Great Scott! It's a hoverboard thread...

[RetrogradeOrbit]

This thread will be my ramblings of my first ever attempt at scratch-building a movie prop 1:1...

What is it? The clue is in the title...

Edited to give warning of picture heavy posts! Which I won't be putting in spoiler tags...

 

[RetrogradeOrbit]

Right then, I started with, a 12mm thick sheet of MDF which I cut in half and glued, screwed and clamped together to form a piece 24mm thick.
It was a very hot day so I left it outside to set with a bunch of weight on top to help bind it together.

 

[RetrogradeOrbit]

Here's the first cut made after the glue had dried. As you can see, I've already marked out for the chamfers.
Trouble is it looks too big... Even though the measurements were taken from a vector graphic I found online. Which stated the board is 1 inch thick, 9.5 inches wide and 37 inches end to end with a 25 degree angle for the tail piece.



Hah! Further research indicated the true measurements for the board are 1 inch x 8 inches x 28 inches...
some rapid re-cutting was performed. Luckily I hadn't done any chamfering...

 

[RetrogradeOrbit]

Here it is after the recut, chamfers are marked. Left a 10mm straight edge around all of the sides as it looked about right. Tail end is propped up from underneath at the moment to show the actual finished angle.
Will need to think about how to attach these together as I don't believe just gluing them will give sufficient strength.

 

[RetrogradeOrbit]

After giving the tail joint some thought and discounting the idea of using nails or screws, I was worried about splitting the mdf or not getting it lined up correctly. I decided to go with a tried and trusted solution that is the staple of build it yourself flat pack furniture...
Holes and dowels!
I bought some 6mm dowel for under £1 from B&Q which seemed an apt size as I have 24mm MDF.

I marked 4 holes at roughly equidistant positions on the tail and estimated the angle I needed to drill so that the corresponding holes in the main part of the board would be perpendicular to the board, giving a good fit. Here's what happened...




The dowels were cut and rounded off at one end, after that glue was applied to the holes and dowels, then the dowels were knocked into the holes on the main board.

 

[RetrogradeOrbit]

I applied glue to the edges of the MDF and tapped the tail down along the dowels until the pieces met... I used my workbench to hold the pieces together and in place while the glue set.



Left it all overnight to thoroughly set.

 

[RetrogradeOrbit]

My word, that glue and dowels really did the trick. It's like it is one piece...
Here's a dry fit photo I forgot to put up before.

 

[Brutikus]

OOH a build thread!

Usually only see those on car forums!

Looking good so far RetrogradeOrbit!

 

[RetrogradeOrbit]

^^^
Why, thank you sir...

I can't take the credit for making this thread, it was young Miss Comic Chick who suggested it.

 

[RetrogradeOrbit]

I did say it looks solid... and by golly it is solid. It really feels like it is one piece. I am impressed with myself!



Shoved some pva into the small joint gap and left that to dry.

 

[RetrogradeOrbit]

Time to cut the excess off of those dowels then...

 

[RetrogradeOrbit]

Fill, sand, repeat... Good grief I hate this part. But I also know the more time and effort spent at this point, the better the paint job is, so...

 

[RetrogradeOrbit]

Took a break from sanding and filling to test fit draft printouts of the decals. I can't credit the author as I found them through hours and hours of DuckDuckGo searches...

 

[RetrogradeOrbit]

Time to get a coat of primer on the darned thing. I used a light grey primer first which did not seem to cover well. So, no picture!
Bought some dark red primer which went on much better. Here's after the first coat...


Some more coats ensued...


Then the obligatory filling and sanding...

 

[RetrogradeOrbit]

Sorry if some of the photos look to be at an odd angle, TinyPic seems to randomly add a rotation at times...

 

[RetrogradeOrbit]

Second coat of primer, still wet, hence the shine!

 

[RetrogradeOrbit]

Nothing much to report, very lightly rubbed down the primer to give a flat, smooth finish and then whacked it with a coat of satin neon pink


Here's after the first coat.


A very light rub down and then a second coat...


It's not perfect, I can see some small imperfections/scratches here and there, but I'll never get the damned thing done if I try to get rid of every single blemish...
Annnnnnnd I now have a neon pink workbench, guess I will have to hand in my "macho man card".

 

[RetrogradeOrbit]

Sized the image files that I have for the decals to my board and then transferred them into foxit pdf reader which allowed me to print them off "posterised".
From that I cut, lined them up and stuck them (temporarily) together on the back side with masking tape and then used Helix Clearseal book cover film to protect and enhance the look of the printouts... Here's how it ended up.



Here's a photo of the cover film. Well, you might want to buy some one at some point...

 

[RetrogradeOrbit]

I took the vector graphic image of the board layout, which although I now know it to be the wrong size. I can still use it to estimate the size of the doodads on the underside, as long as I perform the appropriate and correct scaling. So I split what I needed into several sections and figured out what I needed.

Kinda like this...



I went off to cut a piece of 6mm MDF at a diameter of 165mm and sand it smooth. Well, as smooth as I can...

 

[RetrogradeOrbit]

Tried to make a jiggy thing to cut a perfect circle in one go. It failed dismally...


So, I cut it out manually with my trusty jigsaw. Imagine my surprise when I found it was a bit too big! My scaling brain is obviously a bit off...
Amended cutting followed.

That seemed better when I threw it onto the board... By the way, here's what the board looks like with the decals laid upon it.
The pink is a bit bright I think, but as it is supposed to be a little girls plaything, I am going with it.


In case you are wondering, I am intending to drill out where the black circle is, probably go about 1/2 way through. You never know, I might add a handle one day...

 

[RetrogradeOrbit]

Having resized the thinner, larger disc. From that I estimated what the thicker chamfered disk should be like.
This was cut out and I used my trusty block plane to chamfer all around the circle to get the angle I needed. This was a real pain by the way!
They were stuck together with good old pva adhesive.
That stuff is great for MDF...


Have been scratching and wracking my little brain to figure out what to make the clamps (is that the right word?) out of as they do need to step over and around the disks.
In the end I went with 3 or 4mm EVA foam. Here they after a quick bit of cutting out.


My thought was that I could use my heat gun to soften the eva foam and get it to go around those pesky disks.

 

[RetrogradeOrbit]

Some test fitting followed and lo, it was acceptable...

 

[RetrogradeOrbit]

Think I should give you all a rest for a while. As too much of a good thing is not necessarily a good thing and too much of my crap, is well, too much crap...

 

[RetrogradeOrbit]

My plan was to fit all of the parts together and make silicon moulds, from which I could then make polyurethane casts


Not an exciting photograph, but it does show the silicone mould encased in plaster of paris.


Just have to until the next day so that I can wiggle it about and get it to release from the worktop surface. Bit worried how that is going to go. I really should have used a piece of scrap MDF to do this with so I could easily turn it over when it is all dried out. But I didn't...

 

[RetrogradeOrbit]

So, I waited until the next morning and managed to force it off the worktop surface... I did damage a part of the assembly itself. But as that is not actually going to be needed, not a biggie. Although I would have prefered it not get damaged.


Just have to get the darned thing out of the silicone.
Carefully...