Replacement knobs - Page 1
Forum section: electronics / general

author: Specmaster
author_rank: Super Contributor
timestamp: May 27, 2017, 11:37:38 pm
content: Does anyone know where I could source some replacement small knobs that use collets to secure them to a 2mm dia shaft? I'm refurbishing an old Hameg HM408-1A scope and just can't seem to be finding any luck in finding these as new scopes are in the main mush button controlled these days? I could post a photo of the knobs if it would help but in reality, any small knob that has the ability to be used on a shaft of only 2mm dia would suffice.

author: amspire
author_rank: Super Contributor
timestamp: May 28, 2017, 12:53:38 am
content: A DIY 3D printed knob is a real option if you cannot find anything. The collet may be hard - may have to settle with a screw or friction fit. At least you can make the knob match the shape of the other knobs.You do not have to own a 3D printer. There are plenty of online options to get small 3D parts printed surprisingly cheaply and there are a lot of free easy to use tools to design the STL file (such as Tinkercad). The surface finish can be pretty good now and there are options to get the surface immaculate - like the acetone vapour trick for ABS plastic (see Youtube), or even just auto body filler spray, sandpaper and a final enamel coat.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 29, 2017, 04:43:34 am
content: Have you tried Farnell?http://www.farnell.com/datasheets/1733008.pdf

author: Specmaster
author_rank: Super Contributor
timestamp: May 31, 2017, 08:41:03 pm
content: Quote from: CatalinaWOW on May 29, 2017, 04:43:34 amNo I had forgotten them to be honest, thanks, these look almost perfect for the job, the little pointers I could always file off as these are not required. Thank you for the information.

author: Specmaster
author_rank: Super Contributor
timestamp: June 01, 2017, 07:47:41 am
content: It seems that Farnell only do the 3mm shaft size after all. However going to the Elma website it transpires that the UK distributor for their range is:-Foremost Electronics LtdProduct lines: Rotary Switches/HMI14 Bluegate Business ParkGreat Bardfield, Essex, CM7 4PZsales@4most.co.ukPhone: +44 1371 811171Fax: +44 1371 810933http://4most.co.uk/knobs-handles/elma-knobsSo likewise I'll need to speak to them as well

author: tautech
author_rank: Super Contributor
timestamp: June 01, 2017, 07:55:32 am
content: As there'll be little torque on the connection just some shrink sleeving on the shaft to bulk it up to 3mm should do the trick.

author: DK-1
author_rank: Regular Contributor
timestamp: June 01, 2017, 04:21:56 pm
content: When i must find some knobs i try to find these in some professional audio spare parts shop because some "vintage" gears mount the same of the testing electronic stuff (not really vintage but 80/90 years).....my two centSomewhere in some PC i've many links of these shops ,now i go at home and try to find and post here if you still need

author: Specmaster
author_rank: Super Contributor
timestamp: June 01, 2017, 09:45:35 pm
content: Quote from: tautech on June 01, 2017, 07:55:32 amI did think about this before and discounted it because some of the shafts have on/off switches as well and they do have a fairly high torque requirement and also if I purchase these 3mm knobs and it doesn't work , I'll have wasted a reasonable chunk of cash as these aren't cheap and I really need 6 of them to match up.I could end up looking around for a scope beyond hope and rob knobs from that if all else fails.I have asked for a P&D on 6 knobs already from Foremost Electronics, lets see what they come back with. If reasonable, they are only a few miles from, I could collect them.