Well - define 'Heavy Duty'! There are a number of machines on the market which promise a lot but in reality aren't really 'heavy duty' as we used to know. We've been inside them to inspect and although some claim to have a 'metal chassis' (what else would it be?) the working parts aren't especially beefy - and that's where the strain is when you're sewing heavier projects.
Most heavy projects don't require any special stitches - forward, reverse and maybe a zig-zag - ideally these are activated by solid cams & levers not a computerised switch unit. This configuration means that the needle post is less likely to deviate (i.e the machine is determining the stitch quality, not the fabric).
Sounds like I might need an industrial or expensive machine? No - unless you're pumping out lots of heavy items or using exceptionally heavy fabrics or leather etc - then a dedicated industrial might be best. However a sturdy semi-industrial domestic might be quite sufficient. The good news is that many older domestic machines were built that were simple, strong and easy to operate. We refurbish and service lots of these. They may have a few surface scratches but we buy the best possible. Price wise even a prime example will come in cheaper than a new 'pretender'! We guarantee them too!
Call Tim to discuss your requirements & find out what our current stock is.