Lathe Tool Rests ... What is This?

[JPG]

Looks reasonable to me.

[chapmanruss]

Nice idea and I hope it works out.

It's a location I like about the Model 10's Lathe Tool Rest Assembly as seen below.

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105-2 Lathe Tool Rest Arm with side set screws.jpg (279.35 KiB) Viewed 165 times

[DLB]

If anyone is interested, I have photos of how I drilled, tapped, and supported the new bolt position.

Just let me know and I can post the photos.

Thanks.

I'm interested in the "how-to" for this, especially the material you used to build up the casting. When I looked at the picture I thought you used some type of threaded insert (a nut, for example) but you said tapped so maybe not. Could the material have wrapped further around, strengthening the known weak spot of the hole opposite the original setscrew?

- David

[Cheechako]

It's a location I like about the Model 10's Lathe Tool Rest Assembly as seen below.

Exactly. The set screw in your photo is the same position as my modification of the Mark V 510 tool rest. I can't understand why the 510 tool rest ships stock with the set screw in a coaxial position b/c it is so difficult to adjust. Even my SS Allen wrench was not long enough to turn the original set screw, so the Model 10 was clearly a better design. Thanks for the photo. Sometimes 'Back to the Future' is best....

[Cheechako]

Thanks to everyone for your interest. Here is the latest update on my tool rest modification.

I was digging around in my parts drawer and came across my Rockler Jig Hardware Kit which contained various 5/16 x 18 star knobs and T-bolts. I swapped out all the lever screws with star knobs.

WithStarKnobs.jpg (156.73 KiB) Viewed 109 times

WithTBolt.jpg (145.23 KiB) Viewed 109 times

I found it is easy to turn the star knobs to adjust the tool rest and also swap out the attachments. For a little added gripping power, I also replaced the original set screw with a T-bolt.

I can turn all the knobs and T-bolt by hand, without the need for any additional tools.

I turned a small bowl today and found these modifications very, very helpful. My set up is just a little bit shy of a traditional banjo, but is 90% of the way there. Clearly a vast improvement in the ease of use and versatility compared with the OEM 510 tool rest.

If you don't have the Rockler kit, its definately worth the money. I have used it extensively in the past to build shop made jigs. It is a fortunate coincidence that the threads on most of the Rockler knobs/bolts is exactly the same as the taps on the tool rest casting.

Comments are welcome.

[Cheechako]

I'm interested in the "how-to" for this, especially the material you used to build up the casting.

- David

David:

Thanks for your interest.

Have you noticed that the original set screw on the 510 tool rest travels through a reinforced section of the casting for about 3/4"? (the green outline in the photo below)?

ToolRest3.jpg (16.53 KiB) Viewed 105 times

The wall thickness of the casting recess is only 1/4" thick. So just drilling and tapping a new hole in a different location will leave inadequate support for a compression screw and risks stripping the threads when the screw is tightened enough to actually hold the attachment. Or the screw could just snap off.

So I knew I needed to lengthen the screw path and provide more support to withstand the pressure on the threads when the screw/bolt is tightened.

What I came up with is to add a stainless steel flange nut (5/16 x 18) to lengthen the screw path (see below). However, I am not a welder, and the casting is aluminum. Welding steel to aluminum is not recommended.

However, I have a secret weapon. JB Welds Steel Stick Epoxy. This stuff is nothing short of amazing !! If you have not tried it, please pick up a tube. You can get it at any auto supply store. It is used by mechanics for various extemporaneous car repairs. Goes on as a putty, hardens like stone, and sticks to all metals.

SteelStick.jpg (248.95 KiB) Viewed 105 times

I have used it successfully to bond aluminum angle bars to cast iron when building my Portable Chain Saw Mill. Worked great and is tough (or tougher) than nails !! Steel Stick is the only way I know of to bond dissimilar metals without any special tools or techniques. Just cut off a short segment from the stick, kneed between your fingers for 20-30 seconds and apply like a putty. In 30 minutes you cannot separate the parts.

With the secret sauce revealed, I will post detailed descriptions and photos of the actual tool rest modification. You will be able to do this in 30 minutes using your SS drill press and a simple vice to hold the tool rest. You will need a size F metal cutting drill bit and a standard tap and die set (previously acquired both from Harbor Freight).

You will also need a 5/16 x 18 flange nut as shown in the photo above. Plus a 5/16 x 18 T-bolt or star knob, some denatured alcohol to clean the parts, and any kind of machine oil to coat the bolt threads to keep the epoxy from bonding.

Photos and explanations next.....

[Cheechako]

Here are the steps.

I attached the Disk Sander to the accessory quill shaft which I will explain below. I then lifted the SS into the drill press position and chucked a size F metal drill bit. For a 5/16 x 18 tap into aluminum, charts indicate size F is correct.

Remove the original set screw from the casting.

Mark the new bolt location with a Sharpie.

Casting on its side with new bolt location

Drill#Bit.jpg (188.52 KiB) Viewed 99 times

Secure the casting on its side using a bench vice and align the Sharpie mark to the drill bit. Pay attention to rotating the casting in the vice until the drill runs perpendicular to the axis of the channel so the final screw will also.

Then....

1. Drill through the casting with a size F metal drill bit at slow speed
2. Leave the casting and vice untouched, and swap out the drill bit for a 5/16 x 18 straight flute tapered tap
3. With the drill press OFF, lower the tap down into the F-size hole. Turn the quill by hand by applying a few turns on the Disk Sander attachment while keeping downward pressure on the quill. This maneuver starts the tap into the hole while also ensuring the threads are both centered and perpendicular.
   

   

   F-size metal drill bit

   DrillFBit.jpg (104 KiB) Viewed 99 times

   

   Tap initiated by hand turning quill

   DrillTap1.jpg (220.77 KiB) Viewed 99 times

4. Lock the quill in its current position with the tap still engaged in the hole.
5. Unchuck the tap and remove the vice from the drill press. The tap should remain engaged in the hole.
6. With the vice secured to some work surface, attach a handle to the tap and complete the tap down through the casting.
7. Clear all the chips from the tapped hole with a Q-tip coated with oil

Completing tap by hand

HandTap1.jpg (83.82 KiB) Viewed 99 times

Now you have a tapped 5/16 hole in the new location. Next...

1. Sand the paint off the casting for a distance around the new hole location to expose bare metal. A rough (80 or 100 grit) paper leaves visible scratch marks which help the epoxy grip the material.
2. Sand the flange and all surfaces of the 5/16 nut also to create scratch marks.
3. Remove all traces of oil, grime, etc with alcohol from any surface that will be bonded by the epoxy, on both the casting and the flange nut
4. Use the Q-tip to sparingly lubricate the tapped threads and the T-bolt threads with oil to inhibit bonding to the epoxy.

It takes a bit of finesse to get the epoxy both under and over the flange nut, while at the same time making sure the flange nut seats down against the casting. Practice a few times before applying epoxy. What worked for me was to thread the flange nut onto the T-bolt and then thread the bolt into the new location. Then I backed the flange nut off just enough to squeeze the epoxy putty underneath the flange. Finally, I used a 1/2 inch fixed gauge wrench to advance the flange nut down against the casting, squeezing out most of the epoxy paste which I then molded with my fingers into a generous mound all around and over the entire flange nut. I built up enough epoxy that I could get a strong mass behind and around the flange nut so it would not move when the bolt was tightened. You can see the final shape of the mound in the photos posted previously.

I used a utility knife to clear any excess putty away from the casting and top of the flange nut. I also removed the T-bolt to guarantee it would not get bonded. Now I let it sit for a few hours. Thats it...

Don't ask my why the cured Steel Stick just happens to be the exact same color as the SS signature paint. I like it, but it was serendipity only. Looks like it was put on at the factory !!

Hope this explanation is clear and helpful.

[Cheechako]

Could the material have wrapped further around, strengthening the known weak spot of the hole opposite the original setscrew?

Of course. Thanks for reminding me. I will plug that hole with Steel Stick.
I know this will work b/c I have used Steel Stick to modify a chain saw bar so it will fit a different power unit. I filled the original holes with Steel Stick and then drilled new holes at a different location in the same bar....'chain saw bar recycling'

[RFGuy]

Me thinks you already implemented this solution before you even started this thread...

[BuckeyeDennis]

Thanks for the detailed process writeup, Cheechako. I’ve never used Steel Stick, but it’s clear now that I should have some in my machine-repair arsenal.