I was just asked by someone who found my blog if it was possible to reverse a Mark V.
This is an excellent question and it's something that Shopsmith is working on and will soon offer in the form of the PowerPro headstock. (Wow, this is outdated! The PowerPro headstock was introduced in 2010) The current motor that is within the Mark V cannot be made to run in reverse, but that being said about 20 years ago I saw an idea that actually worked quite well.
The owner of a Mark V found a reversing motor and mounted it on a heavy board which itself clamped on the way tubes behind the Mark V headstock. This device had a set of shafts, belts and step pulleys and coupled to the lower drive shaft on the headstock. When the unit was coupled to the headstock the speed dial on the Mark V was turned to high speed with the Mark V's motor off. This sounds like it would damage the unit, but damage is only done when lowering the speed with the motor off. What this did was create slack in the lower drive belt within the headstock, allowing the second motor to drive the unit without drag from the stock motor.
This is tough to explain, so I've attached an elementary drawing which I hope makes sense.
Click Pic to Biggie Size it. Not only did this allow for bi-directional rotation, but with the pair of step pulleys the machine was able to spin at a much lower RPM that the standard low speed of 700 RPMs for a mechanical Mark V. Had that motor been variable speed, like those found on a treadmill, the design could be much simpler.
Showing posts with label speed reducer. Show all posts
Showing posts with label speed reducer. Show all posts
Reversing and slowing a Shopsmith Mark V without a Speed Reducer or PowerPro
I was just asked by someone who found my blog if it was possible to reverse a Mark V.
This is an excellent question and it's something that Shopsmith is working on and will soon offer in the form of the PowerPro headstock. (Wow, this is outdated! The PowerPro headstock was introduced in 2010) The current motor that is within the Mark V cannot be made to run in reverse, but that being said about 20 years ago I saw an idea that actually worked quite well.
The owner of a Mark V found a reversing motor and mounted it on a heavy board which itself clamped on the way tubes behind the Mark V headstock. This device had a set of shafts, belts and step pulleys and coupled to the lower drive shaft on the headstock. When the unit was coupled to the headstock the speed dial on the Mark V was turned to high speed with the Mark V's motor off. This sounds like it would damage the unit, but damage is only done when lowering the speed with the motor off. What this did was create slack in the lower drive belt within the headstock, allowing the second motor to drive the unit without drag from the stock motor.
This is tough to explain, so I've attached an elementary drawing which I hope makes sense.
Click Pic to Biggie Size it. Not only did this allow for bi-directional rotation, but with the pair of step pulleys the machine was able to spin at a much lower RPM that the standard low speed of 700 RPMs for a mechanical Mark V. Had that motor been variable speed, like those found on a treadmill, the design could be much simpler.
Shopsmith Speed Reducer and Speed Increaser Information, Review and History
Don't get so excited with eBay prices that you pay more than the price of a new tool! The current MSRP of the Shopsmith Speed Reducer is $372.53. The MSRP of the Speed Increaser is $479.99. (Updated Feb 2021) These two tools went extinct for a couple years and the used prices went through the roof! FYI, You can use the Shopsmith Speed reducer on the Mark I (For Disc Sanding and Lathe Turning only), and on the Mark II, Mark V, Mark VII for Sanding, Turning and Drilling! The Speed Increaser can be used for Shaping and Routing on the Mark I, Mark V Model 500, 505, 510, 520, and the newest Mark 7. And yes, you can power these with a PowerPro headstock, but I wouldn't suggest taking the Speed Increaser above the designed 5200 max RPMs or you will damage the plastic friction plate. The Speed Reducer mounted on a PowerPro headstock would have a new low speed of 36 RPMS!
Here's a video I did of a DIY speed reducer:
Click here for Shopsmith Speed Reducer and Speed Increasers For Sale
Ya what more? OK, here goes...
Did you know:
- The Shopsmith Speed increaser was inspired in part by the Snapper lawnmower company (US Patent #US4498552)
- The Shopsmith Speed increaser contains two common parts that you wouldn't suspect: A 3 3/4" faceplate (Yes, a faceplate that you'd use for turning) and a water pump bearing assemblies like the one found on the Mark V, the Shopsmith Bandsaw, and several Shopsmith tools.
- There is a thin plastic disc on the above-mentioned faceplate that must be occasionally replaced. Its life can be extended if you make sure to turn the speed down before you turn your Mark V off (It doesn't need to go all the way down to slow though) and make sure that it's running at full speed before your plunge the wood into the cutter.
- Even though it will raise the speed to 10,000rpm's, keep in mind that this is still half the proper speed for a router bit. That said this is just right for shaper cutters because they have three cutters as opposed to two, and they are usually a larger diameter than router bits. This makes their tip speed much faster than a smaller dia. router bit.
- The Shopsmith Speed Reducer is an amazing device that contains two Poly-V belts, four pulleys, and five bearing assemblies!
I've posted a couple videos using the Shopsmtih Speed Reducer. In this one I use it for powering a Shopsmith SPT (Bandsaw) at slow speed, as well as drilling with a large Forstner bit:
In this video I use it to do some slow-speed faceplate turning of a large maple bowl:
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