Long stroke engine build

[Bernd]

Well fellow PD's, I've started the long stroke demo engine. The methods I use work for me. There are many ways of doing things. For those that would like to follow along and see the parts, just download the Edu-Model file in the downloads.

To start off with I had to cut some .250" (6.35mm) and .500" (12.7mm) thick aluminum. I have a 10" cabinet saw that I cut all my aluminum plate on. It works quite well. It's a bit noisy and the chips hurt when they hit you. I have found a way to minimize the flying chips. Ok course safety glasses are a must have.

The first pieces to be cut are the two legs and the front and rear rail. I didn't get any pics cutting the rails. So I'm starting off showing how I cut the legs on the saw.


Shown is a piece of .500" thick aluminum on the sliding table I made for the saw. The plans call for a width of 1.25".


I've clamped a piece of wood on the side to act as a stop. The second piece of wood on top is to stop the chips from flying out and hitting me in the face. The blade is set to a height just far enough to come up through the plate and cut into the wood. The clamp in back helps hold the wood down. I use one hand toward the front to hold the board down and push the slide with my other hand.


And there is the cut piece. Notice the shallow kerf in the wood I had over the top of the aluminum piece? The majority of chips are forced down the slot the saw runs in. It took me a few cuts to come up with this method.


There we have the front and back rail and the one piece that will become two, for the legs. All I need to do is cut the legs to length.


As Bog's always says, "You can do small parts on a big machine, but you can't do big parts on a small machine." Well, I've sort of have that problem. I need to machine the rails to 1.000" dimension, not a problem, but they are 12.000" long. The table has a travel capacity of 9.000" or so. What to do? Well you mill part of one side, turn it over and do the other side. Also my vise isn't very wide either, the hang over of the part would make it vibrate like crazy. So I did what wood workers do when they plan a long board. Clamp one end in the vise and the other end to the bench somehow. I did similar. I clamped the part in the vise and the other end using a machinist clamp to a 1-2-3 block that was bolted to the table (a 1-2-3 block is 1" X 2" X 3" ground block). Also I've moved the table as far as it will go to the left (standing in front of the mill) and clamped the vise as far to the right on the table and still clear the mill. This will give the max table travel to the right to allow a 9" cut.



Here's a view of the back side.


Here I've traveled the 9" inches and took a skim cut to clean up the sawn surface.


I've flipped the part over and mounted it on the milled surface. Here I'm taking a skim cut of about .025" (.635mm) to clean up the second side sawn surface.


I am able to get a full length cut just by moving the part to the right and cutting to the end. This will finish up the second side and allow me to do the final sizing on side one.


I've now flipped the part back over to the first side. I've also moved the vise back to the center of the table. I can now slide the part along the vise since I have a nice smooth and level side two.


Here I'm taking about .005" (.127mm) to get the final 1" dimension.


I not going to show milling the legs to size since that is a straight forward procedure, plus I didn't take any pics to show anyway. So here I present how to mill the steps on each side were the rails will sit in. The two parts were clamped in the vise together so that the 1" step would be at the same height on both pieces. The cut on the longer of the two legs is an 1" so I used a long two lipped end mill. Because of it's length the machine vibrated like crazy and danced all over the bench. I finally used a 4 lipped end mill that had a tad over 1" long flutes.


Here are the finished legs and rails plus the end mills. The one on the left is the one I started off with. Way to long. The middle was a bit short of one full inch. The carbide 4 lipped end mill, on the right, was the final choice and worked OK.


Here's what it looks like put together. I say put together instead of assembled because the next step is to drill holes in the rails both front and back. That will happen on the next installation of this build.

Next time I will show how I laid out the holes and drilled them. Not much to it.

Bogstandard, your input is most welcomed here. I can stand constructive criticism, some what.

Regards,
Bernd

[bogstandard]

Bernd,

It is not up to me to criticise anyone's work, it is your build Bernd, and you have to make the bits within the limitations of your machinery. Just to say, you are solving problems just fine at the moment, and always remember the saying, 'If it looks right, feels right and runs right, then it is right'.

Here is a tip for the future. When doing multiple long bits (in fact almost any multi bits), stick them together and machine as one. For ali I use double sided tape, superglue doesn't last long on ali because the oxide layer it produces prevents a good bond, and compressing in a vice soon makes the bond fail, double sided gets around this by being slightly more flexible.
Then you end up with a much thicker and hence more rigid part. The only down side is that if you make a mistake (and we all do it), all parts will need to be recycled, not just one. Then to break the join, a little flashover with a bit of heat (not too much) and let it stand for a minute, then the join should come apart easily.
But a word of warning, if machining joined parts, drilling thru holes can break the join, so things have to be clamped together as well.

John

[steamboatmodel]

Bernd,
One trick I picked up when doing long pieces is to clamp some extra material beside the work piece, the more mass  the more rigid the less vibrations, and as John says stick them together.
Regards,
Gerald

[Bernd]

Thanks guys.

I'm joking about the critiquing John. 

Gerald, John, reason I didn't clamp them together was I hadn't quite figured out how I was going to do a long piece like that. I was about half way through the first piece when I came up with the way I did it the second time. They will be clamped together for the drilling work though.

Bernd

[Bernd]

Hi PD's,

It's been a while since I last posted. The first pic will give you a good idea why. I just got my Bridgeport mill back together and finished up some items on it that needed fixing.


I've got the machine in good condition and am very excited about doing some serious work on it.


Ok, so lets get going. Here I've clamped the two rails together and in the vise ready for drilling the holes that will mount the rails to the legs. I've got a "wiggler", device used for finding the edge of a part precisely, installed an am about to find the edge of the rail. If anybody is interested how this works I'll be more than happy to explain.


And now for the end.


The first hole has been located and is being drilled. Using the DRO (digital readout) on the machine the rest of the holes are located and drilled.


Here are the two rails with the mounting holes drilled. The rest will be drilled later.


Same procedure for the legs.


Thru holes ready to be tapped 5-40


And this is what it will look like. Unfortunately I didn't have any screws. I need to order some. So in the mean time I'll make another part for the engine and report back here.

Regards,
Bernd

[Eddy Matthews]

You've made a good start Bernd, I'm looking forward to seeing how the engine turns out when it's finished, but still a long way to go until we're at that stage!

Eddy

[Bernd]

Well Eddy I'm hoping I can get it done before spring. 

Bernd

[Brass_Machine]

Hey Bernd!

Nice work you have going there!

Do you have plans for it? In other words... what are you going to put it in?? Do you know yet?

Eric

[Bernd]

Hi PD"S ...............

Sorry I haven't been on much. Trying to fix the Bridgeports quill feed, so may be down for some time.

Eric,

This is a demo model. It wouldn't make a very good engine in any kind of boat. It has a cam that drives the valve. No way of reversing the engine. Reason for the engine build is to see if I can build a long stroke steam engine. Once I get this done I plan on either designing my own or getting a set of plans for one from Ageless Engines. I thought originally that I might be able to modify this engine. but the more I studied it the more it became evident that it would be very difficult to modify it so you can reverse it.

I'm looking at building a stern wheeler tug. I going to try and follow the Southern Belle that I started a thread here on. Haven't figured out the scale yet. It will depend on how big the engine is.

But before anything else I must work on a project that SWMBO has me working on.  

But don't fret I will get this one done eventually.

Regards,
Bernd