Domanoff's PL4 Upgrades

[DispleasedOwl]

Hi everyone,

 

As requested by @bruce d, i am posting here the upgrades i did to my PL4 machine to make it quieter and deliver higher quality rope.

 

After multiple test runs of the machine, i found that adequate tension from the spools is what secures a well laid rope. That being said, i usually run it for a few spins, tightening or loosening the nuts that apply pressure to the spools until i find the perfect tension where the rope does not just unwind freely from the spool and encounters a little bit of resistance. I believe, after a few weeks of use, that this tension and experimentation is what caused the first cog to break.

 

This is when the upgrades started. First, i had my girlfriend (thanks honey, i know you read this) design a model of a cog similar to the one that broke in order to change it. But i noticed that quite the noise came from this cogs moving, since they are not a perfect "match" with the rest of the cogs they are connected with. This "freedom" of movement is what, at high speeds, causes that terrible noise that everyone who owns this machine knows. So we designed this replacement cog with teeth that are slightly thicker. This reduces the wiggle room the cogs have, which in turn reduces noise. Also, i printed them with a smaller layer size, so they are sturdier than the original ones. I have attached the .stl of this piece, if anyone wants to print it. It requires no supports, and i recomend a generous infill.

 

In this image you can see how the teeth of this 2 cogs fit snugglier with each other:

 

 

Another place where a lot of noise is generated is between the connection of the cog that is connected to the motor and drives the main cog. The connection between this two cogs has a lot of wiggle room, but the problem is that i didnt want to bother my gf again designing a main cog with thicker teeth, so what i did is i wrapped the cog connected to the motor in some masking tape. This turned out to be even better, since after a few layers it leaves a more squishy finish than plain plastic. This results in more noise absortion when the teeth of this 2 cogs are rotating at high speeds. This greatly reduces noise, and is a cheap (and replaceable) solution to the noise. It is a must do in my opinion.

 

 

Also, another issue i had is with the rope laying location. We know that, for a high quality rope, the laying needs to happen between this 2 pieces. Problem is, nothing is preventing it. I found myself laying rope outside this spot, closer to the spools, which just ruins it. It turns from strands intertwining themselves to 1 rope acting as the "core" and the rest going around it. (I know a strand is needed to act as a core in 3 and 4 laid rope, this mostly prevents this issue in 2 strand laid rope)

This following upgrade only "forces" you to do the right thing. It is a replacement for the first, closer to the laying spools, black piece. It has 4 holes in it, in which the individual strands go through, and does not allow the laying to go beyond this piece. Consider it as a guideline. It keeps the original sized hole, in case you dont want to use the smaller holes/use a core strand.

 

This also acts as this wooden guide block which is used in traditional model rope walk machines.

 

After this upgrades, and most important, LEARNING HOW TO USE AND OPERATE THE MACHINE, this is the quality of rope that im consistently getting:

 

Im quite happy with the results. This ropes have just been laid, they are missing some massaging with bees wax, to fully bring the shine in them. This is a close up of a sail i made using this same ropes:

 

Here are the files:

 

PL4_guide.stlPL4_cog.stl

 

Thanks for reading

 

Edited May 8, 2022 by DispleasedOwl
typo

[druxey]

It all looks very effective. Let us hope that you are now less displeased!