Removing and reinserting bearings on planer/thicknesser cutter block shaft - help from anyone with experience appreciated!!

[sams93]

I have asked a few questions recently where people have helped me out with a kity planer i am trying to restore.

I have got the majority of the parts taken apart into their individual components now, the last piece I am onto is the cutter block and its assembly.

It is mounted via two bearings (one at each end), and then the shaft extends further out to the aluminium pulley which is mounted for interface with the driving belt.

I am in the process of working out how to dissasemble this bit, I am trying to start at the pulley side, the aluminium piece will not pull off, I think I am going to need to use a gear or bearing puller to remove this (whoich should arrive tomorrow).

I will next have to remove the bearings somehow from the shaft or housing, and I'm not sure both on how best to do this, and also on how I will eventually go about re-inserting them in the future when I get to the 'putting it back together' stage.

I would be really grateful to anyone who has experience of dissasembling and reassembling these things for any advice and guidance.

I have attached a photo from the exploded parts diagram, and I will put some photos of the assembly in it's current state in a post below.

 

[sams93]

Photos of the assembly in its current state

 

[Spectric]

If that was me I would be looking to remove that ali pulley from the block shaft and then releasing the bearing retaining plates by removing the screws on each end so as you can release the end housings and just have the cutter block with the bearings, now a bearing puller to remove the bearings.

 

[sams93]

If that was me I would be looking to remove that ali pulley from the block shaft and then releasing the bearing retaining plates by removing the screws on each end so as you can release the end housings and just have the cutter block with the bearings, now a bearing puller to remove the bearings.

The aluminium pulley did not want to come off easily When I tried with the bolt removed that you will see on the end. I was going to try and pull it off with a bearing puller.

I then thought about trying to remove the other end however, when I removed the plate over the bearing, it was not obvious how I would remove the bearing from the aluminium housing

 

[sawdustandwax]

Marius Hornberger(?) on youtbe put a spiral head into a 636 years ago and had to disassemble the cutter block assembly. Can't exactly remember how much he showed, there be more in the comments, but I do remember he said it wasn't easy, but he did get it done.

 

[flh801978]

Warm the alloy pulley with a gas blowtorch and it should pull off a lot easier

Ian

 

[clogs]

if u dont have a MAP gas burner an elec heat gun will help to warm up the pulley, keep it close to the pulley......
u'll end up using a puller for the beaings as well...
BUT it will pull on the outter race of the bearing......
qual bearings are not expensive so replace them.....
as for refitting the bearings provided they are a tight fit on the shaft,
I'd polish the shaft with some fine wet n dry paper to remove any rust and or burr's....
a little oil on the shaft wont hurt when reassemb........

 

[sams93]

I will say that my main worry is actually g

if u dont have a MAP gas burner an elec heat gun will help to warm up the pulley, keep it close to the pulley......
u'll end up using a puller for the beaings as well...
BUT it will pull on the outter race of the bearing......
qual bearings are not expensive so replace them.....
as for refitting the bearings provided they are a tight fit on the shaft,
I'd polish the shaft with some fine wet n dry paper to remove any rust and or burr's....
a little oil on the shaft wont hurt when reassemb........

for refitting the bearings will I just be able to push them on by hand or will I need to use some kind of tooling?

I do have a standard butane torch, which I can use to heat the aluminium piece.

The bearings look relatively new but if they are not expensive, I don’t mind replacing them, I will have to work out what ones they are

 

[Doug B]

for refitting the bearings will I just be able to push them on by hand or will I need to use some kind of tooling?

A trick I’ve used before for fitting bearings on a shaft is put the shaft in a freezer over night & keep the bearings in a warm place it makes refitting them a doddle.

 

[Inspector]

Deep sockets are a handy tool to push bearings on with as you can pick the ones that will fit the inner or outer race as needed. Just make sure they also fit over the shafts without catching. If you pre-cool and pre-heat as needed they may not be necessary but should things get tight you can slip the socket on and tap them with a hammer to finish the job and make sure they seat. Pieces of pipe or tube can be used with longer shafts and sometimes plastic pipe can work. Most important thing to watch for is that they do not get cocked over, even a little or they are more likely to jam. I find putting new ones on are usually easier than getting the old ones out if that is any comfort to you.

Pete

 

[Fergie 307]

Have done this on mine. The pulley is an interference fit on the shaft and is a pig to remove. Biggest problem is that the end of the shaft is very small and provides little for the puller to push on. You definitely need to make up a plug to screw onto the end of the shaft, so you are not pressing directly on the end its threaded M6 if I recall correctly. If you dont do this you will damage the end of the shaft, then you are really in trouble. I have a proper garage press and a wide variety of pullers and I couldnt shift it. In the end I had to cut it off and make a new one. If you can get it off the rest is simple. Before you start measure as accurately as you can the distance between the bearing mountings, and how far each bearing sits into its housing, and the distance between the back of each housing and a reference point on the drum, you need a decent vernier gague at least. To avoid problems down the line everything needs to go back exactly as it is. Get the bearings from a decent supplier, and they should be able to match them for size, and speed rating. Knock the bearings out from the reverse side. To fit new ones just use a suitably sized socket to tap them in, better off using a press as you need to get the insertion depth correct with reference to the measurements you took at the beginning. Make a careful note of all spacers and or shims, where they go, and which way round. They look similar but are not the same. As you may have gathered by now, its not as simple a job as you might think. If the bearings are in good shape and dont howl I would be tempted to leave well alone. You can still clean the cutter block by wrapping it in kitchen towel soaked in your choice of rust remover, then wrap in clingfilm while it does its stuff, just dont get it on the bearings. And if you do have to get a new pulley made then remember it is crowned, if you make it flat you wont keep the belt on. Having to make a new one anyway i took the opportunity to convert to a poly v belt, much better and less tension on the bearings. For the motor I used a hollow centre poly v pulley from a car power steering pump the same diameter as the original. I then turned down the original pulley to make a hub for it.
I am a great believer in if it aint broke dont fix it. I got mine pretty cheap because the drum bearings were well and truly shot, so had no choice. If yours are ok I would leave it alone. Nice old machine and you will enjoy using it once its done. A little mod I have done on mine is to make some delrin spacers which screw to the back of the fence and hold it a gnats clear of the tables. Avoids the steel fence leaving marks on the alloy tables as it slides on the delrin. Have fun

 

[Fergie 307]

Worth mentioning that when you are assessing the condition of the bearings they will have a barely discernable amount of play. This is because they are high speed bearings, and have slightly larger clearances than your garden variety. The important thing is that they spin smoothly, with no sign of gritiness. If you have the old design of tables with straight ends then the machine is noisy running. The cutter block forces air through the gap, causing an effect similar to blowing over the top of a beer bottle, but much louder. The later machines with fingers on the table ends are quieter. Dont confuse this noise with worn bearings.

 

[sams93]

Have done this on mine. The pulley is an interference fit on the shaft and is a pig to remove. Biggest problem is that the end of the shaft is very small and provides little for the puller to push on. You definitely need to make up a plug to screw onto the end of the shaft, so you are not pressing directly on the end its threaded M6 if I recall correctly. If you dont do this you will damage the end of the shaft, then you are really in trouble. I have a proper garage press and a wide variety of pullers and I couldnt shift it. In the end I had to cut it off and make a new one. If you can get it off the rest is simple. Before you start measure as accurately as you can the distance between the bearing mountings, and how far each bearing sits into its housing, and the distance between the back of each housing and a reference point on the drum, you need a decent vernier gague at least. To avoid problems down the line everything needs to go back exactly as it is. Get the bearings from a decent supplier, and they should be able to match them for size, and speed rating. Knock the bearings out from the reverse side. To fit new ones just use a suitably sized socket to tap them in, better off using a press as you need to get the insertion depth correct with reference to the measurements you took at the beginning. Make a careful note of all spacers and or shims, where they go, and which way round. They look similar but are not the same. As you may have gathered by now, its not as simple a job as you might think. If the bearings are in good shape and dont howl I would be tempted to leave well alone. You can still clean the cutter block by wrapping it in kitchen towel soaked in your choice of rust remover, then wrap in clingfilm while it does its stuff, just dont get it on the bearings. And if you do have to get a new pulley made then remember it is crowned, if you make it flat you wont keep the belt on. Having to make a new one anyway i took the opportunity to convert to a poly v belt, much better and less tension on the bearings. For the motor I used a hollow centre poly v pulley from a car power steering pump the same diameter as the original. I then turned down the original pulley to make a hub for it.
I am a great believer in if it aint broke dont fix it. I got mine pretty cheap because the drum bearings were well and truly shot, so had no choice. If yours are ok I would leave it alone. Nice old machine and you will enjoy using it once its done. A little mod I have done on mine is to make some delrin spacers which screw to the back of the fence and hold it a gnats clear of the tables. Avoids the steel fence leaving marks on the alloy tables as it slides on the delrin. Have fun

Thankyou all for your advice so far with this..

I watched the Marcus Hornburger video and saw how much of a faff it was for him to remove, and actually even then it was the precise re-setting of the bearings that worries me more!

This response by Fergie was really helpful too, I think that from both having seen it done in the video, and reading the advice particularly fergies about how he would avoid if possible, I have made the decision to try restore this part in one piece rather than dissasemble it.

The bearings are relatively new - I believe they were replaced in 2014, run smoothly, don't make any noise or have any undue play in them, and I think that I will do more harm than good by taking to pieces and replacing versus trying to restore the parts in-situ.

Thanks all for your help!

 

[Fergie 307]

A good idea with something like this is to wrap a plastic bag over each bearing assembly, secured with zip ties around the shaft inside each one. Then you can do whatever needs doing to the cutter block without getting anything in the bearings.