Motor Assembly
Motor Assembly |
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Motor Mounts
Supplied in the kit are 8 bronze bushes. The larger ones are for the steel motor mounts which need to be fixed in place.
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If the bush slips in and out
too easily put a nick on the edge of the hole on the
motor mount using a screw driver and hammer. This will
help hold the bush while you solder it. Oilite bearings are saturated in oil. If you prefer to glue the bearing rather than solder be sure to thoroughly clean the bearing first.
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Fixing the axle bushes We used to recommend soldering the bushes but from experience we have found that the proper oil tollerent bearing fit (Loctite 603) does the job adequately. The down side of applying heat to the oilite bushes is that the oil is burnt off. Using a cold fixing method leaves all the oil in place.
Simply coat the outer face of the bush and the innner face of the mount and push together. If after 10 mins or so the bush is not fixed re apply the bearing fit.
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Soldering axle bushes |
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When using a gas torch to heat up the bushes for soldering, you'll need to know when it is at the right temperature for the solder to melt properly. This is actually easier than you might think. When the temperature is right, the flame around the bronze bush will change to a green colour. Although the solder may flow on the steel the main purpose is to fill any void between the steel and brass. Make sure that the solder does not run further than 6-7 mm from the bush otherwise it may obstruct the motor. Clean off with a file if it does. Using heat burns off the oil in the bearing - re apply plenty of thin oil once cool. |
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If you have used a flux, ensure all traces have been cleaned away otherwise it can etch in to the steel axle and impair the bush performance. Once all the bronze bushes are fitted (paint if required) slide one mount onto the axle with the bush collar facing the nylon gear. Then slide on the other mount the other way around. You are now ready o mount the motors. |
Motor Mount Assembly
Slide one 5mm washer onto each motor stud then place the axle assemble as per picture below and push the first motor into the motor mounts making sure the motor wire are on the upper half of the motor. The washers go between the motor and the motor mount. Temporarily tighten the nuts on the motor. Do not put washers under the nuts as this may allow the motor to slip. It will also push one nut into the back of the wheel.Repeat for the other motor.
Slide the other wheel on and check the spacing between the wheels. The back to back gauge of the wheels should be 119mm. If you have a small bit of play on the motor mounts an additional 5mm washers can be inserted between the motor and mount mount to move the mount along. If the assembly is too tight, file down the 1/2" washer or even the bushes on oilite bearings. Fit the other wheel, cutting the two lower motor studs first, by following the same instructions for the first, i.e. keying in and loctite. Oil the bushes before working with the loctite to help avoid sticking the motor mount bush to the axle. |
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Ensure that the wires from both motors are on the top as pictured in the picture on the left. When putting the motor assembly into the chassis put one set of wires goes through the cutout in the chassis's cross brace/ motor mount support plate. |
Please note.
If your kit was supplied with the black nylon drive gear, substitute the 3mm disk spacer with a 5mm washer between the gear and wheel.
If you have a bearing version then the axle will be shorter and have shoulders at the ends to accept the bearings.
