Sunday, September 25, 2016

Open questions on Musso 5030

My Musso 5030 / L2 / Stella  now works much better after replacing the plastic gear, and also adjusting the height of the motor assembly.

There was a significant force neeeded to push the top plate down to reach its bolts, somehow the motor assembly seemed to high. As the motor bolts was pushing into the gearbox some millimeters was added by this. There was also a thick washer on the motor axis that i removed to get the motor assembly lower.

It is now a bit lower but still a bit high, pushing hard to the top plate.

This also makes the churn blades a bit high (some mm) above the bowl bottom. I think the closer this is to the bottom, the better.

Musso 5030 Gearbox

This post is part of a series of descriptions of the L2 / 5030 / Stella / Pollo ice cream machine.

The Gearbox

The gearbox of the machine transform the speed of the motor to a low rotational speed of the churn arm. 

After disassembly, the gearbox with the churn axis:

Opening it showed the problem, the teeth of the plastic gear had been badly worn, and after the freezing accident some teeth had been lost. The plastic dust is all over.

The plastic gear is fastened to the churn axis with a sprint. This was very difficult to remove, and the replacement wheel that I bought did not have the hole pre-drilled.

The other axis is directly integrated in the motor shaft. It did not look too pretty either, I cannot figure out how this could have been so damaged. I used a file to smoothen the sharp edges a bit.

The motor shaft has 7 teeth. With it's specified rotational speed of it gives 9450 teeth per minute. The churn arm is specified to 84 rpm so the larger gear should have around 112.5 teeth.

Musso 5030 Compressor

This post is part of a series of descriptions of the L2 / 5030 / Stella / Pollo ice cream machine.

The Compressor

There was some dark sticky stuff in the bottom tray of the machine. This could potentially be oil from the compressor, which is not a good sign. It seems to cool well now, but..

The compressor in my machine is a ACC compressor model GL90TB. This is a compressor that seems also to be used in Electrolux fridges. Full datasheet is available.

The refrigerant used has the cryptic notation R134a, which also is known as 1,1,1,2-Tetrafluoroethane. It has a boiling point in 1 atm at −26.3 °C.

One webpages is listing a number of substitute compressors for this one:

  • Aspera NEK6170Z  
  • Danfoss/Secop FR10G
  • L'Unite Hermetique/Tecumseh AE4430Y

A video on youtube showing how a compressor works.

Musso 5030 Motor

This post is part of a series of descriptions of the L2 / 5030 / Stella / Pollo ice cream machine.

The Motor

The motor in my Musso is from RPM badia polesine  in Italy. This is by the way the same provider as the motor in the high end Mahlk├Ânig K30 coffee grinder. 

Type: C019700
230 V 50 Hz
52 W 0.53 A
2.5 uF
450 VL
1350 / min

The axis has tilted teeth, 9 teeth in total.

Note the strange orientation of the outer bolts going upwards. This must be a mistake in the assembly I think as these are pushing into the gearbox then. I change the orientation so the bolt is pointing downwards.

This was how my machine was assembled with the bolts hitting the gear box. This had made some marks in the gearbox and I think it is not the right way.

Disassembly and repair

This post is part of a series of descriptions of the L2 / 5030 / Stella / Pollo ice cream machine.

Disassembly and Repair

For disassembly I was following the instructions at electra-craft. These are repeated here with some of my clarifications/modifications. Remember - all on your own risk!

  1. Remove the 8 screws securing rear panel. Remove panel.
  2. Remove the 4 top screws securing the stainless top to the wrap-around.
  3. Remove the 6 screws (3 on each side) securing the wrap-around to the base. (these screws go from the bottom-up)
  4. Pull the wrap-around away from the machine just enough to access the wires. Mark the wire positions. Remove the wires to the switches and the timer, needed to completely disconnect the wrap-around from the unit. Remove the wrap-around.

  5. Looking from the rear, locate the two 4 mm bolts securing the gearbox to the shaft guide. These don’t have to be removed, just loosened. 
  6. Remove the yellow and black wires from the terminal strip as well as the ground wire. (green w/yellow stripe, 7mm nut)

  7. Prop up the machine to remove the motor mount bolt located under the machine.
  8.  Gently lift up the stainless top and rotate to get the motor and shaft down and away from the machine. Find something to support one corner of the top after removal.

    Now the gearbox and motor assembly can be removed from the machine.
  9. Use a light grease when reassembling. With the lower gearbox secured to the motor, “fill the cup around the motor shaft” with grease. This will do nothing but possibly aid in deterring some liquid from running down into the motor in the case of an overfill. Dab a little grease on all nylon bearing surfaces and on gear face. Reassemble.
  10. Reinstall motor and gearbox assembly into machine making sure shaft guide is seated fully into gearbox collar. Now with the base again propped up, start with motor mount bolt and finger tighten only. You will notice that when you turn the motor it changes the “angle” of the top. What you want to do now is to align the condenser grid to the rear of the top edge. When you think the alignment is correct, tighten down the two 4 mm set bolts. The bolts position should be in the same spot as original. (this can be seen by the original factory wear marks made by the Allen wrench in the Styrofoam)
  11.  Secure the black and yellow wire to terminal strip as well as the ground wire and the yellow and red capacitor wires. 1
  12.  Set the wrap-around close enough to the unit to attach the wires to the switches.
  13.  With churn and chill switches OFF, plug unit into outlet, rotate timer and check to see if churn motor operates. You can now test the chill switch BUT, because of the lack of support from the wrap-around, cooling fan operation may be impeded by the Styrofoam insulation so compressor may operate only. Normal operating procedure is cooling fan operates at the same time!
  14.  Unplug machine and secure churn blade to shaft. Spin blade by hand making certain blade does not scrape bowl. If good, continue. If scrapping occurs, realign motor to bowl.
  15.  Install wrap-around with the 6 screws. DO NOT TIGHTEN AT THIS TIME.
  16.  Secure the 4 screws for the stainless top to wrap-around.
  17.  Install rear panel and tighten screws.
  18.  At this time, tighten the 6 wrap-around screws.
  19.  Re-test blade by hand. If good, test switches. Churn blade should turn without scrapping and with the compressor operating the cooling fan should be as well.
  20.  Tighten motor mount bolt.