Description
The MD001-CNC machine is not just a CNC converted manual mill... I have removed all the negatives you would normally get when converting a manual milling machine with a bolt on kit. The final result is a CNC machine that has all the features of any other dedicated vertical CNC machine but at a substantially reduced price.
The problem
Producing a high quality CNC mill with a large work envelope and having all the features of a much higher class CNC mill while still keeping the price at an affordable level. There is a large gap in available equipement. There are hobby(ish) CNC mills that are under the $10K price range but are limited by features and accessories that reflect the price. Such as stepper motors, low quality ball screws, small work envelope and poor quality spindle and bearings. On the other end of the spectrum there are higher quality VMC's with all the features that you would expect to make the machine perform at its best. However, the price for mills like this can easiily exceed $25K.
There are of course machines available at both ends of the spectrum. Some even start off with an attractive price but quickly grow beyond your budget after only adding minimal accessories and shipping costs.
My Approach
High accuracy can be achieved with a design based on an existing foundation. I have rediesgined the castings to accomodate linear guide bearings. The design also includes a wealth of other features not typically available on lower end hobby style stepper machines...
The features I am incorperating into the design are...
- Custom Castings
- Linear Guide Bearings
- Ground ball screws
- Industrial CNC Controller
- One-shot oiler
- Z-Axis Counter weight
- Full size enclosed cabinet
- Industrial grade servo motors
- Custom dual speed head with cartridge spindle
The prototype is just about completed. The only remaining tasks are to install some way covers to protect the bearings and balls screws as well as mount the coolant nozzle. The video on my Youtube channel shows some of the initial axis movements and spindle movement.
Summary and further work
The overall project is slightly more expensive then a hobby grade stepper CNC mill but when all the features are compared, the cost is easily worth the extra expense. When coupled with my 300mm CNC rotary table, the combination will dramatically improve my machining capability. Building this machine has been quite an experience and will help immensely when further improoving the design to reduce costs and improve efficiency.
Project Updates 29-Dec-2022
I had originally built this CNC machine based on a redesign of the IH Clone RF45 machine I use to sell. I had the factory make some custom castings for it to allow the addition of the linear bearings on each axis. After all that I have learned from this project, I would not make another like this. As much as I like this one, I have found that there are too many things I would change to make it worth trying to re-use the basic RF45 design. I think the features I did change for this version definitely helped but I wouldn't use this platform for a production model. RF45's are not too bad for bolt-on CNC conversions and as hobby mills etc but the next generation will have all the changes I want but contained within a new platform. I would also like to make the platform locally as I have found that dealing with imported equipment like this can have a lot of problems. Sometimes the extra cost of buying/building something domestically can far outweigh the apparent cost savings of buying something imported.
