[WIP] V12 LPE

[Tommy Styrvoky]

I am currently working on a V12 LPE for future models, the engine is only 50% plumbed with tubing, and I had an unfortunate issue with one of the cylinders getting damaged during the modification process. I have a replacement one coming, though I guess I learned my lesson to read the contents on silicone spray bottles, It turned out the one I got had some acetone in it, and I accidentally applied too much to the inside of the cylinder, that resulted in jamming the cylinder and marring the sidewalls. Even with 5 of the 11 cylinders plumbed, I am having issues with getting it to turn over, there seems to be a decent amount of friction, though this could be caused by a variety of issues, such as the remaining unpowered cylinders. At 4 bar I am getting some movement, and the timing is correct, though It struggles to travel more than 90 degrees without some assistance. I have modified the cylinders and the valves, to improve performance, though I think the main cause of the friction is in the sliders/camshaft. The 120° crankshaft added an interesting challenge, though I am debating if it is a better choice to redesign into a V8 with a more robust 90° crankshaft, as I think that would solve a lot of the issues with friction, or to reconfigure to 6 or 8 large cylinders, as I am not sure how powerful this will be, though If it struggles to turn over, it may not have much power at all. As this is being designed for a future model of mine, I would like to remain accurate by having 12 cylinders, though If it fails to provide enough power, I will compromise to use 6-8 large cylinders, as the net power output I am looking for would be the equivalent of 4 XL motors.

Current progress, I will try to finish up plumbing the remaining cylinders sometime in the next week, though after that I won't be able to do anything else for another two months due to 3D printing research at my college over the summer.

V12 LPE by Tommy Styrvoky, on Flickr

V12 LPE by Tommy Styrvoky, on Flickr

Edited August 7, 2018 by Tommy Styrvoky

[mocbuild101]

I think the main problem (like you said) is the unpowered cylinders - they will still introduce a lot of friction even if they're lubricated. Another possible source could be the sliders - if the (pin with pin hole) connectors turn against the axles they can add a bit of friction, and with 12 sliders, that could add up to quite a lot...

Edited May 19, 2018 by mocbuild101

[nerdsforprez]

As a fan favorite of LPEs, I will follow closely.  Once all the rage, LPEs are not as common as they once were.  You may want to contact Alex Zorko at lpepower.com  he has produced some fantastic LPEs over the years.

Not many have produced LPEs with the small cylinders.  Many believe they are too weak though there have been some that look fairly powerful:

 

Though I don't know.  The plastic rod-part seem too weak to me.  Large cylinders, aside from being larger and more powerful, are so much more powerfully built.

[Tommy Styrvoky]

I tried building a V8, from the current V12, and I think the issue is the valves are still too stiff, I will try and remove some material around the selector pivot in the valves. As I got that to turn over slowly, though it would still get hung up.

Edited May 21, 2018 by Tommy Styrvoky

[Tommy Styrvoky]

I got it running on 4 cylinders, not too much power though. I will probably get the large cylinders for powering a large model. It had a lot of friciton, and I was running it at around 100psi.

LPE V8 running on 4 cylinders. by Tommy Styrvoky, on Flickr

Edited May 21, 2018 by Tommy Styrvoky

[Tommy Styrvoky]

I built an I4 from the switching design I used on the V8, it works ok, though It isn't very powerful. I will get some of the large cylinders later this summer and experiment with them. It was probably around 500-800 rpm though I think the main issue is the stiffness in the switches gasket, The V2 switches are stiffer than the V1 ones.

LPE I4 by Tommy Styrvoky, on Flickr

[AFOLegofan66]

This is a very cool MOC. The progress is awesome and look forward to the next video!!

[Tommy Styrvoky]

I installed the older style valves and that made a big difference. I changed out the valve switching design and greatly reduced the form of the entire engine,It now operates at 1000 rpm at 80 psi. The older valves are more difficult to open up and managed to snap 2 light duty #17 chisel blades in half opening them. I am not sure why the older valves are smoother, but It could be something with the rubber component that seals the ports. The torque is rather decent when being geared down, it seems to perform similarly to the torque of an XL motor.

I will be releasing instructions for it later, as this is a small enough model, I should be able to do PDF instructions.

video of it running 

LPE I4 by Tommy Styrvoky, on Flickr

 

I am thinking of installing it in this vehicle, the Czech Panzer 38T, this vehicle uses a 6 cylinder, though my design fits and allows for better scale of 1/10th. There are still a bunch of mechanical decisions I need to make. I want to stay mostly purist, however I really want to replicate the operation of the transmission and regenerative steering mechanism. To do this it would require several 3D printed planetary gear rings that would compose the transmission and steering housings, otherwise I could go for a standard 3+R speed transmission, and still replicate the steering system using differentials instead of planetary gears. Other parts that  will need to be designed and printed are the sprockets, as to make the geometry correct and provide a good interface for powering the model. The only major issue with the purist solutions is the available space, I would like to replicate the interior too, but I only have about a 6X6 area for the transmission design. It could still work with regular driving rings, if I were to run all of the connections in the transmission at a high rpm, low torque and greatly reduce speed and increase torque prior to powering the steering system, to greatly reduce strain on weak components.

Edited August 7, 2018 by Tommy Styrvoky