Help needed with Optimus 11 original short control knob

Hi Stovies,

I'm fettling up an Optimus 11 which I bought a few weeks back without its control knob. I'd like to try to get a reproduction knob 3D-printed as near to the original style as possible, and for that I need the help of somebody who has one.

Can anyone who has an original control knob for this stove furnish me with some dimensions please? I'm going to model up one as best I can by eye from the photos in the gallery, but some proper dimensions would be really helpful.

--
Mike

 

Mike,
I have a extra knob, I'd have to see how close it is to the 11 Explorer, other Optimus stoves like that. Came with some other parts I purchased. Let me know, I can send it to you, no charge if it works for you, I'm headed out shortly for a bp trip to Lassen VNP then a night camping elsewhere.
Duane

 

Since that was so easy......
I am looking for a short rod knob for one of my Optimus 11 stoves.

Thanks,
Ken

 

My error, different stoves. Too many to keep track of.
Duane

 

I do truly understand that

 

Here ya go:

In the first pic the spindle is lined up with the 1" mark. Jerry

 

Any use:

http://www.ebay.co.uk/sch/m.html?_o...&_nkw=control+knob+and+shaft+++stove&_sacat=0

Best Regards,
Kerophile.

 

Duane: Thanks for the thought

Jerry: Thanks for the photos, that's a great help. I'll continue working on my model and when it's a bit nearer completion I might come back and ask if you could make a few specific measurements.

Kerophile: Thanks for the link, I'll consider one of those a "Plan B"

 

Hi @MikeEvans just for information, these contol rod shafts can get pretty hot when the stove is operating and the Original manufacturers used thermoplastic phenolic resins (Bakelite type) for the knobs. The knobs appear to have been moulded directly on the metal shaft so no additional adhesive attachment, nor screw retainer was required.

The old fashioned phenolic resins have very good heat resistance compared to many more modern thermosetting resins ( 2- component setting tyes like epoxies).

If you are commisioning a 3-D printed knob please be sure to ask about heat resistance, and discuss options for attaching the knob to a shaft.

Best Regards,
Kerophile.

 

Hi, OK, I know its not original but I reckon these look really cool:

https://classiccampstoves.com/threads/serpentine-regulator-key.31357/

Best Regards,
Kerophile.

 

Good advice on the material choice there, and that serpentine key looks amazing!

 

OK, I've modelled the knob as best I could from the photos in the gallery, and reckon it looks OK (ish!) If anyone has time to spin a pair of calipers over one to fill in the blanks on the drawing below, I'd be grateful

 

Wow!!!

 

You might want the hole dia and depth, too.

 

@snwcmpr You mean for the shaft? Haven't got that far yet, still mulling over whether to simply heat the end of a piece of tube and crush it square, or to file a square hole into a short brass section and silver-solder it to a tube.

 

Hello @MikeEvans

Have taken the measurements of my Opt 11.
Ø A is 40 mm
Ø B is 43,3 mm
Ø C Ø is 33,6
Ø D is 12 mm
E is 13,7 mm
F is 93,5 mm
G is 6,15 mm

Not easy to measure F as bottom of the groove is rounded. The brass shaft is 56 mm long . The square part is 8,5 mm. Square hole is 4,1 mm.
Diameter of the brass pipe is 7 mm. Hope this will help you make a replacement control knob. As @kerophile says control knob rod will get hot when left in place.
So you need to use some material the can withstand heat. Here are some closeups av my control knob.

Best regards Bjørn

 

Outstanding Bjørn, and very much appreciated.



--
Mike

 

Another post i can't delete.

 

@boknasild Thanks for the measurements... I'm looking forward to seeing what @MikeEvans can come up with. Looks like an error with the decimal mark, is F actually 9.35 mm give or take whatever error there is because the trough is rounded?

Regards
John

 

@Jeopardy@MikeEvans

Thanks for the correction.
F should of course be 9,35 mm. I had made a note of 9,35 mm on paper but on the pc it came out wrong.

Best regards

Bjørn