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[Colin Bishop]

Just a thought! Does it all have to be so complicated when applying a method of speed control?

These old motors were designed at a time when simple rheostats were used to regulate current. Maybe this would be a more appropriate approach in keeping with the idea of replicating vintage model boats?

Applying modern ESCs to Taycol motors does seem to be a fundamental mismatch in trying to replicate the way things were done in the past.

Maybe a Bob's Board would be nearer to replicating the original setup?

Colin

[DJW]

I think you're 100% correct Colin in that a rheostat / Bobs board would have been the go to if requiring smooth / basic speed control for the Taycols back in the day, and would still work well.  And probably more fitting for a true 'vintage' build. There is the heat dissipation issue, but not too great with the smaller motors.  Reversing would still need relays or some mechanism I'd have thought.  And then issues again with workarounds needed for the field wound motors.  I'm still learning about the motors, so I may have this wrong.


But I'm in a position for various reasons where I have more building time than out at the lake time.  So I have time to give what could be a simple fix a bit more thought to look at alternatives, and that has taken me down the electronics path, so I gravitate to trying to find what I'd see as an (eventual) elegant solution, that is smooth Taycol motors that can reverse without drama or damage. But I appreciate that could be seen as over complicating the issue because it quite possibly is..!  But I enjoy doing this part of the build and that's what it's all about I think.


Dodgy and HMS, the 'custom' ESC should be able to handle PWM frequencies from 200hz to 8khz (probably over 20khz but that's academic) with just a parameter change but the interesting range should be in the 1khz to 4khz for the Taycols I think.  And the Mosfets should handle the power line surges. Or maybe I'll eat my words and chalk it up to experience..! We'll see.  I use Ramp slopes on my FrSky ESCs on Brushless motors, just softens that potentially abrupt power delivery, and to my mind adds to a scale power response.


Best regards to all.
David.

[HMS Invisible]

Rheostat reversing is clearer after searching "Bob's Models"+varispeed, then clicking a thumbnail image. You also see it brakes the motor at the centre position.
  1kHz to 4kHz will show a pitch change from the low-throttle winding vibration tied to the ripple current. As the pwm frequency gets stepped the arcing diminishes with diminished amplitude of ripple current. Arcing will not have completely disappeared at 4kHz, but it will get smaller at 8kHz and 16kHz steps. A high inductance motor, by then, will be no worse and no better than smooth dc current throttle by your psu.
  That can be distilled to "crank up the frequency to the limit of your fet drive."

   I wonder if the contradiction you mention is down to 'AI search nonsense' or lack of relevant context in summary. If anyone bothers to eyeball brushed motor arcing at low throttle while you snip out suppression capacitors you will disprove the AI generated search result.
https://www.google.com/search?&q=do%20suppression%20capacitors%20reduce%20commutator%20arcing

[dodgy geezer]

..... Reversing would still need relays or some mechanism I'd have thought.  And then issues again with workarounds needed for the field wound motors.
.......

I'm very happy with the circuit shown on the Taycol site, which seems to function with very good power spike rejection. Probably because it only operates at the 0 volt crossover point, and has no logic components built into it

[DJW]

Afternoon All


Not too much progress to report re the ESC, it's been on my desk for a month...  I have considered Colin's comments re a Rheostat approach and I have planned out a way I'd do it, I have the nichrome, I have a design, just need some more time...  Then it'll be interesting to compare with an ESC, off the shelf, and home brewed.


Reason for this post.  I couldn't resist, I'm now the proud owner of a Taycol Marine...





Bit large for a standard Sea Urchin, but I think could be OK in a 32 inch version.








It's in lovely condition and runs smoothly with no discernible play on the main shaft, these figures are no load:











Ian (Circlip) has kindly sent me a copy of the 'Model Maker' June 1955 review to read through and get some background, power delivery and so on.  Interesting that Taycol are quoted responding to the review, they state that the motor is best used at 1,500rpm drawing 2.5A at 6V.


And @Dodgy, this motor appears to be the same 'EM2' version that you have pictured on the taycol.tk site. Not sure what that means, this one also has steel nuts rather than brass, does that date it as a later version..?


Best regards to all.
David.

[Davo]

Quite some motor.  Lovely engineering.
Can you advise the weight of the item?  Could be quite heavy; even for a 32" hull.


David

[DJW]

Hi David


It is a beautiful piece of work for sure.  And you're right, it's a bit hefty...





So just over 1kg...  We'll see.  I had in mind the Meteor for the larger build, that comes in at 350g, so might be more sensible.  I just saw it up for sale, and couldn't resist...


When I get to the build of the hulls I'll take a view on what weight the larger build can be, and see what the options are.


Best regards
David.

[dodgy geezer]

A real 'Marine'?  With the drum commutator? I believe those to be really rare, and would love to see a picture of yours if it's in great condition.  Take care of it, it should be worth a lot of money to a collector...

[Circlip]

Seem to have lost the photos again, Same for Riva.


  Regards   Ian

[DJW]

Hi Both


Pics were uploaded yesterday, but seems to be an issue with the MBM Image hosting right now. 


https://modelboatmayhemimages.co.uk/


David.

[chas]

What a beautiful motor, and little used. You're going to love it. Maybe a sea commander will suit it.

[dodgy geezer]

..... Maybe a sea commander will suit it.

The big Taycols will drive planing boats, but their weight is always an issue, and the Double Special is more suited to something like a big tug.


The best big motor for a fast boat is probably the Supermarine. The Supermarine Special has the added weight of two sets of coils.


The Marines have a single stator coil, but mine weighs an ounce or two more than my Supermarine - probably because the brushgear is heavier...

[Martin (Admin)]

 
Hi Dave,
Sorry, some photos gone AWOL from Mayhem !
See: https://www.modelboatmayhem.co.uk/forum/index.php?topic=61103.msg775199#msg775199
( I have a back of the old server if you need lost photos.... )

I'll made you moderator over this topic so you can edit your posts, maybe use : Postiage.org image uploader
https://www.modelboatmayhem.co.uk/forum/index.php/topic,61103.msg719443.html#msg719443
[/color]

Hi Both
Pics were uploaded yesterday, but seems to be an issue with the MBM Image hosting right now. 
https://modelboatmayhemimages.co.uk/
David.

[dodgy geezer]

 I might have missed it... have you powered up the motors as yet?

  How do they run?

Remember to oil the brushes first!

[roycv]

Have all the nice Taycol motor pictures gone?
Roy

[DJW]

Afternoon Roy


Well, it's been a bit of an adventure over the past couple of weeks with the modelboatmayhem images website, it went down, and I've been helping Martin to get the archive back up and running, this is now done.  There were a few missing recent images as I'd uploaded the Taycol pics after the last backup was taken on the old server, same issue on the Riva thread.


Slightly off topic... If anyone else is reading this who had an account on the 'old'  https://modelboatmayhemimages.co.uk/  website, there is a new version of the website coming in next few days, it should allow existing users to log in and attach to their existing albums and images, that's the plan.  And anyone else who wants to use it as an image hosting tool to support threads on this forum will be welcome too.  By all means drop me a PM if interested, or once ready I'm sure Martin will add a note somewhere appropriate on the forum.  Aim is to reconnect existing user accounts with their 'old' images, and to allow easy upload to this forum going forward, and to keep it in the legal framework, that's the tricky part..!


Anyway, just about sorted now, and here the Marine pics again:














Best regards
David.

[dodgy geezer]

I never thought that I would see one in such good condition!  Where did you find it?

[DJW]

ebay, not particularly cheap...  But I agree with you it's in such good condition I don't think I could have found a better one...  Original box too.