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  1. #21
    Quote Originally Posted by Clive S View Post
    That's the point they were not specified that's why I asked him to check. They are being sold in a kit with rails so should be AC type.
    As I made it clear, there is no such thing as "should be" unless it is specified. You can wish for anything, unless it is specified, it's just wishful thinking, and if it is as you wish then it is bonus. The only contract between you and the dealer is that what the specification is saying. That's the way things work. Expectations can be set very high, nobody can stop you from that, but it is naive to believe that something as cheap as these are, are the same in every aspect as the much more expensive ones. The OP is an adult, I am sure the OP understand this as well.

    Quote Originally Posted by Clive S View Post
    As the op is a beginner he would not know the difference between the bearings
    That's why it is important to point out not only the fact that your expectations are too high, but also that there is a set of bearings (the OP did not even expect any) and that those bearings may work for HOBBY use, so there is no reason to hurry changing those, unless he experience issues. Non of that did you or anyone else mentioned. You are so hang up on the AC bearings that that you lost focus from the subject, or target, building a CNC for HOBBY use. Your comment to him:

    Quote Originally Posted by Clive S View Post
    Have you checked what bearings are in the BK end bearings
    ...is totally pointless and is what muddying the waters here because it says absolutely NOTHING except ridiculing him for his decision of buying those things. You are not saying ANYTHING about what to expect to see, or which sort you think is the acceptable bearing. NOTHING in that sentence is of any help to the OP or anyone visiting this thread. You didn't even bother to put a question mark after your sentence. The OP did not even expect any bearings in those seats, so the way I see it, any bearing is better than nothing.

    In fact, you are so hang up on the AC bearings that you did not mention the most important parts of a ball screw, the screw and the nut. Those can actually cause a much more serious headache than bearings in those seatings. If the screw is bent or damaged there is nothing he can do, other than buying a new. Same for the nut, if something wrong with it and a cleaning does not solve it, then it's a case of biting the bullet and buying a new. Changing the support bearings is peanuts, easy to fix. Never the less, it can be an expensive thing to do for someone on a limited budget, especially if the current ones work well enough. What is "well enough" is not for you (or me) to define. It is up to him, the OP. Now, THAT is help for a newbie starting a new hobby activity. Just saying "Have you checked what bearings are in the BK end bearings" is pointless muddying. It would have been different if you had said more about how things should be according to your opinion, and explained the difference between bearings, but you did NOT do that, not before I chipped in with my opinion, which I have right to express also, without you telling me to shut up.

    Quote Originally Posted by Clive S View Post
    so why do you muddy the waters.
    Are you always this rude or just today and only here? I think you should stop eating barbed wire for breakfast and take a cold shower in the morning.

  2. #22
    Hi gents

    Thank you all for the input and did not expect the response to this thread.

    You all talk in riddles to me - as i could talk if i started about my industry sector.

    I am not sure if i will be using the end bits with the bearings in, as they might not seat within the aluminium profile?

    I thought that's what the end plates are for? or am I getting that wrong?

    Most kits that i have looked at spec the bearings separately, so naturally assumed that i would not need those brackets (as per the image posted earlier in the thread)

    Hope that makes sense

    WoodKnot

  3. #23
    m_c's Avatar
    Lives in East Lothian, United Kingdom. Last Activity: 16 Hours Ago Forum Superstar, has done so much to help others, they deserve a medal. Has been a member for 9-10 years. Has a total post count of 2,822. Received thanks 346 times, giving thanks to others 8 times.
    Quote Originally Posted by WoodKnot View Post
    Hi gents

    Thank you all for the input and did not expect the response to this thread.

    You all talk in riddles to me - as i could talk if i started about my industry sector.

    I am not sure if i will be using the end bits with the bearings in, as they might not seat within the aluminium profile?

    I thought that's what the end plates are for? or am I getting that wrong?

    Most kits that i have looked at spec the bearings separately, so naturally assumed that i would not need those brackets (as per the image posted earlier in the thread)

    Hope that makes sense

    WoodKnot
    The machines you're looking at, are designed to be as cheap as possible to build, and will typically use a couple basic thrust bearings to control screw end float. To be blunt, it's a rubbish method, as thrust bearings are hard to adjust accurately in such a setup, and they provide little to retain the screw co-axially, so once it starts spinning fast, the screw/bearings will start rattling around in each other and the end plates.
    The BK bearing blocks should use two angular contact (AC) bearings, which get preloaded (aka you can tighten the nuts up so the bearings are loaded, unlike the before mentioned thrust bearings which would just collapse), and provide co-axial retainment of the screw.

    Personally, I'd redesign the machines you're looking at, to make use of BK and BF support bearings (BF is just a basic deep groove bearing to support the screw).
    The reason the mentioned machines don't use them, is they add cost. They cost more than a couple basic thrust bearings, and you need additional mounting plates for them.

    The issue with cheap BK blocks, is it could be a gamble as to what bearings are fitted, the quality of the bearings, and if they're actually fitted correctly.
    Avoiding the rubbish customer service from AluminiumWarehouse since July '13.

  4. #24
    Ok, I didn't really want to take time out of my day to do this or bash heads with you but this needs to be done for the sake of those we are watching or will see this thread in months or years to come because what you are saying is totally wrong.

    Quote Originally Posted by A_Camera View Post
    I am not saying that there are no lemons, but that most are OK for hobby use and there is no reason to rush or assume that everything is bad. Of course if one is replacing the bearings one might as well do it right and get the proper ones.
    It's a simple fact, which if you don't believe me you can go ask SKF or any other bearing manufacturer is that deep groove bearings are completely the wrong bearing for the application these BK bearings are sold for. The whole point of the END fixing is to reduce axial movement and handle the linear forces and to do this then either Thrust bearings or angular contact bearings are the correct choices.

    To say otherwise is WRONG and MISLEADING and no amount of arguing over a poor buying decision to save face will change this.

    Quote Originally Posted by A_Camera View Post
    But you can't say that just because some people have issues all are having them.
    I didn't say that at all so please don't put words into my mouth.! I said that many on this forum had issues, which is true, and if you had been around long enough you would know this.

    Quote Originally Posted by A_Camera View Post
    In my experience there was a huge quality improvement in these things the last few years, can't compare with how things were like ten years ago. Yes, they do use these simple bearings, but unless it is specified otherwise, there is nothing wrong with that, they didn't fool you. It's not for industrial use, if it was then I'd be more critical about them.
    Well, that's exactly the problem here I think.? What experience do you have.? 1 set possibly 2 sets of BK bearings which if they are the same as these how could you know any difference.?
    To say "in my experience" should actually mean you have experience of more than a couple of sets and actually experienced the difference between current and old components. If you had the experience then you wouldn't be making desperate face-saving comments like that and know that the current budget BK bearings are indeed worse and unfit for the purpose intended for the reasons I stated above.

    You have the right to your opinions and I respect that, but I have the right to point out BULLSHIT when I see it and for the sake of others reading this now and the many 100's or 1000's that will read it in months and years to come I'm calling you out as pedaling BULLSHIT to save face for buying inferior components.

    Whether you like it or not, the simple TRUTH is that DEEP GROOVE bearings are wrong for the application of end fixings for ball screws. It's not about AC are the best or the only ones which should be used, far from it, cheaper thrust bearings will work and are correct for the application also but AC is the better type and are what should be fit to the BK type bearings.

    It's a simple financial fact that to produce these kits at such stupidly low prices that something must give and it's 99.9% nailed on most will come with DEEP Groove bearings for this very reason.

    Now back to work.!
    -use common sense, if you lack it, there is no software to help that.

    Email: dean@jazzcnc.co.uk

    Web site: www.jazzcnc.co.uk

  5. #25
    Quote Originally Posted by WoodKnot View Post
    Hi gents

    I am not sure if i will be using the end bits with the bearings in, as they might not seat within the aluminium profile?
    The 1605 BK/BF bearing holders fit exactly (but not perfectly) into the 45 mm gaps of 45x90 extrusions if you want to install them across in two T-nut tracks using 6 mm screws, but you must consider the ball nut because that will need some spacer or other solution, due to the fact that the HGR20 + HGH20 is 30mm high while the ball nut flange demands 45mm...

    Click image for larger version. 

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    ...or 50mm if it is turned 90 high from the bottom.

    Click image for larger version. 

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    You can solve that in many ways, but it must be solved somehow. I think you will see that more clearly once you get the stuff. It's easier when you have something in front of you to look at than just CAD drawings or words.

  6. #26
    Relax Jazz, I am not exactly disagreeing about the differences with you or others, but as you say, it's about costs, so it is a compromise.

    Regarding experience, I should actually ask the same... because honestly, if you have such low views on those BK/BF bearings then I have to assume that you don't use them. On the other hand, I am waiting for the 10th, so yes, I must claim that I have some experience with them, more than you think. OK, only for 1605 and 1204 screws, but none the less... I was not born yesterday just because I ask some questions occasionally.

    Anyway, I am NOT saying that those bearings are as good as AC bearings. What made you believe that? All I am saying is that he should wait and see and decide on his own for the final decision. Of course it's good that the alternatives are clear and drawbacks are highlighted, but as been said before, replacing the bearings is easy and can wait. But then again, if replacing means complete redesign of bearing seats to fit AC bearings then it is a huge job for an amateur and also a large one for a pro. It's also a hobby machine, so aiming for something reachable is better than aiming at the stars and never get there.

  7. #27
    Quote Originally Posted by A_Camera View Post
    The 1605 BK/BF bearing holders fit exactly (but not perfectly) into the 45 mm gaps of 45x90 extrusions if you want to install them across in two T-nut tracks using 6 mm screws, but you must consider the ball nut because that will need some spacer or other solution, due to the fact that the HGR20 + HGH20 is 30mm high while the ball nut flange demands 45mm...

    Click image for larger version. 

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    ...or 50mm if it is turned 90 high from the bottom.

    Click image for larger version. 

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    You can solve that in many ways, but it must be solved somehow. I think you will see that more clearly once you get the stuff. It's easier when you have something in front of you to look at than just CAD drawings or words.
    Thanks A Camera

    I had noticed that all the converted ones that i had viewed that they had to create some sort of spacer block, but yes, i was waiting for the arrival of the parts, i think holistically first, so then have to work backwards to get all the joined up bits to work.

    So i see what i want to achieve and how the look is perceived in my minds eye, then have to work backwards to achieve what i am seeing.

    My issue is that i don't work to plans and do everything 'off the cuff' sort of speak, which can be a bit problematic!

    WoodKnot

  8. #28
    Hi A Camera

    Just been on your channel - cant believe you actually CNC in your house?

    That's what it looks like!

    Like the actuators, totally wicked idea - i just use the mechanical leverage style ones in the workshop.

    I also hope that you are not going to use that tablesaw in your house - that will make a mess!

    WoodKnot

  9. #29
    Quote Originally Posted by A_Camera View Post
    Relax Jazz, I am not exactly disagreeing about the differences with you or others, but as you say, it's about costs, so it is a compromise.
    I'm 100% relaxed Camera but this isn't about costs at all, it's about what is suitable and what's not and those BK bearings with deep groove bearings are not suitable for a CNC machine because they are not designed to handle the loads in an axial direction. It completely defeats the point of fitting ball-screws if the end fixings are allowing the screw to float which they will with these deep grove bearings unless they are highly preloaded and it's this high preloading they are not designed to handle so they quickly wear excessively which in turn put stress on other parts of the machine. It quickly becomes a vicious circle of wear and stickiness.!

    Quote Originally Posted by A_Camera View Post
    Regarding experience, I should actually ask the same... because honestly, if you have such low views on those BK/BF bearings then I have to assume that you don't use them. On the other hand, I am waiting for the 10th, so yes, I must claim that I have some experience with them, more than you think. OK, only for 1605 and 1204 screws, but none the less... I was not born yesterday just because I ask some questions occasionally.
    You are correct that I don't use these and never would, but I do have lots of experience of replacing them and helping other people who have unwittingly bought these, and the number is far more than your measly ten.!
    In terms of experience fitting BK/BF bearings in general then I buy them by the 100 and just today I've fit 8 sets so you could say I know a little about them.!!



    Quote Originally Posted by A_Camera View Post
    Anyway, I am NOT saying that those bearings are as good as AC bearings. What made you believe that? All I am saying is that he should wait and see and decide on his own for the final decision. Of course it's good that the alternatives are clear and drawbacks are highlighted, but as been said before, replacing the bearings is easy and can wait. But then again, if replacing means complete redesign of bearing seats to fit AC bearings then it is a huge job for an amateur and also a large one for a pro. It's also a hobby machine, so aiming for something reachable is better than aiming at the stars and never get there.
    First of all, I didn't think you thought they were as good and never implied that you did. My objection to your comments is solely based on the fact that you advised the OP and advocate to others the use of Deep grove bearings for BK bearings was perfectly fine, they are NOT.

    The other thing I don't agree with or understand is why anyone would buy these knowing they are poor quality or in this case plainly wrong and pay again to make good.? Crazy to me when for not much more you can buy the correct BK bearings.


    On another note, I also feel you owe Clive S an apology because his comment was a valid one, even if it was short and to the point, your attack on him personally was unjustified and out of order in my opinion.!..
    -use common sense, if you lack it, there is no software to help that.

    Email: dean@jazzcnc.co.uk

    Web site: www.jazzcnc.co.uk

  10. #30
    Quote Originally Posted by WoodKnot View Post
    Hi A Camera

    Just been on your channel - cant believe you actually CNC in your house?

    That's what it looks like!
    Yes, you seen it right. I have a fairly large room, which is a home office / hobby room / software, firmware and electronic development center, photo studio, as well as other hobby activity room. My CNC and my two 3D printers are used in this room as well. However, I NEVER use any liquids to cool and lubricate, I print only PLA and PETG, my spindle is air cooled, my CNC is covered around and I use a dust shoe when milling PCB and most other things. I don't mill any wood. Anyway, this solution suits me well.


    Quote Originally Posted by WoodKnot View Post
    Like the actuators, totally wicked idea - i just use the mechanical leverage style ones in the workshop.
    Thanks. I made that mod a few months ago. Got tired of the primitive method I used before when I had to move my CNC. It is just soooooo much easier this way. Now I can easily clean behind the CNC or make any sort of modification / improvement or whatever which may demand moving the machine.

    Quote Originally Posted by WoodKnot View Post
    I also hope that you are not going to use that tablesaw in your house - that will make a mess!

    WoodKnot
    That was only opened, unpacked and "dry" run for a minute in the house. It lives in the actual workshop / storage are (a separate building) where other machines and tools are.

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