PDA

View Full Version : Suggestions for making NMTB tool holders



rsr911
10-21-2006, 10:56 PM
The CNC lathe thread got me thinking as I'd love to have a CNC lathe for many reasons. From time to time I've used my CNC as a mini lathe with a lathe tool clamped to the table and this brought me to my current idea.

What if I where to rough machine some round bar down to the ID of the OD of my largest #30 endmill holder then place it in the endmill holder and use the CNC to cut the taper and flats as well as drill for the threaded part. Then I could indicate it into a 4-jaw on the lathe and cut the internal threads. Move to the mill and cut the slots for the drive tangs then install it in the CNC spindle and machine whatever end I need to hold various endmills and reamers.

Does any of this make any sense? What steel should I use? Will I need to put a grinder on the CNC table to finish grind the taper?

All of this is just the planning stage of course, I've got a lot of parts to finish on the CNC before I can play around making holders.

J. R. Williams
10-22-2006, 12:08 AM
Christain

Save your time and purchase the holders as they are difficult to get right and not all that expensive.
I have a CNC mill and would not consider machining a tool holder.

JRW

rsr911
10-22-2006, 12:14 AM
JR,

It's not the expense that gets me it the availability, or I haven't looked very hard. I need more 1/4 holders, I've never seen a 5/16 holder and I need two. 1/2" and up seem easy to find, it's the smaller ones that get me.

Of course you make a valid point that I didn't think of at first, getting them right. The hole for the EM's on the store bought holders is very precise and may not be that easy to replicate, I assume they are ground?

John Stevenson
10-22-2006, 03:23 AM
Christian,
I'm in the same boat but I want QC30 to ER32.
I don't use EM holders as I find them too restrictive being limited to one size.

There has recently been a rake of NMTB30 to SA100 holders on ebay for not a lot of money.
I pointed one of our UK user to them as he is standardised on SA100 collets.

I do have a stack of NMTB40's machined up with just the taper on, done on a CNC lathe and I have an old cut down 40 spindle that I can hold in the 4 jaw for odd holders.

.

Timleech
10-22-2006, 03:52 AM
Christian,
I'm in the same boat but I want QC30 to ER32.

.

John

Did you convert that BT30/ER32 holder you had from me to QC30 OK?

While we're on that track, I'm on the lookout for a 50 taper to ER40 chuck

Tim

John Stevenson
10-22-2006, 04:04 AM
John

Did you convert that BT30/ER32 holder you had from me to QC30 OK?

Tim

Yes, not a problem, it was tough but an old tip reground with better rake got under the skin and licked it up.
I have also done a Jacobs chuck holder I bought at Harrogate the same way.

Ketan at Arc Euro is looking at bringing a line of QC30 to ER32's in from China now he's found a good supplier. Waiting for a sample to arrive.

Timleech
10-22-2006, 04:22 AM
Ketan at Arc Euro is looking at bringing a line of QC30 to ER32's in from China now he's found a good supplier. Waiting for a sample to arrive.

Get him to ask about QC30 to ER40 ;)

Tim

John Stevenson
10-22-2006, 04:39 AM
Sorry Tim,
Can't see that happening as he max's out at ER32's
He carries ER11, 16, 20, 25 and 32 and not many, if any, home shop guys run ER40's

Timleech
10-22-2006, 04:49 AM
Sorry Tim,
Can't see that happening as he max's out at ER32's
He carries ER11, 16, 20, 25 and 32 and not many, if any, home shop guys run ER40's

John

I appreciate that, there wouldn't be much market (at present) among his usual customers.
I do wonder, though, why ER32 (20mm capacity) seems to be the biggest size generally used or available with a 30 taper, when other collet styles on 30 taper go up to an inch or more, which would correspond to the ER40?

Tim

rsr911
10-22-2006, 06:07 AM
Christian,
I'm in the same boat but I want QC30 to ER32.
I don't use EM holders as I find them too restrictive being limited to one size.

There has recently been a rake of NMTB30 to SA100 holders on ebay for not a lot of money.
I pointed one of our UK user to them as he is standardised on SA100 collets.

I do have a stack of NMTB40's machined up with just the taper on, done on a CNC lathe and I have an old cut down 40 spindle that I can hold in the 4 jaw for odd holders.

.

John,

I like to setup each job with it's own holders, crossing over only when the same tool is being used like a 4 flute carbide for example. I number all the holders and note that on my job sheets. Around here I'm the ATC and I'd just like to have more holders. I don't care for collets as they can slip on plunge cuts and that messes up the whole program. Another annoyance with collets is that it's harder to get the flood nozzles right as the collet nut is in the way. All of my store bought EM holders have a taper near the tool so there's clearance for the coolant stream.

Anyway you didn't answer my questions. ;) What type of steel? Grinding? etc.

billr
10-22-2006, 06:15 AM
good morning.

Christian;

what about making some end mill adapters for larger holders?

i have a 50 taper mill and use adapters to fit the smaller end mills. i cannot take credit for this being an original idea because a friend has the original ones that i modeled mine after.

it may take a try or two to make them run concentric, but they will if you are careful. i made mine out of 1" drill rod O-1.

good luck.

peace.
billr.

motorworks
10-22-2006, 07:25 AM
Guys
I use the NMTB in my Boss B/P as well.
They run about $80.00 Canadian for an ER32, at KBC Tools Canada.
It is not worth the time etc to make these.
You can also get them from Kennametal and on ebay.See item # 7627954718.
The ones from KBC and on ebay are Bison and are very well made.
eddie

thistle
10-22-2006, 09:06 AM
www.victornet.com
has a good price on 30 taper tooling,though I dont see 1/4 and 5/16- like has been said it might be easier to make a sleeve for a bigger sized hole.

thistle
10-22-2006, 09:25 AM
oh , and here is 1/4 and 5/16

http://www.usshoptools.com/current_year/all_products/2005_06_pdf/PGS_215_219.pdf


ouch ouch on the price

rsr911
10-22-2006, 01:27 PM
Guys
I use the NMTB in my Boss B/P as well.
They run about $80.00 Canadian for an ER32, at KBC Tools Canada.
It is not worth the time etc to make these.
You can also get them from Kennametal and on ebay.See item # 7627954718.
The ones from KBC and on ebay are Bison and are very well made.
eddie


I don't know, if I automate most of the machining using the CNC as a lathe anything over about $30 seems high priced to me. The trick of course will be getting the endmill hole right. I'm thinking a reamer chucked to the table would do it. Remember I'm thinking only to turn one end down to about 1.5" to fit in my largest holder then machine the taper and drill the hole for the threads, I'll then take this to the lathe and cut the threads. At this point I'll have a blank that I can machine anyway I like. First I'd drill then ream to size, then cut the OD. Cutting the taper is a simple X,Z movement and I can run the feed really slow for a nice finish. I'd probably make 20-30 of them so at $80 ea that's like $1600-2400 worth of tool holders, seems at least worth a try. My biggest concerns are whether or not the taper needs to be ground and getting the EM hole the right ID and concentric. Perhaps this would best be done with a spindle blank held in my lathe.

I can buy 1/2" holders for about $30-35 locally so the sleeve idea has some merit. Heck the smart money might be an MT to NMTB adapter to fit my big lathe so I could do the EM holes using the accurracy of the lathe spindle.

motorworks
10-22-2006, 02:14 PM
"I'd probably make 20-30 of them"

Why so many?
I have 6 tool holders.Two that are ER32 , two that are TG75, one takes 3/8 shank end mills and one that has a 1/2" drill chuck.
I set these up as needed.
Many more would perhaps save time, but endmils break or go dull.Same for drills etc.
Most job runs are different?!
take care
eddie

rsr911
10-22-2006, 02:33 PM
"I'd probably make 20-30 of them"

Why so many?
I have 6 tool holders.Two that are ER32 , two that are TG75, one takes 3/8 shank end mills and one that has a 1/2" drill chuck.
I set these up as needed.
Many more would perhaps save time, but endmils break or go dull.Same for drills etc.
Most job runs are different?!
take care
eddie


For example I have 4 1/2" holders, they contain 1 cobalt rougher, 1 HSS 4 flute, 1 carbide 2 flute and 1 4 flute carbide. My shop time is limited as the shop is in a corner at work and I have to work around my wife's work schedule so there is someone to watch our daughter. On occasion I'll bring the little one down to the shop but she gets bored quickly at 8 years old. By having tooling setup for each job it takes less time to get a job going. I typically set my zero height at 1 inch so all I have to do is zero to the stock with the proper tool and away I go. I currently have about 10 different jobs that I run on the machine with a bunch more ideas in the pipeline. Each job has it's own tooling. Maybe this is crazy but it works well for me from a time standpoint. To me EM holders are like dovetail holders for the lathe, you can never have too many. I'm using the CNC to make dovetail blanks as I'm typing this, these are going to another board member. Later this week I'll make a bunch for my CA post on the big lathe and my AXA Dorian on the little lathe, some will be left blank and others machined into #1 style holders. I plan to do the same with the #30 NMTB holders, make 4-5 each of the common sizes and leave the rest blank until I need them.

Beside what fun will the tooling caddy I'm building be if most of the holes are empty. :)

motorworks
10-22-2006, 02:49 PM
"I'll bring the little one down to the shop but she gets bored quickly at 8 years old"

My kids do as well (10 and 13)
I keep lots of paper for them to draw on!

Post pics of your finished EM Holders when they are done!
take care
eddie

John Stevenson
10-22-2006, 04:37 PM
Christian,
The ones I have made have been special and not EM holders or collet holders [ except one ]

I had the taper done on a CNC in 10's just out of a decent steel, probably what you call 4140 and then left.
When I need a holder I chuck the old machine spindle I have in a 4 jaw and clock it true then machine on what I want.
After that I send then for a process called Tuftriding which puts a very thing hard coating on them but it's done at a low temperature that doesn't distort so need need to grind.

If I was doing what you want I'd put the metal slug in the lathe and machine the nose to size then drill, bore and final ream to the finished size.
Remove from the chuck and drill the clamp screw hole.

Then fit a collet chcuk and chuck a pin up or piece of drill rod to the tool size, put the new holder on the pin and tighten onto a flat on the pin.
Then running quite slowly and very carefully I'd put a centre in the back end, support and then machine the taper.

This is the easiest way I can see to make sure that the EM diameter runs true.
Chucking a reamer up on the bed can't guarantee that it's 100% vertical and any error makes the operation a waste of time.

Even though they are reasonable priced getting setup to do a load can pay, especially if you have the QC fitting as the NMTB 30 isn't the same flange.

.

outback
10-23-2006, 11:24 PM
http://img.photobucket.com/albums/v30/jglass/30NMBTholders.jpg
I made these nmtb #30 toolholder close to the way you describe. Keep in mind the flange dimensions are very important relative to the taper. I made the tapered sleeve bushing to measure the top and bottom of the flange. I also thought the sleeve could be used as a setup fixture but have yet to use it that way.

I made the toolholders out of cold rolled steel. But, one has an edge finder permanently mounted. The others for smaller endmills. They seem to hold up okay.
http://img.photobucket.com/albums/v30/jglass/drawings/30nmbtholder2.jpg
Jim

rsr911
10-24-2006, 12:39 AM
Outback,


Thanks much for the info. How did you drill and bore the hole for the endmills?

As for getting the dimensions correct my first thought was to touch the tool off in various locations but thanks to your diagram I can just straight program the code. Any tips to make the job go easier?

BTW I figured out a good way to line up a bit and reamer. I plan to use the mill itself to drill into a block on the lathe fixture, I'll plunge cut with an endmill for both the bit and the reamer then use reamers in the spindle to ream the holes, this will make the bit and reamer holders on the fixture concentric to the spindle as well as give me exact coordinates. I'm also going to bore a hole in the lathe fixture for repositioning in the future. The fixture will be clamped in the soft jaws of my vises and machined in place so that everything is square in relation to the spindle.

outback
10-25-2006, 01:46 PM
The hole for the endmill was bored in the Bridgport spindle. I just held a boring bar in a vice, wrote a little program to bore it's own hole. Needless to say it is perfectly concentric.

The coldrolled steel tool holders work fine for light work. I also made a toolholder for a Jacobs drill chuck with tapered arbor. Even machined the arbor in the Bridgeport spindle so it is concentric. Also made a toolholder with an 1" arbor for driving plain milling cutters for slotting.

Thanks for the compliments
Jim

rsr911
10-25-2006, 05:37 PM
Jim,

What steel would you recommend for more durability?

The "lathe fixture" I was refering to would be a fixture mounted either in my vices or directly to the table, operating a drill bit, boring bar, reamer, and lathe tool all from one fixture.

outback
10-26-2006, 10:50 AM
Tool holder materials; I do not have much experience with #30 toolholders. I have had this Bridgeport retrofit for about 9 months. I use the cold rolled toolholders all the time and they still do not have a scratch on them. I'm sure high production would soon take it's toll on cold rolled toolholders. I'm running them in my home machine shop nights and weekends.

4140 prehard would be my first choice.

A-2 or most any tool steel left soft would also work well.

Jim