Buying advice sought re Milling Machines: e.g. Proxxon: FF230 vs. BFW40/E vs. MF70

I have. It works.

If expect to be chewing away metal at a rate of knots then you will be disappointed. My jobs on steel have been mainly making pretty small fixings for the (similarly diminutive) Cowells lathe or making fine adjusting cuts to refine the fit of work done on bigger machines. Size-wise they vary but they are all small - think around 1/2 inch or less on each side.

I've mainly used the Proxxon cutters and they got the job done on steel with an excellent surface finish but more experienced contributors here have said that these cutters have a geometry better suited to non ferrous. More recently have bought an Arc Euro stub sized cutter which ought to be better suited to steel. I have only used this on brass so far so I can't report back on its performance on steel.

My most recent job was drilling a couple of 1/8 inch holes through some 5/8 aluminium. I'd had previous experience of the nasty noise that 3mm or 1/8 drills make when used at 5000 RPM in the MF70. I had thought that the noise was coming from the (usually pretty thin) workpiece but even with a 5/8 block I got the same awful screech. I switched to a stub length drill (maybe 2.8mm) for the first few mm of the hole and this ran tolerably quietly. I then went back to the 1/8 (standard length) drill and made sure that I stuffed it into the pre drilled hole as quickly as possible. Once it was a few mm deep the screeching didn't happen. My theory then is that the screeching happens because of resonance in the drill itself and my experience is that any standard length drill much over 2.5mm will protest in this way when used at 5000 RPM.

As ever show and tell. These rocker arms were milled from 6mm square silver steel with a Proxxon 3mm end mill. The 2mm keyseats in a medium carbon steel crankshaft (ST50 maybe similar to EN8) and a silver steel camshaft were cut with a Proxxon 2mm end mill.

Nice work Roger.

FWIW I've also cut a 1mm screwdriver slot in a broken high tensile bolt using the MF70. TBH I wasnt expecting this to succeed but I really needed to get the broken part out. Anyway... it worked and I got the bolt out.

Crumbs - that's rather amazing. Out of interest, what milling bit(s) did you use for all that?

Also, beyond setting the Proxxon to minimal speed (5000RPM) what special techniques did you use?
(I am assuming that you did mill rather than abrade/grind the silver steel, yes?)

Did you need to push the workpiece at the milling bit very fast, so as to get to slow the thing down enough for create a half-sensible cutting speed?

Did you need to use oil to cool & lubricate (if so what oil did you use?)

Did it squeal like a Banshee or did you find any clever ways to stop it doing so?

Please forgive the dumb questions as I am new to milling...!

J


PS In the absence of anything else that is small and light in weight but of build better quality I am on the very verge of buying a Proxxon MF70. When funds permit I plan to also buy something more 'grown-up', probably a Sherline 5400 metric at some point.

Just to reiterate... the nasty squealing that I mentioned was from drilling, not milling. I'd estimate that any drill over about 2.5mm is likely to do this. Milling wont be silent though... few machining operations are.

I was using the Proxxon cutters, the 2mm cutter for the keyways was probably run at around 10 000 rpm with the feed as fast as I could turn the handle. The 3mm cutter for the rocker arms was probably run at around 8 000rpm with a slightly more gentle feed. No lubricant was used.

I have a FF230. Same story; space restrictions. In my case I was also buying in a hurry. In hindsight I'd have held out for a jig borer, Aceira, ff500, Cowells or whatever. It works, some of the bits are reasonably high quality. The motor needs to run at higher speeds, round column is bad design (it's not that bad, but it's still bad; dovetails are better), and if the table were ever so slightly bigger it would be very helpful. Also the ability to mill at an angle .... it kind of forces you to mill at angles. Tramming is difficult and the dogs don't hold it well; I've had endmills catch on work and had the head twist over on the angle axis. It's just a friction screw thingee. Lame.

You can totally drill 6mm and mill whatever without it making too much noise on soft steel "hogging" at a half mm at a time. Basically it's better than nothing. I don't do a huge amount of milling and I'm pretty sure it's better than milling on a lathe, so it's OK for now. Not ideal though.

I wouldn't be without my Proxxon BF40/E. Versatile, accurate, and I do just about all my sheet metal work and fine milling with it. It drills 6mm holes in MS without a grunt, squeek or noticeably slowing down. I recommended one to a friend and he said that he blesses me every time he has to drill small holes quickly and accurately.

Although I have an FB2 for the heavy stuff, most of this has been made with it...

[img]https://i.imgur.com/ZYsMEo3.jpg[/img]

> I wouldn't be without my Proxxon BF40/E

I take it you mean the Proxxon BFW40/E... which sounds brilliant. I am regretting buying my MF70.

The thing that put me off most was about the BFW40/E is the round column. I am surprised to hear that you find it to be accurate, but it certainly seems amazingly versatile and what a joy to have the option of a quill as well as the ability to change the angle of the mill itself, rather than mess around changing the angle of the work piece.

I might try and get one second hand.

e.g. I found one on eBay called "Proxxon bfw 36" but I can't find any specs.
Either way, do you know what the "/e" stands for ?

J

I don’t know about the prices … but please do be aware of this statement :

The BFW 40/E is shown here as a tool combination with the mill/drill unit BFB 2000 and compound table KT 150. Neither tool is included.

MichaelG.

.

Ref. **LINK**

https://www.proxxon.com/en/micromot/20165.php?search

In the fresh light of morning, I have found prices: **LINK**

https://www.germantools.co.uk/product-category/proxxon-precision-engineering/proxxon-precision-engineering-proxxon-mill-drill-system/

MichaelG.

.

Edit: __ and I’ve found details of that motor unit:

http://www.proxxon-tools.com.au/downloads/manuals/20165%20BFW_40_E.pdf

… which looks pretty tidy

Edited By Michael Gilligan on 23/09/2021 08:44:18

Thanks Michael

I have blown a chunk of money on a Proxxon MF70 (one of my worst decisions) and so can't afford a new BFW 40/E, but am considering getting something second hand on eBay or similar.

Do you have any thoughts about how it compares with this "Proxxon BFW 36" ?**LINK**

And it is this BFW 36 that I can't find a manual for.
I am also wondering what the "/e" stands for.

The BFW36 is on for £458.00, but given how old and beaten-up it is I can't imagine he'll get anything close to that. I am considering making a (very) cheeky offer for it.

J

I would presume that /E denotes electronic speed control, and likewise I would presume that 36 is an ancestor of 40 … but I could be completely wrong.

Not really familiar with the  Proxxon range

MichaelG.

Edited By Michael Gilligan on 23/09/2021 10:08:22

> I would presume that /E denotes electronic speed control, and likewise I would presume
> that 36 is an ancestor of 40 … but I could be completely wrong.

Yes, I have just had confirmation from Proxxon that this is all correct.

OK I have created a separate thread to see if I can draw in anyone who has experience of the BFW 36/E.

www.model-engineer.co.uk/forums/postings.asp?th=174870

J

John - Your experience has inspired me to look again at buying a BFW 40/E (or possibly its predecessor BFW 36/E)... however I just realised that you were talking about "DRILLING 6mm holes in MS without a grunt". But I am planning to used it more for MILLING than drilling.

Realistically what is it like at milling mild steel?

J

John - What is so bad about your MF-70?

Dave

1. I need to work in mild steel quite a lot. The MF70 CAN mill the stuff but but it's very slow.
e.g. I just needed to mill a 90° edge of 1mm thick MS into becoming a 45 degree chamfer.  It could do it just but it took about 4 or 5 passes, and if you try to mill deeper it gets slower and slower.

Ultimately the MF70 spins too fast and generates too little torque to make it much good for milling MS. It's motor is rather under-powered at 100watts.

2. You can't change the angle of the device on the MF70, so you have to rotate the part being machined. And this can be tricky. Whereas on the BFW-40/E (and also I think BFW-36/E[?]) you can change the angle of the device.

3. I haven't yet measured the 'runout' but the MF70 is painfully noisy. I don't really know why... but I suspect that there is quite a lot of runout / wobble in the spindle.

4. The build quality of certain aspects is appalling. For example of the 4 screws to hold the milling table in place one of them was so badly manufactured that it was physically impossible to fully screw it in. The other 3 screws were fine. In the end I had to find an old bolt and cut it down to size. For a brand new machine to arrive with such a low build quality is APPALLING.

Passing Comment
Ever since I have known Proxxon it's the same overall feeling. Their kit is definitely quite expensive but nonetheless one minute their kit is a dream, you are glad you bought it and it really makes you smile... but in the next minute you are cussing and swearing that they didn't make the damned thing properly!

If there was a brand that was just like Proxxon, and maybe even a bit more expensive and but at least properly made, I for one would be all over it. Tragically they don't seem to have any such competitor.

J

Edited By John Smith 47 on 24/09/2021 15:16:42

Just to put the record straight and to attempt to level the Proxxon a phobia let me speak up for Proxxon kit. In my opinion it is ludicrously expensive, usually under powered but reasonably well made. I have quite a bit of Proxxon kit and taken within the bounds that it is intended for, it performs extremely well. Taken outside it’s comfort zone into areas where it was never intended to go, it will not perform well. The main Proxxon kit I own that may be of interest to this forum and the OP in particular is the 250E lathe, and the BFW40e milling system. Used within the capacity of the lathe, I have not yet found a task that cannot be done. It would not suit many people. You won’t be making 100 thou cuts. You have to learn to work within its limitations. In a commercial environment it couldn’t cut it, as it would be too slow. Brass and aluminium is a breeze. Mild steel at least EN1 or 3 is also simple but a little slower. I have cut stainless steel and cast iron castings without issue, albeit in small model sized pieces. Much the same can be said of the mill system. I have only used the mill on metal. It’s first ever use was on a block of steel that I squared up and machined to size to replace my compound on the lathe and bring the tool post to size, as I don’t always use the compound, and can benefit from the increased rigidity. It coped perfectly well with this. Yesterday I machined some extra T-nuts from mild steel bar, again without problem. Come to think of it, I also drilled the 5mm holes in them using the drill function. I have many times on other occasions drilled 6mm holes in steel without issue.

The Superpower of this Proxxon kit is that when I’ve finished, I can, even at my age, pick it up and store it on my table saw. When I want to use my table saw I have to move it again. I would dearly like a Myford or a SC4 but I just have not the the space to commit to something that I cannot move. But the real point is that this small kit is very capable of machining metal albeit slowly. The flavour of the argument on this thread seems a bit like the owners of fast expensive exotic or luxury cars rubbishing the guy in the small family compact. They will both take you where you need to go, albeit at a slower pace. This is my first post. Please be gentle with me!