# BF20LV Draw bar thread confusion



## marvin_schwartz (Nov 10, 2017)

I'm just about to buy my first mill and just before I placed the order I got totally confused.

The mill in question is the BF20LV.
The Hare and Forbes web site shows the spindle as MT3 M10.
But I can not find any MT3's with a M10 thread. They all seem to be M12.
Given this is a 9x20 very popular late I wonder why I can't find an M10 shank.

The next thing that confuses me is under accessories in the the manual it shows all the collet chucks as MT2 M10. Which I can find everywhere . But how did an MT3 taper suddenly become an MT2? 

So is it an MT2 or MT3?
What's the thread? M10 or M12?

What am I missing?


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## bazmak (Nov 10, 2017)

If you can go to R8 rather than MT its a much better fitting


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## marvin_schwartz (Nov 10, 2017)

I don;t think this model can do that


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## miglincit (Nov 10, 2017)

marvin_schwartz said:


> So is it an MT2 or MT3?
> What's the thread? M10 or M12?


Mine has MT2 and M10 of course.

Thomas


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## deeferdog (Nov 10, 2017)

Hi Marvin, I have the mill in question and I purchased it from Hare and Forbes a couple of years ago. Unless they have changed the spindle is MT3 and the draw bar 1/2" Whitworth. All my tooling was M12 so in desperation I ran a 12mm die over the thread and promised myself that I would make a new draw bar ASAP. I will one day. The machine, by the way, is excellent. Cheers, Peter.


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## marvin_schwartz (Nov 10, 2017)

awesome.

thanks


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## marvin_schwartz (Nov 10, 2017)

Hey Peter,

I assume you are running collets. Are you using a a collet holder with an MT3 or MT2? 

The user manual on the H&F site shows the collet accessories as MT2 which sound wrong to me.

Any recommendation on collet size I hear ER32 are problematic in clearing chips when you right down the bottom of a hole. I was thinking ER20 or ER25. Any thoughts.

PS.
I think I've decided to do what you did and run an M12 over the draw bar and maybe make a new draw bar with M12 if I stuff it up. Could be a good first project for the lathe.


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## grapegro (Nov 10, 2017)

Hello Marvin, I have a  BL 17 mill which is a very good unit. The original makers design quoted an MT 2shaft, but the company I bought it from supplied an MT3 shaft which I needed to be able to use tools I already had. Problem was a 1/2 inch drawbar. The price of tools for this drawbar was far too high so made a 12 mm bar in my lathe and all is well . This the way I would advise by experience, Norm


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## deeferdog (Nov 10, 2017)

Hi Marvin,

I use ER32 collets in an ER32 collet chuck with a MT3.  The MT3 is the spindle size of the BF20LV that I own. I also have a set  of ER11 collets with an ER11 collet chuck. This also has a MT3. ER11  collets range from 1.0mm to 7mm in 0.5mm increments and are especially  good for holding small size end mills as the chuck is quite small and  does not get in the way like the ER32 chuck does. I like ER32 as it goes  all the way up to 20mm and I use this size for a lot of my tooling. I have posted some pics, you can see the difference in size between the ER11 and 32 collets. My face cutter is held in a 20mm straight shank arbor so I hold that with the 20mm ER 32 collet, likewise thw general purpose tool holder that I made.
I  looked at the latest spec sheet on the BF20LV mill from H & F and  they state the spindle size is MT3.  https://www.machineryhouse.com.au/M650 I understand your confusion, some  of the sales people at H & F are not as well informed about their  products as they could be, I also sometimes get the impression that the  hobbyist is a bit of a nuisance to their main business of selling "real" machines. Apart from that I have found them to be an excellent company to deal with and they have solidly backed their products when needed. I woulden't buy from anyone else.
 Having said that, the mill is excellent and allows for extensive modifications. There are numerous sites about the machine, generally it is referred to as the Grizzly GO704 as this is the name it is sold under in the US. If you Google that you will find lots of information. Feel free to contact me if I can help further, Cheers, Peter.


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## Wizard69 (Nov 10, 2017)

marvin_schwartz said:


> Hey Peter,
> 
> I assume you are running collets. Are you using a a collet holder with an MT3 or MT2?
> 
> ...



If you haven't purchased the machine I'd suggest going R8, giving you far more flexibility.   Here in the USA decent MT tooling and collets are actually hard to find compared to R8 taper.   Now a  lot of R8 tooling was originally designed for Bridgeport style machines but is still applicable on a small mill.

With R8 you get the ability to run end mills in R8 collets directly or use a host of different collet extensions.

I'm not sure what the demand in your country is for MT shanks in a mill, but such is not even salable over here.  In fact some vendors have tried to move such hardware eventually dropping the machines for R8 variants.


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## Wizard69 (Nov 10, 2017)

deeferdog said:


> Hi Marvin,
> 
> .......
> Having said that, the mill is excellent and allows for extensive modifications. There are numerous sites about the machine, generally it is referred to as the Grizzly GO704 as this is the name it is sold under in the US. If you Google that you will find lots of information. Feel free to contact me if I can help further, Cheers, Peter.


In the USA the G0704 is sold with an R8 taper.    I still haven't figured out is the usage of MT shanks in the UK is due too demand or companies like H&F forcing the taper on users.    I just find it interesting that the same basic machine comes with entirely different spindle tapers on the other side of the pond.


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## marvin_schwartz (Nov 10, 2017)

Thank Peter,

You have confirmed what I thought.
If you look at the manual for the BF20 on the H&F site, they call out MT2 for all the collet accessories for that machine, which you have now confirmed is rubbish.

I'll go with MT3 tooling. 
I'll definitely get the ER32 as I already have a number of bit's that have 20 mm  shanks. 

Now the question is do I go ER20 or ER11? I never considered the ER11 but if it works well it could be a great idea as I'm planning to get a cheap CNC engraver for plastic and PCB boards, which would take an ER11. 

Thanks again


Hey Wiz,

I agree the R8 looks like a better arrangement, but this mill doesn't come with an R8 option and the nearest Sieg is around $500 more. Given everything here is metric the Bridgeport is not as prevalent as in the states. Also MT is easy to get as long as it's MT3 M12. So I'll start with MT3 fingers crossed. 

Shame the mini mill 2nd hand market is non existent down here otherwise I would have gone down that path.

Once I get the gear I'll post some pictures and what I did to make the draw bar work.


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## deeferdog (Nov 10, 2017)

Wiz, I'm not sure R8 gets a lot of traction in Oz. Morse taper still seems to be the preferred style for bench top mills, larger machines use NT. Morse taper collets are readily available, I have some myself but I do like the ER system. My lathe has a MT3 taper in the tailstock and a MT4 in the spindle so it sort of made sense to stick with this for me. All my large drills are either MT2 or three, thus I can use them in both machines. I have never used R8 so I can't say which is better, my advice to any hobbiest would be to stick to the system that is the most popular in the country you reside in, that way you are more likely to pick up old tooling at car boot sales that will fit your machine, particularly if you are a bit of an old scrounger like me!
Cheers, Peter.


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## deeferdog (Nov 10, 2017)

Hey Marv, check out this mob,https://www.banggood.com/search/er-collets.html  I find them good to deal with. Cheers, Peter


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## bruedney (Nov 11, 2017)

Have al look at James' thread on threads here http://www.homemodelenginemachinist.com/showthread.php?t=26059&page=2


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## marvin_schwartz (Nov 11, 2017)

Thanks that post was exactly what I need to do.
The cad diagram was great, that will save a bunch of measuring.

I have some nice stainless which should suit this job well.

So all I need is get the gear and make the bar.
After I practice a bit.

Still don't understand how anyone can put a product on the market that requires you to modify it before it's really usable. 12 inch WW really what sorta rubbish is that.


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## Wizard69 (Nov 11, 2017)

If R8 isn't available locally or just not popular I can see why you might want to go to MT.    Around here Bridgeport's are everywhere, in the summer I see many sitting in garages if the garage door is open. ( don't have one though, madness)  That extreme popularity in the past has lead to a lot of cheap R8 shank tooling both used and new.



deeferdog said:


> Wiz, I'm not sure R8 gets a lot of traction in Oz. Morse taper still seems to be the preferred style for bench top mills, larger machines use NT. Morse taper collets are readily available, I have some myself but I do like the ER system.


The ER system is nice but you do end up buying a lot of collets because you end up with a bunch of machinery all using a different ER size.


> My lathe has a MT3 taper in the tailstock and a MT4 in the spindle so it sort of made sense to stick with this for me. All my large drills are either MT2 or three, thus I can use them in both machines. I have never used R8 so I can't say which is better, my advice to any hobbiest would be to stick to the system that is the most popular in the country you reside in, that way you are more likely to pick up old tooling at car boot sales that will fit your machine, particularly if you are a bit of an old scrounger like me!
> Cheers, Peter.



I have to agree with this, it is just around here MT spindle tapers are very uncommon in milling machines.    At least in small machines they are uncommon.      Some of the older mills did have MT tapers but they are long out of production.


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## marvin_schwartz (Nov 12, 2017)

Have to stop thinking about this mill. every time I do I come up with another question.

The latest is. Does the supplied drill chuck and shank come with a threaded taper?
If so is it a 1/2" WW that would match the draw bar?
Which means if I make an M12 draw bar the drill shank is on no use. Right?
Or is it a simple tang end which doesn't use the draw bar?


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## Journeyman (Nov 12, 2017)

You are over-thinking it a bit Just use 2 drawbars one M12 and the other .5"whit, it is only a matter of a few seconds to swap them over. Failing that it is easy to change the arbour on the drill chuck to M12. I had this problem with my smaller mill, supplied with 3/8"whit drawbar but most of my tooling is 10mm. I just made a new 10mm drawbar and the 3/8" is there if I need it. I rarely use the drill chuck, just put the drills into the ER collet - gives you more headroom.

You also say in an earlier post:I'll go with MT3 tooling. 
I'll definitely get the ER32 as I already have a number of bit's that have 20 mm  shanks. 

Now the question is do I go ER20 or ER11? I never considered the ER11  but if it works well it could be a great idea as I'm planning to get a  cheap CNC engraver for plastic and PCB boards, which would take an ER11.​You only need the one  ER32 milling chuck (at least to start with). The collets go from 1.5mm to 20mm so will hold any cutter up to 20mm if you have the full set of 21 collets. Most of the cheap Chinese CNC routers come with the collet holder system built into the high speed spindle so don't need an extra collet chuck.

Good luck with the new mill
John


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## marvin_schwartz (Nov 12, 2017)

Sounds like the best option is to have 2 draw bars. The 1/2" WW and the M12 this way I have the best of both worlds.
Easy


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## deeferdog (Nov 12, 2017)

Marvin, I don't own, nor have I seen for sale here locally any new tooling with 1/2" WW. When I inquired of H&F why they bring in the machine with this thread in the drawbar, the salesman I spoke to didn't know that it was. Makes you sad, doesn't it?  Unfortunately, the world today is not what it was or perhaps it's just that I'm getting old. Two drawbars would drive me nuts. I would make all the tooling M12. (Too be honest, I don't think you'll have any choice). Cheers, Peter


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## Cogsy (Nov 13, 2017)

I have to use 2 drawbars. Probably half my tooling is M12, the others 1/2 WW. I keep the appropriate drawbar with the matching tools and it's become a habit to change it so that I don't even notice I'm doing it. Would be nice to standardise but I can't afford to. Maybe one day.


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## goldstar31 (Nov 13, 2017)

I agree with Cogsy and would go on to suggest thatas one's accessories grow, appropriate draw bars should be made/bought.
Furthermore, it is good engineering practice to have correct sized and tapped draw bars for other tools such as lathes and drilling machines.

I have a lot of the things

N


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## marvin_schwartz (Nov 13, 2017)

Spoke to H^F they import the unit with a 1/2" draw bar but the guy mentioned there was another importer that brings them in with an M12 draw bar. 
Does anyone know who this other importer might be?
If they have a replacement M12 draw bar it would save making one up.

BTW just placed the order fir the mill should be here this week.


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## Cogsy (Nov 13, 2017)

marvin_schwartz said:


> If they have a replacement M12 draw bar it would save making one up.


 
If you have to make one, rather than turn a 1 piece type I cheated a little and just used some 12mm bar, threaded one end M12, then silver soldered a brass hex I'd made on the other end for the bolt 'head'. Took maybe an hour start to finish and cost very little.


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## bazmak (Nov 13, 2017)

An even quicker cheaper way is to cut a piece of M12 allthread and weld a coupling nut to the top. Done


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## deeferdog (Nov 14, 2017)

Unfortunately the draw bar for the BF20LV, at least the one I own, is not made like that, it is a bit difficult to describe so I have taken some pictures. Cheers, Peter


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## marvin_schwartz (Nov 14, 2017)

wow that is a bit different

PS I had  a look at what running a M12 die over the 1/2 WW thread, as some people have done.
     Looks like it might work but only 2 to 3 threads of the old WW pitch are meaty enough to hold a decent M12. in every 7 or so threads. 
     Which means less that 1/3 if the resulting threads are doing the holding. Not something that I would recommend, even though it's not really holding anything much.


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## deeferdog (Nov 14, 2017)

Hey Marvin,
Running a 12mm die over a 1/2 WW thread is a bit butcherous but I'm quite capable of that. I did it over two years ago and like I said, I will make a new bar one day. I use my machine a lot and the bar is still going strong. A MT 3 taper does not need a lot of drawbar load to hold it in place. I use a battery impact screwdriver to do and undo the bar and I have never experienced ANY toolholding slippage or jamming of the taper. There is a lot I don't know about milling machines in general, but I know the BF20LV well and I can say with some confidence that you are not going to be disappointed with it. PM me at any time as I have modified my machine extensively and you may be interested. Cheers, Peter


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## marvin_schwartz (Nov 14, 2017)

Thanks Peter, I agree, it's likely to work, but not likely to ever hold a 1/2 tool again. From what I see it's an easy job to make a new bar, so that'll keep me busy for a bit. Thanks for your offer to PM, I'll take you up on that some day I'm sure.


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## rodw (Nov 19, 2017)

I don't know if it helps but before they sold Optimum, I purchased a Seig SX3 from Hare and Forbes with MT3 spindle and a 1/2" thread. I made a new drawbar. I've never used any 1/2" tooling. I just made sure every MT3 tool I bought had a M12 thread as I'm a metric only guy!

Details of making the drawbar start on page 4 of my "Rod's Aussie Shed" thread. The guys here were very helpful teaching me how to cut a thread.
http://www.homemodelenginemachinist.com/showthread.php?t=19885&page=4


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## deeferdog (Nov 19, 2017)

I finally got off my rear end and made the new draw bar for my BF20LV. The hardest part was cutting the internal M20 x 1.0 pitch internal thread on the ejector, I didn't want to remove the part from the lathe until I was sure the thread was correct. I cheated by making a male threaded plug first that I new was right, then used that to check the internal thread. (I tried to buy a M20 x 1.0 bolt but was told that they are not made). For the bar I used a grade 8.8  M12 bolt, removed the head and threaded it to take 16mm ring for the ejector. I capped it off with a dome nut, loctited and pinned to end. Works well but it took me the best part of the day to make. I'm the same as Rod, a metric only guy, I,m not going to make another for WW! Cheers, Peter


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## marvin_schwartz (Nov 19, 2017)

New toys in the garage, 

All I need is some younger creatures with bigger muscles to help with getting them on the bench.
I settled for the BF20LV mill and and L160 lathe.
Should have everything I need to nail this draw bad thing once I clean the gunk off them.

Wish me luck.


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## deeferdog (Nov 19, 2017)

Marvin, love to see some pics of your shed when you have it all set up. Cheers, Peter.


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## marvin_schwartz (Nov 19, 2017)

sure, it'll be a bit squeezy but i think it should work well


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## miglincit (Nov 21, 2017)

marvin_schwartz said:


> All I need is some younger creatures with bigger muscles to help with getting them on the bench.



Do not rely on muscles - they will rip in the worst case as will your back 

I bought me a motor-crane to handle these parts between floor, machine base and every were else.

Thomas


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## Wizard69 (Nov 21, 2017)

miglincit said:


> Do not rely on muscles - they will rip in the worst case as will your back
> 
> I bought me a motor-crane to handle these parts between floor, machine base and every were else.
> 
> Thomas



Another option is a chain fall and a place to hang it.   But I otherwise totally agree find a way to take the muscles out of the equation.  Besides if those young guys drop something you are going to feel real bad.    Frankly anything more than 75 pounds can justify a mechanical aid.


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## marvin_schwartz (Nov 22, 2017)

We wound up using a motorcycle hydraulic lifter. 
The sort of thing you service motorcycles on.

We were able to walk the units across to the lifter, Pump it up to almost bench height and then slide it over to the bench space.
That way no one needed to lift the units and there was no danger of dropping them.


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## marvin_schwartz (Nov 27, 2017)

That was fun,

Got the mill in place, bought some M12 all thread and made an M12 drawbar. Took two attempts the first was over engineered the second was a little more rugged but looks like it will do the job.
Today my first collet chuck turns up. MK3 pheww lucky that's the same as MT3 with a 1/2 thread on the end for a 1/2 draw bar.

OMG now I find out there are two 1/2 threads UNC at 13 TPI and 12 TPI BSW WW. I am learning so much that I never wanted to learn. Looks like it's time to make a third draw bar.
So the adventure continues.

I'll post some pictures soon.


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## marvin_schwartz (Nov 27, 2017)

Just before launching into a third draw bar I thought i'd just try it out on the two that I already have.

Popped it onto the 1/2" WW and as suspected half way down the threads started to tighten and jam.
*Popped it onto the M12 bar and low and behold it went all the way in, no jamming and held real snug. 

The collet holder is a 1/2" 13, well I'll be buttered on both sides. *
This looks like it's work well.
How strange.


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## marvin_schwartz (Nov 28, 2017)

This little puzzle has been has been bugging me all day long.
Finally I solved the puzzle and feel better now.
If you are interested read on.

Firstly I drew all three threads to scale M12, 1/2UNC-13  and 1/2BSW-12 they look like the first picture.
Not until you lay them over each other do you see what is happening. See the second picture.

You can see that over an inch or so UNC1/2-13 and M12 are within 0.45 mm which is whay my M12 drawbar worked and feels snug. Even though 1/2 is a slightly bigger hole 12.7mm instead of 12mm.
Also shows why combinations of UNC/BSW and M12/BSW will jam up after 4 or 5 turns.

Now you know.


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## goldstar31 (Nov 28, 2017)

Speaking as someone- with a 'lot of draw bars' trying to adopt one thread size for another merely advances the evil day of having to replace 'fretted' threads

As you wrote-- Now you know!

Norm


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