Thread: Draco Solum 16 drum motor failure

So I have a number of choices now:

IMG_4151 2.jpg

1. Use direct drive like the photo above. The concern I have here is there's no slip clutch and little space for preventing water ingress.

2. Use a drive like above but use an armature with the gear being the armature pivot - issue is the the gear will have to rotate away from the engagement to move the drum in the correct rotation. Then have a couple of gears on the armature to transfer rotations. A better way may be to have a belt drive on the armature as this allows the rotation of the pivot for the armature to move towards the drum, hence putting pressure on closing the drum-tooth to geartooth engagement.

3. Use a longer rod with the gear attached to allow a longer gap to the gearbox. This could be done on either the of the two option above.

I have two adapters for connecting the shaft and a larger plastic rod for inside the drum.

That was a fast delivery from China.
I measured my shaft and its 15mm which a big difference from the 7mm on yours,so that would be a big step if I used the original cog.

What are the 4 x wires for?

Originally Posted by john1

That was a fast delivery from China.
I measured my shaft and its 15mm which a big difference from the 7mm on yours,so that would be a big step if I used the original cog.

What are the 4 x wires for?

A stepper has two coils, alternate from each other. So each coil has two wires. The stepper controller then alternatively powers each and it steps backwards or forwards (a little more complex but that's the easy answer).

A motor has two wires, internally it may work a number of ways but essentially there's no external stepping, simply a "go" when power is applied.

This was my telescope focus control using a stepper and chopper to prevent the thing from overheating with 12V:
https://youtu.be/4AiSM_1Wbg0
In this case it has a 64 micro step for each 2.3deg step, which then goes through a 50:1 gearbox giving a 500,000 step per revolution of the telescope focuser which is a 1:1. In short it gives an accuracy around 1.5 million steps for the focuser full throw.

So basically the Draco box does the same.

So I temporarily connected up the new stepper and gearbox to check it work and also to check the variable speed adjustment:


Only wiring differences are as follows (for my reference). This new stepper motor has two coils with blue-red and green-black.

Old stepper colour -> New stepper colour
Blue -> Blue
Red -> Red
Green -> Green
Yellow -> Black

What's making the funny noise Nick?

Originally Posted by john1

What's making the funny noise Nick?

That's standard for pulse-width modulation. The on-off pulses for each step. The pitch change is the of the modulation speed changing (ie speeding up or slowing down the pulses).

It's the same way that EV cars make that whine at low speed.

I have also looked on Temu they have quite a few on there for under £20 and local as in UK.
Some are variable speed and reverse but maybe a load of crap.

Originally Posted by john1

I have also looked on Temu they have quite a few on there for under £20 and local as in UK.
Some are variable speed and reverse but maybe a load of crap.

Is that the same part number from your original?

Note that a motor and a stepper "motor" are not compatible. Hence we need to be clear what you have and what you need.

Attachment 43518

No, this is a completely different motor on mine,but I want to keep the cog which is on a 15mm shaft.

So this should work:

IMG_4173.jpg

The idea is that I'm reusing the existing bearing support and if need be I'll make it a swing arm. The side of the drum chamber will go in the gap between the two pieces (they'll go around the shaft when fitted). The reused long screws will hold the everything together. There's a couple of other bits that will prevent water from going along the shaft and into the gearbox.

So an initial test fit:


The stack of pieces will securely hold a ceramic bearing so that the brass shaft will rotated without wanting to skip.

How you getting on with it Nick?

Originally Posted by john1

How you getting on with it Nick?

I've not had chance to complete the last holes due to painting most of the house. I had a look today but it was so cold that I'll wait a couple od days when it should be warmer.

So I've now got the motor fitted securely and the drum filter is operational for the first time since its failure.

I will upload a video later once the phone has charged back up.

Sounds good Nick, working on one myself but not useing a stepper.
Will do a post when up and running.

Originally Posted by john1

Sounds good Nick, working on one myself but not useing a stepper.
Will do a post when up and running.

I had a look at your part number - it's a brushless motor and not a stepper motor, so it sounds like they made a revision at some point.

Originally Posted by RS2OOO

I really should read the whole thread for context before bursting out laughing at the size of your tiny shafts lol

Ha ha, didnt realise that one Steve.
Well spotted

Gave the pond a but if a spring clean yesterday. This morning it was back to the clarity I would expect. From the conservatory, you can see through the water to the back of the pond with ease. Also the to the bottom too -- the fish seem very relaxed which is good:
IMG_4249.jpg

Now I just have to sort out the frost damage (left tiles).