Up one level Neidrauer Adventures Photo Album » Building a Live Steam Locomotive - the Mikado Project » Section 11 - Valve Gear
Section 11 - Valve Gear
Completed! Valve Gear. Lots of little levers: Link Trunion, tumbling shaft lever, eccentric crank, eccentric rod, radius rod, combination lever, union link, lifing link. July 2008-January 2009

At first page Next page 1-64 (of 133 found)
 7-July-10 Bill finishes installing the new 1/2  Putting the lifting arms on the shaft.  Using a rotary dial indicator to center the mill before boring the pillow block out to 1/2  Using a rotary dial indicator to center the mill before boring the pillow block out to 1/2  A  Indicating the mill over the center of the existing hole prior to enlargement.  Indicating the mill over the center of the existing hole prior to enlargement.  Boring the firemans (left) side lifting arm.  A fixture to hold the already machined lifting arms.  We must not move the centerlines of the hole when boring out the tumbler shaft boss for the new, larger shaft.  Hand locating where the hold-down screws will go.  Hand locating where the hold-down screws will go.   23-June-2010 - 18 months after making the original tumbling shaft and seeing it flex/rotate when running the engine on air, Bill has never been happy with it.  Tonight he started making a new one without a bend in it, and from larger 1/2  Indicating the setup on the mill to drill holes in the end.  31-Jan-09 Drilling the roll pin holes for the tumbling shaft lifting arms.  Reviewing the blueprint notes, we could not see how we could accurately match drill the arms to the shaft and guarentee the ends of the arms are in the same position on both sides of the locomotive.  31-Jan-09 With the shaft held between centers (we had drilled center holes in the ends before bending), we use a dial indicator to measure the total indicated runout after the bending operation.  The stresses of the cold-formed bend caused the ends to move around, with a very large runout next to the bend point. We focused on getting each end to be within a thou of each other, around the area held in the pillow block. With this we are confident the tumbler shaft will rotate without binding.  With a guess on how much spring-back to accomodate, we crank the vise down and the bending jig goes to work.   31-Jan-09 The bending jig loaded and secured for use.  24-Jan-09 A mock-up of the bending jig.  Using a depth mike to measure the depth of the block relative to the hole.  We do this on both sides to make sure the machined surface is parallel to the reamed hole.  Using an indicator to roughly make the hole level with the table.  Drilling the pilot hole, then we will enlarge the holes and ream to a finish through the block.  Deep-drilling a hole like this will make you wish for a lever-action tailstock.  The Tumbling Shaft bending jig needs to hold the bar ends in place during the bending operation.  We will use two 4  The tool and the finished pass.  Bill keeps one hand on the carriage crank and the other on the tool holder keeping a toolbit shim from rattling out during the interrupted cut.  21-Jan-09  The big 1925 Rahn-Larmon cone head lathe is fired up to turn a 12  While Bill was making the Tumbling Shaft bending jig, I finished making the six bolts for the valve gear.  The quality of what I can make has improved since we started this project several years ago I'm happy to report!  Drilling the bolting holes for the vise bending fixture.  19-Jan-09  Bill and I have been puzzling how to put that 6  I managed to make a few bolts on the lathe and hold the dimensions pretty good.  19-Jan-09.  The end of another night and this section is nearly complete.  19-Jan-09 Turning our attention back to the unfinished Tumbling Shaft Levers, we re-use the tooling plate fixture to hold the levers perfectly square.  We have put two dowel pins in the plate, one for the right lever pin hole and another shorter pin that both levers have been slipped over and clamped across.  With the tooling plate clamped to an angle plate and indicated flat to the table, we can insure the Tumbling Shaft pinning holes are in line with each other.  With the redundant hub nearly gone, the eccentric rod is close to being finished.  Taking a light cut and CONVENTIONAL milling the end of the eccentric rod.  Foregoing the hassle of setting up a rotary table, we clamp a dowel pin in the vise, and making sure to take light cuts and CONVENTIONAL mill only, we rotate the eccentric rod by hand and cut away the redundant nub on each rod.  My eccentric rods were cast as both lefts and rights, and needed to have the 'oil fitting' nub machined off.  Using a small 1/4  14-Jan-08 Time to drill some oil holes!  Using a protractor and eye-ball-that-oughta-do alignment method to put the oil hole near the center of the  shaft hole, we then use the wiggler to line up the hole location.  Our drill bits were just barely long enough to drill the holes before the chuck body interferred with the side of the part.  The second step to machine the radius rod is to put a spacer in the ends of the finished 'ears' which is exactly the same width as the slot opening.  We then re-clamp the part on the finished end so we can mill away the middle while securely holding it.  Checking the thickness to get the finished size.  The finished first step.  The first step is to mill about 3/4 of the slot away, which also allows us to set our numbers on the DRO.  Because the 'ears' of the radius rod are so long and thin and will not leave us much material left to clamp with when we are done, We decide to cut the radius rod slot in two steps.  10-Dec-08  Levers with slots!  This wraps up another year in the shop, nothing more until after the new year holidays are over.  We had some discussions on how to hold the Eccentric Rod to mill the slot.  In the end we decided to just clamp it in the vise and mill the middle away.  The risk of this setup is the vise might put force on the tiny amount of material not machined away, causing the machined part to bend or have taper when done.  It's hard to hold Combination Lever with an offset in the vise, so a couple of blocks are used to pinch the part in the jaws.  Then we mill the slot in a conventional horizontal position.  Back and forth we go, taking a little more off each time.  After we have milled the middle away, we go back and do a finish pass on each side to get the 'ears' to the finished thickness.  10-Dec-08 time to cut some slots.  The lifting link is short enought to hold in the vise jaws.  A quick bump of the cutter a close fitting pin allows us to get a reference dimension to set the slot cut depth.  Progress at the end of the night.  Without disturbing the setup, we drill and bore the Eccentric Rod.  Next it's a simple step to drill and bore the holes.  Not seen is the machinist's jack to support the end of the fixture hanging out of the vise.  3-Dec-08.  To accurately lay out the holes for the Radius Rod and Eccentric Rod, we build a drill fixture.  using a piece of aluminum tooling plate, we machined the top and bottom clamping side parallel, then drilled, bored and pushed a dowel pin in which exactly fits the un-bushed hole in the radius rod.  28-Nov-08 At the end of the night, most of the rods have been drilled and bored.  Next to drill the Radius Rod, Eccentric Rod and cut the slots and put the bearings in.  You can never have enough clamps! Here's what we ended up with to hold the Radius rod in line.  Using a magnifying glass to align the clamping fixture under the scribed centerline on the part.  To machine the Radius Rod, we start at the valve end and machine a flat for a reference surface.  How do you hold these castings?  With the draft (taper) in them from the moulding process, there isn't a straight spot to start from.  Cutting the other side. We are using the end of the vise like a vee-block, most of the clamping force is on the left end of the link.  Machined ends, one side.  12-Nov-08 Using space blocks to hold the Lifing Link in the vise.  Preparing to drill the holes.  Cutting the right-side lever  Cutting the other end.
Page 1 of 3 Next page