(old) Proxxon BFW 36/E vs. (new) Proxxon BFW 40/E

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… or at least a hundred bags of Compost [or whatever took your fancy]

But surely you wouldn’t

MichaelG.

Moderators there is no solution to this issue and respectfully suggest the topic thread is closed

Robert Butler

Correct. But if poo is your thing, you could also I get x9.5 crappy Aldi/Ferrex Belt & Disk Sanders!

Up to you. Does the existence of this thread cause inconvenience?

I have learned a lot, but if so I'm happy shut up.

Edited By John Smith 47 on 30/09/2021 17:13:26

One more thing...

>>>
Posted by John Smith 47 on 29/09/2021 22:23:26

1. Z-direction repeatability

Because the pillar is circular without a key slot of any sort, every time you loosen off the clamping screws in order to move the mill in the Z-axis (vertical), the whole thing can rotate around the pillar!
[Can one buy better pillars that DO have key-slots?]

>>>

For anyone interested in using EMCO Unimats for any serious milling, I thought this was interesting.

This guy obviously has the exact same concerns that I had, about the difficulty of re-centering after you change the vertical height if you run out of quill travel, due to the lack of any form of key in the round column, so he set about cutting a slot himself and added a dog point set screw.

https://www.youtube.com/watch?v=SwI3a3sEIWA
https://www.youtube.com/watch?v=SwI3a3sEIWA

** Part 2 **
https://www.youtube.com/watch?v=DQY2z33qxRg

** Part 3 **
https://www.youtube.com/watch?v=B-KuOYzbfxs

Nice work. 

J

Edited By John Smith 47 on 01/10/2021 00:08:40

I'd be surprised if that arrangement gave 0.5mm repeatability, you've got slop between the dog point and keyway, slop in the thread of the screw, depends what you think is acceptable for your purposes.

I think if the column had been scored lightly with a pointed milling cutter of some description, or in a shaper, then a mark on the clamp for alignment, you could repeat the position by eye as well, if not better.

I'd have thought it less likely that one would run out of Z travel when milling.

Drilling with progressively increasing diameters (and therefore drill lengths) on the other hand are very likely to require the head to be moved further up the column. I've found that the resulting loss of position is a pain. Likewise, drilling and then using a centre to keep a tap perpendicular will have the same issue.

Pete, Agreed. Although I think that rather than let the keyway rattle one could gently rotating the milling head each to to aligning with one of the edges of the slop. Maybe that would help.

But was he right to use dog point? Wouldn't V at the bottom of the slot (plus a V point on the screw) help centre it?

Andy, agreed. e.g. If one does the usual thing of starting with a (short stubby) centre drill before then using a larger drill the problem appears immediately. And of course if one doesn't have a separate machine for drilling then one is likely to be doing a lot of drilling on this mill!

With a drill chuck capacity of 8mmmax and the use of stub drills you can easily spot drill and drill upto 8mm and still get a hole the full 25mm depth of the quill travel without having to move the head. Any drilling above that diameter can be done using the lathe 3-jaw in place of the drill chuck and either stub drills with shortened shanks or plunge cutting with milling cutters upto when you start to stall the machine.

Please can people stop mudslinging?

The OP is happy to continue, but I suggest that just those making positive comments continue to participate.

As for repeatability when moving the head, a popular solution for round-column mills is a vertical line on the far side of the workshop and a laser pointer attached to the mill. A distance of several feet gives a workable level of accuracy/.

Neil

I've not actually used the laser and line method and my current milling machine is already constrained by a keyway but it occurs to me that the line on the wall does not need to be vertical (in the gravity sense) but more that it should be parallel to the axis of the machine column.

If the machine is just sat on a bench and has not been set up so its column is dead vertical then surely errors would be introduced.

I suppose if a laser pointer (mounted sideways) in the quill could be used to 'draw' a short line on the wall which could then extended upwards and downwards, that would ensure it was inline with the machine column.

Ian P

I hope that applies to the OP as well; he has form for airily dismissing almost all attempts at help.

Andrew

I think he was - it would only take a very small amount of wear, or a very small loosening of a V-pointed screw to have a large effect on the possible angular movement. Whereas a dog-pointed screw would at least be consistent until it fell out altogether.

Although I don't think either would be a good enough method to be relied upon for accurate positioning. I like Pete's suggestion of marking the column and clamp and aligning by eye.

+1 on what Andrew said as well, people tend to respond to how they are addressed.

Rob

Edited By Grindstone Cowboy on 05/10/2021 09:53:16

This was a good suggestion.

Although I don't need a lathe at this point, the more I research I've now done, the more I think this was an extremely good suggestion.

Had I been aware of the existence larger Unimat 3 milling table I would have gone for it, particularly given that the previous owner had upgraded the original weedy (75w?) motor.

FWIW, I'm still thinking about this Unimat Milling Machine even though I definitely cant really afford it! (£850)
>**LINK**
It sounds like it's in extremely good condition with a spindle nose runout of "0.01mm".
Unfortunately it also sounds like I would probably need to upgrade that "2 speed Unimat 3 motor" (75watt?)
Also it would be coming from Italy...

> As for repeatability when moving the head, a popular solution for round-column mills is
> a vertical line on the far side of the workshop and a laser pointer attached to the mill.
Yes, a bit fiddly but a clever idea. Although given the choice, I still think I would prefer using the side of a keyway slot + dog-pointed screw...


One misunderstanding is that just because I don't explicitly thank & acknowledge each and every comment does not mean that I am dismissing them - not for a second! The truth is that my silence often means that I am still digesting/researching a suggestion... an example being the Unimat lathe/mill. Ignoring to personal commentaries, in my opinion, the standard of technical suggestions regarding is generally extremely high here, but I think people have enough to read as it is.

J


PS Where else might search for an EMCO Unimat Milling Machine to buy other than lathes.co.uk and eBay?

+2.

I admire Andrew's tact for choosing "airily".

Edited By Bill Phinn on 05/10/2021 17:23:46

FFS, can we get back to workshop tools model engineering, please?

I haven't read the whole thread because frankly I can't be bothered But I might as well throw my opinion into the mix since I collect these small machines.

Ok so first the Emco 3 mill is a nice little machine (I own one) but they are quite rare and rather collectable and therefore expensive. Parts and accessories are readily available second hand. However there are better alternatives.

Probably the best of the lot (other than the mega expensive watchmakers machines) is the Cowells mill. Unfortunately they rarely come up for sale and prices are high. Parts and accessories are available both new and second hand but expect to pay up!

The Sherline mill is the next best, they aren't particularly cheap new and can be difficult to find in the UK second hand. Parts and accessories are available new and second hand but they aren't so common in the UK. Lots available in the US if you are willing to import them.

One not mentioned is the Proxxon FF230. It is very similar in a lot of ways to the Emco 3 mill and is of at least equal quality if not better. It's worth knowing that not all proxxon tools are created equally. Some are dire while others are quite good. The FF230 and PF230 are two of there better products. Again they aren't particularly cheap but parts and accessories are fairly common within the UK and Europe.

Forget the rest. Those 4 are the pick of the bunch if you absolutely must have a micro mill.

I thought I'd read most of this thread, but I seem to have missed that bit.

Andrew

Hollowpoint - thanks.

>... if you absolutely must have a micro mill.
Indeed, I must.

I definitely have no space for anything larger. 

I had forgotten about Cowells. The Cowells vertical milling machine does look like an extremely nice piece of kit. You weren't kidding about being pricey, current retail price on http://www.cowells.com/pricelist.htm is £2485.00 for the B100. But they sound rare and unsurprisingly I can't find a single second hand one for sale.

[Btw, is it a better design to have a cross table on a 'knee' that comes up to the milling head or for the milling head to come down to the table?]

I have been considering Sherline. They are made in the US of course and windup being pretty expensive if new. Also I don't like the idea of not having a quill for drilling. I may get shot down for this but it just seems like poor design to me. I mean, why can't a machine be a drill if it's already a mill?

I see what you mean about the Proxxon FF230 being a similar design to the EMCO 3. The Proxxon PF230 appears to effectively be the same product as the FF230 except that it can attach the former to a lathe - much like the EMCO 3 could. The FF230 is a nice weight at just 17K, but new it's c. £910 and does seem to have rather a slow top speed (280 to 2200 rpm).

However in my experience it's a brave man around here that says Proxxon is as good as... well pretty well anything! And certainly EMCO Unimat seems to have a lot of fans. But you sound like you have a lot of experience.

Btw, do you have any experience or firm opinions on the Proxxon BFW 40/E Mill/drill system?
[e.g. Axminster are selling a "Complete Mill/Drill System" for £624.98 all in, consisting of BFW 40/E Mill/Drill Motor and Controller, BFB 2000 Mill/Drill Stand, KT 150 Compound Table & Step Clamp Set].

Given the lack of vertical screw, I rather like the idea of having the power/controller in a separate box... 900-6000rpm, 250watts consumption,...



...however its mill/drill unit (BFB 2000) looks like it might flex somewhat when under milling load, no?

Conclusion
The more research I do, the clearer it becomes that any sensible milling machine for mild steel would need to be second hand, and not new. Also being a milling novice, that may not go so well.

e.g. If the Proxxon FF230 is genuinely quite well made, and only 17Kg maybe I might consider buying one of them second hand, even though the Proxxon brand definitely has its detractors.

Edited By John Smith 47 on 05/10/2021 22:25:43

I haven't used the proxxon bfw40 but have played around with a display model. (Not running). IMO the construction of the machine is way too light for milling. It's more like an accurate drill.

The Emco 3 which is better and of slightly heavier construction is only just rigid enough for light milling. So you can see the problem.

The FF230 is about the same quality of construction as the Emco 3 but has a few small tweaks that the Emco lacks. The column although still round is slightly larger diameter and the head has a proper vertical adjustment aiding alignment.

Both of the above are less rigid than either the Cowells or Sherline and so both of the latter make better milling machines. It's true they are not so good for drilling without the quill feed. However a sensitive drilling attachment is available for the Sherline which is good for drilling small holes.