Marelli Chain Pull 8 inch

[Louis Luu]

Took apart an 8 inch motor to study.  I'll be drawing the whole thing minus the rotor....those are easy to source.  The flower motifs will be drawn with openings just like the 12 inch big brother along with flower motifs on the base.

 

[Jeff Whitfield]

https://youtu.be/jrduXS3VffI

[Jeff Whitfield]

The 30cm fan is a Restelli. Cool fan. The chain on yours is not original.

Paul Graves once told me he worked on these. The bull gear and worm needed to be addressed -- can't remember if he recut the worm or gear or what -- but that's the design weakness.

Edited August 19, 2023 by Jeff Whitfield
Clarity

[Jeff Whitfield]

DC version.

[Jeff Whitfield]

Your home-made Japan? Nice. 

[Steve H Jordan]

Louis - I bow to your superior skills.

Excuse my ignorance, but how do you get from the images above to the finished article ?

 

[Steve H Jordan]

16 hours ago, Louis Luu said:

I'm a novice.  Join the club....there are lots of members here to help.  (Korey Kreitman and Seth Anderson are professionals and do this for a living).  I chime in where I can.  I most likely do it the long way but it works.

Here is my approach, I first either get a very good flat picture...which is hard to do with a camera.  Instead, I make a mold along the center of the object I want to scan.  From there, I simply rotate the image many times till I get something that you see.  That is just a draft.  Once I get the draft, I tell the software to smooth out and to cut out the areas I don't need.  That is pretty much the basics of it.  You can find lots of tutorial of this on youtube which is what I have done.  The more you practice, the better you get at it. 

For this project, I still need to work on the decorative relief.  Will do that next week.  Prepping stuff for work tomorrow currently.

 

I recommend Krita to make the vectors and Meshmixer, FreeCad along with TinkerCad....they are all free.  Once you learn the basics, you can search out which program suits your needs.  I like Rhino3D.

Thank you - that's very informative, now I just need to find a way to fit more hours into the day !!

[Paul Michael]

21 hours ago, Louis Luu said:

 

Here is my approach, I first either get a very good flat picture...which is hard to do with a camera. 

You could try using a Graflex. (-;

Real film, baby. "There is a great future is plastics!"

[Paul Michael]

 

4 minutes ago, Louis Luu said:

Graflex, never heard of it.  Will you please enlighten me.

 

This is humor. These were cameras used, for example,  in copy rooms, for photo-ready art for reproduction. Adding a film step would obvious only complicate your process much further! (-;

[Jim Kovar]

52 minutes ago, Louis Luu said:

...8 inch GE motor and see if the rotor and stator will fit?

You'll need an armature with long shaft ends (both sides).

 

Also the armature stack width should match the pole face width.

Stack to commutator spacing needs to be right too.

[Jim Kovar]

A series motor, so...

You'll need to know what the (no resistor, high speed, with blade) current draw of the donor motor is.

Then by trial and error, wind the field poles (number of turns) to get that current.

[Jeff Whitfield]

The rear housing does not have the bracket cast into it on the original fan. 

 

[Jeff Whitfield]

Jan didn't need to be welding or brazing anything to the back cover. The bracket is held in by screws. 

[George Durbin]

Freaking beautiful!

[Jeff Whitfield]

On 8/28/2023 at 8:33 AM, Louis Luu said:

Jan was a perfectionist....He said he did not trust them screws.  Jeff....you do realize the fan I showed is an actual reproduction made by Jan?  He took an ornate Marelli and cobbled it together.  He gave me a prototype so I can make the small ones.

My guess is that he would've had to have used a 10-inch Marelli as a prototype if he wanted to use floral castings. The 12-inch stationary here has a beautiful casting as well, but the rear housing would make it tricky to attach the bracket without some serious engineering and design changes. 

Edited August 29, 2023 by Jeff Whitfield
spelling

[Jeff Whitfield]

Jan's prototype is impressive. Glad you have it and are planning to reproduce these. Your reproductions are always interesting to read about when you post them.

Screws for the brackets on the larger 12-inch models have wide threads. I think this was their solution at the time to avoid potential flaws. Because of the bracket size, I can understand why smooth-body Marelli housings were used and ornate castings might not have been used. Smooth body Marelli fans that I've seen are DC -- so I wonder if the majority of Restelli fans are DC fans as well. I don't know. The caveat is I can not say if all smooth body Marelli models are DC. 

I see Jan's prototype and wonder if the screws should be larger? Casting into the motor looks to be an improvement from Jan, but it's almost like the screws are an afterthought that is still being investigated.

For an 8-inch model, I can understand why Jan might not like them. 

I always considered the bracket as aftermarket antique bling someone could add -- their version of spinning rims on a Caddy.

I've seen these referenced as Restelli (other than the video above), which I presume is another vendor modifying and rebadging Marellis.

 

 

[Louis Luu]

Finished with the motor housing and base.  Just need some tidbits....worm gear, spur gear, holder for gear.

[Paul Michael]

Amazing work. You're having too much fun!

[Louis Luu]

I sourced two motors for this project...should be arriving from overseas from France in about 3 weeks.

[Jeff Whitfield]

Nice job. 

This is just a guess on my part, but ...

The teeth on this gear are larger and fewer than the teeth on an original gear, which mounted to the back of a 12" fan. You might have to add teeth to this gear as, judging by the look of it, this gear might make the oscillator move more quickly on what looks to be a 10" fan.

That said, it's hard to tell from this photo if the gear is on a 12" model ... Or where it's mounted ... It may even be the same diameter as a gear that went on the 12" model. 

 

 

Edited September 6, 2023 by Jeff Whitfield

[Louis Luu]

27 minutes ago, Jeff Whitfield said:

Nice job. 

This is just a guess on my part, but ...

The teeth on this gear are larger and fewer than the teeth on an original gear, which mounted to the back of a 12" fan. You might have to add teeth to this gear as, judging by the look of it, this gear might make the oscillator move more quickly on what looks to be a 10" fan.

That said, it's hard to tell from this photo if the gear is on a 12" model ... Or where it's mounted ... It may even be the same diameter as a gear that went on the 12" model. 

 

 

The fan is a 12 inch.

[Louis Luu]

Finishing up the gear assembly.  While taking it apart, I saw what Jan was trying to solve.  Very clever.  He used a pin to ensure both arms were locked.

 

Edited September 9, 2023 by Louis Luu

[Louis Luu]

Decided to make the bracket gear holder as one piece for added strength.  Has clearance for spur gear.

Edited September 9, 2023 by Louis Luu

[Louis Luu]

Marelli motors arrived....a bit smaller than I had expected.  No big deal....now I get to make a 6 inch version.  Luckily the base has the same dimension.  I will simply shrink down the motor housing and redo the midsection for the stator.