Installing cone point set screws

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ericfox

Plastic

Joined

May 23, 2011

Location

OHIO, USA

• Apr 27, 2019

• #1

Hey guys

We will be installing some cone point set screws on some bearing collars on conveyor shafts that keep walking. We were going to use a center punch into the set screw holes on the bearings to make a big indent where the set screw would seat. I wonder if this might later cause issue with removing the bearings as they must slide over this spot for removal. Maybe better option is to drill small shallow hole in shaft and install the cone point screws?

Thanks for any ideas. Eric

 

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projectnut

Stainless

Joined

Mar 4, 2006

Location

Wisconsin

• Apr 27, 2019

• #2

Option B would certainly make future disassembly much easier. Another option would be to mill a flat on the shaft where the set screw makes contact.

 

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cosmos_275

Hot Rolled

Joined

Jun 9, 2015

• Apr 27, 2019

• #3

Dog point set screw and a shallow hole

 

Wlodek

Aluminum

Joined

Nov 15, 2018

• Apr 27, 2019

• #4

Both above suggestion are the correct answer. In any case, a punch mark is not deep enough to secure a set screw, the cone of the screw should be fully engaged in the shaft. When making a similar assembly I am using a small countersink that fits the set screw thread (without damaging it) in the collar or part to be secured and drill through it to the required depth.

 

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atomarc

Diamond

Joined

Mar 16, 2009

Location

Eureka, CA

• Apr 27, 2019

• #5

The fact the the drum is walking is a sign of a different problem..one you're trying to fix by capturing the shaft with a little screw. At the very least, a bearing should be used that has a squeeze-loc feature or an eccentric lock feature.

Stuart

 

EPAIII

Diamond

Joined

Nov 23, 2003

Location

Beaumont, TX, USA

• Apr 27, 2019

• #6

Yes, it sounds to me like you have a vibration problem. You should fix that.

As for keeping the shaft from getting buggered up, a flat is the usual solution. You don't have to take it apart to mill it, you can probably just use a file in place. It does not need to be super precise.

 

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atomarc

Diamond

Joined

Mar 16, 2009

Location

Eureka, CA

• Apr 27, 2019

• #7

Most conveyors would never run fast enough to ever reach a vibration speed. Often the culprit is a very wide conveyor with shafts that are too small allowing them to 'gyrate'..for lack of a better word. This motion will naturally make the shaft walk out of the pillow block or bearing..that's been my experience.

Wimpy head drums and tail drum with marginal shaft sizes are prone to this problem.

Stuart

 

E

ericfox

Plastic

Joined

May 23, 2011

Location

OHIO, USA

• Apr 27, 2019

• #8

Thanks guys - it is actually a set of 12 screw conveyors on the bottom or a bin. They call it a live bottom bin since the whole bottom is basically moving. The screws push material forward to fall onto a collection screw. Most of the screws stay put but a few traveling so we’re just trying to keep in place. The set screws are 1/2-13 so I’m inclined to drill a 3/8 hole into the shaft and put in the cone point screw. If you guys think a dog point screw would be mire effective to warrant returning the cone point ones let me know.

There are no vibrations enough to create issues. The screws turn at about 5 RPM.

Thanks for all the advice so far

 

Spruewell

Hot Rolled

Joined

Sep 8, 2015

Location

Northern California

• Apr 27, 2019

• #9

You will not be able to put a significant enough depression for a 1/2” set screw using a punch without severely damaging the shaft and making it extremely difficult to remove the bearing. As the punch drives its way into the material, it will also upset the material around it creating a small volcano shaped feature that will interfere with the bearing. Just slide the bearing to one side and use an angle grinder to put a flat spot in the shaft then use the standard cupped point set screw. There are also set screws available with a serrated cup point.

 

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Leadfootin

Cast Iron

Joined

Feb 5, 2009

Location

London

• Apr 27, 2019

• #10

On my gravel conveyors I used eccentric locks on the bearings. This way the set screws only have to hold the lock collar tight enough for the eccentric to lock the bearing in place. Note, on tail pulleys only lock one side and let the other float. If both sides are locked bear life can be quite short and other problems such as belt wandering and spillage will arise.

 

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ericfox

Plastic

Joined

May 23, 2011

Location

OHIO, USA

• Apr 27, 2019

• #11

Thanks guys - here is the bearing that is installed on each side of the screw. It is the OEM spec'd bearing - I'll have to see if something is available with eccentric collar.

It is a Dodge FCE307R 3-7/16" shaft size. I'll call our distributor on Monday to see.

If we can't get anything better then I guess we will see about pulling the bearings and grinding flat spot with serrated cup tips

 

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atomarc

Diamond

Joined

Mar 16, 2009

Location

Eureka, CA

• Apr 27, 2019

• #12

Wow..that's a moose of a shaft and bearing. I'll bet that all the movement of the shafts is in the opposite direction of the material flow..they're being shoved back by the reaction of the flights against the material. If that's the case I'm surprised there isn't a spacer of something between the bearing and the flights of the screw that would keep it from pushing backward.

Stuart

 

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gmach10

Hot Rolled

Joined

Dec 27, 2008

Location

N.E. Illinois

• Apr 27, 2019

• #13

Several years ago I worked out of the hall at one of our newspaper printing facilities. Huge Goss presses. We were doing a cut down. Essentially resizing the press to print a physically small size paper. Anyway Goss had supplied us with a spotting drill with a body diameter of the tap drill for the set screw going in hole. Locate the bearing, spot drill the shaft and they stayed put. Don't know who made them or what they were made from but they cut with very little pressure.