Motorized slip roll speed

[Firstram]

I just built a stand for my Enco slip roll and added a 60:1 DC gear motor to power it. While I can slow the motor down with controller adjustments, I'd like to keep the max speed at a reasonable level mechanically. What RPM does a powered roll usually run at?

 

[BukitCase]

I bought this one off CL about 10 years ago, still tryin' to find time to finish it up - it has 4" diameter rolls and a 1-1/2 horse 1725 rpm motor. Surface speed on the rolls is around 10-12" per minute. Don't remember actual numbers, but the large pulley you can see runs a 60:1 gearbox after the 2" motor and 6" gearbox pulleys divide the 1725 by 3 - running the math, it comes out to roll surface speed of just over 120" per minute.

The enco's rolls are smaller, so your math would be different - but when I had it running, the 120"/min felt real comfortable.

The beast turned out to be a home build by the seller's deceased dad, who worked at the same rare metals plant I did (but 'way before my time) - supposedly they used this one to roll 4 foot diameter rings out of 1" x 12" steel flat bar - I didn't see that, but DID watch it turn 2 foot wide 1/4" plate into a 16" diameter cylinder ( 2 passes) and the speed never changed.

The second pic is of the included ring roller add-on that came with it; driven by the other end of the driven roll, several dies included. IIRC, those drive chains are #70.

I don't think you could go wrong with 120 surface feet/minute, not sure what power would be needed with the smaller rolls... Steve

 

[Firstram]

Thanks Buk, that is a beast! My motor is only 1/2 hp but the roll is only rated for 16 ga so it should be fine. Targeting 120 IPM I'll need to drop my speed by 2.25:1 after the gearbox.

 

[BukitCase]

Couple things -
one, everybody's "comfort level" is different, might wanna play with it a bit before commiting to another mod -

two, having spent the last 34 years of my working life in HEAVY industrial if I were going to do a speed reduction with belts and pulleys, I would put that part BEFORE the gearbox - MUCH lower torque requirement on the belt, so a LOT less chance of belt slippage.

Then again, your 16 gauge roll might never have that problem. ( there's a fair chance your job DIDN'T entail working on 10,000 PSI 300 horsepower hydraulic systems pushing 3 foot diameter cylinders :=) ... Steve

 

[dkmc]

I have an Enco powered slip roll, same model as shown in this video

In the spec sheet, it says the roll speed is 200 IPM. You can see the rolls turn in the video, way too fast in my opinion. I intend to replace the gearbox sprocket with a much smaller one, and slow things down quite a bit. 120 IPM sounds much more sane to me. The couple times I've used it since refurbishing it, have been...interesting....it just turns too fast.

 

[BukitCase]

Yeah, me too; among other hobbies I play guitar, bass, drums, keyboards and a tiny bit of cello - makes me VERY aware of where my fingers are, and the speed of the beast I have did NOT make me run and hide ... Steve

 

[Firstram]

I plan to use chain for the final drive so I’m not too worried about belt slip. If 120IPM is too fast I’ll adjust the max speed trimpot to slow it down to a comfortable level.

I will add a polarity reversing switch on a bar across the front of the stand, instant reverse.

 

[dkmc]

I'd like to see pics of that when you get it installed. Sounds like a great safety feature. My motor is 3phase, I'm considering installing a VFD. One of the 1phase to 3phase units, then it can be plugged in anywhere. Also the braking feature would be nice to have. It would probably be near instant stop with such low inertia in the system. The VFD's at 1-2hp are quite cheap now.

I will add a polarity reversing switch on a bar across the front of the stand, instant reverse.

 

[vpd66]

The slower the better for slip roll speed. I've been a sheet metal worker for over 25 years and have seen at least 3 times where guys have had there fingers crushed by a slip roller that went too fast. I'm still a sheet metal worker but I'm working in a production shop and the rollers we have now are much slower then the ones I've ran in the past. They also have a guard made out of 16ga steel that come down in front of the roller so there is no way of having your fingers getting sucked in.

 

[Firstram]

They also have a guard made out of 16ga steel that come down in front of the roller so there is no way of having your fingers getting sucked in.

Thats a good idea! Thanks

 

[JJohns3WG]

Not a slip roll, but I put a drive on my bead roller. Runs at 10 rpm. which gives around 70 inches per.min. Its slow enough that you don't panic trying to keep up in the turns, a little faster would be nice on longer runs. I just remind myself shop time is good time.