How to clamp work....?

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rudd
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Re: How to clamp work....?

Post by rudd »

Spro, you are a faster typer than I am, but the advice bears repeating.
On second read - " dropped the bit to line up"
The spindle needs to be fully retracted, not extended. If it is hanging out, it will flex. The table should go up, or the head should come down, depending on what kind of mill this is. Can you post an overall picture of the mill, or give us a make and model?
Last edited by rudd on Sat Sep 17, 2016 7:57 pm, edited 1 time in total.
TechTony
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Re: How to clamp work....?

Post by TechTony »

Mount your work piece on 1-2-3" blocks to move it closer to spindle. Most mills by raising the table or dropping the head or both should allow the spindle to touch the table when extended.
Table and head are stationary. It's a Bolton BT800. Looks like the bottom of the bit to the top of the table is about 5". It's been a learning experience... I suppose I am going to need to square up some nice blocks that I can have on hand for this sort of thing in the future.
TechTony
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Re: How to clamp work....?

Post by TechTony »

I.e., is there a long threaded rod of some sort
Yea - there's a drawbar. And yea, I thought it was a little sketchy with the EM in the chuck, but it's taken everything I've thrown at it thus far - mostly cutting thin plate so I've been rolling with it... not knowing any other way really. I guess now that you mention it, a collet probably is smarter.
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rudd
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Re: How to clamp work....?

Post by rudd »

Uses MT3 in the spindle. Endmill holders will solve some of your headroom problems.
I have no relationship with LMS, I don't think I've even bought from them, but here is a set. Lots of other folks sell the same thing, posting the link so you can see what we are talking about.
http://littlemachineshop.com/products/p ... uctID=1636
TechTony
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Re: How to clamp work....?

Post by TechTony »

Thanks a bunch rudd - huge help! ....and I thought I was gonna get an Aloris type tool holder system this payday..... so much for that.... guess I'm buying EM holders....
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rudd
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Re: How to clamp work....?

Post by rudd »

http://www.boltontools.net/pdf/BT500.pdf
On p. 27, I see two clamping handles (part no. 508) on the column - do these just keep the head from swiveling, or could they allow it to go up and down in some way I can't make out?
(LMS has a pretty good reputation as far as I know, you might be able to score some on ebay for less money, but then buying used... they could have dinged up tapers you'd have to stone down, though I've bought lots of taper tooling on ebay - another kind of taper that is now uncommon - and never had any real issues.)
spro
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Re: How to clamp work....?

Post by spro »

MT#3 collets aren't so expensive these days and you don't need a bunch. 5/16" 3/8" 1/2" for now. Eventually a collet head but even though a collet head extends near as far as a j ish chuck, it is so much more supportive of the end mill and of precise location that it will work. Direct collets will show you the ability before that.
spro
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Re: How to clamp work....?

Post by spro »

There is no mill which cannot either lower the head and or quill or raise the table.
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GlennW
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Re: How to clamp work....?

Post by GlennW »

spro,

It's a lathe mill combo.

No way to raise the table.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
spro
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Re: How to clamp work....?

Post by spro »

Glenn, I didn't know yet now I know why you suggested the precision blocks to space it up. What's the word, conundrum ?
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GlennW
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Re: How to clamp work....?

Post by GlennW »

Not sure if it's a conundrum or a debacle.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!
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BadDog
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Re: How to clamp work....?

Post by BadDog »

Just for clarity, to get everyone on the same page, this is what he's working with.

With that situation in mind, and knowing that the mill itself is far from ideal where rigidity is concerned, much less hanging it out even further with EM holders, when you really need rigidity (the first time you need to make pockets or features in steel solid, and/or want good finish), then I would suggest having a set of MT3 collets to get the end mill right up at the spindle. But then you'll also need a variety of precision blocks to get the work piece within that envelope. They make precision "blocks" that are often called a "machinist knee" (thought that usually seems to refere to a thing more like a angle plate with a butress). I would suggest keeping an eye open for these when appropriate, and perhaps trolling ebay for a deal on a properly sized option. I've got some that are square blocks about 4" on a side and 6" long, all surfaces precision ground except the hollow cast center (like a square tube) But in a pinch, you can stack a few inexpensive 123 blocks like these on their side (or even splurge for expensive larger size (246?)) blocks flat on each other to get the height. And a good clamp set will have the step-blocks to get the clamps in range. The clamps can also be used to hold a small vise in the elevated position, perhaps supported by a on of those blocks like I mentioned earlier. But getting the work surface elevated would be a high priority if I were working with that. Would be nice if you fabricate/machine a solution that would provide a t-slot table at a convenient height that would just mount to the existing table. Then if you need the room for a bigger part, just don't use the elevated table. Likewise for the cases where convenience is more important that maximum rigidity, you are going to LOVE those EM holders over MT collets. That's mainly because MT collets are a "locking taper" collet, which means removal, particularly after tightening to a point where you are sure the EM won't slip, becomes a bit of a bear. And THAT is why many folks unfortunate enough to have an MT taper in their mill use an ER collect chuck, and THAT is a whole new discussion.


Welcome to the asylum, and good luck!
Russ
Master Floor Sweeper
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