@wirelesscps They need to be 90 degrees apart. The displacer piston should be set so that it does not touch the bottom or the top nor the sides of the cylinder. The power piston should also not touch bottom . There is no top to touch for the power piston. Friction is the biggest enemy of the engine. Look closely and you will see that the cranks are 90 degrees apart.
@wirelesscps when the power piston is all the way down the displacer piston will be in the middle of its' stroke. half way up. That means the rotation should be counter-clockwise when looking FROM the flywheel side.
@MojaJinonice I am very serious about the baby powder. When I used a J.B. Weld piston, and after scrubbing it and the copper cylinder very well with a toothbrush it still would feel scratchy and gritty when sliding by hand. tried everything Even expensive silicon oil. Everything I tried made it worse than using no oil I was then using baby powder to polish the aluminum top disc and decided to try powder in the cylinder. It worked great and also seals the clearance.Piston would slide at 10 deg
I made my first pow. piston by Dentacryl (it is two-parts material like liquid plexi-glass), but after two days hardening the diameter of pow. piston was smaler then inside diameter of copper cylinder and I had to make another piston. The second pow. piston was made of usual Epoxy, but the sliding is not good. When the piston's temperature is higher then room temp.e, the diameter of piston enlarges a little bit and the friction in copper cylinder stops the moving of piston.
Did you try the baby powder yet.?. Do you have J.B. Weld available? I was ready to give up on J.B. because of the gritty feeling until I tried the BP . I promise , it seals the voids in the piston and the cylinder.. Look closely at my 2nd. stirling and you can see the BP in the cylinder. Let me know if you don/t have JBW available. Keith
@keithecampbell1 Baby powder does NOT work with close tolerance fits such as a cox .049 nitro engine piston and cylinder. It DOES work with loose fitting pistons such as J.B Weld cast piston and copper cylinder with .002 clearance as mine shows. my .049 engine piston, cylinder clearance is only .0001 ,anything, even ultra thin oil will make it tighter. I tried it.
When I looked closely at Your 2nd. Stirling video I really saw the rest of Byby Powder in the copper cylinder above the pow. piston. At my first glance I didn’t noticed this detail.
@keithecampbell1 Using of Byby Powder to lubricate an epoxy resin power piston in copper cylinder is quite new for me. I am going to make some experiments with it, especially when I will make another new piston for my next Stirling engine. The second possibility: I have some old pistons with smaller diameter then cylinder and I can test the properties of Byby Powder on them.
@keithecampbell1 I didn’t try Baby Powder (BP) as a lubricant in my recent pair of Piston/cylinder. I am going to make a new experimental copper cylinder and a molted (poured) plaster power piston. I saw somewhere here in You Tube Stirling engine with a piston made from plaster (gypsum). Zero temperature diameter changes and simple and low-cost solution. This piston could be lubricated by BP.
J-B WELD epoxy is also known in the Czech republic, where I live. But there is not easy to buy it here directly. I didn’t try it intensively. Producer LOCTITE offers some similar kinds of special epoxy resins, for example.
@keithecampbell1 On the web-page of J.B.WELD producer I noticed, that among a lot of parameters is also mentioned “Shrinkage: 0.0%”. Common Epoxy resin has Shrinkage in temperature range (0 / 70 deg.) so big (typically 3,2 %), that the pow. piston shrinks during the experiments. (Colder epoxy piston looses in cylinder and hotter epoxy piston grinds in cylinder)
hi i am making on how should the psiton and plundure e set should they bot be at the top or both be at the bottom
wirelesscps 1 year ago
@wirelesscps They need to be 90 degrees apart. The displacer piston should be set so that it does not touch the bottom or the top nor the sides of the cylinder. The power piston should also not touch bottom . There is no top to touch for the power piston. Friction is the biggest enemy of the engine. Look closely and you will see that the cranks are 90 degrees apart.
keithecampbell1 1 year ago
@keithecampbell1 thanks so whne the power pistin is all away donwn where should the displacer be up or down or in between?
wirelesscps 1 year ago
@wirelesscps when the power piston is all the way down the displacer piston will be in the middle of its' stroke. half way up. That means the rotation should be counter-clockwise when looking FROM the flywheel side.
keithecampbell1 1 year ago
Nice! COngratulations
impazzitoinvolo 1 year ago
Hi, I can't believe my eyes: “Lubricant for power piston .... Baby powder!!!!!”¨
Are You kidding or is this a serious information? In every descriptions of LTD
Stirling Engines (I red) is recommended not to lubricate the power piston !!!
On the other side, it is extremely difficult to do compromise between
sealing and friction in power cylinder. And this is a reason that constructors make
graphite power pistons in glass cylinders.
I am looking forward to your answer
MojaJinonice 1 year ago
@MojaJinonice I am very serious about the baby powder. When I used a J.B. Weld piston, and after scrubbing it and the copper cylinder very well with a toothbrush it still would feel scratchy and gritty when sliding by hand. tried everything Even expensive silicon oil. Everything I tried made it worse than using no oil I was then using baby powder to polish the aluminum top disc and decided to try powder in the cylinder. It worked great and also seals the clearance.Piston would slide at 10 deg
keithecampbell1 1 year ago
@MojaJinonice
Did you get my answer?> reply if you will/.
keithecampbell1 1 year ago
I made my first pow. piston by Dentacryl (it is two-parts material like liquid plexi-glass), but after two days hardening the diameter of pow. piston was smaler then inside diameter of copper cylinder and I had to make another piston. The second pow. piston was made of usual Epoxy, but the sliding is not good. When the piston's temperature is higher then room temp.e, the diameter of piston enlarges a little bit and the friction in copper cylinder stops the moving of piston.
MojaJinonice 1 year ago
@MojaJinonice
Did you try the baby powder yet.?. Do you have J.B. Weld available? I was ready to give up on J.B. because of the gritty feeling until I tried the BP . I promise , it seals the voids in the piston and the cylinder.. Look closely at my 2nd. stirling and you can see the BP in the cylinder. Let me know if you don/t have JBW available. Keith
keithecampbell1 1 year ago
@keithecampbell1 Baby powder does NOT work with close tolerance fits such as a cox .049 nitro engine piston and cylinder. It DOES work with loose fitting pistons such as J.B Weld cast piston and copper cylinder with .002 clearance as mine shows. my .049 engine piston, cylinder clearance is only .0001 ,anything, even ultra thin oil will make it tighter. I tried it.
keithecampbell1 1 year ago
@keithecampbell1 Thanks for Your answer.
When I looked closely at Your 2nd. Stirling video I really saw the rest of Byby Powder in the copper cylinder above the pow. piston. At my first glance I didn’t noticed this detail.
MojaJinonice 1 year ago
@keithecampbell1 Using of Byby Powder to lubricate an epoxy resin power piston in copper cylinder is quite new for me. I am going to make some experiments with it, especially when I will make another new piston for my next Stirling engine. The second possibility: I have some old pistons with smaller diameter then cylinder and I can test the properties of Byby Powder on them.
MojaJinonice 1 year ago
@MojaJinonice
Did you try this yet? I am very interested in your result. Thanks for your reply. Keith
keithecampbell1 1 year ago
@keithecampbell1 I didn’t try Baby Powder (BP) as a lubricant in my recent pair of Piston/cylinder. I am going to make a new experimental copper cylinder and a molted (poured) plaster power piston. I saw somewhere here in You Tube Stirling engine with a piston made from plaster (gypsum). Zero temperature diameter changes and simple and low-cost solution. This piston could be lubricated by BP.
MojaJinonice 1 year ago
@MojaJinonice Did you try this yet?
keithecampbell1 9 months ago
J-B WELD epoxy is also known in the Czech republic, where I live. But there is not easy to buy it here directly. I didn’t try it intensively. Producer LOCTITE offers some similar kinds of special epoxy resins, for example.
MojaJinonice 1 year ago
@keithecampbell1 On the web-page of J.B.WELD producer I noticed, that among a lot of parameters is also mentioned “Shrinkage: 0.0%”. Common Epoxy resin has Shrinkage in temperature range (0 / 70 deg.) so big (typically 3,2 %), that the pow. piston shrinks during the experiments. (Colder epoxy piston looses in cylinder and hotter epoxy piston grinds in cylinder)
MojaJinonice 1 year ago
@MojaJinonice
Moj, Did you try anything new yet, baby powder? new piston and cylinder? Let me know, Keith
keithecampbell1 3 months ago