BF20LV Draw bar thread confusion

[deeferdog]

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

 

[Cogsy]

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.

 

[goldstar31]

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

 

[marvin_schwartz]

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.

 

[Cogsy]

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.

 

[bazmak]

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

 

[deeferdog]

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

 

[marvin_schwartz]

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.

 

[deeferdog]

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

 

[marvin_schwartz]

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.

 

[rodw]

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

 

[deeferdog]

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

 

[marvin_schwartz]

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.

 

[deeferdog]

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

 

[marvin_schwartz]

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

 

[miglincit]

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

 

[Wizard69]

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.

 

[marvin_schwartz]

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.

 

[marvin_schwartz]

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.

 

[marvin_schwartz]

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.