Motorizing the HG-one - Page 8

Grinders are one of the keys to exceptional espresso. Discuss them here.
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FotonDrv
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#71: Post by FotonDrv »

Thank you!


I am looking forward to your observations on any differences in grind that you might see. Also, what rpm are you going to turn it?
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Bikeminded
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#72: Post by Bikeminded »

I ended up using a drivetrain from a Kitchenaid commercial stand mixer. It's a 120VDC motor. Using the control board out of it also. (Ordered as spares from a parts place). I didn't clock it, but prob can vary it from 30-150 RPM-ish. Been running it '3 clicks' from the off position which looks to be in the 60-70 RPM range.

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FotonDrv
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#73: Post by FotonDrv »

Sounds very nice! You will always be able to get parts for it and at a reasonable price.
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Bikeminded
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#74: Post by Bikeminded »

Here's a couple photos, one with the hood off and other other on. It works very well. The Kitchenaid motor has a ton of torque. I do have some cleanup items that I want to do to it soon.





A couple test videos...sorry for the shaking, aspect ratio, etc.
http://youtu.be/0IcyY7LaHLI
http://youtu.be/OA3TcYFIAPw

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arcus
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#75: Post by arcus »

Yes, I agree! The hood is a nice touch.

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CoffeeMac
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#76: Post by CoffeeMac »

FotonDrv wrote: <image>
I notice you have your motorized HG-one next to a Versalab. Both on my list of potential upgrades from my Mazzer Mini. Can you make any comments on usability, results in cup between the two? Which do you use most? Unfortunately I can't afford to do both!
Eventually you will end up with a lever.

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FotonDrv
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#77: Post by FotonDrv replying to CoffeeMac »

VL=super fluffy grounds and easy to turn it back to DRIP and then back again to ESPRESSSO. But the belt will slip if super light roast/hard beans are just dumped into the running grinder; you have to trickle them in.

HG-1E=not picky about beans at all and a very wide range when it comes to grind setting AND I can dump beans into it running or not and just turn it on.

Bikeminded, that looks very nice! You did /are doing a good job. What is the cover? 3D printed? How do you tighten the lock/set screw for the grounds adjustment?

Did you ever see any torque specs on the Kitchen Aide mixer motor?

It sure is good to see others way of accomplishing the same task :)

I notice in the videos a rhythmic noise in the videos, is that coming from the KitchenAide gearbox?
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Bikeminded
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#78: Post by Bikeminded »

Thank you guys.

I was never able to locate torque specs on the motor/transmission. The best thing I could find is some KitchenAid literature stating it is a 1.3 HP motor and delivers .44 HP at the bowl (I guess drive losses).
Converting 0.44 HP to torque using a (randomly selected) 60 RPM speed, that calculates to 462 in-lbs. That seems high.
That being said, the given HP values are sales literature BS, so take that with a grain of coffee.

The original intent was not to even have the control knob exposed, set the speed 'internally' to the enclosure and just have an on/off switch. The KA control board has a safety feature in it though that prevents it from starting if the control knob is not in the off position when power is applied. There is also a hall effect sensor that goes from the control board to the motor. I think this is either for sensing a stall situation and cutting power and/or for increasing power to the motor if it senses speed dropping under load.

It's basically the motor/transmission, control board, and power cord from one of these:
http://www.kitchenaid.com/shop/countert ... KSMC895ER/
(May need to copy/paste that.)

The cover is stainless steel sheet metal formed and covered with some black furniture type fake leather. I wanted to do real leather, but couldn't find a piece that size I was willing to pay. There are a few asthetic items remaining to complete on the cover. (The gap at the top, fitment around the control lever., etc.)

I'm not sure on the sound. I need to go back and listen to that.

I'm getting a contact tachometer from work and going to measure the rotational speed at each speed 'detent'.

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FotonDrv
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#79: Post by FotonDrv »

Very cool indeed! Faux leather included, which probably makes for less maintenance :)

Looking forward to finding out the RPM of the HG-1 shaft.

That published torque is very high but it might compare to the torque spec of the motor I used which has a published spec of X and a stall torque of 2X. So KitchenAide might be telling you the stall torque.

Did you find any difference in the grounds between powered and hank cranked????
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bostonbuzz
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#80: Post by bostonbuzz »

Neat-o. Tons of torque and tiny motor = very low rpm, not that a high rpm is super important for this task. Now what do you do that you don't have to hand grind all day? :wink:
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