Heater cartridge undersized?

Discussion in 'Volcano' started by Sarah Nicholson, Jun 22, 2016.

  1. Sarah Nicholson

    Sarah Nicholson Well-Known Member

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    I'm trying to assemble some Volcano heat blocks which came with my BigBox, using some additional 40W heater cartridges I purchased separately (also from E3D direct), however I can't get one of the heater cartridges to clamp tightly into the block, I've tightened the clamp screws as much as I can without stripping the screws and it still slips around.

    I don't think it's the block as I can clamp the other heater cartridge in the same block. Has anyone else encountered this, is it just a question of contacting E3D support and trying to swap the heater cartridge? As the Volcano mounts the heater from the top it probably won't fall out but I don't feel very happy about not having it securely mounted.
     
  2. elmoret

    elmoret Administrator

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    What's the diameter of the heater? If much less than 5.9mm, contact E3D for a swap.
     
    #2 elmoret, Jun 22, 2016
    Last edited: Jun 23, 2016
  3. R Design

    R Design Well-Known Member

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    Aaargh...

    Just measured my as-yet-unused 40W heater and it's 5.8mm. On testing with the unmounted (but grubby!) volcano block it is indeed too loose.

    Thanks @elmoret @Sarah Nicholson for bringing this up!
     
  4. Sarah Nicholson

    Sarah Nicholson Well-Known Member

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    Thanks for the info, I measured both of mine and the one that I am able to clamp is about 5.85mm and the other one is between 5.7 and 5.75, so I think a mail to support is in order. I still have the high temp parts for the IR sensor and fan mount to print before I'm ready to mount them anyway.
     
  5. Old_Tafr

    Old_Tafr Well-Known Member

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    Why not apply a gentle squeeze on the block to narrow the gap. If you are afraid of squeezing it too tight then find a drill bit that is just the right size and and then squeeze it. A small vice would be better than say mole grips or pipe grips to apply some force as you have more control. Obvious, but don't put the heater in and then squeeze it. :confused: Try a little force with a drill bit or similar rod in there and then try the heater for fit. The very brave would apply a light tap with a small hammer with something solid under the block, like the jaws of the vice !!

    If the thermal compound works at that high temp then maybe a coating of that on the heater would help the heat transfer too.

    OR as there are two holes to tighten the heater in, with the heater out (and maybe a drill bit shank in) try tightening them a little just to squeeze the gap closed a little, take care not to strip the threads though.

    Just off to see what size drill bit just fits the hole... 6 mm is a good fit (the shank measures 5.95 mm) ... but I don't have a heater to try.......... are these from e3d or another supplier?
     
    #5 Old_Tafr, Jun 23, 2016
    Last edited: Jun 23, 2016
  6. Sarah Nicholson

    Sarah Nicholson Well-Known Member

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    These are genuine E3D heaters. I actually have some spare heater blocks since I'd already ordered some Volcano bits then got the extra freebies for the preorder delays so I guess it wouldn't hurt to try it on one of the spares, although it really is quite loose so I'm not particularly confident.
     
  7. mike01hu

    mike01hu Well-Known Member

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    As you are awa
    As you are aware, a loose mechanical fit means poor thermal contact and will affect the PID performance quite badly. Unfortunately, thermal paste is not a solution either as high temperatures that it may experience will degrade the silicon and make it worse but I would have expected that you could clamp effectively anyway by a liitle more twist on the screws. If you are concerned about threads stripping, use a much longer screw with a washer to pass right through the block and tighten with that first to distribute the load on the full thread and put a nut, gradually taking up the slack on the other side to assist as well; once done, you should then be able to use the original screw. I would not be frightened to gently squeeze the empty block in a vise beforehand if the difference was only about 0.2mm.
     
  8. elmoret

    elmoret Administrator

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    @Old_Tafr , @mike01hu at much under 5.9mm diameter, it is not possible to put enough torque on the fasteners without stripping the heads of the button head cap screws.
     
  9. Old_Tafr

    Old_Tafr Well-Known Member

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    Agreed.......... I wasn't suggesting this as the first option I think I did mention to be aware of stripping the threads too, and all solutions have in the end to rely on the skills of the builder.

    There is also the chance of breaking the heater block. (But I rather like the solution of hitting it with a hammer :D) I'm perfectly happy experimenting with this but others may not be. Mike01hu also mentioned running a small screw all the way through to avoid damaging the threads in the block, this potentially will have the same effect of stripping the very fine screw thread on the tiny screw that would fit through the hole. I'm happy with drilling out the existing threads and tapping a slightly larger size or even drilling a clearance hole straight through and always using a bolt straight through, clearance with other parts permitting (probably simpler on the Volcano as the heater block is mounted vertically.

    So yes, great care is needed, if the heater or the block is out of spec then the best route is ask for a replacement and e3d need to either change their quality control and/or contact their suppliers.

    PS Those button head screws are a pain !
     
  10. Bluemalu

    Bluemalu Well-Known Member

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    I went for the aluminium foil shim to avoid distorting the block. Once that was sorted my PID difference between heads was much more reasonable.
     
  11. Sarah Nicholson

    Sarah Nicholson Well-Known Member

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    E3D support are replacing my heater cartridge, so it's all good. As for the screws, I managed to find some 10mm M3 hex head bolts which are a good replacement for the button head screws as they are still fairly low profile but less prone to stripping, and it's a lot easier to get decent torque with a ratchet socket wrench.
     
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  12. sga

    sga Member

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    Just to my experience, E3D support was really kind and helpfull and changed my heaters for new ones. But the new ones are again in the 5.81 - 5.83 mm diameter. And the holes in the blocks are around 6.00. It requires quite a bit of force to screw things in and bend the bottom "limb". And after a few thermal cycles it is impossible to unscrew the button head screw without destroying it. The thing is there is a limit to how much the lower limb can be bent because after a few degrees the screw would have to bend too since it is an M3 full thread according to the drawing here:
    http://wiki.e3d-online.com/wiki/File:DRAWING-V6-BLOCK.png
    I have to check that the parts agree with the drawing tonight but maybe making the entry part of the screw hole a bit wider (3.2mm) could help as the limb could then bend more without in turn bending the screw and destroying the thread. I just came home and measured the screw hole entrance to be 3.1mm. This means since the screw hole in the bottom limb is about 3mm deep that for tan-1(0.1/3)=2° of deflection the screw thread is already touching the entry hole.
     
    #12 sga, Sep 28, 2016
    Last edited: Sep 28, 2016
    mike01hu likes this.
  13. sga

    sga Member

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    I just wanted to visualize the problem with the screw and drew the block dimensions and measured heater dimensions to scale to compare it with the gap between the screw hole and an 3mm screw.
    It seems clear enough to me that in order to bend the lower limb, the diameter of the screw hole needs to be a bit larger or the tolerances between heater and the block hole need to be a bit tighter.
     

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  14. R Design

    R Design Well-Known Member

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    You should get back to them once again.

    I guess the shipping department needs a pair of calipers on hand.
     
  15. sga

    sga Member

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    Well I got back to them a few times over the last month, they kind of admited they had a problem at some point in the past.
    But I wrote a number of e-mail detailing the issue that being unable to unscrew the thermal heater due to tolerancing of thermal cartridge was not my favorite option.
    I asked if they would receive new cartridges in the future, would modify the design or do anything about it. I got answer that the engineer don't see the problem... and now they don't even answer to me anymore... I am bit sceptical about the outcome of this.
    They do claim, I am the only one complaining...
    I can guarantee that it's impossible to get the heater out of the block now, I don't feel like throwing away the whole block because I can't replace the cartrige...
    Anyone having noticed the same please advise and let me/them know what you think.
    Specifically I must say that I asked them to ship me with the long cable heaters they had in stock due to the size of my build (which they very kindly did) but which might be linked to the fact that those heaters could be undersized (I only have speculations here).
    And yes I do trust my skill at using a caliper.
     
  16. R Design

    R Design Well-Known Member

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    Here are a few things I'd consider (in sequence):

    - pick up the phone and explain your problem to someone there in clear and simple terms "The heater was a tight fit / now I can't swap it out / I measured the bit sticking out with the calipers and it's out of spec. Is that reasonable?"; Normally this sort of thing is a communication problem because nobody wants to lose a long term customer over a small-ticket item.

    If no luck

    - buy a new block / cartridge and when it arrives (so you can carry on printing) send the entire old assembly back to their lab for analysis / refund; Continuing with the communication problem - if words fail then give them the offending item!

    If no luck

    - buy a new block from e3d (the only way) - but in a show of frustration source your cartridge heaters from aliexpress; If you've wasted too much time on this and just want to get on with life.
     
  17. sga

    sga Member

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    1. I actually have a few of the blocks 4 or 5 sitting and I must say the block to block tollerances are very good. that's not the problem.
    E3d actually sent me new heaters but they were the exact same dimensions (to 10-20 um) as the ones I already had which cause the issue so they asked me to return them, which I did.

    2. I agree maybe I'll try my luck with a few heaters from aliexpress and return e3d their heaters. The thing is indeed peace of mind .. I buy from them to get that peace of mind and not have to deal with these things... but unfortunately it's not so honky dory...
     
  18. R Design

    R Design Well-Known Member

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    I think they need is a "go" "no go" pair of holes in the packing department. When packing orders they stick the heater in the first hole, then the second, to ensure that the cartridge is within tolerance. If not it goes in the reject box which is used to supply uber heated beds and other less demanding applications.

    @Sanjay will enjoying making the testing block on his new PocketNC ! ;)
     
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  19. elmoret

    elmoret Administrator

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    @sga, have you thought about perhaps swapping to a socket head cap screw for the tightening?

    I agree E3D's heaters run undersize, about 5.8-5.85mm on average. But I've never had a heater block/heater cartridge that wouldn't clamp properly.
     
  20. sga

    sga Member

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    @elmoret,

    The problem is not that you can't clamp it properly, you can, but you can't unscrew it afterward.
    (I mean after a few heat cycles the screw which was hard machined into the too small too much deformed lower lip hole is stuck forever).
    Going to a stronger screw head is a possibility but then what about the silicon socket....
     

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