The slot you query at about 10:45 - that's to take the last of the water (last few mm of pump stroke) into the outlet port isn't it? If it wasn't there you would have a pocket of dead space at the end of the stroke.
That makes sense Simon. I had not assumed that the ram would go that far into the bore on its stroke, but that's an easy check in Fusion 360. Much appreciated 👍
@@markshomeengineering5243 well, the ram might not go that far and at the end of the day its the stroke that matters, not the length of the piston. I suspect though that Don designed his piston to go right to the end of the bore, which he might have done to get the maximum stroke in the space you have available. By the way, I really admire your patience and tenacity! It's been a fascinating series so far.
I concur with Simon's Comments. A Concern of the small Locomotive Designers (LBSC, Don Young, Martin Evans) was the possibility of an Air Bubble forming in the Axle Pump which would reduce the Output of the Pump. I would imagine that Don Young would instruct you to make either the Pump Ram or the Eccentric Rod such that there is a minimum of Clearance at "Top Dead Center", the idea being this would drive the Air Bubble out. Another Concern I have heard is the Bottom Suction Ball Valve sticking after a long Period of Storage (say Winter). Some people have piped their Hand Pump such that it delivers Water THRU the Axle Pump. This can be used to "exercise" the Valve Balls. The Pump By-Pass Valve must be closed to feed Water in this Case.
By minimum clearance, I imagine something like 1/32". I assume you know that the Balls need to be seated in their Seats by giving them a tap with a Hammer (although others make a Tool with a sacrificial Ball in the End to burnish the Seat, others use a 90 deg Seat, others use hard Nitrile Balls). The Pump should be built with new Balls, not the ones used to form the Seats. There really is a "love - hate" relationship between Model engineers and Ball Valves.
Hi Bruce, thank you for the info. I was aware that the ball needs a tap to form the seat, I did not know that the same ball cannot be used, so much appreciated.
Hi Mark having oddities on drawings is what raises us above the animals lolprogres is going good
🙂
There is a noga internal holes countersink manual tool that’s can help you to make what you need
Very interesting.... i never worked with castet parts.... a Kind of "one shot" job....
Looking forward
Cheers
The slot you query at about 10:45 - that's to take the last of the water (last few mm of pump stroke) into the outlet port isn't it? If it wasn't there you would have a pocket of dead space at the end of the stroke.
That makes sense Simon. I had not assumed that the ram would go that far into the bore on its stroke, but that's an easy check in Fusion 360.
Much appreciated 👍
@@markshomeengineering5243 well, the ram might not go that far and at the end of the day its the stroke that matters, not the length of the piston. I suspect though that Don designed his piston to go right to the end of the bore, which he might have done to get the maximum stroke in the space you have available.
By the way, I really admire your patience and tenacity! It's been a fascinating series so far.
I concur with Simon's Comments. A Concern of the small Locomotive Designers (LBSC, Don Young, Martin Evans) was the possibility of an Air Bubble forming in the Axle Pump which would reduce the Output of the Pump. I would imagine that Don Young would instruct you to make either the Pump Ram or the Eccentric Rod such that there is a minimum of Clearance at "Top Dead Center", the idea being this would drive the Air Bubble out.
Another Concern I have heard is the Bottom Suction Ball Valve sticking after a long Period of Storage (say Winter). Some people have piped their Hand Pump such that it delivers Water THRU the Axle Pump. This can be used to "exercise" the Valve Balls. The Pump By-Pass Valve must be closed to feed Water in this Case.
By minimum clearance, I imagine something like 1/32". I assume you know that the Balls need to be seated in their Seats by giving them a tap with a Hammer (although others make a Tool with a sacrificial Ball in the End to burnish the Seat, others use a 90 deg Seat, others use hard Nitrile Balls). The Pump should be built with new Balls, not the ones used to form the Seats. There really is a "love - hate" relationship between Model engineers and Ball Valves.
Hi Bruce, thank you for the info. I was aware that the ball needs a tap to form the seat, I did not know that the same ball cannot be used, so much appreciated.