Hey mate, you can buy the parts and build your own, please, look at these options: https://arxiv.org/ftp/arxiv/papers/1311/1311.4829.pdf , https://iopscience.iop.org/article/10.1088/2515-7639/ab6a72/pdf , however, for a more "sophisticated" assembly, it´s nice to consider a heater with vacuum. Best! Alisson