DIY ebike conversion with MPIII Goldenmotor

I bought a  used  Merida Cruise bicycle and converted it to an electric bicycle with the Magic Pie 3 from Goldenmotor. This is how I did it and a test of the finished ebike.

My initial picture after assembling the Magic Pie 3 and performing my first test run. 

I try to bike to work using my regular bike as often as possible, and then showering when getting there. But some days I have to meet customers, with no option to shower. Then there is also the case when I wake up and just do not feel like pedaling at all. In both these cases I often end up taking the car. My goal now is to keep the car parked, and enjoy life with this amazing ebike.

Since we have many hills in Norway I wanted the bike to have a powerful motor. I found the 1000W 48V MagicPie 3 (MP3) from  GoldenMotor in China. I like the simplicity of the front wheel motor, but decided to go for the rear wheel motor. It gives a better grip and perhaps better handling. I also liked the idea that the controller was integrated in the hub motor. The performance can be tuned by connecting the MP3 to a PC with a special USB cable. A legal limited power motor or a full power bike? You decide by programming.

After about two weeks I got the delivery. There are some special bike tools needed to take off the 6 gear cassette so I went to the local bike shop and got some assistance.

Cassette before adding washer

Cassette with needed washer

MPIII can be used with most 3 to 6 gear bikes. Mine is 6. Take the cassette off the old rear wheel and move it to the MPIII rear wheel. First we forgot the washer and ended up with a cassette that did not free wheel. It was not easy to get off again! So make sure you remember to add a washer that will make the cassette free wheel.

Mounting the washer , then the cassette

After this I fitted the rear wheel with the motor to my bike and tightened the nuts on each side firmly.The first week I used a twist throttle for adjusting the power to the motor. I did not like it much as I found it too easy to twist. It was also tricky to avoid twisting while breaking. So I changed to a thumb throttle that I like much better.

So on the right side I now have the thumb throttle. It moves nicely with my thumb. I also have the rear hand break from Goldenmotor which includes a switch  that detects when breaking. This signals to the controller inside the MPIII to cut off the motor and activate the regen breaking. The factory setting in my controller was set to 50% regen which gives a good portion of extra breaking power. I have adjusted this to 15% to minimize the risk of slipping. The hand break also activates the original mechanical rear breaks of the bike.

I moved my gear shift from right to left side. That is why the numbers are upside down, but it works just fine. I also decided to not install the hand break with regen breaking on this side. I have kept the original front wheel hand break here, then I can use this for very light breaking with out the powerful regen breaking cutting in. The red button is cruise control. Use the  thumb throttle to achieve desired speed, then hit the red button to maintain that speed. Power to the motor is cut off when hitting the red button again or when breaking with my rear hand break.

The power connector to the battery broke when I was on my first bike trip in March 2013. I fell on my bike when making a turn. I was just barely moving, but the black power connector broke when the bike hit the road. This was at +2C, so it was rather cold. The plastic housing just broke up in many pieces. Seems to be a cold weather problem with this. I replaced it with a original Anderson housing SB50 P/N 992G2-BK. It can be bought several places, such as www.mouser.com where it has P/N: 879-992G2-BK

The + and - metal pins from Golden Motor snaps right in to this housing, so it is easy to replace. No resoldering required. If you do cold weather biking it might be good to get a spare now.

Twice I had a flat before understanding the problem. The last time it was obvious. The pressure of the tire was a bit low and when breaking hard the tire and inner tube must have moved slightly. Inside the rim there was a very sharp aluminum edge that corresponded to the razor sharp cut in the inner tube.  In the picture to the left I have sanded it down. Please check for this before putting your tire on the Golden Motor rim.

The performance of the MPIII can be adjusted by connecting a USB cable to a PC and running the free PD-280 software. This is the setting I got when pushing the "factory setting" and then "get config".

Factory setting on my MPIII rear wheel motor controller.

I have not been able to find a good guide on how to use this program, so I give you my experience with it in my post Programming the MPIII electric bike controller

Both LED and CFL have good color in test

Over the years I have been disappointed when buying LED light, but not anymore. Here I have compared CFL and LED as sources for light above our kitchen table.

The light bulbs I have been testing, left to right:
Osram Dulux Superstart Micro Twist 2500K 11W 650lm CFL 10000h 7000on/off Hg=1.4mg 93x42mm
Parathom  Classic A 40  Warm White 3000K 8W 345 lm LED, 
Megaman LED Classic LG0408dv2 2800K 8W 420lm LED 25000h  118x60mm, dimmable 100-10%

I tried one light bulb at the time. My impression using just my eyes was that the CFL had a warmer color and somewhat stronger light than the two LED bulbs. The LEDs gave a very good white light, not like some of the ones I have tried before that was either too blue or too green. My eyes did not manage to see a color difference between the 2800K and 3000K, but so did my camera.

For the pictures below I used my cellphone camera set at a fixed daylight or lightbulb setting. So when the sheet of paper in the picture is white, the color is what the cellphone expect for its setting of lightbulb or daylight light.  All the light bulbs are warmer than daylight, and it is also possible to see the difference between 2500K-2800K-3000K.

 

2500 K CFL white balance: lightbulb

2500K CFL white balance: daylight

2800K Megaman LED WB: Lightbulb

2800K Megaman WB: daylight

3000K Osram LED WB: light bulb

3000K Osram LED WB: daylight

I walked over to our neighbor, that have a dimer on their kitchen table light, to test the Megman LED that is dimmable. With the particular dimmer they had I managed to dim the light only a little perhaps 100-70%. Not all dimmers work well with dimmable LED lights. Megaman have a good catalog, Professional Lighting Solutions, that explains a lot of different aspects of LED lights. It can be downloaded from http://www.megamanlighting.com/download-centre

Frost heaving and cold bridge fixing in foundation wall

Last fall we got a new big sliding door to our garden deck. During the winter we had problems opening it, probably due to frost heaving. Our carpenter suggested we should insulate the outside of the concrete slab that the house is built upon. This concrete is also a nasty cold bridge into the house floor. So I got the spade out and started to dig.

The concrete slab is about 50 cm ( 2 feet) deep, at least around the perimeter. I also removed the lower plank to make sure to expose all of the concrete.

Today it is common to add 5 cm ( 2 in) of styrofoam insulation to the foundation wall, so I decided....

...5+5 cm should be good. I think it is a good idea to add as much insulation as possible while at it. I managed to cover all the exposed concrete.

Then there is an issue of leading any water away. So I added some fabric, "Leca balls" and a drainage pipe.

Close it up.

I also added 60cm of 5 cm thick styrofoam from the wall and out. This will also help to insulte, and will later be hidden under the new deck that will reach all the way to the sliding door. All set for the winter! When it gets real cold, it will be interesting to compare inside floor temerature close to this wall  to similar positions close to walls with no foundation wall insulation.
Update: It turned out that the problem with the sliding door was the upper wood above the sliding door that twisted during the winter. Some additional screws have now solved that problem.

Summary in Norwegian: Vi har installert en stor skyvedør mot hagen i vårt rekkehus fra 1978. Forige vinter begynte den å gå treigt, antagelig på grunn av telehiv. Dermed gikk jeg i gang med drenering og isolering av betongplaten som hele huset står på. Hensikten er å unngå at det blir frost under denne, og å fikse den enorme kuldebroen det er å ha sementgulvet i stua koblet rett ut i kuldegradene utenfor. Isolasjon er ikke noe man skal spare på, det er bare å kline til med det det er plass til. Her ble det 10cm mot veggen og  5cm plate 60 cm ut fra veggen. Til sommeren kommer vår nye hage platting her oppå isolasjonen i bildet. Andre steder i hagen planlegger jeg å få hvertfall de 10cm mot muren. Gleder meg til å se hvor varmt gulvet blir der hvor det er ekstra utvendig isolasjon i forhold til der hvor det ikke er. 

One hidden master switch for TV, PS3 and surround sound

Kill your standby losses with a master switch.Below our TV we have a decoder, HDMI switch, PS3, Wii, and a sourround sound amplifier. First I tried to use a smart strip to turn off everything when the decoder goes into standby, but it was difficult to adjust the sensitivity, because the decoder used almost the same amount of current in standby as in normal use! So I simplified and made an easy to access master switch placed behind the TV screen (blue arrow). It turned out real good. The kids love it since it is much faster than using all the remote controlls. On an average day our family uses 1.2kWh on our entertainment centre. Our plasma screen uses about 170W on an average bright picture when set in standard display mode. When set to dynamic it uses almost twice as much. So keep the brightness down, and turn everything completly off when not in use.

Insulate inside walls step by step

Our wodden house from 1978 has only 10cm (4") insulation. This winter I decided to add an additional 10 cm of insulation to the inside of the wall while upgrading our home movie theater in our living room. I wanted to hide all electrical and video/audio wires. I did some research on how to do this correctly, while keeping a tight vapor barrier. Here is how I did it, step by step. 

 This is a section of the original wall where there is also a window. I started by removing the winow trim and cutting away 10 cm of our wooden floor to give room for the new wall.

With all the dry wall removed you can see the old 0.15 mm thick plastic vapor barrier. It should be placed on the warm side of the wall. In Norway that is the inside of the wall. It is, however, ok to have a maximum of 1/4 of the wall insulation on the inside of the vapor barrier.

Since the original insulation was in the vertical direction, I added the next 5 cm in the horisontal direction. Then I added the new vapor barrier which was taped together with the old one. Any holes found was fixed with some duct tape. I also useed silicon around adjacent walls. It is very satisfaying to have a completely tight barrier.

Here is where you see the advantage of having the inner most 5cm of insualtion inside of the vapor barrier. All electrical wires, can be hidden here without any worries of punctuate the barrier and getting condensing problems in the wall. The inner most 5 cm insulation was in the vertical direction.

Insulation on the inside completed, a full 20 cm in total for the wall. Some of the dry wall in place. To the very left you can see a hole for a speaker cable.

There it is. The completed wall with the first layer of paint.

You can find more technical details on vapor barriers here: Vapor Barrier explained

How I converted a car to an electric vehicle

This brings back good memories from 1997 when I was the first in Norway to convert a car to an EV.

I spent about 200 hours on this conversion, and it was not really that hard. I got my parts from http://www.evamerica.com/ and made a deal with my wife to work in the garage every Monday after work. My old website from Geocities have some interesting pictures, particular on the clutchless design of connecting the original transmission to the electric motor. If your are thinking of making a conversion I would suggest you to check this out:  How I converted a car to electric . It also have my log of the joy of driving an electric.

How much should tires be over-inflated to save gas?

The sticker inside the door of my car suggest that tires should be inflated to 2.3 bar (33 PSI). I have usually been driving with 2.4 bar (35 PSI) in my tires. Before going on vacation this year, I increased the pressure to 2.6 bar (38 PSI). Since the car was loaded with my family and luggage this should be about right. It seemed to handle ok.

After the vacation I decided to leave the pressure at 2.6 bar to see if I could increase my mpg. I noticed that the car was not as comfortable to ride as usually, the ride was stiffer. When driving into a bend I noticed that as I turned the steering wheel more and more I would get to a point where the car would all of a sudden turn a bit more than what I was really turning the steering wheel. After a while I decided that it was just too uncomfortable to ride my car with over-inflated tires. When correcting my tire pressure I noticed a bit of damage on one tire. Then I looked closer, I found that the damage was all around the tire at the same distance from the shoulder of the tire. It was most on the outside shoulder of the front tire, but also on the inside shoulder. And also slightly on the rear wheel tires. I stopped by the local tire shop and the guy said that I must have hit something and that the dammage was small and nothing to worry about. I think the real reason is that the tires was so over-inflated that the dammage shows where the tire shoulder was when the tire was at 2.6 bar. I can picture the tire in a bend, and how the smaller area in contact with the road is strugling not to slip. Then it slips or skids a bit and the road tears loose a small part of the tire.

I was not driving enough to make any good data on what the gas savings might be from this, but based on the tire wear and umcomfortable ride, I can not recommend this. Check you tire pressure often. It is well documented elsewhere that too litle pressure increases the rolling resistance and hence also the gas used. So make sure you use the recommended pressure or just slightly above.

Summary in Norwegian: Sørg for å sjekke tryket i dekkene ofte slik at de aldri går under det som er anbefalt. Min erfaring er at +0.1 ekstra også går helt fint. Noe særlig utover det går for mye utover dekkslitasje og veigrepet.