Coolant tank advice

[Bigbloke]

Hi

I have a Chen Ho (Bridgeport Clone) vertical mill.

New to me but definitely not new. I am just at the cleaning up and getting it back to some sort of useability.

The coolant tank for this is inside the base of the machine and when I got it, was absolutely packed with swarf held together with what seems to be left over tramp oil degenerated to almost a wax consistency, this may sound nasty, but it don't smell too good either.

Obviously there will be ways of preventing the big stuff from getting in there, but it was so packed with swarf and waxy oil / coolant remainder that I cant even get it all out. I am considering a hot strong detergent mix and a pressure washer to try to break down the grease holding it all together and to blast the swarf free.

So, I guess I have 2 questions here:

1. The only way in I am seeing for cleaning is the 2 small holes in the base, is there a better way to access the tank for cleaning ?

2. To get around having to do this again, has anybody put a remote coolant tank on this kind of setup. I see people talking about external tanks for settlement of particles and ease of changing fluid, this sounds ideal but difficult when the coolant collection point is basically at floor level.

Any suggestions would be appreciated.

Thanks

Paul

[HimyKabibble]

Have you considered using mist coolant, instead of flood? Mist will do all the cooling you need on a BP-sized machine, with virtually no mess.

Regards,
Ray L.

[JHCHOPPERS]

I made a coolant container for my BP Series II Special CNC Knee Mill. Then added a $100.00 Enco Coolant Pump and Tank, this has been working great for me.

Container (before the drain was fabricated and installed)


Drain, Tank and Pump




Coolant Flowing


Hope this gives you some ideas...
Joel

[Bigbloke]

Hi Joel

That looks a good way to go. Pretty watertight and easy to use. It would mean I could seal the base of the machine up and the external coolant tank would be easy to access and clean.

An interesting looking part in the vice.

A couple of questions about the table guard....

1. How is it attached to the table ? I can probably figure something out but you obviously have a method that works already.
   
2. What thickness of clear sheet did you use and what sort was it ?
   
3. Is the base metal or clear sheet ?
   
4. What would you change if you did it again ?

Thanks

Paul

[JHCHOPPERS]

Paul,

I made a rectangle frame out 8020 and attached it to the table by drilling into the casting and tapped it for ¼ 20 bolts. With the frame built and attached, I added the upper supports for the plastic glass to slide into. I used 8020 as it was here in the shop, the plastic glass has varying thickness as it was scrap from an older job too.

The base is made of aluminum sheet, the drain is a PVC shower drain, and the drain hose is for a swimming pool (local hardware store).

I then used 2 stackable plastic storage containers to catch any of the chips that leave the tub before they enter the tank and pump. The one on top has over 4000 holes drilled in it to catch chips, the lower tub has one big hole for the coolant to drain into the tank.

The only thing I might change next time, is to increase the angle of the aluminum sheet pan to help drain the coolant faster when the coolant flow stops.

I have attached a picture of the final part we were cutting that day…





Joel

[HimyKabibble]

I'm curious how you close off the back side of the table, without reducing the Y axis travel. With the Plexi wall there, you'd be unable to move the quill closer than several inches from the back edge of the table, right? But if the wall is moved away from the table, then you limit how far the table can be moved back, before the wall hits the machine base.

I wonder if, instead of a rigid Plexi wall, a rubber "bladder" could be stretched across the back of the table to deal with this. It could then normally be even with the back of the table, allowing full rearward movement, but when the table is moved forward, when it contacted the head it could stretch to move out of the way, still allowing the head to come to the rear edge of the table, or beyond.

How effective is the enclosure? Do you still get coolant/chips splashing on the floor, or is it all well contained?

Regards,
Ray L.

[JHCHOPPERS]

We didn’t loose any Y travel on this machine, but this is not your standard BP, this is a Large Series II CNC Special (4600lbs with 15inches of travel in the Y). However, you can only load parts into the machine that will fit into the tub envelope, longer parts will no longer work. This is fine for us, as we have another machine for that.

I think a rubber bladder might work nice. On our back wall we used 2 pieces of plastic that overlap, then as the knee is moved up or down for a particular job, you can adjust the height of the back wall as needed.

How effective is this? Well its not fully enclosed VMC. So you will get some coolant and chips on the floor when using a Large End Mill. But with smaller tools, its work great and you can adjust the flow of coolant to help minimize the mess.

Better than a mist coolant and all the chips on the floor, everything has a trade off I guess.

[Bigbloke]

Hi Joel

Thanks for the clarification, I have ordered the stuff to make something similar today, 20mm aluminium section and 5mm polycarb. I'll sort out the aluminium base sheet tomorrow.

The stuff should all be here Monday.

I'll post some pics when it's done.

Paul

[Bigbloke]

Just a mock up of the base to make sure the travels and clearances are ok.

I think the rubber bladder idea at the back might be useful to ensure that the table retains full travel without the head crunching into the back of the tank if the table is set high.

Paul

[Bigbloke]

Just an update, finally got my coolant /swarf guard finished a few weeks ago but other things got in the way of using it.

It works pretty well, I had to use a sealant on the joints but now almost nothing comes out apart from the odd chip which gets thrown over the top, unless the drainage blocks in which case it can flood the floor pretty quick.

Anyhow, here are some pics.



And my first parts, before, note the high tech mounting for the coolant nozzle



and after...



Paul

[JHCHOPPERS]

Looks great Paul, it should save you much time on the clean up side of things. Plus, running coolant gets you a better part and longer tool life.

Joel