Turret spindle thingy project

[Graziano]

Been in the shed cutting up some 150mm wide channel to make the "turret" for want of a better word to mount the homemade ball bearing spindles on. I'd originally planned to angle the three lengths of channel at 45 degrees to the rotating disc so that the unused spindles angle up and take up less space for the unit. Anyway I'm glad that I took the time out to mock up the turret and see how the pieces assembled before doing any welding as the wheels tend to get in the way of each other a bit, once I angled the channel bits to about 30 degrees the distances increased.

Can anyone see a problem with the current setup?, about all I can see is that the access to the tops of the wheels is a bit obstructed, but I don't plan to use the tops anyway.

Edit: I'm also interested in name suggestions for this thing other than "Spurret" .

When in use the selected spindle will have it's channel base horizontal as per the rough sketch.




Original setup with 45 degree angled channel, the channel to channel angle is less than the expected 90 degrees due to the geometry.



45 degrees with a 200mm grinder wheel and 200mm buff mop propped in position.




30 degree angle setup with increased clearances.

[Anorak Bob]

It's worth mocking things up. I'm keen to see how you resolve the turret locking problem. Would a sprung ball detent be better than a dowel?

BT

[Graziano]

It's worth mocking things up. I'm keen to see how you resolve the turret locking problem. Would a sprung ball detent be better than a dowel?

BT

Hmmm, I don't know if a ball detent is going to lock it positively, I expect it could move if you were leaning into the buff mop or wire wheel and giving it some. I seem to be stuck on the taper pin idea, say 10-15mm diameter and pulled out from below by the same footpedal that lifts the motor to slacken the belts. It could be drilled into the turret disc periphery somewhere.

[morrisman]

I am trying to get my head around this project

Takes me a while to see whats going on

How are you going to drive the spindles ?

It's a 6 station grinder / polisher I think

Mike

[Bryan]

Mark I think belt swapping is going to be tedious. How about a friction drive? As a spindle dropped into position it could engage a drive wheel on the motor.

[Ueee]

Hi Mark,
Looks good, but when you first mentioned this i imagined something more like a ferris wheel. This way you could have your motor back of the center and belts to all 3 heads, but only the front head's belt would be tight. Make sense? I would also use either a taper pin or an arm that pivots into a notch for locking the rotation.

As for the name, how bout MK1 Multi Spurret? (pun intended) Spurret, yet another word to add to spell check.

Ewan

[Michael G]

Well, there are six ends and you are grinding and buffing with it -
How about a "Hexagruff"

One of the things I would be concerned about is flicking metal particles from grinding into a buffing mop. Are you going to have covers for the mops, or just rely on having the right things adjacent to each other?

Michael

[Graziano]

Morrisman: Gee... from the detailed artist's rendering I really thought the entire concept was self evident..... Only a single spindle is belt driven, you'll step on a foot pedal to lift the motor and take the belt tension off also unlocking the turret so the next spindle can swing into position and then you hand fit the belts and let the motor drop again.....simple eh??.


Bryan: friction drive might have to be another modification, I'll try the belts for now. I expect infrequent spindle changes........oops now I've jinxed myself!!. I suppose three bench grinders on a turret mount could have been simpler.

Ueee: I had thought of a setup like that, it does get complicated fast, in that you need two posts with the spindles in between on a rotisserie thing (that's a tech term) which may take up even more space than three basic pedestal units and three motors.

Michael: I don't know how I'll prevent cross contamination, a cover sounds good...either that or hope that turning it on flicks a huge shower of crud everywhere on take off. The beauty of inventing stuff is effectively dealing with all the "bugs" as they rear their ugly heads.

So we have "Mk1 Multi Spurret" and a more descriptive "Hexagruff", sounds good, they have a certain ring to them. Hmmm I wonder if I could come up with a plausible acronym based around "CLOACA" or something.

[Anorak Bob]

Hmmm, I don't know if a ball detent is going to lock it positively, I expect it could move if you were leaning into the buff mop or wire wheel and giving it some. I seem to be stuck on the taper pin idea, say 10-15mm diameter and pulled out from below by the same footpedal that lifts the motor to slacken the belts. It could be drilled into the turret disc periphery somewhere.

I like the idea of the pedal operated pin. Rather than root around with a ball and spring which then requires a separate locking mechanism, the pin would locate and lock in one action. Nice.

[Graziano]

The Spurret Mk1/Hexagruff is coming along a lot faster than I expected, been having a few wins and a few issues to overcome. The design issues could have easily been sorted out by making a detailed drawing instead of diving in headfirst. The advantages are as expected, the spindles give room at the rear of the unit so it should tuck into a corner pretty well, you can see from the middle pic that the spindles shouldn't poke much past the motor when wheels are fitted. The use of a mongrel trailer hub and stub axle (Holden bearings with Ford stud pattern) I had lying around gives excellent rigidity to the turret, which has a fair bit of mass to dampen vibrations. At present the three channels used as spindle bases are angling up about a degree or two as I didn't quite get the stub axle at 60 degrees to horizontal, I may fix that up later on. The motor is a 1Hp old school GMF "Cadet" made in Sydney that I cleaned up and fitted a new set of bearings to, it has the dumbell iron pulley on it.

Where I am seeing a potential problem is in the length of the belts required and in the fact that I'd like the motor movement to give a lot of belt slack....I can't see that happening easily with the original plan of the motor moving up and down the column. I may have to try a few motor positions and mounting methods to get it to work, I'd like to avoid an idler pulley for now but that may end up being the easiest option.

Cheers,
Mark

[Stustoys]

Hi Mark,
Things are certainly moving along.
As far as your belt problem goes, have you thought about mounting the motor on a hinged plate. Hinge at the top if the motor is on the front of the post, on the bottom if the motor is at the back of the post.

Stuart

[Graziano]

Hi Stuart, that's pretty much what I'm thinking of doing. For it to all work smoothly I have to lift the belts over the grinder wheels, mops etc. each time I select another spindle. The motor itself if hinged would need to move a fair bit, so If I ran a few short lengths of 25mm RHS off the motor base and then hinged those I could get a fair bit of swing hopefully, then run a pushrod down to a foot pedal.

[BobL]

I assume that only one end of the turrets can hold a wheel and the other will hold a pulley?

If so then this is how I would have oriented the spindles


The motor could be much higher up so the belt could also be made much shorter and in this orientation will naturally hold its tension better as it is not pulling on the side as in your design.

The arms could also be much shorter as the wheel would be hanging put in the breeze a lot more and be even better accessible. Also a protective shield around the belt might be easier to facilitate.

The arms would either need to be thinner so the belt will not rub on them or wider (or double armed) so the belt could pass through an opening on the arms. something like 2" steel pipe? If this still gets in the way then slightly offsetting the spindles from the arms would be another option.

I agree with Bryan, changing the belt is going to get really tedious. I would even think about using leaving belts on all spindle pulleys so you only unhook the motor end.

[Log]

I assume that only one end of the turrets can hold a wheel and the other will hold a pulley?

.

Hi BobL,
Actually the pulley goes on between the grinding wheel or buff and the bearing housing. I have a couple of old J.D spindle assemblies and on the double ended one, one side of the pulley is used as the inner flange that the wheel(or whatever) butts up against.

Graziano, if you want I can put up a pic of each of the ones I have. You did a great job of the spindle housings/spindles. Once upon a time these spindle assemblies were common in the catalogue's (another word for the spell checker), not anymore it seems.

Cheers.

If I'm not right, then I'm wrong, I'll just go bend some more bananas.

[BobL]

Hi BobL,
Actually the pulley goes on between the grinding wheel or buff and the bearing housing.

Ok - I'd still prefer to have the motor around the front, under the arm and keep the belt as short as is practical.