124 electric fan - Page 5 - PeachParts Mercedes-Benz Forum

Roncallo · #61 09-19-2021, 12:24 AM

Quote:

Originally Posted by Frank Reiner

Tilting the head 15-20 deg. (or more) should lift the outboard edge of a grinding wheel well clear of the outer fan ring. If you reverse the rotation of the spindle the direction of cut will be reversed, and will be "outward" across the trailing edge of the fan blade.

The broken edges suggest that the resin is hard enough that a grinding wheel will not clog.

Sounds like a good idea, especially if I could dress a wheel with a 3/8" radius so I could blend the blades into the hub without changing the tool. If I do another one I may give it a try. But today I was very successful. Got all blades milled, without indecent. 2° head tilt did the trick. I went to the full 3/8" depth which I believe is the depth I will really need. I still need to blend out the transition to the radius. But after all that, I really think I should be looking into the 211 fan, where I can get the full blade performance. This now looks to be a good solution but with the blade taken down it will act more like a 500W fan instead of a 600W fan.

Roncallo · #62 09-22-2021, 08:30 PM

So the quest for the installation of the 211 fan is underway. I designed this fitting to support the fan motor. It will allow me to orient the fan motor in any direction and put mounting struts in any orientation that will be clear of pulleys.

The last picture showed all the areas where a strut can be mounted.

Next is to get this thing 3D printed for trial fits.

I also have to make a dummy fan for fit checks in the car. That will consist of a plywood disk screwed to spacers at bring the disk to the height of the outer ring of the shroud. That fit test will be the test that will confirm that this is a go or not. Unfortunately I cant do that at the moment as it requires removal of the radiator. So the goal is to only take the car apart once when I'm ready to do the final designs and have everything ready. In any case I will be on vacation for the next two weeks so work is coming to a screeching halt.

Once all is ready, I do have access to a CNC milling Machine to make the motor mount out of Aluminum.

Roncallo · #63 10-04-2021, 04:09 PM

Back from up north. Waiting for me was the 3D printed fan motor plate. It came out better than expected and fit almost perfectly with a few tweaks of a dermal. I wont be making this out of steel until I take the car off the road for the winter and verify the fan has a hole in hell of fitting in place. So things will slow down for a bit.

duxthe1 · #64 10-04-2021, 09:59 PM

Nice piece! What did you print it with ABS? Nylon?

Roncallo · #65 10-05-2021, 03:22 PM

Quote:

Originally Posted by duxthe1

Nice piece! What did you print it with ABS? Nylon?

That is just a PLA prototype piece from Xometry. It was $27.00 delivered. Anything above PLA is over $100.00. I also just ordered an Ender 3 3D printer for myself. 3D printing with cheep PLA is a really good way to mock stuff up before having stuff fabricated out of metal. I did my AC manifold and tubes the same way.

Roncallo · #66 10-08-2021, 10:23 PM

I received my new Ender 3 V2 3D printer yesterday but unfortunately it came through with a broken filament feeder. A new feeder should be in tomorrow.

In the mean time I decided to play around with balancing the fan. Balancing the fan will not be necessary with the 211 fan since I wont be cutting down the blades. But if I end up having to use the 203 fan it will be necessary to at least check it.

So I got my optical trigger installed and working today, which is necessary to perform the balance operation. It also helped me characterize the fan. I ran the fan at 20%, 30%, 40%, 50% and 60% duty cycle. The fan ran at 732, 986, 1235, 1486 and 1722 RPMs respectfully. Unfortunately I cant run above 60% with my limited power supply, but with that, I was able to plot the speed vs duty cycle and find it is absolutely linear. Therefor extrapolating to 100% the fan runs at 2500 RPM.

Just tried to balance and found that I am without a 9V battery required to run my accelerometer power supply. To late to get one tonight so that will be for tomorrow.

I did find a shift linkage clip cut in half will make a suitable balance weight, but unfortunately I don't have a gram scale to weigh it. A full shift linkage clip is shown next to the factory weight in the last picture.

Roncallo · #67 10-11-2021, 11:47 PM

Printer is back up and running. Printing has just started. 15 hr to go. I believe this is the final configuration except for the number of struts and hole placement.

From the blue fittings, I will be able to weld tubes on to support the fan motor. I may end up needing to weld the fittings to the plate because the single point screw mounts will be in torsion during fan acceleration as well as them being in a high vibration environment. Unfortunately that would require making that plate out of steel. A solution may be to weld a ring of tubes about 3in out from the bolt circle.

Frank Reiner · #68 10-12-2021, 10:39 AM

JR:
If the three pairs of 90 degree (steel? or aluminum?) fittings are eventually joined with a welded strap, so as to become three double fittings, the torsion that would be experienced by individual screws will now be resolved as shear at the pairs of screws.

Roncallo · #69 10-12-2021, 11:04 AM

Quote:

Originally Posted by Frank Reiner

JR:
If the three pairs of 90 degree (steel? or aluminum?) fittings are eventually joined with a welded strap, so as to become three double fittings, the torsion that would be experienced by individual screws will now be resolved as shear at the pairs of screws.

Those will be steel to be welded to thin wall steel tube. I cant put a weld strap over the top but possibly in between.

Roncallo · #70 10-12-2021, 06:21 PM

After 15hr of printing. A mock up that fits perfectly. Probably 8 hrs of the printing was from the rafting that had to be removed. See last picture.

Unfortunately the free software that comes with the printer is very wasteful on support structure. For $150, I could get Simplify 3D software that would save a lot on time and material, and has other advanced features as well.

Roncallo · #71 10-12-2021, 06:29 PM

I'm also working on an oil cooler manifold to fit in tight spaces. Currently my oil cooler is plugged off. I was watching an interview at SEMA and one of the custom radiator manufactures mentioned that an oil cooler plays a major part of engine cooling. I currently have mine plugged off. On of the M120 engine installation did not use an oil cooler and had plugs which I currently have installed on my car. Fortunately I have a spare oil cooler housing to mock it up with.

SpartanV · #72 10-15-2021, 02:31 PM

Nice work!

VaiFanatic · #73 10-20-2021, 04:26 PM

I've been printing parts like crazy since the wife got me an Ender 3 Pro; absolute game changer!

Funny to see something about an electric fan as I swapped in a Mark VIII fan into my '98 Durango where the clutch fan just wasn't able to do what it needed to do (the early cars had poor cooling, especially in hotter climates). I used a Dakota controller that allowed me to adjust it via Bluetooth and sync it up to an IssPro gauge.

Roncallo · #74 10-20-2021, 07:12 PM

Quote:

Originally Posted by VaiFanatic

I've been printing parts like crazy since the wife got me an Ender 3 Pro; absolute game changer!

Funny to see something about an electric fan as I swapped in a Mark VIII fan into my '98 Durango where the clutch fan just wasn't able to do what it needed to do (the early cars had poor cooling, especially in hotter climates). I used a Dakota controller that allowed me to adjust it via Bluetooth and sync it up to an IssPro gauge.

How big is the Mark VIII fan especially how thick is it. Fan thickness its what is driving this whole fan selection process for me. I even had a separate thread on finding the thinnest fan. I need thinner than 3.2" at the center and even thinner further out.

Roncallo · #75 10-20-2021, 07:12 PM

Quote:

Originally Posted by SpartanV

Nice work!

Thanks