<p>The good news is that the geometry of pyramids is completely known and you can find numerous calculators online that can calculate the distances and angles in this shape. The bad news is that I have no idea how this would help you build one from plaster bricks.</p>
<p>Since the pyramid on this roof is much wider than tall, you'll end up with very sharp angles where the tiles join. For example, I entered a width of 6 cm and height of 4 cm (including a tip you'll want to cut off) into the <a href="https://www.blocklayer.com/pyramid-calculator" rel="nofollow noreferrer">blocklayer.com pyramid calculator</a> and got:</p>
<blockquote>
<p>If you're cutting ply (or any thick material) for your pyramid, when you cut the triangle segment's hip edges, set your circular saw bevel (tilt) angle to the Triangle Segment Edge Bevel Angle <strong>27.7°</strong> so the edges join neatly.</p>
<p>Set your circular saw bevel angle to <strong>48.8°</strong> when you cut the base of the triangle segments to level the base.</p>
</blockquote>
<p>(The calculator page also provides technical drawings with those angles that may be easier to understand)</p>
<p>I don't think plaster can be cut or ground into a 27° angle without damaging the edge. Specialty crafting plasters tend to be harder and sturdier, though, so you might succeed if you're <em>extremely</em> careful.</p>
<p>To me personally it seems like the easier way would be to cast the entire roof in one piece. You can cut plastic or acrylic sheets into triangle shapes following the directions of a triangle calculator and glue the edges together with a hot glue gun. I would cast a complete pyramid including the tip and cut (or grind) the tip off later.</p>
<p>To reduce the weight of the finished roof, you can make a second, smaller pyramid shape and use that as a negative mold. Fix it to a lid you can put on the big roof mold and press it into the fresh plaster while casting.</p>
<p>But that will only give you smooth surfaces that have to be transformed into a roof texture later.</p>

CC BY-SA 4.0
2024-06-26T05:28:54.667Z
2024-06-26T05:28:54.667Z
Elmy
<p>I am making HO-scale (1/86) buildings for a model train layout.  I primarily use balsa wood and plaster casts from a set of <a href="http://www.linkaonline.co.uk/linka-moulds.html" rel="nofollow noreferrer">Linka molds</a>.</p>
<p>How do I determine the angles and how to bevel the roof pieces?</p>
<p>Buildings with standard gable roofs are fairly easy, but how would I go about planning and measuring for the angles on a roof like the one below, which is shaped like a pyramid?</p>
<p><a href="https://i.sstatic.net/pBljHrLf.jpg" rel="nofollow noreferrer" title="Sepia tinted photo of a house with a gable roof"><img src="https://i.sstatic.net/pBljHrLf.jpg" alt="Sepia tinted photo of a house with a gable roof" title="Sepia tinted photo of a house with a gable roof" /></a></p>

<measurements><model-building>
How to achieve a pyramid-shaped roof on a model built with Linka bricks?
nuggethead
# How to achieve a pyramid-shaped roof on a model built with Linka bricks?

(Asked by: username_0 on 2024-06-24)

I am making HO-scale (1/86) buildings for a model train layout. I primarily use balsa wood and plaster casts from a set of [Linka molds](http://www.linkaonline.co.uk/linka-moulds.html).

How do I determine the angles and how to bevel the roof pieces?

Buildings with standard gable roofs are fairly easy, but how would I go about planning and measuring for the angles on a roof like the one below, which is shaped like a pyramid?

[![Sepia tinted photo of a house with a gable roof](https://i.sstatic.net/pBljHrLf.jpg "Sepia tinted photo of a house with a gable roof")](https://i.sstatic.net/pBljHrLf.jpg "Sepia tinted photo of a house with a gable roof")

**Tags:** measurements, model-building


---

## 1 answers

### Answer by username_1 on 2024-06-26. Score: 1 | Accepted answer

The good news is that the geometry of pyramids is completely known and you can find numerous calculators online that can calculate the distances and angles in this shape. The bad news is that I have no idea how this would help you build one from plaster bricks.

Since the pyramid on this roof is much wider than tall, you'll end up with very sharp angles where the tiles join. For example, I entered a width of 6 cm and height of 4 cm (including a tip you'll want to cut off) into the [blocklayer.com pyramid calculator](https://www.blocklayer.com/pyramid-calculator) and got:

> If you're cutting ply (or any thick material) for your pyramid, when you cut the triangle segment's hip edges, set your circular saw bevel (tilt) angle to the Triangle Segment Edge Bevel Angle **27.7°** so the edges join neatly.
>
> Set your circular saw bevel angle to **48.8°** when you cut the base of the triangle segments to level the base.

(The calculator page also provides technical drawings with those angles that may be easier to understand)

I don't think plaster can be cut or ground into a 27° angle without damaging the edge. Specialty crafting plasters tend to be harder and sturdier, though, so you might succeed if you're *extremely* careful.

To me personally it seems like the easier way would be to cast the entire roof in one piece. You can cut plastic or acrylic sheets into triangle shapes following the directions of a triangle calculator and glue the edges together with a hot glue gun. I would cast a complete pyramid including the tip and cut (or grind) the tip off later.

To reduce the weight of the finished roof, you can make a second, smaller pyramid shape and use that as a negative mold. Fix it to a lid you can put on the big roof mold and press it into the fresh plaster while casting.

But that will only give you smooth surfaces that have to be transformed into a roof texture later.


---

