I apologize in advance for the use of improper terminology. I am new to this hobby. I have Accucraft Mason Bogie on rolling gear. I steamed it up twice now and can't get it to move its rods. After about ten minutes, I am able to raise up to 45 PSI with the throttle closed, and I have tried a number of throttle and the reversing gear settings. I set the steam throttle at about 1/8 turn open and the reversing gear in reverse. I tried cycling through forward and reverse. How much butane valve opening is appropriate? The last time I had it open 1/2 turn open. I can achieve slightly more than 20 PSI. But if I open the throttle to 1/4 turn open, pressure drops below 20 PSI. Steam issues from the stack, but the rods never move. I am able to manually move the wheels, but the loco makes no attempt to take off.
Mason Bogie Live Steam Won't Run
RefrigEng
61 - 73 of 73 Posts
I need to study the timing subject, but this evening I pursued the leak angle. I connected some air at low pressure - not even registering on Bogie's gauge. Sound immediately emanated from the stack. I rigged a stethoscope to some brass tubing and probed the engine joins and pivots. There was a lot of noise in the stack and less but alarming noise in the smoke box and boiler tube (term?). I could not tell for sure if there were leaks in addition to the air blowing through the pistons and out of the stack vent tube. I listened for a difference in pitch or volume as I rotated the wheels, but there was very little change. So I removed the stack and pinched the vent tube holes closed. The whole engine was quiet up to 20 PSI. All of the joins and pivots were quiet. I believe the air was rushing through the pistons with little resistance and venting from the stack. Now I plan to study the discussion regarding timing. I visited Trains Magazine web site and registered. No references to back issues into the 80's Thanks again, folks.
p.s. I purchased the Bogie new from Accucraft in January.
p.p.s. Andrew, the right side rods and cranks on this Bogie align with your photo.
p.p.p.s. I downloaded the Dockstader programs, thanks, Charles M. Thanks for the primer on Fairly and bogie.
4p.s. David, I assume that you mean that the equivalent amount of hole is uncovered at each end of the stroke?
5p.s. Bill, blow-by resonates with me right now. I will investigate the front cylinder cover tomorrow.
p.s. I purchased the Bogie new from Accucraft in January.
p.p.s. Andrew, the right side rods and cranks on this Bogie align with your photo.
p.p.p.s. I downloaded the Dockstader programs, thanks, Charles M. Thanks for the primer on Fairly and bogie.
4p.s. David, I assume that you mean that the equivalent amount of hole is uncovered at each end of the stroke?
5p.s. Bill, blow-by resonates with me right now. I will investigate the front cylinder cover tomorrow.
Joined
·
5,578 Posts
Just to clarify a couple of aspects of the valve settings:
The Eccentric/Crank Arm should be at 90° to the Main Pin on the wheel. The apex of the angle is the center of the Axle. See the drawing below for where that angle is measured!
Another thing that maybe has not been stated clearly is that the eccentric crank arms should both be in the same direction from one side of the loco to the other and there is always some confusion when you look at one side of the engine and then turn it around to view the other... You have to remember that in doing so you have just reversed the direction of "forward" so, Clockwise and Counter-Clockwise (or Anti-Clockwise for my friends across the pond) is a poor choice for a description! To eliminate any confusion, if you roll the engine forward, both eccentrics should either be Leading or Lagging (following) the Main Pin. If the Valves are "outside admission" (like your engine is) then the Eccentric should Lead the Main Pin. (NOTE: The drawing implies that the front is to the right, because the Main Rod goes off in that direction, thus it shows the Eccentric Arm "Lagging" the Main Pin, which is the opposite of what you want on your engine. I made the drawing for my 'Valve Gear' article series in "Steam in the Garden" magazine [2006] and I drew it that way because it is easier to "SEE" the angle that way instead of obscuring it behind the Eccentric Rod.)
When you roll the engine and watch the valves, they should both move the same amount (but are separated by 90°; i.e.: when one is at full travel in one direction, the other should be in the middle of its travel) Both should expose the steam passages to the cylinder an equal amount in both forward and reverse.
The distance traveled is controlled by how far Lifting Link from the Reverser Lever (in the cab) moves the Radius Rod (from the Valve to the Expansion Link) in the Expansion Link [that slotted, curved doohickey that is being wiggled by the Eccentric Rod as the wheels turn.] (How's that for technical jargon!)
When the Radius Rod is in the center of the Expansion Link the Valves will move only a very small amount and when the Radius Rod is as far as it will go in the Expansion Link (either up or down) the Valves should move the maximum amount.
If either Eccentric Arm has slipped in its attachment to the Main Pin then you need to set that first.
If the Lifting Links are not moving the Radius Rod to the same position in the Expansion Link then those may also need to be tightened to the common axle they are on. When the Reverser Lever is in the middle position, the Lifting Links should put the Radius Rods in the center of the Expansion Links.
If you get all these settings right, and assuming the manufacturer made all the parts right, then you do not need to know more about Valve Gear.
By your latest test, I guess it seems like you are getting "blow-by" in the Cylinders. Time to pull the front Cylinder heads off to see if you have a problem with the Piston Heads and Rings.
The Eccentric/Crank Arm should be at 90° to the Main Pin on the wheel. The apex of the angle is the center of the Axle. See the drawing below for where that angle is measured!
Another thing that maybe has not been stated clearly is that the eccentric crank arms should both be in the same direction from one side of the loco to the other and there is always some confusion when you look at one side of the engine and then turn it around to view the other... You have to remember that in doing so you have just reversed the direction of "forward" so, Clockwise and Counter-Clockwise (or Anti-Clockwise for my friends across the pond) is a poor choice for a description! To eliminate any confusion, if you roll the engine forward, both eccentrics should either be Leading or Lagging (following) the Main Pin. If the Valves are "outside admission" (like your engine is) then the Eccentric should Lead the Main Pin. (NOTE: The drawing implies that the front is to the right, because the Main Rod goes off in that direction, thus it shows the Eccentric Arm "Lagging" the Main Pin, which is the opposite of what you want on your engine. I made the drawing for my 'Valve Gear' article series in "Steam in the Garden" magazine [2006] and I drew it that way because it is easier to "SEE" the angle that way instead of obscuring it behind the Eccentric Rod.)
When you roll the engine and watch the valves, they should both move the same amount (but are separated by 90°; i.e.: when one is at full travel in one direction, the other should be in the middle of its travel) Both should expose the steam passages to the cylinder an equal amount in both forward and reverse.
The distance traveled is controlled by how far Lifting Link from the Reverser Lever (in the cab) moves the Radius Rod (from the Valve to the Expansion Link) in the Expansion Link [that slotted, curved doohickey that is being wiggled by the Eccentric Rod as the wheels turn.] (How's that for technical jargon!)
When the Radius Rod is in the center of the Expansion Link the Valves will move only a very small amount and when the Radius Rod is as far as it will go in the Expansion Link (either up or down) the Valves should move the maximum amount.
If either Eccentric Arm has slipped in its attachment to the Main Pin then you need to set that first.
If the Lifting Links are not moving the Radius Rod to the same position in the Expansion Link then those may also need to be tightened to the common axle they are on. When the Reverser Lever is in the middle position, the Lifting Links should put the Radius Rods in the center of the Expansion Links.
If you get all these settings right, and assuming the manufacturer made all the parts right, then you do not need to know more about Valve Gear.
By your latest test, I guess it seems like you are getting "blow-by" in the Cylinders. Time to pull the front Cylinder heads off to see if you have a problem with the Piston Heads and Rings.
Semper, I am in awe of the information now contained in this thread. Thank you for your post. Even if this is a simple piston attachment or wear issue (how could that be?), I will understand the timing subject. Always more tomorrow!
I took a peek under the front cylinder covers. They looked good, no debris or disconnected pistons. I am now in contact with The Train Department for professional help. Thank you all for your comments. I will be back with a report when the train is running.
Hugh
Hugh
Finally Runs
I wanted to tie up this loose end. It has been more than a year since I chronicled my problems trying to get my Mason Bogie to run. The Train Department did a marvelous job with the loco. The flexible steam lines were damaged by heat transferring from the smokebox to the unions. I was guilty of running the gas valve open pretty far as I tried to get a reaction. Not sure exactly how I got there, but I am very pleased by the way things turned out. The engine runs very well. If anyone is so inclined, I posted a video of my run on YouTube. Thanks again for the feedback.
.
I wanted to tie up this loose end. It has been more than a year since I chronicled my problems trying to get my Mason Bogie to run. The Train Department did a marvelous job with the loco. The flexible steam lines were damaged by heat transferring from the smokebox to the unions. I was guilty of running the gas valve open pretty far as I tried to get a reaction. Not sure exactly how I got there, but I am very pleased by the way things turned out. The engine runs very well. If anyone is so inclined, I posted a video of my run on YouTube. Thanks again for the feedback.
Joined
·
2,402 Posts
Leaks were external and tubing gone; steam leak was under the smokebox resonating through the opening. Melted through from overheating through the smokebox opening. Were a plastic type not 100% sure. The Roundhouse used teflon and special fabricated clamps and fittings. This is simlar in hardness. Ive replaced with the shielded tubing as its high temp rated for sitting near exhaust manifolds on autos.
Joined
·
1,691 Posts
Yes
Those smokebox fires will do you in every time
I've used PTFE (teflon) tubing with success when a dog bone connection isn't practical
As Roundhouse does I have special fittings which are shown in my "Making Parts" thread. Haven't had any fail yet but I would think they would melt if they got hot enough
I am trying to recall what tubing is used in autos that holds up to this heat level but you have me stumped.
Those smokebox fires will do you in every time
I've used PTFE (teflon) tubing with success when a dog bone connection isn't practical
As Roundhouse does I have special fittings which are shown in my "Making Parts" thread. Haven't had any fail yet but I would think they would melt if they got hot enough
I am trying to recall what tubing is used in autos that holds up to this heat level but you have me stumped.
Joined
·
1,253 Posts
Jay, what is it braided with? Unless it is braided with metal such as stainless steel I do not see why it should not burn. In fact if braided with fabric it will burn more easily. Although it will not melt as easy as whatever stuff is used by Accucraft. I doubt they use teflon, its melting point is 326 degrees Celsjus. The locomotive would fall apart before reaching this temperature... I guess teflon tubing is optimal from the point of both flexibility and heat resistance. Best wishes from Tokyo, Zubi
Joined
·
1,691 Posts
Zubi
It sounds like there was a smokebox fire which could have raised the temp over 326c (611f) but I agree that teflon is probably best. That being said, the braided tubing sounds interesting.
Jay, is it your TD102 that is on your site?
Do you attach it with normal hose clamps?
What is the outside diameter?
Have you done any tests on it for heat resistance?
It sounds like there was a smokebox fire which could have raised the temp over 326c (611f) but I agree that teflon is probably best. That being said, the braided tubing sounds interesting.
Jay, is it your TD102 that is on your site?
Do you attach it with normal hose clamps?
What is the outside diameter?
Have you done any tests on it for heat resistance?
Joined
·
1,253 Posts
Bill, OK, smokebox fire is a different matter, and this can be - and often is disastrous, resulting in serious damage to the locomotive. For that reason alone there should actually be some kind of an early indication of smokebox fire and extreme temperature. Melting steam delivery pipe plus a lot of smoke of the wrong kind serves as such an indicator... Best wishes from Tokyo, Zubi
61 - 73 of 73 Posts
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
