Model Boat Mayhem

Technical, Techniques, Hints, and Tips => Modelling tools => Topic started by: DJW on June 08, 2022, 12:44:44 pm

Title: DIY Foam Cutter
Post by: DJW on June 08, 2022, 12:44:44 pm

I needed a foam cutter, so looked at the Proxxon one, and while it's nice, it's not cheap...  So looked at YouTube and there are a lot of DIY builds, and so this is my version.

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114820_resized-Custom.jpg)

Seems you have to put a low DC voltage and current through a length of Nichrome wire, which then gets hot and cuts the foam cleanly.

Very few parts.  I had a general purpose 12v PSU already:

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114833_resized-Custom.jpg)

I used a 5-35V 5A DC PWM motor controller from Amazon, about £3.00, it incorporates an on/off switch and allows temperature to be controlled:


(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114827_resized-Custom.jpg)

Frame is cut from spare 15mm ply, I used spare 20AWG wire to hook it all up, and 0.7mm Nichrome wire which cost £7.49 from Amazon for 5m...

Negative is connected to the lower end of the Nichrome, I used a pair of nuts to clamp the Nichrome:

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114856_resized-Custom.jpg)

Positive is routed to the top 7mm mild steel bar (ex component of a filing cabinet):

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114907_resized-Custom.jpg)

A spring is used to keep tension as the Nichrome can expand / contract as its heated, and I recessed / epoxied a flat washer on the work surface to prevent the hot wire burning the base.

First task, cutting out a couple of shapes that will be used in place of real LiPos during the build process.

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_114921_resized-Custom.jpg)


(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_115439_resized-Custom-1.jpg)

And the 'Lipos' in place ready to mark the cutouts in the frames and generally help with internal layout.  I don't want to buy the real Lipos yet as they're almost £100 each for 8,000mAh 6S Graphenes, and the build will probably take a couple of years...

(https://modelboatmayhemimages.co.uk/images/2022/06/08/20220608_115551_resized-Custom.jpg)

I intend to cut foam to give my new Aquarama build plenty of sound suppression and the extra buoyancy is always useful.

Cost of new parts around £10.00...  The wife will be pleased..! (Well, until I buy the real Lipos..!)  :-))

Best regards to all.
David.

Title: Re: DIY Foam Cutter
Post by: Capt Podge on June 08, 2022, 03:16:55 pm

That's another good idea you've had there David and I guess the money saved by making it yourself will be put to good use. (for other boat related stuff that is)  ;)


Ray.

Title: Re: DIY Foam Cutter
Post by: Tug Fanatic on June 09, 2022, 06:17:32 am

I use the wire from an electric heater element but I understand that the top string from an electric guitar works well and is cheap.

Title: Re: DIY Foam Cutter
Post by: Martin (Admin) on June 09, 2022, 10:01:26 am

 
Nice build David.   :-))

Title: Re: DIY Foam Cutter
Post by: Circlip on June 09, 2022, 11:42:26 am

Have been using 0.5mm dia piano wire for years.


 Regards  Ian.