The Dickson!

[Peter A Lawrence]

Guys, Ahha, photo #3 is an iron armature core, so it should be easy to calculate after all. Sorry for my confusion. Peter.

[Peter A Lawrence]

Guys,  I always make my bobbins out of Delrin, the perfect plastic for machining,
very dimensionally stable and uses regular cutting tools.  The secret to winding
level coils is a layer of paper between each layer of winding.  The secret to the
paper layers is to use velum rather than paper, its strong enough that it doesn't
collapse at the ends.  I've been using "16 lb traditional" weight (.003") for wire
in the range #36 all the way up to #26, and I'm sure you could go thicker.
HTH, Pete Lawrence (BAEM).

[Dennis]

Thank you for the information Peter, and the good ideas.
My son ground a special cutter for the UHMW I used for the coil bobbins and it works very good.  I have some Delrin in the shop left over from another project but not enough to make all the bobbins, the Delrin machines a little easier and I would recommend using it over UHMW.

I will try the layer of velum between layers when I rewind my bobbins.  I had given up on getting a flat winding and sent my bobbins and mandrill to a coil winding company.  The coils were as good as they promised but not as good as I want for my model.  Their engineer said everything was fine until the last 3 layers and they would loose control at that point.  I don't have enough experience at winding to understand why this would happen.

How thick was the velum you use between layers?

Getting a set of castings may be more difficult than winding the coils.  If you are interested, contact me separately at dandshowe@aol.com and we can discuss offline.

Dennis

[Dennis]

Hello everyone, I need to apologize for not posting for the last two years.  This project has been stalled for a long time due to many reasons, however I have started working on the engine again and have made some progress on the dynamos.  I am building three dynamos, two for my model and one for Maury's model.  The machining is nearly complete on all three and I have been reworking the field coils to make them look better.  Cleaning and priming the castings is next and then completing the brush holders. 

I want to especially thank Peter for his comments about the secret to getting a good level coil winding.  Peter your suggestions work perfectly.  I think the commercial coil winder I used should contract with you as a consultant.

As soon as the parts are primed and assembled, I will be posting some photos.

I should also add, that most of the patterns have been donated to a foundry in North Dakota to hopefully make castings available for anyone who is interested.  You can contact me separately at: dandshowe@aol.com

[GWRdriver]

Glad to see you back in the saddle again Dennis!   

[Roger B]

Glad to see you back on this    There is a lot of stuff to be learnt out there 

[Dennis]

Hello everyone, As I said earlier, I have started working on the Dickson project again.  The attached photo is the field for the dynamo.  The coils are wound, dipped and installed.  The dynamo will be shunt wound with the 14 coils in parallel as the original engine was.  I do still have to connect all the coil leads so I am learning more about soldering before I start work on the actual armature connections.  For those of you with soldering experience, do you have any recommendations for cleaning the magnet wire leads before soldering?

The armatures are completely machined and ready for winding.  I have been experimenting with armature windings a little bit and decided to do a lap winding instead of the series windings on the original engine.  More to follow on that idea later.  I have made a form and started winding the coils but it is a slow process.

The commutators are also machined and ready to install.  I want to get the coils in place before adding the commutator to the assembly.

I will try to post progress phots more consistently in the next few weeks.
Dennis

[Admiral_dk]

Looks really good 

Modern Transfomer Wire is really nice to work on compared to the old stuff 

The old stuff required you to manually remove the Lacquer before any solder opperation was possible (knife, sandpaper etc.) 

With the modern stuff - you just heat it the wire with the Soldering Iron set to 300-350C and apply some Flux-Core Solder to the Tip + Wire. This both Strip the Lacquer away and Pre-Tin the wire - so it is ready for soldering together with other items 

Per

[Don1966]

Hi Dennis very nice job on the field cold. I am interested in your commutator fabrication and see if you will show how you went about it. Cutting the Mica and forming the V in the ends of the hard copper commutator bars that will be squeezed together by a threaded V groove washer. Are you making a jig to assemble it?

PS I am also interested in the connection type your using since you said your making a series winding. A Lap winding is a parallel connection a wave is a parallel connection but only two coils are parallel at any time where’s as lap has as many parallel as poles. The lap connect produces more current.  Correct me if I am wrong…

Regards Don

[Roger B]

Glad to see you back on this     

[Dennis]

Don and Admiral,
Thank you both for your comments and suggestions.
 
First, I will try the higher temperatures with soldering tomorrow, That will save a lot of work making connections.  Thank you for the suggestion Admiral.

Second, I made a big mistake when I said I was going to use a lap wind on the armature.  My apologies!  It has been 55 years since I took the AC/DC motor course in collage and this is the first time I have used that knowledge since.  Don, the windings are going to be wave and you are correct, the lap winding develops a higher amperage while the wave windings develops a higher voltage.  I hope I have that correct this time.

The original machine has a lap winding which I am sure was for the higher amperage.  However, duplicating that on my model ended up being very difficult because I did not leave enough room between the armature core and the support for all of the wires to pass through.  I will post a picture of the armature as soon as I get one completed and that design error will be obvious. 

The commutators are nearly finished and I will post photos of them soon.  When I started designing the commutator, I wanted it to be vertical like the original but the parts ending up being too small for me to work with.  As a result, I came up with an idea to use potting compound to hold the commutator segments.  The commutator ring was machined in one piece and a backing plate was machined to hold the commutator ring.  Then the commutator ring was bedded in the backing plate with potting compound.  After curing a few days, the commutator segments (70) were cut with a slitting saw using a rotary table on my milling machine.  A very delicate process.  The cut was deep enough to cut through the copper ring and into the potting compound making separate segments.  After cutting the segments, the cuts between segments were also filled with potting compound.  Finally, parts of the backing ring were machined away to expose the ends of the commutator segments.  The backing ring also served as a mounting base for the commutator.  I will make some sketches and take a couple of photos to show this design better in my next post.  Everything I have now is much too large of a file to attach.

Thanks again for coming back to this thread after such a long pause in postings.  I appreciate your comments and advice, I am not an electrical engineer so this is learning experience for me trying to be as true as I can to the original machine but make a design that others can build.

Dennis

[Dennis]

I just saw that the PDF file will attach and you can download it so here is the commutator drawing which I hope will clarify my description above.

[Don1966]

Awesome it will interested in seeing it develop, thanks for the drawing.


Regards Don

[Dennis]

Good morning everyone, I hope you all had a Merry Christmas.

I have been meaning to get these photos uploaded with some progress for several weeks now so here goes.

First, there are two photos of the commutator assembly.  The commutator will bolt to the face of the armature after the armature is wound.  In the first photo you can see the segments separated by the potting compound that holds everything together.  In the second photo, you can see how the brass holder has been machined on the edges to expose the ends of the commutator segments.  When the winding is complete, I will cut a small notch in each end of the commutator segments and bolt the commutator to the armature face.  The small notches in the commutator segments will hold the winding wires and the wires will be soldered in place. 

The last photo shows the armature winding in progress.  In the photo, the first 9 coils are laid in.  The wave winding spans 5 slots which is equal to the face of each pole.  Winding the armature is proving to be more of a challenge than I expected, mainly do to lack of experience with dynamos and electronics.  After 5 attempts I am finally making some slow progress. 

If anyone wants to share their experience with winding, I would love to hear from you.  I have a lot to learn about dynamos.

Thanks for reading this thread.
Dennis

[Dennis]

Just to let everyone know, I am still slowly working on the Dickson Dynamo.  The included photo shows the first armature with all 70 of the coils installed and labeled, ready to be attached to the commutator.  A time consuming task, made more so by my fat fingers and leaving Michigan for several weeks over the winter months. 

Next task to to bolt the commutator to the armature and solder the 140 leads to the 70 commutator segments.