UniLoc pin diameter?

B

BJK

AzB Silver Member
Silver Member
Anybody know what the standard is for the original UniLoc pin diameter? And what the acceptable tolerances are? I ordered some components and one of the stainless pins is larger than the rest and it bound and galled up one of the brass inserts after I test fit it by hand. I had to whack it out with a little drift.

The offending pin mic'd at .2790 while the rest measured .2786 or .2787. For reference, my Lucasi and Predator cues measure .2785 and .2787 respectively.

I can't reliably measure the bore of the inserts I received, or the inserts in my shafts, but aside from the one ruined on the big pin they all have a nice slip fit on the normally sized pins.

I'll reach out to the company to get these items replaced, but I'm curious what the spec is on these things, and how 4 tenths caused me such a headache.

Thanks.
 
K

KJ Cues

Pro Cue Builder & Repair
Silver Member
Calipers are designed to measure 'id' as well as 'od'. What are you using ?
I'm intrigued, you galled brass doing a hand fit-up (dry-fit) ?
If it doesn't fit, it doesn't fit. Don't force it.
Without pics we have no idea what prts you're using or where you got them.
I can tell you this. I have installed maybe 1,000 Uni pins and inserts.
Every one fit. It's possible you've found a knock-off. Look to your source.

KJ
 
B

BJK

AzB Silver Member
Silver Member
I used a micrometer, hence the ability to easily measure to .0001. The funny thing is, it slid on and threaded by hand but then locked up to the point where I couldn't budge them. The galing occurred as I got them apart.

They are definitely not the high polish pins with the U stamped in them, but I ordered them from what I think to be a reputable dealer (I could be wrong), but I won't reveal the source publicly until they have a chance to respond to me.

If you are able to source genuine UniLoc brand pins and inserts, would you mind PMing me about that? I'll PM you my source and we can discuss if you think they are reputable or not privately, if you are willing to do that.

Thanks for the reply.
 
Michael Webb

Michael Webb

AzB Silver Member
Silver Member
Using a Bolt tumbler has become very popular by manufactures today. It's ok but not as good as actual polishing. I polish every joint screw myself. For uni loc screws, you can see the scratches when they come in. Scratches allow dust build up. (dirt) which will cause the insert to bind, then create a bur when you try to force it loose. I wet sand the front shank with 2000 uni grit paper and polish with a buffing wheel. I've had maybe 1 insert out of 100 that is to tight when dry fitting. Toss it.
 
B

BJK

AzB Silver Member
Silver Member
Ah, I had wondered about polishing them myself. Seems like it will solve two problems for me. Thanks for the advice.
 
K

KJ Cues

Pro Cue Builder & Repair
Silver Member
bstroud said:
Probably a knockoff.
The only way to measure the ID of the insert is with a plug gage.

Bill S.
Click to expand...

You are correct Sir. Calipers are not an accurate instrument for measuring the 'id' of a Uni insert.
I've just proven that to myself. The internal radius won't allow the blades to set properly.
I'm not about to sharpen them either. Plug gage it is. Thanx for pointing that out.

KJ
 
K

KJ Cues

Pro Cue Builder & Repair
Silver Member
Here is what might be considered a cost savings tip for those interested in internal diameter measurement.
Plug gages are the way to go, they were made for this purpose. However, an accurate set of plug gages is expensive.
Not many will justify the cost as the gage's use is very limited in our trade. As in, almost never.

However, this tip may get you within a thou. and you may already have them in stock; think drill-bits.
Drill-bits come in a wide range of sizes, Number drills, Letter drills, SAE, Metric; you get the idea.
Drill-bits are 'ground' to size and sometimes they even get close.
Seriously, they're pretty accurate if you know how to measure them.
The key here is that the shank of the drill be burr free. If you've spun it once or twice in the chuck,
it's accuracy may be in question. Brand-new, unused drills are preferred.
The measurement procedure is the same. Insert the drill's shank (your alternate plug-gage) into
the hole until you find one that fits perfectly. Read it's size or measure for greater accuracy.
If all you want to measure is the id of a Uni insert, you may have to buy one drill-bit............
unless you already have it.

KJ
 
Canadian cue

Canadian cue

AzB Silver Member
Silver Member
KJ Cues said:
Here is what might be considered a cost savings tip for those interested in internal diameter measurement.
Plug gages are the way to go, they were made for this purpose. However, an accurate set of plug gages is expensive.
Not many will justify the cost as the gage's use is very limited in our trade. As in, almost never.

However, this tip may get you within a thou. and you may already have them in stock; think drill-bits.
Drill-bits come in a wide range of sizes, Number drills, Letter drills, SAE, Metric; you get the idea.
Drill-bits are 'ground' to size and sometimes they even get close.
Seriously, they're pretty accurate if you know how to measure them.
The key here is that the shank of the drill be burr free. If you've spun it once or twice in the chuck,
it's accuracy may be in question. Brand-new, unused drills are preferred.
The measurement procedure is the same. Insert the drill's shank (your alternate plug-gage) into
the hole until you find one that fits perfectly. Read it's size or measure for greater accuracy.
If all you want to measure is the id of a Uni insert, you may have to buy one drill-bit............
unless you already have it.

KJ
Click to expand...
Actually drill bits are only on size at the cutting end. There is a taper across it's length, they are smaller on the end that you chuck on. So they do not make great plug gauges for accurate measurement. If you are only measuring a few sizes time and time again mcmaster carr sells individual ground pins. Just need to order a few sizes.
https://www.mcmaster.com/#pin-gauges/=1b8mtqd
 
Last edited:
C

Cocoa

AzB Silver Member
Silver Member
Without knowing the tolerance of the pin and insert what good will any of these ideas do?
 
K

KJ Cues

Pro Cue Builder & Repair
Silver Member
Canadian cue said:
Actually drill bits are only on size at the cutting end. There is a taper across it's length, they are smaller on the end that you chuck on. So they do not make great plug gauges for accurate measurement. If you are only measuring a few sizes time and time again mcmaster carr sells individual ground pins. Just need to order a few sizes.
https://www.mcmaster.com/#pin-gauges/=1b8mtqd
Click to expand...

This is the first I'm hearing of a taper on a standard drill-bit.
I have some HSS bits that measure a thou. or two larger at the cutting edge but no taper is involved.
The vast majority of the bits that I use are solid carbide and measure true from end to end.
 
Canadian cue

Canadian cue

AzB Silver Member
Silver Member
KJ Cues said:
This is the first I'm hearing of a taper on a standard drill-bit.
I have some HSS bits that measure a thou. or two larger at the cutting edge but no taper is involved.
The vast majority of the bits that I use are solid carbide and measure true from end to end.
Click to expand...

Accurately measure a drill and you will find that they taper the full length. I just measured a 15/32" drill from a quality set of drills and it measured 0.006" of taper over it's length. The taper probably varies from manufacturer and size of drill but my point is they are not very accurate gauge of size measuring from the shank.
 
K

KJ Cues

Pro Cue Builder & Repair
Silver Member
Suffice it to say, we use different tooling. How about we say that a drill-bit was an example.
It doesn't matter what you stick in the hole. Measure it first and you have a reference.
Just make sure it's not tapered.
 
Canadian cue

Canadian cue

AzB Silver Member
Silver Member
This is all relative to your tolerances. In the example we have been given with the Uniloc joint the tolerances would be in the quarter thou range so a drill wouldn't be a great gauge. If your measuring holes that are +-0.002 they would do the job.
 
DaveK

DaveK

Still crazy after all these years
Silver Member
Canadian cue said:
This is all relative to your tolerances. In the example we have been given with the Uniloc joint the tolerances would be in the quarter thou range so a drill wouldn't be a great gauge. If your measuring holes that are +-0.002 they would do the job.
Click to expand...

Perhaps drill blanks could make an OK poor mans plug gage. While a set is rather costly a selection around the sizes of interest might be a reasonable expense. They are spec'd fairly tightly (+0.0000 - 0.0003", much better than +- 0.002").

The category :

https://www.mscdirect.com/browse/Holemaking/Drilling-Drill-Bits/Drill-Blanks-Sets?navid=12106172

One example :

https://www.mscdirect.com/product/details/71100168?fromRR=Y

Dave
 
B

BJK

AzB Silver Member
Silver Member
The vendor replied today and has shipped replacements free of charge. I'll definitely continue to use this company, and I'll also be sure to polish & measure the pins ahead of time.

He suggested that the pin & insert were not fully clean when I test fit them, which may have been the case. However, with that big pin it would have been a ticking time bomb with getting jammed in an actual shaft. No idea how I would have gotten them apart then.

Thanks for the input everyone.
 
You must log in or register to reply here.
Top