Thread: BM30A mill

Originally Posted by Ueee

I know you are at least 2 hours behind us, but really?

Which job is yours BT, the guy on the left or on the right??

Easy Ewan,
Bob's the one on the right with the whip. I figured that on account of the standard of Bobs work and how he has cracked the whip and got me going with a better standard of work

Thanks Bob
I'm dreading that part of it.

Originally Posted by rodm

I am reasonably settled on the BM30 now and just waiting for next pay packet to top the play money up to get one.

I think they would be fairly decent mills... I have a X6323A turret mill, it is just a generic turret type that every woman and her dog makes over in Taiwan and China...

Does not have precision spindle bearings just plain SKF ones, but it is a really good machine for a lot of the things I do...

I think you will be very happy with that mill...

I ended up getting a right angle head for mine, it opens up a lot of machining options and is surprisingly rigid to the point I would nearly call it an essential attachment..

Thanks RC
It is good to know this type of mill doesn't get the negative feedback like their smaller cousins.
A right angle head sounds interesting. Was looking at a slotting attachment but the right angle head sounds more useful than the slotter. I'll look into it.

right angle head in action on my mill

[ame=http://www.youtube.com/watch?v=03JngD9C9q8]Bridgeport style right angle head - YouTube[/ame]

That is impressive and so is your work.
Did you cast the square?

I bought a BM20A from H&F some years ago. It is made in Taiwan. I don't know how relevant it is but this has been my experience.

Build quality was very underwhelming. The base contained much swarf and casting sand. There was much more casting sand still adhering to the inside of the body - this in what is the coolant reservior. Where they had rried to drill a hole to attach the coolant pump, the casting had chilled and was too hard to drill - so they just left the pump hanging on the bolt sitting loose in the partially drilled hole. The locating / drive pin in the R8 spindle was broken off. The spindle bearings needed adjustment. The fitting of the one shot lube system was appalling. The oil is delivered by aluminium tubes. At the delivery end, most of these had just been poked loosely into a hole in the casting. When you activated the pump, the oil pressure just pushed the pipes out of the holes and oil went everywhere except where it was supposed to. Also. some of the oil passages in the castings were blocked with crap. I had to remove the table to correct these problems.

However, after fixing all those problems it has turned out to be a good machine. I can't detect any misalignment or inaccuracy, and it has run perfectly for many years.

Regarding the 1 or 3 phase issue; it may be that the extra speeds on the 3 phase model result from a 2 speed motor. It may further be that if you can run this motor from single phase via an inverter, you won't get the 2 speed function. Others with more knowledge may comment on this.

Mine was single phase but I fitted a 3 phase motor and 240V to 3 phase inverter because previously, every time I switched it on all the lights dimmed for a few seconds. This becomes worrying when doing jobs that require frequent stops and starts. No probs now with the "ramp up" function of the inverter. Also the variable speed is great.

Good luck
Graham

Originally Posted by GDD

Mine was single phase but I fitted a 3 phase motor and 240V to 3 phase inverter because previously, every time I switched it on all the lights dimmed for a few seconds. This becomes worrying when doing jobs that require frequent stops and starts. No probs now with the "ramp up" function of the inverter. Also the variable speed is great.

Graham

Hi Graham,
Thanks for that. Did the VFD work with the X axis drive motor or did you have to trick that to work?

Originally Posted by rodm

Did you cast the square?

No got it in from the US... I actually got a couple and finish scraped one at the scraping class.

clickable image

Originally Posted by .RC.

right angle head in action on my mill

Bridgeport style right angle head - YouTube

Of course if you had a horizontal mill, you wouldn't need to use such a flimsy, lightweight attachment and then you could take a decent cut....

PDW (back from a week+ on the family property where net access doesn't happen)

Originally Posted by rodm

Hi Graham,
Thanks for that. Did the VFD work with the X axis drive motor or did you have to trick that to work?

The new VFD and 3 phase motor are independent of the original electrical system. The X axis power feed and the coolant pump still run on 240 volt as original.

Graham

Thanks Graham,
Could be a problem then if I buy the 3 phase mill.

Hi Rod,
All the powerfeeds of the type fitted to the BM30A I have seen are either 240V or 110V single phase. If you bought a 3 phase mill you'd want to check that the transformer in the control box had a 240V primary tap(which you would want anyway to be able to run the controls off 240V).

The coolant pump will be an issue. Though you could ask them to supply with a 240V pump but I think they would start talking about warranty.

Stuart

Thanks Stuart,
Looks like it is the safe path for me and get the single phase version. I will miss out on the higher speeds but not a big issue for my intended use.