Gerrit’s Vise

In addition to making reels, I have dabbled with rod ferrules and reel seat hardware. Gerrit (The Netherlands) has found yet another project for the home shop machinist, fly tying vises. This is a beautiful design and execution.
Gerrits Vise
I wonder how he did the curved beam.

Posted in Work Holding | 3 Comments

One Piece Spool, Again

This post is not so much about how to make a one piece spool (topic covered June 2013) as it is about a comparison of two types of metal lathe available to hobbyists.

I now have both a MiniLathe (China source) and a Sherline lathe (California). You would think that just one lathe would be enough to make a simple thing like a fly reel. And indeed, over the course of several years I figured out how to do all the necessary turning operations using the Sherline lathe. (One key development was special jaws for the “3 inch” chuck, May 2015.) When I bought the MiniLathe, my vision was to do all operations with it while taking advantage of its greater weight and torque. But the need for the Sherline lathe has not yet disappeared.

The outside surfaces of the spool are no special problem, it is turning the inside that requires special tools. I made one turning tool for the MiniLathe (April 13, 2017) but it has a large overhang from the toolpost and tends to chatter. So to get the needed stiffness at the cutting edge, I made a special tool that supports the carbide cutter by a solid column of steel all the way down to the cross slide.
The cutter here is a round RCMT type. It can finish all the interior surfaces.

This new tool displaces the compound slide. With the compound gone, I have to rely on a dial indicator for axial motions.
This spool is nearly finished. The interior was first roughed out using a vertical mill and a rotary table (supported by a right angle bracket).

I have a similar cutter for the Sherline lathe. But with the MiniLathe I have much more torque (quite noticeable at low speed) and can take a bigger bite. The job is done quicker.

Part of the trouble with the Sherline spindle drive is its “open loop” speed control. ¬†It only sets an armature voltage and cannot sense when the spindle is about to stall. Stall torque decreases as the armature heats up. My MiniLathe has brushless DC drive, which inherently senses speed as part of the commutation logic. Speed is directly regulated, which is quite ¬†different thing from armature voltage regulation.

While turning, the spool in supported by a simple mandrel held in an ER32 collet. Also shown here are aluminum spacer plates.

When I am done with the special cutter, I still need to put a small radius on the inside of the spool flanges. I do this by first cutting a 45 degree chamfer, and the finishing with a file.
With the MiniLathe there seems to be no way to bring a cutting tool to the rim of the 2.5 inch diameter flange, when the compound is set at 45 degrees. The cross slide does not have enough range. I could retract the compound further, but then run out of carriage travel towards the headstock.

So, back to the Sherline to cut the chamfers.
Why is this little lathe so capable? I think that the rotatable headstock is an important feature. It does things that are impossible with a compound slide. Just wish it had better torque at low speed, bigger spindle through hole, etc.

Posted in Spool, Turning | Leave a comment

Fitting Reel Foot to Seat II

This post is additional material to my post of 15 June 2015. In that post, I did not say enough about the interface of the reel foot and the reel seat sliding ring. Here again I am discussing “cap and ring” type seats. These problems do not occur with screw locks seats, in my experience.

A discussion on The Classic Fly Rod Forum, “Nice fish make my reel fall off”, addresses the problem. I replied, saying that the radius on the top of the foot should closely match the inner radius of the ring. The reply following mine was probably closer to the target, pointing out that the ring should be as compliant as possible; i.e., deform with a low spring rate. A compliant ring is less likely to loosen from shock and vibration.

I want to point out that the relative compliance of the ring has a lot to do with the radius of the top of the foot. If the foot top radius is larger than the inner radius of the ring, then the ring is loaded at three points.
Ring B
Ring D
In the lower sketch, the load at the bottom of the ring is contact with the reel seat insert.
But when the foot top radius is less than the ring inner radius, the ring is loaded at two diametrically opposite points:
Ring A
Ring C
In this latter case, the ring is much more compliant, and therefore better able to hold when subject to shock.

It should also be apparent from the sketches that contact stress between the ring and foot is much less in the latter situation. So the foot is less likely to be scarred by contact with the ring.

A more recent discussion on the forum is “How do you make your reel feet?” . Several replies show fixtures that are simple straight, cylindical rods. Such a rod will be 0.70 inch diameter in order to fit the foot bottom. When the top surface is turned, the top radius of the foot will be about 0.39 inch out at the tip, and will increase toward the foot center to about 0.50 inch (the foot top is a portion of a cone). Rings that I have seen are in the range of 0.67 to 0.73 inch inner diameter, and so fit such a foot poorly, causing three point contact between ring and foot and damaging the foot.

It is possible to turn the foot top radius so that it is 0.35 inch radius (or even less) over its entire length, but this requires a more complex fixture (see my blog post of 24 July 2016, “A Foot Fixture for the Lathe”.)

I still own a few commercially made reels, and they have different foot top shapes. My Orvis reel has a foot top that is conical, and is greater than 0.35 inch radius everywhere. It fits both ring and cap poorly and is damaged by contact with a sliding ring.
My Sage reel has a foot top that is 0.35 inch over its entire length (is cylindrical in shape). It fits both ring and cap nicely and there is no significant damage to the foot.

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Cool Air

We moved to New Mexico last November, and up until a month ago the climate seemed quite pleasant. But June and July here means daily highs of 95 to 100F, and I found that too warm for working in my garage. (Fortunately the overnight lows are about 60F so there is a good time in the day to take a walk.) I could have pumped in house air because the HVAC unit is located in the garage, but garages have big doors that open periodically and that seemed to me a waste of refrigerated air.
So I have bought a “swamp cooler” and it seems to be quite effective. Keeps the garage about 15F below the outside temperature. It sits in front of an open side door so that it has a good supply of dry air to humidify.

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Diamond Toolholder

Somehow the Diamond Toolholder (a.k.a. Tangential Toolholder) came to my attention and I thought it sounded like a great idea. Uses a standard 1/4 inch HSS bit, easy to sharpen, easy to adjust height. So I put my money down.
The reality was a big disappointment: here it is on my 7×16 MiniLathe. The cross slide is fully retracted and I can only cut at radii less than 1/2 inch.

When I use a conventionally ground tool bit, I can reach the OD of this 3 inch faceplate.
Maybe if I had bought the left hand holder, I could get to a somewhat larger radius, but still not to the 1.5 inch radius of this faceplate.

I am not saying that this is a bad tool or a bad design, only that it is not suitable for the popular MiniLathes. If you buy one for use on your Southbend lathe, just be aware that the overhang from toolpost to cutting point is about 1.25 inch. What ever diameter you could cut with a conventional bit will be reduced by 2.5 inches. This is the “R8” model toolholder; the penalty is probably greater with the larger toolholders.

Interestingly, it works out better on my Sherline lathe.
Here I have it in Sherline’s standard holder for 3/8 inch bits and I can adjust the cutting point to center. I do not intend to use it here, however; the long overhang is likely to cause chatter.

Posted in Cutting, Turning | Leave a comment

Magnetic Base

This is my new magnetic base for indicators, and I am finding it to be very useful.
It is just the right size for use on MiniLathe and MiniMill and has plenty of articulation. All the joints tighten when you twist one knob. It is readily available at the big auction site.

It even clamps to the quill on my mill.
Here I am using it to center a rotary table.

I had earlier bought this larger magnetic base, but found it to have too little articulation to be of any use.

Posted in Alignment | Leave a comment

Thrust Plate for Compound Slide

I have had a MiniLathe for several months now, but am still having trouble making it function well enough to replace my Sherline lathe for routine reel making operations. One particular problem is that the dial of the compound slide will slip relative to its acme screw, thus losing my zero reference for an axial direction cut.

To understand the design flaw that lets this happen, we have to examine the parts of the slide drive screw.
Front to back here are
– clamp screw and lock washer
– crank
– washer
– dial and its loading spring
– screw guide
– acme screw
Notice on the acme screw the largest diameter portion (only about 1/8 inch axial length) which I will call the thrust collar.

The cross slide drive, which does not have the dial slip problem, has a similar acme screw with thrust collar. Its thrust collar is trapped between two parts of the apron assembly and thereby takes thrust reactions for both tension and compression of the screw. But the thrust collar of the compound screw is not trapped. The collar takes the thrust reaction (against the back of the screw guide) when the screw is in compression. But when the screw is in tension (as it is whenever the compound slide is advanced) the thrust reaction passes through the washer and the dial onto the guide plate.

The dial is subject to three sources of frictional torque:
– from its loading spring
– from the washer
– from the guide block
The problem with this is that the friction from the guide block can overcome the other two frictional torques. When this happens, the dial slips in angular position relative to the acme screw. This is a disaster for someone like me who depends on the dials. It would be much better if the the thrust collar was trapped so that the dial was not exposed to axial thrust.

So here is the part that I made to trap the thrust collar of the compound acme screw.
The flat on the top provides clearance from the bottom of the slide, and the notch at the left clears the gib.

This part screws to the back side of the guide block.
The axial travel of my compound is now reduced by about 1/4 inch, but this is a small price to pay for a dial that actually works.

For adjusting the MiniLathe, see the 3 videos “Cross Slide & Compound” on this Youtube channel:

My efforts to adjust the cross slide and compound gibs were relative ineffective until I lapped the slide dovetails. My lapping procedure:
1. Remove all the parts shown in the top photo of this post.
2. Slather valve grinding compound (500 grit) on the dovetail and gib surfaces.
3. Manually push the engaged slide back and forth several dozen times.
4. Clean off the grinding compound (now contaminated with metal).
5. Repeat steps 2, 3, 4 several times.

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