Re Post #14: Hear hear Roy👍

Re Post #15: Hear hear Ronald👍
Doug😎

Hi Roy,

"Hi Alessandro I shall be in Australia this time next week."
You travel faster than the internet, lucky you, ahahahahahah.

Hi Roy, sorry for the digression.

I don't want to create constants.
This practical experiment (which I would have already done if I had had everything I needed) will give easily interpretable results.
In my opinion the results will be significant and not misleading.
All parameters will be the same: weight applied to the winch, supply voltage, technical data of the motor. We are not interested in reading the actual number of revolutions, we will only read the value of the electric current because from that I will understand which engine is working harder.
Which motor is demanding more current from the battery and is therefore more likely to heat up.
Logically by rpm, I mean the nameplate data, not the actual data.

Hi Alessandro I shall be in Australia this time next week.
Roy

Hi Ron, forgive me, you're right but I had this curiosity.

It's true the topic is different but it's not the first time it's explored other fields, before me there's a long list of confessed criminals who have already committed this crime, ahahahahaha.

Roy cited an A+ from his son and I couldn't resist.
It's a wonderful thing to hear how things work in other parts of the planet, not on the internet but using the internet (the internet as a medium and not as a source of information).
Is it the same in Canada as in the UK that you know?

To think that in Australia or Canada there is someone who is building boats like me and I can ask him for information directly is fantastic.

Alexandro

Your education posting doesn’t fit with …gears to match speeds… how about removing it and begin a new topic. Say “what is the educational path in your area of the planet ?”

I am a retired teacher and in our faculty of education course on the philosophy of education there are many varieties that have been developed over the years.

But, this topic doesn’t fit under the forum topic of “Using gears to match speed”

My opinion

Hi Alessandro re post 11.
I think you are creating constants that do not stand up with a load involved. If the motor drives a prop of given size then there will be a particular rpm.

With a geared motor the motor will spin faster as there is less load from the prop per revolution of the motor, so the geared motor prop speed is probably slower but unkown. Only the load produced by the prop has remained constant.
The prop tube and shaft will have a different effect due to differences in speed and therefore friction.
The identical motor is performing in a different part of its operating spectrum so although the same motor, its performance is different.

However that is why we have some rules of thumb which cover an expected average performance. The boat will be in varying conditions, open water wind small protected pools and even the depth of water. So with these unknowns we make our initial choices.

So you can still do your research and testing but the weather conditions often determine events. I play for safety with extra power available if needed.

With my yachts my test at home before they go into the water is to turn them upside down to see if all the controls inside still stay in place.

My dynamometer experiments detailed before were really of personal interest and also to measure o/p of some steam engines built by a friend.

My email system was out for 2 days due to the fighting which broke out in my laptop where 2 security systems were suddenly active. They were fighting each other and slowly destroyed all around them! It had to have professional help to restore a working system. That seems to be a metaphor for what is going on in the world at present!

Roy

Good morning everyone.

Leaving the opinion of Roy and all the modelers pending and awaiting the practical experiment that I intend to do as soon as possible, the question of A+ as a grade came to mind.

I was intrigued and I would like to know how it works in the UK and if it is also like this in Anglo-Saxon speaking countries.
In Italy it is roughly like this:
1. Up to the age of four, children go to nursery school (they play with them and do drawings or manual work).
2. Ages five to ten go to primary school (once called elementary school) for five years.
Until some time ago, ratings were given by adjectives such as: excellent, good, fair, sufficient, mediocre, ineffective. Today they use letters A to D (along with a verbatim report) but there are no more failures. In primary school today no one repeats the year. It is a compulsory school.
3. From eleven to thirteen years old they attend lower secondary schools (once simply called middle schools) for three years. The evaluation is made with numbers from 0 to 10, up to 5 you are insufficient, from 6 to 10 you are promoted. It is the same for everyone and is mandatory.
4. From fourteen to eighteen years old they go to a high school (now called secondary school) for five years. It's optional.
You can choose between various types which already lead towards subsequent humanistic, technical or scientific studies or towards a profession.
For example, there are: Scientific High Schools, Classical High Schools, Linguistic High Schools, Industrial Technical Institutes (electronic, electrical, mechanical, IT, telecommunications, nautical, etc. etc.), Technical Institutes for Surveyors, Commercial Technical Institutes, etc. etc.
The votes are numbers from 0 to 10 (accompanied by detailed textual explanations), up to 5 you are insufficient and from 6 to 10 you are promoted.
5. After graduating from high school you can enter university. The master's degree lasts a minimum of five years and you can become: doctor, engineer, architect, lawyer, physicist, mathematician, chemist, man of letters, psychologist, philosopher, etc. etc.

I would like to know how it works in your countries.

Actually, even better.
Consider only one engine.
Measure once with the reducer and once without.
What outcome do you foresee?

Sorry Roy, but to answer the question I asked you (two experiments hypothesis), consider two identical engines. Identical means equal rpm (before putting the gear reducer). Afterwards one will logically have fewer turns than the other. Same supply voltage (which we will not vary) and same power as the motor's data on the plate. In these conditions, in your opinion, which of the two motors will absorb more current, the one with the gear reducer or the one without?