Elmer's 43 "Build" Questions

[Flyboy Jim]

Wanting to make the main bearing now. The plans call for bronze. I don't have bronze (too expensive); but I have brass. I see that Jim (in his build thread for his #43 engine) used brass instead, not anticipating much use.

Jim, how's the brass holding up?  Any other comments on using brass or other metal, instead of bronze with a steel crankshaft are welcome.

No more than these engines get run, the brass will hold up just fine. If the brass bearing should happen to wear out, it's simple enough to make a new one.

Jim

[Bear]

Thank's, Jim.

[Bear]

I didn't quite know where to put this information on very good clearance deals at Grainger. I thought that members could benefit. I have no affiliation whatsoever with Grainger other than as a new customer. I stumbled upon them when looking for machine screw size dies. I ended up buying a 3-48 die for $2.37, 2-56 die for $1.48, some reamers for well under $2.00 each, boxes of screws in various sizes starting at 2-56, and even a small bore gauge set for about $5.00.

In any event, if you are interested in this type of item or other items, you may desire to check out the Grainger website and search for "clearance" items.

[Bear]

A little progress today. I gave some more thought to what I had planned to do with the Tilting Guide in my post (#44) above. Instead of finishing in the mill, I finished the mill work today. so that all there is left to do is cut the length to size, and then turn the round portion in the lathe.

I figure it would be difficult to turn the round portion up against the chuck, which is what I would have had to do if I proceeded as originally planned. Then the mill work would have little support from the small chucked diameter.

I hope I am going about this correctly. I hope I will be able to chuck the rectangular portion in the independent 4 jaw chuck so that the round portion of  the tilting guide will be square to the rectangular head.

Here are some pictures, including what I have made so far. The ugly square of aluminum is a rough cut for the cylinder that I will attempt to true up in the mill.
 

[Bear]

Today, I finished the Titling Guide. There was so little for the 4 jaw chuck to grip, so I made a tight fitting aluminum block that fit into the slot of the Tilting Guide. I machined it so that the ends were at an exact measurement with the ends of the Tilting Block. You also see that the chuck jaws gripped the block and the Tilting Guide so that the block could not come loose. See photos. Although the photos make it look like the block was not square in the guide slot, it was square.

Then after cutting the Tilting Block to length, I proceeded with squaring it in the 4 jaw chuck. I think I got it squared ok, because it turned out nicely. I also took very light cuts so as to avoid a potential for the piece to be knocked out of alignment, or even worse, come out of the chuck. 

[crueby]

Nicely done!  One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.

 

[mklotz]

Good job but wouldn't it have been easier to reverse the order of operations; first turn cylinder, then cut slot.  A fabrication would also have been a possibility; mill channel, drill hole in bottom and silver solder in length of rod.  On the one I built years ago, I went with the fabrication.

[Bear]

Nicely done!  One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.

 

Thank's. I was going to use my tailstock center; but, I didn't have enough length with my center, unless I did something wrong.

[Bear]

Marv, I think you are correct that it would have been easier the way you stated; however, I am prone to doing things the hard way  .

[crueby]

Nicely done!  One thing to consider for next time - for a part like that, putting a small dimple in the end and supporting it with a live center in the tailstock can reduce the pucker factor a bit.

 

Thank's. I was going to use my tailstock center; but, I didn't have enough length with my center, unless I did something wrong.

I had same issue with the stock Sherline center not reaching far enough, found an aftermarket longer one, more recently Sherline came out with a long one they market for pool cue turning.

[Bear]

Crueby, that is good to know. I have been meaning to do something about mine.

I just got done rough squaring my cylinder, rough being the operative word, because it is not exactly square. Will have to start again with my square sides, and hopefully I can square it all up to size. I am through for the day. Time for a beer .

[Bear]

Okay, got the cylinder moving along by drilling and tapping the mounting holes, and boring the bore. I have also mounted the column using a counter bore for the screws. Also, I shaped the base. As you may recall in one of my earlier posts, I drilled the base upside down for the cylinder, so I reversed it and did it correctly. I was not decided on what to do with the 2 extra holes. I ended up milling one out and leaving another as a potential mounting hole, as can be seen in the photos.

Now to try to figure out how best to drill the 25 degree angle port holes in the top of the cylinder.

Edit: I did use the 4 jaw chuck to bore the cylinder. I should have taken a photo.

[crueby]

Looking good!  For the angled holes, one thing that can help is to use a small end mill to create a small flat at the angle of the hole, so that you can center drill and drill the hole into a flat surface that is perpendicular to the hole. Otherwise, the drill will want to skate downhill slightly.

 

[Bear]

Thanks; good idea.

[Bear]

Got the vise and mill all "trammed" to get ready for the port holes at the 25 degree angle. Think about using an adjustable triangle that I have and set it to 25 degrees. Then I will attempt to set the angle of the cylinder up against the triangle in the vise, and then drill from the bore out. Please let me know if there is a better way without angle blocks or special attachments.

While I was not ready to start the port holes, I did start on the piston rod. Threaded one end after getting it to size. it is now sitting in the 4 jaw chuck with the part opposite where the piston will be extending slightly from the jaws so that I can machine it accordingly.

However, I am at a standstill on how to mill the slot in the piston rod. The plans appear to call for a .093 wide slot. The smallest diameter end mill I have is 1/8" (.125"). Would it be okay to make the slot .125" or should I just order a 3/32" end mill? The width of the area containing the slot is .250, thereby leaving only .0625 thickness around the slot. Suggestions would be appreciated.