P1000 DIY Skidplate washer ??

[Superthrill]

My 1/2 " uhmw is on the way and I have the Honda factory washers. They are about 1 1/2" in diameter and I am going to recess them using a Forstner bit.
Question is the center simple. It measures 7/8" diameter.

So, make another 7/8 recess inside the 1 1/2 recess or just drill the 7/8 all the way through?

 

[Admin]

 

[Hondasxs]

I use a spade bit to get deep enough to make the washer flush. Then a step bit to create the hole. sorry I forget how deep or size. But it was the fat step bit.
Worked great.

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[Hondasxs]

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[Superthrill]

I have

I use a spade bit to get deep enough to make the washer flush. Then a step bit to create the hole. sorry I forget how deep or size. But it was the fat step bit.
Worked great.

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Whole assortment of step bits, just didn't know if people were taking that extra step or just drilling all the way. I kinda like the b idea of two steps and a hole.

 

[Hondasxs]

Oh ya..
Spend the time and do both steps.

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[Hondasxs]

Step as in...
The spade bit or foster bit.
Then
The step bit.

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[ToddACimer]

I think my holes are 7/8", the washers self center fairly well and sit flush when they are tight

 

[JTW]

The spade bits are the way to go with the uhmw... keep in mind the uhmw needs room to expand and contract. I left a 1/4” on the washer holes and drilled 1/2” hole for the bolts. I just bought fender washers (can't recall if they were 1” or 1 1/4”) and 1/4” grade 8 bolts. I also replaced all the stock bolt thread with rivitnuts as well as all the self tapping screw holes from the old aluminum skids. I’ll be replacing the rivinuts with weld in t-nuts next time I take the skid plate off.

 

[Superthrill]

The spade bits are the way to go with the uhmw... keep in mind the uhmw needs room to expand and contract. I left a 1/4” on the washer holes and drilled 1/2” hole for the bolts. I just bought fender washers (can't recall if they were 1” or 1 1/4”) and 1/4” grade 8 bolts. I also replaced all the stock bolt thread with rivitnuts as well as all the self tapping screw holes from the old aluminum skids. I’ll be replacing the rivinuts with weld in t-nuts next time I take the skid plate off.

When you say room to expand, are the washers not clamping on the skidplates?
Or are the washer clamping tight to the metal and the skidplate has extra clearance underneath the washer as well?

 

[JTW]

When you say room to expand, are the washers not clamping on the skidplates?
Or are the washer clamping tight to the metal and the skidplate has extra clearance underneath the washer as well?

The washers are pulling the skids to the frame.. the room I’m refering to is lateral movement between the fastners and washers and the material. Again, I’m just using flat fender washers. @Cuoutdoors was suggest to leave room by the guy he purchased his UHMW material from that has been dealing in plastics for 30 years. I mention it because I haven’t had any issues... you could maybe get by with exact holes, but I don’t know that. I do know that I haven’t had any issues by following those suggestions. The last thing I wanted was my skid cracking because I didn’t leave room for expansion. As best I recall, he said a 5x10 sheet could move as much as 1/2” due to expansion and contraction.