New Tachometer For Sheldon Lathe

As many of you know I purchased a Sheldon MW-56-P lathe earlier this year. The spindle speed is changed by a gear motor that is connected to a Worthington All Speed Drive. As such speeds are infinitely variable between 40 rpm and 2,200 rpm.

The machine originally had a mechanical tachometer with a drive similar to the old style automobile speedometer. The tachometer is long gone and replacement parts are no longer available. I am considering installing a MachTach V 2.6 in a stand alone enclosure.

http://www.machtach.com/About.html

The tachometer build and installation appears relatively easy.

Has anyone tried one of these tachometers, and if so would you recommend one for this purpose? I am also considering one for a Bridgeport Series I vertical milling machine.

Thanks in advance

I was using successfully a similar device. Got it from the web as "LED Tachometer RPM Speed Meter + Hall Proximity Switch Sensor"

projectnut said:

As many of you know I purchased a Sheldon MW-56-P lathe earlier this year. The spindle speed is changed by a gear motor that is connected to a Worthington All Speed Drive. As such speeds are infinitely variable between 40 rpm and 2,200 rpm.

The machine originally had a mechanical tachometer with a drive similar to the old style automobile speedometer. The tachometer is long gone and replacement parts are no longer available. I am considering installing a MachTach V 2.6 in a stand alone enclosure.

http://www.machtach.com/About.html

The tachometer build and installation appears relatively easy.

Has anyone tried one of these tachometers, and if so would you recommend one for this purpose? I am also considering one for a Bridgeport Series I vertical milling machine.

Thanks in advance

Click to expand...

Replacement parts may be very much available. Just not with Sheldon's logo on them. OTOH, they bought-in the tachos anyway.

"A while ago.." expecting to ADD a mechanical tacho to a mill... or two.. I scarfed-up a slew of NOS Stewart-Warner "Diesel/Marine" tacho heads, complete. 3,000, 3500 and 4,000 RPM tops, as opposed to 6K to 8K (and beyond) RPM auto/motorbike enhanced performance units..

I have two types: Mechanical cable drive. Electric analog (tachogenerator) drive. AND NOT electronic pulse-train with integration. Diesels are a tad short of sparking plugs, ordinarily.

If your original was cable driven, a mechanical, 3K RPM max should be a near-as-dammit drop-in fit, mechanically. The readout head may be larger. Or not.

All that stuff is still "out there" for medium or "high" speed Diesel/Marine use - a reasonably fair match to your peak RPM.

Shoot me some dimensions. I'll see if I have anything that Just Fits.

Monarchist said:

Replacement parts may be very much available. Just not with Sheldon's logo on them. OTOH, they bought-in the tachos anyway.

"A while ago.." expecting to ADD a mechanical tacho to a mill... or two.. I scarfed-up a slew of NOS Stewart-Warner "Diesel/Marine" tacho heads, complete. 3,000, 3500 and 4,000 RPM tops, as opposed to 6K to 8K (and beyond) RPM auto/motorbike enhanced performance units..

I have two types: Mechanical cable drive. Electric analog (tachogenerator) drive. AND NOT electronic pulse-train with integration. Diesels are a tad short of sparking plugs, ordinarily.

If your original was cable driven, a mechanical, 3K RPM max should be a near-as-dammit drop-in fit, mechanically. The readout head may be larger. Or not.

All that stuff is still "out there" for medium or "high" speed Diesel/Marine use - a reasonably fair match to your peak RPM.

Shoot me some dimensions. I'll see if I have anything that Just Fits.

Click to expand...

Thanks for the offer. I'm out of town right now and won't be returning until about the 16th of the month. I should have mentioned that in addition to the tachometer itself being missing all the drive mechanism has also been removed. This includes the mechanical drive, jackshaft frame, drive pulley, drive belt, and cable. In short there are no tachometer components remaining on the machine.

I have searched several sources to see if any of these could be obtained either new or used without success. This system was only used for a very short time period (I believe late 1959 to early 1960). Late in 1960 they changed from a mechanical tachometer to an electronic one made by Simpson. I've found a couple electronic ones, but none have the pulse generator. According to some articles the pulse generator was similar to a wheel mounted bicycle headlight generator. I can't find enough information to know if a compatible generator is still available.

If I was to put a tach on my lathe, it would be an analog type. Those digitals make my eyes explode!

projectnut said:

Thanks for the offer. I'm out of town right now and won't be returning until about the 16th of the month. I should have mentioned that in addition to the tachometer itself being missing all the drive mechanism has also been removed. This includes the mechanical drive, jackshaft frame, drive pulley, drive belt, and cable. In short there are no tachometer components remaining on the machine.

I have searched several sources to see if any of these could be obtained either new or used without success. This system was only used for a very short time period (I believe late 1959 to early 1960). Late in 1960 they changed from a mechanical tachometer to an electronic one made by Simpson. I've found a couple electronic ones, but none have the pulse generator. According to some articles the pulse generator was similar to a wheel mounted bicycle headlight generator. I can't find enough information to know if a compatible generator is still available.

Click to expand...

As said, ALL the parts can still be had - just not collected as Sheldon-specific.

Shaft-end right-angle gearbox, stock flexible cabe in sheath, mechanical (speedometer-cousin) Tach, and you are back in business.

Otherwise.. Analog electronic, full kits are out there, Diesel RPM range the closest common fit.

Digital flickering can be smoothed, but still.. AT LEAST the last digit is chronically changing, each sample period if they have any degree of precision worth mentioning.

I would much rather find all the pieces to put together a mechanical tachometer. So far the only things I have been able to come up with are the tachometer head and cable. If you could point me in the direction to find the right angle gear box I'm sure I can fabricate the remaining parts. I'm certainly not hung up on having the name Sheldon on the faceplate. I believe the originals were made by Stewart Warner. I would be interested If you have any pieces you are willing to sell. When I get back home I'll measure the size of the opening in the spindle cover. If I recall correctly it's 3 3/8" diameter, but it's been sometime since I measured it and I don't trust my memory.

I do agree that a digital readout could be maddening if the last digit continues to fluctuate. The only digital system I've used was an upgrade on a 1980's era Clausing machine. The last digit was stable, but I have no idea what circuitry was in place to keep it that way.

I do recall some of the early 1980's Cadillac's could be ordered with a digital speedometer. I only drove one with the option. The customers complaint was the continual changing of the bright blue 1.5" high numerals in the middle of the instrument cluster. I agreed with him that it was more than distracting, however at the time there was no resolution for the problem. Needless to say I've never purchased a vehicle with a digital numeric speedometer.

projectnut said:

I would much rather find all the pieces to put together a mechanical tachometer. So far the only things I have been able to come up with are the tachometer head and cable.

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Might want to seek for this sort - 2500 RPM full-scale:

Vintage 197's White Freightliner Stewart Warner Truck Tachometer 3 3/8" Gauge | eBay

If you could point me in the direction to find the right angle gear box I'm sure I can fabricate the remaining parts.

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There's enough general-purpose RA drive stuff around I hadn't even given that part much thought.

On edit:

Stewart-Warner.... of course. Still a current item, two versions:

Right Angle Adapter for Flexshaft

Expects clockwise rotation.

Right Angle Adapter for Flexshaft

Expects COUNTER clockwise rotation.

1:1.04 ratio probably applies to both.

Just to cover the ground, shaft encoders are readily available in a wide range of counts per turn. Red Lion has a digital readout that has worked well for me. In one case I wanted a tach on a South Bend lathe. I used a magnetic pickup on the large back gear teeth. In such an application the normal thing is to use a 60 tooth gear or other toothed item so a one second counting time reads direct in RPM. The South Bend has a 72 tooth back gear. Red Lion makes a unit that can be configured for any number of teeth, for more money, of course. I noticed that the cheaper version had settings for 50 and 60 cycles to generate the time base, so I set it for 50 cycles and ran it on 60. The 5/6 second interval is correct for a 72 tooth gear, maintaining the fearful symmetry of the universe. It has been a set it and forget it unit, have never had to do anything. The numbers changing never bothered me.

Bill

9100 said:

Just to cover the ground, shaft encoders are readily available in a wide range of counts per turn. Red Lion has a digital readout that has worked well for me. In one case I wanted a tach on a South Bend lathe. I used a magnetic pickup on the large back gear teeth. In such an application the normal thing is to use a 60 tooth gear or other toothed item so a one second counting time reads direct in RPM. The South Bend has a 72 tooth back gear. Red Lion makes a unit that can be configured for any number of teeth, for more money, of course. I noticed that the cheaper version had settings for 50 and 60 cycles to generate the time base, so I set it for 50 cycles and ran it on 60. The 5/6 second interval is correct for a 72 tooth gear, maintaining the fearful symmetry of the universe. It has been a set it and forget it unit, have never had to do anything. The numbers changing never bothered me.

Bill

Click to expand...

I have both programmable divider-chain encoders and programmable digital readouts.
Also mag prox, optical, and Hall-effect sensors. Plus a few Servo-tek DC tachogenerators kicking about that are seriously accurate if read with an ignorant Voltmeter - Analog OR Digital.

Even so - the OP's lathe was built for mechanical S-W tacho, and we now find that it seems S-W themselves still offer most of the relevant parts, eg: R/A drives and cables.

So.. seems simplest for his case to basically restore it to OEM concept and function.

Even if some of the parts - such as a "Diesel" tacho head - are not 100% identical to those as left the factory, they'll do the same job in the same general manner, and with not a great deal of hassle or much fabrication required.

2CW

Simpson is still in business. Still made in USA.