Bearing Change Align 50

[pmc1972]

Hi all, After some help and advice please. I need to change the bearings on my Align 50 engine and I can't get the cooling fan off the crank shaft. so to give me a head start with ordering bearings from a non RC source (i.e. through work) while I source a fan removal puller,

Can anyone tell me the physical size of the bearing so I can get ahead start.

p.s. I am presume the fan slides onto the crankshaft and is not screwed and just needs a bit more than gentle persuasion to come off i.e. a puller

Thanks in advance Paul

[Gate88]

You wont need a puller, if youre sure everything is undone just put the nut on the end of the crank (to protect the thread) get someone to hold the fan and give the crank a little tap with a punch (or old screwdriver) and a hammer.

[pgkevet]

I take off the carb, wedge a palstic toothbrush handle in there to stop the crank turning and then grab the fan with a towel and twist... but do make sure you undid the 2 bolts on the fan hub and the crank nut.

[electricsceadu]

if your going to use a drift on the end of the crank make sure its of a soft metal, don't use a steel drift
the rear bearing is a 6902
and if i remember correctly the front is 9.5x22x7
but look on modelfixings.co.uk it should have it on there

[Andy from Sandy]

p.s. I am presume the fan slides onto the crankshaft and is not screwed and just needs a bit more than gentle persuasion to come off i.e. a puller

That depends on what model it is for. Some models have a screw on hub and fan.

Part numbers and sizes are here

http://www.rc-bearings.com/catalog/p...roducts_id=707

Generic part numbers are the same for all manufactures of these bearings

[waveydavey]

Assuming it's an Align 600 the fan hub just pushes over the crank and is held in place with 2 M3 cap heads and the crank nut. The problem is that the crank is cast and the hub is ally, they tend to pick up a bit and it becomes locked fast with a burr under the hub. I find that removing the cap heads and then wedging a flat blade screwdriver in one of the slots in order to open it up helps, whilst using a crank lock and a tea towel to turn it and pull. Use a file or some emery to smooth the end of the crank before you put it back together.

[pmc1972]

Thanks for all your helpfull replies. my fault for not mentioning it, but the engine is fitted to a Raptor 50 (joys of second heli's) and it turned out that the fan hub screws onto the crankshaft and had threadlock on it. Took a bit of heavy persuasion, but crank shaft is now out and bearings on order along with new fan hub which was Damaged in getting all apart.

Thanks again and hoping weather's good next weekend.

Paul