Motor sizing and power train..?

I've been following builds and researching as I - slowly!- gather the parts, tools, and ideas needed to make one of these things/mullers/ox-mills...

Trouble is, there's no room for even a Dexter Bull (miniature cattle) at either furnace location. So it's going to need to be a motor. I'm thinking I'm going to need a stiff one - 1 hp - and it had best be totally enclosed, ball-bearings at each end, and fan cooled.

Am I full of <censored> in thinking this? Am I over-thinking this?

"Mullers, if I go by the commercial ones, *need to be swine for stout* and *pigs for grunt*"

 

Usually the reasoning for electric motors goes something like this: "Hey this motor costs next to nothing from the scrap metal guy/recycle shop/illegally dumped rubbish pile, I'll have to be creative with mounting and pulley reduction to get the RPMs I need to do the job. If given a choice, get the motor with the lower RPM range like a 4-6 pole instead of the more common 2 pole as the pulley reductions can be handled with one belt and two pulleys rather than having two belts, four pulleys and an idler shaft. They tend to be physically bigger for the same HP rating (if you halve the speed you have to have double to torque to arrive at the same horsepower).

 

True. I was figuring on NOT being able to get the bargain-priced motor, as those tend to be uncommon in my area. What is much more common is said scrounged motor being sold for nearly as much as a new one! (By sordid individuals...)

Given what I have to work with, I'll most likely need to shop with care when I buy/order a motor - which will most likely be one sold as new.

Of course, I'll be looking at a 1725 rpm motor in 60hz land.

As for the power train, thought was to use a 168 tooth Chevy flex-plate, with the matching starter gear portion. This would be enclosed in a cast sump, wih some means of squirting gear oil at the mesh.

 

Buying a motor, even surplus or secondhand will give a lot more choice on what you get. Motors aren't exactly growing on trees so you have to keep an eye out for them as opportunity permits: things like exercise treadmills are a source for 90-180VDC motors that can be controlled by a PWM motor controller. Another good source of 2HP single phase motors are electric woodchippers, I was given one for free as it was "dead" and all that was wrong was the breaker needed to be reset. So having a mental list of appliances like clothes dryers, treadmills, woodchippers etc. that contain motors rather than loose motors in the wild is a good strategy. Recently I scored several ABB brand three phase motors that were sold as 415V star but on closer study they had links to configure as 240V delta motors....they were new from the distributor but had been knocked off a pallet so the lifting lugs were bent and one had a ding in the fan housing. Worst case, I'll have to put bearings in them but they were 1/4 the retail cost.

 

While I think about it, the good thing about A section belts is the fact that they can slip in the event of an accident or failure whereas tooth belts or gears are too positive a drive method when things go wrong.

 

The gears provide about 17 to one. The remainder is done with a belt. (So it can slip if something gets bound up). Then, there's also to be either a shear pin or spring clutch...

 

Wish I had a tractor. The livestock references come from fiction. I'm getting the block out right now, and hoping to resume writing soon...

 

I do plan to use belt for connecting up the motor to the "gearbox", with a spring-loaded tensioner...

 

Yes, I know. Welders, crucibles, specially formed cutters, supplies, sand - I yearn for 140+ mesh Petrobond...

 

It sounds like you want to build a muller “ from the ground up.” Fine and dandy. But one reason in favor of converting a small-batch mixer to a muller is that all the gear reduction, bearing mount for the drum, dumping/pivoting has been worked out. I converted a vintage mixer to a muller I really like. And yes, a 1 HP TEFC ball bearing motor is just the right size and configuration. I bought mine from Grizzly which is about a mile from my house. The motor has been good. The 1/2HP motor that came on the machine worked pretty well. But once I converted to 1 HP, the benefit was obvious.

Including a big paddle-style shut off switch seems like a good idea.

Denis

http://forums.thehomefoundry.org/index.php?threads/another-cement-mixer-muller.286/

 

There's a lot to be said for repurposing ready made components or assemblies. The artform is in putting them together to make them work in new roles. There are several types of design to decide on as well: moving tool/fixed drum, or fixed tool/turning drum.
My first muller was a Von Torne (google images) built from the ground up. It works well for greensand but I was told-rightly I believe- that it wouldn't have the chops for petrobond. My second muller was built from a piece of surplus industrial equipment, a carousel assembly table, that already had frame, motor, gearbox, and drivetrain in place. I had to fabricate the drum sides and fixed tooling. Both required some ingenuity and I admittedly reinvented the wheel more than once, but both were functional and satisfying builds.
To touch on the OP, both have 3/4 hp motors and both have slip built into the drive trains.

 

Here's where the ox-mill idea comes from

 

I am not sure. Both locations have somewhere between two and six hundred pounds of sand, and all of that sand needs mulling badly. Thought was to run all of it through once thoroughly, then just do the facing sand when it's used.

 

Ps: I would most likely need to buy either new, or (used at near-new prices) were I to go the cement-mixer route - and then end up with a marginally-functioning (or barely-functioning!) makeshift. I've followed that advice before, and I ended up cursing myself a lot. Other people seem to do lots better going that route than I do.

The bike stand - built from the ground up - however... Few regrets, there. That works better than I thought it would! (5 castings used in it)

 

Sounds like you need something portable to throw in the back of your truck, haul to one site, mull their sand and ditto to the other.
The HF mixer conversion sounds about right for the job. You would be hard pressed to keep the weight down to that level with a purpose built muller. We'll call you 'Have Muller, Will Travel'.

 

I wish I had a truck. Or car. (Cannot afford the operating costs at this time.)

Thankfully, both places have them, so that's not much of an issue.

So let's see: 1 HF mixer, 200+ for a motor upgrade, (grizzly wants 2 1/2 bills) and a similar added amount for converting it into a muller. Sound about right? That doesn't include correcting the likely deficiencies that will be present when I get gamed by the people I buy the mixer from. (Happened with the hydraulic press. Only good thing from that one is the jack and the plates. The frame is not something that can be improved readily, unlike the bolt-together version.)