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Star knob jig #1: Star knob jig - make your own star knobs

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Blog entry by mafe posted 05-14-2019 08:50 PM 1068 reads 1 time favorited 7 comments Add to Favorites Watch
no previous part Part 1 of Star knob jig series Part 2: Star knob jig - the write up for view »

Star knob jig
make your own star knobs

The other day I opened LJ and saw a post I could not resist, from our buddy Gerry TheDane, in fact I’m a Dane, so there are a wee confusion here… ;-D It was a star knob jig, he had just made, I found it so cool, that I had to make one, even I don’t need any star knobs at the moment…
Thank you for the inspiration.
Gerry found the jig on Youtube, where a guy called Christofix had put it up in a video, thank you Christofix.
As much as I appreciated the video, I found that I had to go forward and backwards, again and again to make a copy, also I thought it could be simplified a wee bit – so I decided to share my build, hoping it can make it more easy to make one.
(Btw, jump to 1:30 on the video, I have never seen such a long intro in my life). :-D

IMPORTANT:
I found that the jig I made following the video were brilliant, but not precise enough in the hold part, so I made a updated version, the difference is that I take the saw kerf (saw blade thickness) into account, so the jig holds the knob in place better and there are less guess work, you will see this in the following – also I skipped the hold down arm, since I think a wing nut is just fine.

My version, with the geometry, a build guide and a how to use it manual, can be found here: STARKNOB JIG.
Link; http://www.felding.net/image/pic/starknobjig/low/starknobjigmafe2019.pdf
(I had great fun making the pdf, it brought me back to the days, where I worked advertising).

So here we go, making a star knob jig.


This is what we will end up with, a jig for making star knobs.
Here examples of different types with nuts or bolts, I made on it, while trying it out.


This is the hole saw I use for the 40mm jig.


But first we need to make the geometry and this was where video, really came short – or perhaps it was me who came short… At least I had to see it again and again to get it done.
So I’ll go slow, so even I would be able to follow.
First find the hole saw you want to use, I use a 40 mm / a divider / a rule and a piece of paper.
Set the compass at the radius (half the diameter) 20mm here.


Draw a circle.


The circumference of a circle is 6 times the radius.
So lets take a walk around the circle and mark the six points.


Amazing yes? :-D


Now time to offset the points we made.
So I set the compass at 3 mm.
Note:
Ok, this is where I take a step off the video and perhaps a wrong one…
I wanted to use a 40 mm hole saw and not a 60 mm.
So I made the offset distance a wee shorter than was described.
(I’ll get back to the offset problem later).


Now make marks offset away from the six point division we made.
As you can see, the offset points are only away from every second space.


I marked them with red here.
Now place the compass in the offset point and draw a circle partition.


Then from the other side, so they intersect.


Now draw a circle from the intersection.


Now we repeat the steps, two divisions away.


New intersection.


Again draw a circle from the intersection.


We only needed the two, but I found it pleasing to make the third…
Just for joy.


So here we are!
Now with the numbers in place.

IMPORTANT:
LOOK IN NEXT ILLUSTRATION FROM THE PDF FOR EXPLANATION:


This is where you should offset the circle to the most right, the thickness of your saw kerf, towards the circle in the middle. Otherwise you will have a loose fit on the holder.


Finding the kerf . saw out a hole with your hole saw.
Saw kerf = the diameter of a cut hole, minus the diameter of the outside of the cut out circle.
(Here again from my second jig).


Measure the hole.


Measure the cut out.
Now subtract the inside from the outside and divide by two, then you have the kerf size and that is the offset distance you need.
Here: (5,7-5,2):2=0,2cm.


Draw line between centers and mark the kerf thickness for the offset.
(This picture is from my second jig).


Draw the offset circle, this is where it should be positioned.
(In fact you only need the center points, but draw it to see what you are doing).


Next step is to draw a line between the center of the mid circle and one of the others.
(Now we are back to the photos without offset sorry, just use the new offset center).


Like so.


Finally time for some wood!
Plywood in a good quality (many layes), a 9 mm thick and a 15 mm.
(Use what you have, but not too thin for the base).


App. 26 cm long (I just tried my way, later I cut it off, app. half, so perhaps you want to do this by now…).


App. 14 cm wide (this is fine).
(So perhaps 15×15 cm / 6×6 inch, would be a fine jig size).


Now make a line 6 cm down from the edge.


Put double sided tape on the back of your drawing, or use spray glue.


Put the line from the drawing on top of the one on your plywood.
I used the 9 mm ply on the top, but I think I would reverse that, if I should do it again, but it’s not important, just that the base don’t get too thin, so 9 mm will be minimum.


Again I use tape, this time for the back of the plywood, with the drawing on it.


So I can stick the two plywood boards together.
Also marking the centers of the circles, with an awl.


Drill out the holes, but only through the first layer of plywood.
You should drill and remove the two outer circles first and then the one between, then you have two pieces for the first knobs ready.
(Not like me here – sorry, learning by doing…).


We got three holes!


Place your hole saw in the outer hole – bring a square up to it and draw a line there.


You see the outer hole is outside now.


We now have three holes and our cut outs (this is the cut outs you will have if you follow my text).


Gently clean up the outside, if needed.


At the table saw, make a cut along the line, on the side of it, that goes away from the two circles, so your saw kerf is away from the two.
(Hope it makes sense).


The line should be just visible on the small part, with the two holes now.


This is what we should have at this time.


Put the hole saw in one of the holes on the base and glue on the back of the small jig part.


As you can see at the end, I also made some line up marks before gluing.


Now time for some hand tools…
Ok, driven by the wind.
They have a place over my Festool MFT table, a little shelf, for air tools and a plastic drawer under, for most used nails and stuff.


I just shot some short brad nails in it, to hold it together, so I could continue without waiting for the glue to dry.


Find a bolt that fit the drill bit diameter of your hole saw.


Drill a hole just shy of the bolt head diameter and as deep as the bolt head on both of the holes to the back.


Mix some epoxy glue.


Glue on sides of holes, not too much, so it gets on the bolt.
(Or dry it off with a cloth – like I had to do).


Perhaps just glue here instead, but I did both.


Finally knock them in with a hammer.
This is why the holes need to be shy in size.


Now we got this.
Time to find some washers and wing nuts that fit, two of each.


Now we need these two parts.
A star knob and a cut out, with one hole cut, to make the hold.
I already made them here, glued them on top of each other and gave them a brad nail.


This is what we are after – a guide for the knob blank to rest against – with a washer and wing nut on top, instead of the arm, that are suggested in the video.
IMPORTANT:
Here you see that they don’t meet up, due to the thickness of the saw kerf, so this is why the hole for the hold should be offset towards the knob blank.


Washers and wing nuts on both, to secure them while sawing with the hole saw.


Finally we can bring the jig to use.
Align the saw area with the drill press and clamp the jig to the drill press table.


Put a knob blank in and secure it.


Saw off first hole part out.


Turn the hold and the knob, so they match up.
(Will be better in the offset version).


Saw the second hole part out.


Release, lift and turn.


Lock in place.


Saw the third hole part out.


We got a star knob!!!


To make blanks, put wood against the jig side.


Saw out.


Blank is ready.


You can optimize by making fitting strips.


Double or high knobs.


Here double.


Different types of knobs.
To the left simple type, where a bolt is knocked into a double layer knob.
In center the nut type.
To the right a bolt type, with hidden bolt.


For the nut or hidden bolt, bore a hole fitting the bolt wrench size or a little smaller.


Epoxy glue and hammer the nut or bolt in place.
(Bolt type, put bolt through hole and bang it in).


Then glue on the surface.


Stack them and if you want nail them on the underside.


Easy yes?


On the left, I put a thin wood on top of a hidden bolt version, like this, you get an elegant type.
But they can also be made from hardwood, with matching top.


The jig and knots.


Notes for me to remember.


Here the jig shortened, just because I did not need more.

UPDATE:
Only needed if you did not offset as I described or already made one from the video.
Since I was not happy with the first version, I made a new hold in place knob.


Drill a hole, close to the corner, in some scrap wood.


I cut out a larger blank, with a size bigger hole saw and put a bolt trough.
Have sketched, app. where I need to stop.
Then just rotate as you sand it to size.
Take it on and off to test your fit.


This was much better, but not perfect I admit…


This is on the 57mm jig I made after, with the offset, that’s close to perfect.


Using this hole saw for the second version.


Both jigs ready to make some knobs now.


Think these two sizes should cover it.

My pdf writeup, with the geometry, a build guide and a how to use it manual, can be found here: STARKNOB JIG.
Link; http://www.felding.net/image/pic/starknobjig/low/starknobjigmafe2019.pdf

LINKS for different star knob videos:
https://www.youtube.com/watch?v=C9D683to0uY
https://www.youtube.com/watch?v=58LFXQ6qVK8
https://www.youtube.com/watch?v=Di_xHYgCE88


View on YouTube
Think it’s time for a song, before we say goodbye. :-D

Hope it can be to some inspiration, or perhaps even star knobs.
It was great fun, digging into this and making the write up also.

Best thoughts,

MaFe

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.



7 comments so far

View Joe Lyddon's profile

Joe Lyddon

10585 posts in 4414 days


#1 posted 05-14-2019 09:19 PM

Very COOL…

Thank you!

-- Have Fun! Joe Lyddon - Alta Loma, CA USA - Home: http://www.WoodworkStuff.net ... My Small Gallery: http://www.ncwoodworker.net/pp/showgallery.php?ppuser=1389&cat=500"

View lew's profile

lew

12736 posts in 4117 days


#2 posted 05-14-2019 10:13 PM

Thanks, Mads for taking the time to create this post.

I, too , am a Lumberjack but I don’t wear women’s clothes!!

-- Lew- Time traveler. Purveyor of the Universe's finest custom rolling pins.

View kaerlighedsbamsen's profile

kaerlighedsbamsen

1275 posts in 2075 days


#3 posted 05-15-2019 08:26 AM

This must be your most thorough blog so far, super usefull!

-- "Do or Do not. There is no try." - Yoda

View Notw's profile

Notw

714 posts in 2115 days


#4 posted 05-15-2019 02:06 PM

new title “Mafe does black magic with a compass”

View madts's profile

madts

1898 posts in 2702 days


#5 posted 05-15-2019 02:53 PM

Very clear and informative Mads. You should have been an architect!

—Madts.

-- Thor and Odin are still the greatest of Gods.

View Tony_S's profile

Tony_S

967 posts in 3445 days


#6 posted 05-17-2019 09:27 AM

Even though I don’t comment a lot, I always look forward to your projects/blogs Mads. I’m always intrigued somehow.
I don’t give a shit about star knobs…lol….Your just a badass, cool dude.
Too bad you live on the other side of the world. I’d love to shake your hand and BS with you for a few hours.
Love that calculator btw…awesome!

-- It is the mark of an educated mind to be able to entertain a thought without accepting it. Aristotle

View mafe's profile

mafe

11972 posts in 3451 days


#7 posted 05-17-2019 11:56 AM

Hi guys,
Joe, thank you.
lew, ahhhhh come on…! Ok, I actually don’t wear a dress too often, did in Egypth though, there the men wear them and it makes sense, due to the heat. :-D
Ty, overthinking… who me? Naaaa. Laugh, yes I had a good time with this one. Smiles.
Notw, ha ha ha. And almost lost his direction.
madts, Laugh big time, you got a point there. That was a good one.
Tony_s, Those are really kind words, thank you. I try to bring not only wood, but also a human into these blogs, so I am really happy you can read taht. The words do make a difference, these comments and words, they incourage to keep on. ;-) Yes I was in the sky when I foyund that calculator a few weeks back in an antique shop, soooooo cool! Remember looking at them when I was a wee boy and dreaming of having one.
Best thoughts to all of you,
Mads

-- MAD F, the fanatical rhykenologist and vintage architect. Democraticwoodworking.

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