Large hanging sign for work

I wanted to create a hanging sign for our new office.
Some of the requirements I wanted were

  • Letters to be at least 50mm thick
  • Large enough to be legible from a distance
  • painted white with a smooth finish
  • Letters must be replaceable, If one gets damaged i want to be able to easily replace it

Initial ideas
Simply Stacked
The obvious route would have been to stack layers of cutout letters but the plywood is 3mm thick so would have been around 16 layers thick to reach 50mm, also there being twenty letters would mean that there would be around three hundred and twenty letters cut out, so would be unnecessarily expensive and also pretty heavy if it fell on someone.

This method uses less material than stacked. It works by using three cut outs of each letter then joining them with struts
but only builds the frame of the letter and would need covering with somthing!
Struts Strut1 Strut2

Kerf cuts & finger joints
Kerf cuts for any of the curved parts of the letter, and finger joints to hold it together.
I wanted the finger joints to run along the kerfed edge as well, but it is a little complicated to do.
I found a page that instructed how to do this on instructables

I liked the finish but wasnt really suitable for this project and when i tried to hide the kerf edge with filler it just ended up in a mess
Kerf1 kerf2 kerf3 Kerfing

Foam Sandwich
so cutting a front and rear template of each letter then sandwiching it between some blue modelling foam then used a hot wire to cut through it.
It took a little while to perfect the hot wire cutting around the template but once i got the hang of it it came out well

Aligning each side of the foam
Making sure the letters lined up perfectly was achieved by marking the letters and drawing a perfectly symmetrical cross on each side and aligning the markings

Modeling foam cant be painted with normal spray paint as it melts it so a normal acrylic paint was used. (as the foam absorbs the paint it took about 10 coats before you could no longer see any traces of the blue foam)


Fix to backing
When starting this project I knew that I wanted to be able to replace individual letters if necessary
so made holes in the rear plate of the letter to fix to a board with dowels

To align the holes with the dowels I printed off a very rough to scale template of the sign (by sticking A4 sheets together) then over laid it on top of a sheet of mdf and drilled where the holes should be


Looks very nice. With those dowels in the back you could conceivable “pop” the letter our a little bit and have back lighting with some LED’s


Great write-up. Always like to hear about the decisions made during the design process.
Do you have a commercial or DIY hot wire cutter?


It came out great.

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where do you get the modeling foam?


Now that is a beautiful job! :grinning:

(Next time you have to paint something like foam, I believe that the cosplayers use something like a coat of white glue on it to seal it before painting. It keeps the foam from soaking up the paint.)


I used a 3D Simo Mini, with a wire cutter attachment to cut the letters out
(It was more because I had one lying about than specifically getting this tool for the project)

It had a temperature control on it, it let me dial down the temperature so as not to melt the foam too much, as its hand held it has great dexterity, but 50mm really was the limit that I could cut with it.

Its also worth noting that sanding the edges of the letters really helps as the wire will catch on any little burs and end up over burning the edges

I think that it is entirely possible to do this with a home made wire cutter, but would recommend having a voltage control to set the temperature.


Love the sign. Thanks for sharing your process as well as the result.

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could you say some more about aligning the front and back - i dont understand…

Also, could you have done a stack say half inch foam layers? Would that have worked?

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Superb write up. Love that you tested multiple methods an took pics along the way. Sign turned out amazing as well.


Wow that was an awesome write up showing your entire thinking and working process. Looks really good.

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Great approach, great write-up, great idea!

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Method used for aligning letters either side of the foam


Really enjoyed your write-up and all the photos. Sign looks amazing!


Amazing job, and I really enjoyed reading about your process!

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Can you illustrate all of the posts here on the forum?


Thank you for that - I get it now, I couldn’t work out in my head how you would make sure they lined up. That is a fiddly process isn’t it.

If the stacking doesn’t work, could you do something without the tray, score the foam front and back?

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Superb work, excellent write up and documentation. Been thinking about a wire foam cutter and you might have convinced me that it is worth making one. Looks nice! Thanks so much.

I find myself looking at signs and wondering how they make them now. In fact, I don’t look at a new sign without thinking, “I wonder if @jbv makes signs like this!”


…or at least mine… :wink:


Your illustrations are exceptionally insightful. Thanks for outlining the whole process! Your time and effort definitely paid off.