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Delrin mast bearings?
http://www.hobie.com/forums/viewtopic.php?f=9&t=58671		 Page 1 of 1
Author:  matseski [ Tue Aug 02, 2016 10:28 am ]
Post subject:  Delrin mast bearings?
I am looking to make my own mast bearings since the precut teflon chips are stupid expensive. A 12"x12" sheet of 1/16" teflon costs about $20 (+$10 shipping). I believe the mast bearings are about 1.25" diameter, so that should yield about 90 bearings for $30 instead of 3 for $8 (+shipping). I also noticed that Hobie used to make a Delrin mast bearing cup. Delrin is much cheaper than teflon ($5/12"x12" sheet), but is a little more rigid, not quite as slippery, and absorbs a small amount of water.

I just purchased a 30 year old Hobie 16, so I am not yet concerned about racing performance and am on a tight budget. I am just looking for a low cost bearing solution.

Has anyone tried making their own bearings out of Delrin sheets? Any feedback on their performance/longevity compared to teflon?

Also, can someone confirm that they are 1.25" diameter? I do not have any to measure.

Thanks!
Author:  mmiller [ Tue Aug 02, 2016 11:23 am ]
Post subject:  Re: Delrin mast bearings?
Don't use delrin. It was mold in the shape of the cup. Never very good. I don't think flat delrin is going to form to the cup properly.
Author:  MBounds [ Tue Aug 02, 2016 12:55 pm ]
Post subject:  Re: Delrin mast bearings?
Ditto on that (don't use Delrin). Delrin squeaks. You don't know annoying until you listen to the mast squeak on every wave in light air. Chinese water torture.

I bought a bag of 100 Teflon chips from Sailing Systems, Inc. back in the late '80s. Four 16s and two 14s later, I still have ~25 left - even after using them as trailer roller bearings and who knows what all.

The stock chips are a bit thicker than 1/16". 1/16" thickness from McMaster-Carr is $50 for a 12"x12" sheet. A 1.5" hole punch is $57. (Mast chips are 1.5" diameter, not 1.25")

So, for a little over $100 (+shipping), you could have a 40 year supply of mast chips. Most people find that 3 for $8 isn't that bad.
Author:  matseski [ Tue Aug 02, 2016 7:06 pm ]
Post subject:  Re: Delrin mast bearings?
Teflon it is. I ordered a 12"x12"x1/16" sheet for $23.50 shipped and have a 1 1/4" pipe scrap that I will use to make a punch by filing the edge. This should yield 63 or 68 bearings depending on exactly how it's cut and will come out to about $0.35 per bearing. Will report back once I try it out...
Author:  mmiller [ Wed Aug 03, 2016 9:43 am ]
Post subject:  Re: Delrin mast bearings?
MBounds wrote:
The stock chips are a bit thicker than 1/16". 1/16" thickness from McMaster-Carr is $50 for a 12"x12" sheet. A 1.5" hole punch is $57.


MBounds wrote:
(Mast chips are 1.5" diameter, not 1.25")
Author:  hrtsailor [ Wed Aug 03, 2016 2:33 pm ]
Post subject:  Re: Delrin mast bearings?
I don't understand why you need so many mast chips. I owned my boat for 30 years and don't remember buying more than a dozen chips in that time. I turned the boat over to my daughter and her husband (I still have access to it) and there were three chips with it. One probably used up, one dished and still usable and the third still unused. I bought those chips a long time ago. I did a lot of sailing with that boat. On one extreme day, the mast chip was squeezed thin by the force on the mast but that was the exception not the rule.
Author:  MBounds [ Wed Aug 03, 2016 2:35 pm ]
Post subject:  Re: Delrin mast bearings?
So a guy on a budget spends $25 + time (to 1. make the punch and 2. punch them out) to make chips that are thinner and smaller than OEM - that will give him a 30-year supply - for a boat that's already 30 years old.

When he could have just paid $8 for 3 chips that will last longer than his boat.

Something ain't right here. :roll:
Author:  Blaster182 [ Sat Aug 06, 2016 7:28 am ]
Post subject:  Re: Delrin mast bearings?
+1 I have owned my boat for 11 years and only replaced twice

Sent from my SAMSUNG-SM-G900A using Tapatalk
Author:  TexKat [ Sun Oct 30, 2016 9:09 pm ]
Post subject:  Re: Delrin mast bearings?
Time or two over the years I've been caught without one. Laid a quarter in there and set the mast. Worked real well without damage to mast socket but the quarter wasn't worth a quarter anymore. Emergency situations only, wasn't gonna let a little piece of plastic cost me a day of good sailing :D
Author:  Tom Kirkman [ Mon Oct 31, 2016 6:54 am ]
Post subject:  Re: Delrin mast bearings?
Go to any store that sells golf stuff - Walmart is fine. Buy some of the small plastic wiffle type practice balls and cut one in half. It will fit perfectly in the mast base cup and last for a long, long time. It's self lubricating and will do what you need it to do.
Author:  Tom King [ Tue Nov 01, 2016 5:42 pm ]
Post subject:  Re: Delrin mast bearings?
The best thing I've ever used was a 50 cent piece with the copper core.

edited to add: I checked ebay, and they're going for a buck fifty now.
Author:  okuhn [ Mon Jul 16, 2018 6:22 am ]
Post subject:  Re: Delrin mast bearings?
I stumbled across a possible material to use for a mast bearing, already nicely formed in the right shape - a golf ball outer shell. When I was golfing yesterday I found a golf ball that had been chopped in half by a lawn mower, and the shell was kind of half separating from the core - that's when the light bulb went off! I've tried a few other materials and they have been unsatisfactory, including the little disks you can buy, which tend to squeeze out.

I took a Pro V1 ball and cut around the equator, then peeled off half of the shell very carefully. It appears to be about the right thickness, very tough yet flexible. The outside is shiny, the inside less so. I've turned it inside out so the ball of the mast will sit on the shiny side, and it seems perfect. The spec diameter of a golf ball is 1.68 inches, but I think it's flexible enough that it will mold to the cup. I'm going to install it this weekend and will report on how it performs.
Author:  A1cnc [ Mon Jul 16, 2018 10:55 am ]
Post subject:  Re: Delrin mast bearings?
When I bought My 14t it came with a bag of spare parts. 3 discs were in there. I KNEW I had them. The first time I went to go sailing I could not find them anywhere! So I went the make it myself route.

I am a machinist and a lot of what I machine is plastic. I went to my supplier and they gave me a scrap of Teflon sheet that is 3/32" thick. I have been using them for a few weeks and I made mine 1-1/4" diameter. I can say definitely they are too small and I will be Making more at 1-1/2" Diameter. The material works fine it is just too small in diameter and sometimes has moved out of place.
Author:  SlowSL [ Wed Aug 08, 2018 10:15 am ]
Post subject:  Re: Delrin mast bearings?
Any reason UHMW could not be used? It is very similar to PTFE.
Author:  A1cnc [ Thu Aug 09, 2018 4:57 am ]
Post subject:  Re: Delrin mast bearings?
Should be no reason uhmw wouldn't work.

The ones I made at 1-5/8" diameter seem better than the 1-1/4 ones I made first.
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