PBD40 is not a precision bench drill

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Firstly, you do not need to grease anything, gears are seated in a sealed gearbox with grease in it. That noise is typical of the machine, it changes with the gear selected and temperature.

You might use a bearing extractor (https://www.izeltas.com.tr/en/products/pullers/7010-standart-puller-two-arms) to remove the ball bearing. I wish I have taken photos of the steps of the change to make life easier for you. Unfortunately, I do not have the machine near me right now.

This post was edited by dr1l on 22.09.2020, 01:38 o’clock
Reason: Added info about standart puller with two arms

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You might use a bearing extractor to remove the ball bearing. I wish I have taken photos of the steps of the change to make life easier for you. Unfortunately, I do not have the machine near me right now.
Copy that. But to even get the hold of the bearing I need to get the shaft+bearing out of the "frame". I presume that the assembly is friction fitted and that I just can knock it out forcing it downvards with a rubber- coated mallet? Haven't found anything else that holds it in place after removing the locking ring right below the bearing. 

Or maybe you're talking about a tool similar to this one that would pull the bearing of the shaft with the assembly still mounted in the frame (you would have to penetrate/remove/damage the cover of the bearing to use the tool). The shaft actually has a small opening prepared in the end that would suit this tool well. 


 

This post was edited by alexndr on 22.09.2020, 13:12 o’clock
Reason: Updated with image of assembly still in "frame".

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Horray! It came apart. Gentle tapping with a hammer on the shaft did the trick. Next will be to separate the bearing from the shaft. Might try the tool suggested.
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Ok, done. 

Hardest of it all: To reset the shaft and bearing in the setting after the bearing- change. I had to lathe me a small plastic distance (see last picture) to be able to tap it back evenly in the setting. Even then it took some time. It's important to get it straight. 
I also had to buy two pliers for locking rings. One for outer and one for inner rings. I used my vice to remove/reset the bearings from the shaft instead of a bearing extractor. Felt safe enough. 

If you're trying this at home, get some rubber gloves. The gearbox that you have to dismount is smacked with grease. And finally, the gear- wheel (or what to call it) can be reversed. Make sure that you put it back in the same direction as it was. 

The result? Well, not that big difference when just budging the chuck I would say. I can still feel it wobble. I have no tools to measure the deviation though.
As discussed in this thread https://www.bosch-professional.com/gb/en/community/category/when-there-will-be-blue-version-of-bosch-pbd-40-bench-drill-press/386177-t/p3#/main I'm thinking that the problem probably lies elsewhere.

Interesting that you was satiesfied with the result dr1l? Have you measured the improvement?  

This post was edited by alexndr on 24.09.2020, 22:54 o’clock
Reason: xxx

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Thanks for the detailed hints you gave. You are right, problem is more fundamental than the internal clearance of the single ball bearing. You need to have two ball bearings at both ends of a shaft to properly minimize deviation. But this machine has one bearing by design, hence it is a green machine not blue. This is one of things you can do to improve precision.  I think it is a practical appliance for prototyping despite all the design flaws.
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So it worth the hassle changing to a CM bearing dr1l? Have you measure the improvement of play/wobble/movement of chuck?

alexndr did you replace it with a CM bearing or a bearing with normal play?
 
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I depends on the precision you need from the machine. I was unsatisfied with the machine, so improving precision was the only option. Position accuracy and diameter tolerances are certainly better. Machine sounds different as well. I do not have the precise tool that is necessary to measure play. If somebody can do that measurement, answer to your question will be more precise as well. 
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alexndr did you replace it with a CM bearing or a bearing with normal play?
 
I went for the CM- bearing. 
 
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There is a video on youtube of someone replacing the chuck with a slightly better quality one, and they reduce the wobble on a spinning drill bit from 0.2 mm (with the original chuck) to ~0.07 mm. So I imagine with the bearing hack and the better chuck you could end up with quite an accurate machine.