Thrust Block.

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Journeyman
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Location: Pembrokeshire

Thrust Block.

Post by Journeyman »

Hi All,
As you might know I bought a Bolt-on Transom Bracket from Tam. It’s a really good bracket and just what I needed.
Now I’m looking for a thrust block to go with it.
Apparently there is a Bronze and Nylon versions. Either would do but my preference would be Bronze.

Dave.
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Charles uk
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Re: Thrust Block.

Post by Charles uk »

Dave take the thrust bock assembly from your existing 102 cc size transom bracket, & try it for size in your new one.

It's difficult to be certain from the pictures, which block you require Century or QB for your new bolt on bracket.
Make it idiot proof and someone will make a better idiot.
Journeyman
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Re: Thrust Block.

Post by Journeyman »

Hi Charles,
Thanks for looking after me, the new bracket is the same size at the top but is 2" wider between the horns,
Old 1 5/8" New 3 5/8"
The Drive Tube on the Century is 1 3/32" diameter, do you know what the diameter is on the QB?
Do I need a Century Thrust Block with two one inch spacers or will a QB Thrust Block fit on the Century dive tube?

Thanks for sharing all your knowledge I’m just making it up as I go along!

Dave.
Journeyman
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Re: Thrust Block.

Post by Journeyman »

Decided it’s a Century Thrust Block I need.
Did a bit of research and as Charles said the bracket is from a QB but it suits my set up so I will use it with a Century Thrust Block and spacers.
The QB Thrust Block is very different and incorporates a fitting on the drive tube which would negate a quick change over.

Dave
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Hugz
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Re: Thrust Block.

Post by Hugz »

You could probably just make one yourself with a bit of shaped timber. Varnish it up and it could look quite well. You wouldn't be the first. 2" x 1" x 3 5/8". Drill a hole for the bolt and notch for the drive tube.
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Charles uk
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Re: Thrust Block.

Post by Charles uk »

There is a great deal of merit in Hugz's suggestion, a square bit of hard wood with a bit of a groove in the middle & an 8mm hole offset from the centre & you could end up with a 4 thickness thrust block adjustable by rotation held in position with a much cheaper 8mm stainless nylock nut & bolt for less than £2.00!
Make it idiot proof and someone will make a better idiot.
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Hugz
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Re: Thrust Block.

Post by Hugz »

Use a holesaw 1 1/4" or thereabouts. Two parallel cuts and you have your notch to suit drive shaft. Personally l would make it a bit bigger and line the inside with leather and lubricate with a bit of oil to protect the chrome on your driveshaft. Drill the hole a little to the rear so you are drilling about 25% airspace and you will have enough meat/strength for your securing bolt.
Journeyman
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Re: Thrust Block.

Post by Journeyman »

Thanks Hugz and Charles,
If nothing shows up I’ll search through the scrap material I think I have some Delrin in there and do as you say.
What I want to avoid is getting sidetracked and spending time on this when I need to be getting on with rebuilding the boat.

Dave
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Charles uk
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Re: Thrust Block.

Post by Charles uk »

A length of turned Delrin with a decent groove in the middle, would be ideal.

Seagull didn't help by putting the parallel face on the outside, it will mean you can't tighten the retaining bolt very tight without loading the casting up.

That's what I used when I re-manufactured the FV series thrust blocks for John.
Make it idiot proof and someone will make a better idiot.
Journeyman
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Joined: Thu Aug 16, 2018 6:26 pm
Location: Pembrokeshire

Re: Thrust Block.

Post by Journeyman »

Hi Charles,
Yes to avid putting any stress on the casting I had intended threading the spacers so they will tighten up against tapered washers on the inside and use lock nuts on the outside. That should control any bending moment in the retaining stud. It will also allow the Century Thrust Block to tilt and align as normal.

It’s good to be able to bounce ideas here on the forum.

Dave.
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Hugz
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Re: Thrust Block.

Post by Hugz »

First I've heard of delrin. Will procure some and play with.
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Charles uk
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Re: Thrust Block.

Post by Charles uk »

Similar to nylon or acetyl, machines well & very slippery.
Make it idiot proof and someone will make a better idiot.
Journeyman
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Location: Pembrokeshire

Re: Thrust Block.

Post by Journeyman »

Hi All.
Just to let you know that I took Charles and Hugz advise and made a thrust block so I’m no longer looking for one.

Found the Delrin but it was much bigger than I remembered and it seemed a pity to cut it down so I made a block out of recycled plastic (HDPE) oil cans and fashioned the thrust block from that.

Thanks again to you all for your help
Dave.
PS how do I post photos?
tambikeboy
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Re: Thrust Block.

Post by tambikeboy »

On your reply page scroll up to next page below submit you will see attachment box click on it then click add file select file and submit...job done and if your not sure it's there click preview then of course click submit......
Roll me up and smoke me when I die
Regret is just a memory written on my brow
Journeyman
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Re: Thrust Block.

Post by Journeyman »

Thanks Tam,
Here is a photo of the Block before machining.
Outboard 056.jpg
And the finished Thrust Block.
IOutboard 066.jpg[/attachment]
t’s going on to a raked transom so I made it to reduce most of that angle.
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