Mounting servo on top of table

[dikman]

Sorry, but I'll have to resort to asking. Uwe posted some posts/photos on his experiments with top mounting a servo but I'll be blowed if I can find them! I think they were inside another post, can someone point me in the right direction?

[R8R]

Seems easy enough aside from having nowhere to tilt the head back...

[SARK9]

56 minutes ago, R8R said:

Seems easy enough aside from having nowhere to tilt the head back...

Most of these "servo" motors are reversible, so you can mount the bulk of the motor outboard and it won't interfere in the slightest with tilting the head. I really like NOT having to weaken the table with the belt slot that is needed for an enormous underslung 40lb watermellon-sized noise generator.

-DC

 

[dikman]

Thanks Sark, that looks like the motor I intend to get (looking at the single pivot point) and pretty much as I envisioned it fitting.

R8R, you're right, it is pretty easy, but I recall Uwe did some work on this idea and sometimes he tends to think slightly outside the box, so to speak, but I can't remember exactly what he did.

I've decide to fit a motor to my 111W117 'cos hand cranking it is a great idea - as long as you've got 3 hands!! I can pick up a (nominal) 550w motor for about AU$112, but I would have to remove the steel reinforcing bar underneath the table to fit the belt plus the slot would be too close to the cutout for my liking. So the obvious thing is to fit the motor on top. Besides, once I got the idea into my head I just have to do it!

[Michiel]

Do you mean this photo?

(i saved it because i was working on a "transporteble industrial")

 

[dikman]

That could be it. That will work on a cylinder arm machine, but not on a flatbed. Looks like I'll be doing the same as SARK, as he points out it also makes use of some "dead space" on the table. At least now if anyone does a search on table top servos much of it will now be in one thread (so if anyone has anything pertinent to the subject feel free to add it here).

I've ordered the servo (I made sure it had separate controls) and it should be here by the end of the week. I've ordered the 109 leatherpoint needles (thanks Wiz) which should also be here about then, and made a new, better fitting bushing for the large pulley on the machine (there was a bit of slop in the old one which didn't matter for hand cranking but not good for a motorised system). I'll refit the original metal Singer pedal - a bit heavy, but looks good!

And then I wait.....

[Michiel]

If you mount it that way you will be able to turn your machine backwards (which is good)

but you have to change the rotation direction of the servomotor (just for the record, i am sure you already know)

i did the same for one of my flatbeds.

here is the quick device i made for the footpedal:

 

[Michiel]

Quick meaning that it was temporarily (but nothing is as permanent as temporarily

 

[leecopp]

Thanks Sark9 and Michael for the photos  ..  I am not familiar with the multi-chunk motor style.  Is the belt being tensioned by the weight of the motor or am I missing something.

Michael .. at the power company .. we had a temporary substation built out in the wilds on wooden cribbing and such at it had been there for more than 30 years when I connected to it last!.  

 

Happy Day

[SARK9]

2 hours ago, Michiel said:

here is the quick device i made for the footpedal:

 

When I'm using a table with a "normal" stand and existing pedal, I made up some adapter brackets for the remote sender unit:

-DC

[dikman]

Leecopp, in the case of SARK9's motor it is tightened in place by the large nut and bolt at the motor pivot point. I figure it shouln't be hard to make up a tensioning device if necessary. As I'll be using a conventional table I'll be mounting the speed control like SARK9 has done, should be easy as it is already mounted on a suitable bracket.

Michiel, looks like that workbench has seen a lot of use!

Edited October 7, 2018 by dikman

[Matt S]

Here is a machine I mounted on an old cutting board. It's a feed-up-the-arm so doesn't get used enough to warrant a table of its own. I mounted the servo on top so I can chuck it on the bench when I need to use it or keep it on the shelf otherwise.

9 hours ago, leecopp said:

Is the belt being tensioned by the weight of the motor or am I missing something.

1 hour ago, dikman said:

Leecopp, in the case of SARK9's motor it is tightened in place by the large nut and bolt at the motor pivot point.

Same with the motor in these pictures, and a few others I have. It's pretty efficient and quick to adjust, whichever way up the motor is mounted.

 

[DonInReno]

I’d have to have some sort of speed reducer - perhaps something compact like on a Sailrite, or a well thought out compact 2:1 model with a largish 1000w servo.

[R8R]

Artisan makes a "portable" 335 machine:

 

 

I am going to stop by there soon, they moved to a new location in San Bruno south of SF, which is a little closer to me now. I'll take some pics.

 

 The 1100w positioner motor Keystone is selling would work great on many different versions of this kind of setup. With a big enough pulley on the machine, no reducer required.

[dikman]

4 hours ago, DonInReno said:

I’d have to have some sort of speed reducer - perhaps something compact like on a Sailrite, or a well thought out compact 2:1 model with a largish 1000w servo.

I've taken care of that with a 7" pulley on the head and a 1 3/4" for the motor, which will give me 4:1. I'm a great believer in fitting larger pulleys on the head as it's much simpler than making reducers with shafts, bearings and pulleys and then trying to figure out how to mount the thing (I now have several in a box!), plus it makes handwheeling easier.

Nice one Matt. Lots of good ideas coming out of the woodwork.

Edited October 8, 2018 by dikman