What is "The Lehr" and how is it changing our glass studio?

Maximizing Efficiency: The Journey of the Conveyor Kiln at Bicycle Glass

In 2016, Bicycle Glass Co. emerged as a result of David Royce and Michael Boyd's shared passion for glass art. Both artists were leading independent careers, often on the road for over 20 weeks a year at art shows. Seeking a more balanced lifestyle, they envisioned a company where glass artists could thrive while minimizing their environmental impact.

This vision propelled us to explore innovative ways to boost efficiency without compromising the dedication to quality craftsmanship and sustainable practices.

Annealing is a crucial process in glassmaking. At Bicycle Glass, we have utilized standard art glass annealers to manage this step. These annealers run extended cycles, lowering the temperature of the glass at a controlled rate. This gradual cooling is vital to prevent internal stresses that can cause the glass to shatter. Unfortunately, due to the length of these cycles, the process requires a significant amount of energy. Enter, “The Lehr”.

The Lehr shortly after purchase in 2020
The Lehr shortly after purchase, 2020

The Origin of “The Lehr”

We acquired the lehr from a company going out of business in late 2019; it was originally used as a decorator kiln for applying enamel and decals onto glass tumblers. Some of us like to think of it as a giant bagel toaster: put your bagel in the front end and it slowly moves through on a belt until it comes out perfectly toasted on the other side. To translate that to glass, our pieces go in the front end straight from the hotshop floor and come out the other end perfectly annealed. The kiln presented a unique opportunity for us to increase our production capacity.

We knew it would be a game-changer for our studio. However, the kiln was in rough shape and required significant renovation before it could be fully operational. It sat idle for two years until we had the time and resources to devote to its restoration.


Looking inside the Lehr from the off-loading end, 2024
Looking inside the Lehr from the off-loading end, 2024

Rebuilding the Kiln

The process of rebuilding the kiln was a labor of love. It had to be tailored to our specifications, ensuring each section was properly set up to anneal recycled glass. Challenges arose, but with determination and perseverance, we successfully transformed the kiln into a vital component of our studio.

The large machine, measuring just under 60 feet long, 8 feet wide, and 8 feet tall, couldn't fit in our previous Bicycle Glass Studio. This was a driving factor in our decision to relocate to our current studio right outside of Minneapolis, Minnesota.

The Lehr after significant repairs in 2024
The Lehr after significant repairs, 2024

Impact on Operations

The Lehr operates on a conveyor system, with glass pieces loaded at one end and unloaded at the other. The continuous motion of the belt means all our glass pieces fit within a single kiln. Additionally, the cycle runs much faster than in a typical annealer. This efficiency has reduced stress on the glass pieces and significantly improved our overall throughput.

Since integrating the lehr into our studio, we've experienced an increase in efficiency. We can now handle larger batches with reduced cycle times, ultimately maximizing our potential output. The lehr may have an industrial look, but it lets us keep our focus on crafting unique, handmade pieces. Our commitment to bringing new ideas and products to the market remains unwavering, and the lehr has only enhanced our ability to do so.


Loading a 767 piece in to the Lehr in 2024

Loading a 767 piece into the Lehr, 2024

The journey of the conveyor kiln at Bicycle Glass Studio represents a significant milestone in our pursuit of efficiency and sustainability. It's been increasingly tough to produce handmade items, but efficiencies like the lehr allow us to continue without cutting corners in other areas. We're so glad you've been part of our journey. Please keep supporting handmade, artist-made, and American-made businesses. We couldn't do it without your support!

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