Lathe toolpost holder for Dremel flex shaft

There are lots of adapters for mounting the Dremel (or other high speed rotary tools) into the lathe toolpost (lathe tool post grinder), but very few for mounting the Dremel flex shaft; a nice example of these last is that by PJs (Dremel holder).

The holder I show here was made with a 1/2 x 20 nut (thread of the hand piece cap of the flex shaft), and a 6 mm square bar. Two segments, one short and one large, of the square bar are welded to the nut, so the upper face of the long segment is aligned with the center of the nut, and both with the center of the headstock, once mounted in the toolholder.

Attachment 18037

Attachment 18038

Attachment 18039

Attachment 18040

Regards, morsa.

Thank you for this interesting post. I often saw posts describing grinding accessories on a lathe and i am wondering if the discharge of abrasive particles is very
good for the health of the lathe. Maybe a protection would be useful.

Thanks, Mike_of_Clermont.
Not only is convenient to protect the lathe ways, but is a must. In the picture shown the Dremel flex shaft and the point in the chuck are mounted just for demonstration. Of course, afterwards I've used this device (protecting the lathe ways), with good results.

Most machinists and hobbyists are loathe to grind on the lathe, with very good reason, like cleaning a lathe or other precision machine with compressed air. Even the thought of turning wood on a metal lathe feels wrong to me.

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Thanks morsa! We've added your Dremel Flex Shaft Holder to our Lathe Accessories category,
as well as to your builder page: morsa's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-dremel-flex-shaft-holder"> <img src="/uploads/169813/homemade-dremel-flex-shaft-holder.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-dremel-flex-shaft-holder">Dremel Flex Shaft Holder</a> <span> by <a href="http://www.homemadetools.net/builder/morsa">morsa</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/lathe'>lathe</a>, <a href='http://www.homemadetools.net/tag/dremel'>Dremel</a>, <a href='http://www.homemadetools.net/tag/holder'>holder</a> </div> </div> </div> </div>
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Thanks Morsa for the link to my site. I hadn't seen this until today as I've been out of pocket so to speak. Nice build and you are right about the dust protection being a must. I find I don't take off huge amounts so the dust isn't tremendous. If I'm doing a lot with it I have rigged a little hose support for my small shop vac with a small nozzle and especially if I do wood like my Scraper Handle. It's a bit noisy but very effective for the most part. It still requires a good cleaning afterwards though, which is par for me after any job. I also made my way covers for the Mini very early on from old place mats...but not sure what you could use on the Unimat other than a drop cloth of some kind. Paul would probably have some good ideas. Thanks Again! :hattip: ~PJ

morsa,
Thanks for posting this! I too will be making this same attachment for my Unimat as well. I ALSO have the nut to make the same tool holder to hold the whole rotary machine from Dremel as well. ( I have 2 Unimats, and I got a Microlux 7X14 as well, which is probably where the whole Dremel rotary tool holder will be used.

My biggest issue right now is that I don't have a welder to weld the nut to a un-used tool bit, which I have to either find a welder, and or have someone I know with a welder weld it for me....

Morsa,

I like your ideas for the Dremel tool mounting on the Unimat. I also appreciate the link to PJs website/blog.

In regards to Hemi's dilemma about not having a welder, that can be easily solved. The nut and shaft can be joined with silver soldering the steel parts (I like this old technique because it is more an art than technology) or making solid piece from aluminum (or steel) and drilling/tapping the thread using a common drill press. Spindle nose on Dremel is either 3/4 x12 or 3/4 x 16 with the 3/4x 12 being the most common. Buying the HSS tap is the most expensive part of the whole assembling but the tap will last you a lifetime for other Dremel adaptation projects.

Regards,

Paul Jones

It's also easy to single point the 3/4-12 thread if you can find someone with a screw-cutting lathe.

Marv,

Great advice. I am sure the Microlux 7X14 owned by Hemi can swing at least a 3.4" long rectangular steel part and single point thread a 12 pitch thread part with the correct change gears. This would be a great way to learn the technique and with a few side shims could do this in a 3-Jaw chuck and no need for a 4-jaw chuck. The Microlux also has a faceplate and this may be a safer way to hold the part. That is how I originally learned how to do single point threading with a little experimentation.

Paul

He doesn't need to swing the full 3.4" while cutting the thread. Make the part in two pieces.

If I were doing this, I would take a length of about 2" of 1.25" cylindrical stock and thread it 3/4-12. [As long as you're going to cut threads, thread a longer piece with this useful thread size and you can, in the future, cut off lengths for other Dremel-holding devices that you might want to make.]

After threading cut off a slice and cross drill and tap it for some thread for which you have dies. Take a piece of square stock that fits the tool post and turn a tenon on the end and use your die to thread it. Use Loctite 609 to secure the Dremel-holder or silver solder it in place. This threaded joint isn't going to receive much stress in use (grinding is a delicate operation) so a two-piece assembly should work just fine.

Marv,
Really great advice on the construction. I use a lot of Loctite to joined small parts and never a problem. Silver soldering is fun but so much easier and faster these days assembling using a Loctite product.
Regards,
Paul

If you missed the link to PJ's excellent site:

-->Click here for PJ's Mini-Lathe Site<--

Quote:

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Originally Posted by Paul Jones

Morsa,

I like your ideas for the Dremel tool mounting on the Unimat. I also appreciate the link to PJs website/blog.

In regards to Hemi's dilemma about not having a welder, that can be easily solved. The nut and shaft can be joined with silver soldering the steel parts (I like this old technique because it is more an art than technology) or making solid piece from aluminum (or steel) and drilling/tapping the thread using a common drill press. Spindle nose on Dremel is either 3/4 x12 or 3/4 x 16 with the 3/4x 12 being the most common. Buying the HSS tap is the most expensive part of the whole assembling but the tap will last you a lifetime for other Dremel adaptation projects.

Regards,

Paul Jones

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Paul,
I'm not sure silver solder would be enough to hold it... I TOO thought about that way of doing it but I thing a weld to the nut onto the unused tool bit be a stronger bond..... I have a couple friends local that I'm going to take both nuts (one for the flex shaft, and one for the whole rotary tool) to them with 2 unused tool bits to have them welded.....

Doing a threaded attachment, might be difficult too just because the vibration would eventually loosen the threaded rode into the flat side of the nut, so..... -Maybe I'm not thinking of how it was mentioned here.... -Enlighten me if you would, (I think Marv, made that suggestion there of)

Hemi,

Marv's suggestion is the best approach for construction using two parts. Assuming the Dremel tool post holder is for a 14" or smaller engine lathe, the technique for silver soldering steel parts or using Loctite is very strong when done correctly. The parts can be joined together using a high quality silver solder (remember to use plenty of the special white flux for silver soldering and the heating the parts to almost red hot - you will know when by capillary action the silver solder is sucked into the joint) or glue with Loctite (I like the 620 and 680 products) for a simpler and easier sliding fit construction and let the Loctite do its work. The extra strength of the joint comes by using a side hole drilled perpendicular to the middle (either drilled straight through or perhaps drilled and then tapped with a 1/4-20 or 3/8-16 thread for the perpendicular part) into the side of the part previously made with an ID threaded for 3/4 x 12. This should work as well as just welding on the part on side-to-side.

Trust me, the two parts will not come apart unless you totally crash the Dremel tool into the lathe chuck and most likely the Dremel tool will be destroyed long before the two parts ever come apart.

Regards,

Paul

Two other remarks to add to this...

When grinding with something as small and underpowered as a Dremel, the maximum depth of cut will seldom exceed a thousandth or two. With such a light cut the reactive forces on the holder are very small.

I know very little about welding but I've never heard of welding to a (presumed HSS) tool bit. Does HSS weld well? Wouldn't a piece of ordinary steel serve just as well? Why waste a tool bit unnecessarily?

If welding will make you feel better, then do it. However, I have to agree with Paul; it isn't required for this device.

Hemi,

I think Marv and I have both shown several examples of using a Dremel or Foredom tools held in the lathe QCTP for precision grinding of parts (e.g., http://www.homemadetools.net/forum/u...6880#post67090 ). In these cases we are only removing 0.0005 inch to 0.001 inch in diameter per pass (actually two to three passes before moving in for another grinding cut) and there is very little side force to contend with.

Regards,

Paul Jones