6x4 bandsaw hydraulic down feed system

[thehomeengineer]

Hi All

I have finally replaced the spring feed tensioner with a hydraulic system on my 6x4 bandsaw.

it took a while to purchase all the bits as I didn’t want to spend to much on the project and wasn’t in a rush to finish it. The overall cost was £65 for all the bits. The only fitting I made was a thread nipple to ensure I could keep all the fittings between the inlet and outlet ports on the cylinder.

The ram is a pneumatic cylinder as hydraulic rams are really expensive in the UK. The working pressure of this system is well within the working rated pressure of the pneumatic cylinder.

I didn’t intend on fitting a pressure gauge. But after thinking about it, I thought it would be good opportunity to see what pressure is on the blade and find out what pressure works best on different materials. Once happy with cut, a cutting pressure table can made for feed pressure for different materials. This should also indicated when the blade need’s replacing due to an increase in pressure when the blade is worn. (not sure if this will be the case but will be interested to see).

The needle valve is fitted with a check valve, so the saw frame can be lifted with the needle remaining set at the required pressure feed rate. The 1/4 turn ball valve can then be used to close the oil flow. This allows the frame to be lifted and not travel down at the set needle valve rate. This is important for setting the stock material in the correct position in the vice for cutting.

The cylinder is set so the main body of the ram/ cylinder is below the stock material to try and prevent swarf landing on the ram and damaging the seals.

The idea of this project is to maintain a constant feed rate and not allow gravity to take over and put more pressure on the blade. This system also allows the frame to be held without dropping while setting up the stock to be cut.

The blue handle is the 1/4 turn ball valve next there is a needle valve/check valve and then the pressure gauge.







photo shows the complete assembly which I tried to keep as compact as possible.
The photos below show the assembly fitted to the saw.


I am currently working on several other improvements to the saw and will post on HMT once completed and will make a YouTube video of all the changes made to the saw.
Hope this of interest
The Home Engineer

[DIYer]

Thanks thehomeengineer! We've added your Bandsaw Feed System to our Bandsaws category,
as well as to your builder page: thehomeengineer's Homemade Tools. Your receipt:

Bandsaw Feed System by thehomeengineer

tags: bandsaw

[auswelder]

Looks like a neat setup, do you have more details on the needle valve that you used?

Thanks

[thehomeengineer]

Hi auswelder
Thank you for your interest.

The valve is a combined needle valve with an internal check valve. The needle valve controls the flow of oil when the saw descends, and in this direction the check valve is seated and closed. To lift the saw the oil lifts the check valve off its seat which allows the oil to return rather than against the needle ( so can be lifted easily but maintain the needle setting) The blue handled 1/4 turn valve also has to be open to allow the saw to be lifted or to descend. With this valve shut the cylinder is locked as oil cannot travel through the system. Hence once shut in the lifted position the saw cannot descend until the valve is open. This also allows the needle valve to maintain its control feed position so making multiple cuts has the same feed rate each time once the 1/4 turn valve is opened. This is why I also think it might be possible to use the pressure gauge not only as a tool to see what pressure is on the blade to give an indication of what a good pressure to feed rate ratio, but any increase in pressure could indicate the blade is becoming blunt. Still not sure about this as I have not had a chance to set it up to see.
Thank you Again
The Home Engineer

[auswelder]

Thanks for the clear explanation on how it all works.

I really like the idea of the gauge, being able to set the correct feed rate for different materials will be a game changer. Hopefully it will work out.

Do you have the part number for the needle valve that you used?

Thanks

[thehomeengineer]

Sorry no part number. I bought a load as the price was cheap, got 10 for the price I would have paid for one, so thought get them and worry about what project I will use them on later. At the time I knew that I needed one for this feed unit and these valves started the ball rolling to get all the other items to complete the hydraulic feed. I also have other projects in my head I know I can use them on (like you do lol.) What I can tell you they are: KLM 1/4 Hydraulic Fluid Control Valve. 1/4 is the thread size BSP. That is all I know. Not even sure if the company are still around and manufacture them. https://www.phoenixhydraulics.co.uk/...eck-valve.html this is the closest I can find.
I have lots of idea’s in my head but not the wallet to support them, so I tend to buy bits and pieces for future projects at prices I can afford when I see them, then store until I have got or made all the bits. Can be frustrating as it can take months or even years to have a project ready to complete. I have several boxes on a shelf for each project and just keep adding to them as and when I find, buy, recycle or sometimes even given materials.
I am also a very experienced skip diver
I will post a video soon on all the bits I have changed on the saw to date
thank you again
The Home Engineer.