut and it went like a breeze.  I upgraded my little Harbor Freight mill from gear to belt drive a few years ago and the difference is wonderful.  Quiet and much easier on the small end mills.  Here is a pic of the parts before separating them from the post.  You may now recognize them as the valve release hooks for the Reynolds style Corliss engine.  I had previously said that I didn't think I could make this part in this scale.  I was wrong.  A little touch with a 3-cornered file to square up the inside of the hook and  think this will work just fine.



They look like a matched set to me.  The pivot hole is .078" dia.







I made another pair for good luck.  Wired together, the may be easier to keep track of.



 Now I need to start thinking about the bell crank.  I think I will do them the same way. 

If I can't get the Reynolds design to work with these parts, I have a couple of other designs that I may try.  I may try them any way.  So far, this is still a test.

Jerry                                                                                                                                                                                531

[Admiral_dk]

Hi Jerry

For some reason I can't see your pictures - I tried the direct links too and get page not found ...

It's weird, because I could see the pictures in your posting from October 8th, when you posted it, but they have gone too ....

I'm not sure if I'm the only one who can't see them.

Best wishes

Per

[Captain Jerry]

Hi Jerry

For some reason I can't see your pictures - I tried the direct links too and get page not found ...

It's weird, because I could see the pictures in your posting from October 8th, when you posted it, but they have gone too ....

I'm not sure if I'm the only one who can't see them.

Best wishes

Per

Thanks for the 'heads up'.  Something must be wrong at Photobucket.  They don't show up for me either.  I'll see what I can do.

Jerry

[Captain Jerry]

I don't know what it was, but Photobucket seemed to take forever to open the album for these pics.  When it finally opened the album, I returned to this page and the pics were here too.   If you or anyone else still has problems, let me know and I'll contact them directly.

I went back to the Photobucket page to sign out and got a screen message that they were down for maintenance.  They have done a lot of that lately.

Jerry

[Captain Jerry]

Yesterday I was afraid that a flycutter would knock the pieces (5/8" CI disks off of the steel block that they were superglued to and spent an hour getting dirty hand filing cast iron.  Dumb!  Today I did the same process using four 1" cast iron disks and a brazed carbide fly cutter in about 5 minutes.  Yes, the 1" disks have more surface for glue but it really seemed to cut dead easy.



Four disks within .002" of each other,  .085" - .087" thick.



Two of them were stacked and glued to the end of the bar that they were sliced from and milled using a rotary table.  The slots are 1/16" wide and 3/16" deep made in single pass, full depth. 



Here is a pic with the Reynolds hook in position to verify proportions.



This is a pick in approximate position on the test bed cylinder block, just to verify proportions.  The block is 3" long.   If the bell crank looks a little thick, that is two of them still stuck together for finish filing.



There is a good chance that this will turn into something.   

Jerry

[Captain Jerry]

In an attempt to get some help, which I got, I let this project branch over to the thread titled "Relationships - Help" but it should remain together in this location so here is a picture of the results of the "Relationship" question.



I am now going to try to work out a method of attaching the leaf spring that keeps the cam follower leg of the hook against the cam.

Thank for your comments,

Jerry