Page 1 of 1

Reaming polyurethane bushes

PostPosted: Mon Aug 15, 2016 10:44 pm
by Storkfoot
I have bought some polyurethane bushes to repair my rear shock. They weren't expensive and they aren't made to fit my shock. Essentially, I need to ream out the centre to 23mm (it's about 26 at the moment).

I suspect I could take it to an engineers to sort but I'd like to look at buying an adjustable reamer to do it myself. I don't have a pillar drill.

Any thoughts please?

Re: Reaming polyurethane bushes

PostPosted: Mon Aug 15, 2016 11:09 pm
by Knowledge
My thought is that everyone needs a pillar drill in their life.

Re: Reaming polyurethane bushes

PostPosted: Mon Aug 15, 2016 11:16 pm
by Knowledge
Storkfoot wrote:I need to ream out the centre to 23mm (it's about 26 at the moment).


Paul,

Did you mean, it is currently 23mm and you want it reamed out to 26mm?

I have a small adjustable reamer which I bought from a guy who does car boots sales with a stall about 60m long full of machine tools ( his name Paul too), and it was not expensive. However, I suspect that an adjustable reamer required to take a hole out to 26mm would be expensive. Also, it would need something to get the hole close to 26mm first, as adjustable Ramses don't take up as much as 3mm on the diameter, more like 1mm.

While you are in Machinemart buying a pillar drill, have a look at the lathes. One of those might be the answer.

Re: Reaming polyurethane bushes

PostPosted: Mon Aug 15, 2016 11:29 pm
by Storkfoot
Sorry, it's been a long day. It's about 20mm and needs reaming to 23mm.

I was having a conversation about pillar drills at the weekend. I am aware that I really do need one for all sorts of uses. If only money grew on trees :-)

Re: Reaming polyurethane bushes

PostPosted: Tue Aug 16, 2016 7:13 am
by gaz_powell
Send them to me and i'll do them - I've got access to adjustable reamers and I have a pillar drill. It'll only cost you a stamp to send them.
You'll get more use out of a pillar drill than adjustable reamers (which aren't cheap!) keep an eye out at Lidl or aldi for a pillar drill.
There is a cheaper alternative to a pillar drill, a drill stand - where you fix a standard pistol drill in then can raise and lower with an arm - not as good overall as a pillar but definately better than trying to work with a drill in hand.

Re: Reaming polyurethane bushes

PostPosted: Tue Aug 16, 2016 7:22 am
by Storkfoot
Thanks very much, Gaz. IM sent.

Re: Reaming polyurethane bushes

PostPosted: Tue Aug 16, 2016 7:12 pm
by Warkton Tornado No.1
Re: Reaming polyurethane bushes
Post by gaz_powell » Tue Aug 16, 2016 7:13 am

Send them to me and i'll do them


It gives me a sense of pride in the LCGB to see such selfless responses.

I was going to suggest that the better alternative to reaming would be to get them bored on a lathe, but Knowledge more or less beat me to it.... :)

Re: Reaming polyurethane bushes

PostPosted: Tue Aug 16, 2016 8:37 pm
by gaz_powell
Got lathe on hand aswell - once I see them and see what exactly needs doing I'll decide what to do.

If we can't help each other there's something wrong, there's plenty people on here done me favours.

Gaz

Re: Reaming polyurethane bushes

PostPosted: Tue Aug 16, 2016 9:32 pm
by coaster
Storkfoot wrote:Sorry, it's been a long day. It's about 20mm and needs reaming to 23mm.

I was having a conversation about pillar drills at the weekend. I am aware that I really do need one for all sorts of uses. If only money grew on trees :-)


Now if ity'd been the other way and you needed to reduce the hole size I could have sent you a reel of my special green insulating tape :lol:

Re: Reaming polyurethane bushes

PostPosted: Wed Aug 17, 2016 9:38 pm
by Storkfoot
If electrical insulation and gaffer tape hadn't been invented, your Jet would be a pile of bits :-)

Bushes are on their way to the very nice Mr. Powell. Pillar drill joins ever growing Christmas wish list.

I did try and post some pics last night but had problems and gave up.

Re: Reaming polyurethane bushes

PostPosted: Thu Aug 18, 2016 10:14 pm
by Storkfoot
Image
Image

Re: Reaming polyurethane bushes

PostPosted: Fri Aug 19, 2016 8:43 am
by coaster
Daft question maybe but are you sure you actually need the sleeve in there? You would normally expect a sleeve in a rubber bush but it would not necessarily be needed in a nylon/Teflon bush. For example, the Teflon bushes sold for R1 convers=ions have no sleeves fitted.
Of course this would all depend on the size of the hole in the bush ;)

Re: Reaming polyurethane bushes

PostPosted: Fri Aug 19, 2016 11:05 am
by Warkton Tornado No.1
Post by coaster » Fri Aug 19, 2016 8:43 am

Daft question maybe but are you sure you actually need the sleeve in there? You would normally expect a sleeve in a rubber bush but it would not necessarily be needed in a nylon/Teflon bush. For example, the Teflon bushes sold for R1 convers=ions have no sleeves fitted.
Of course this would all depend on the size of the hole in the bush ;)


Not a daft question, but I think I know the answer:

The inner sleeve not only serves as the item to control the position/geometry of the shock absorber but it’s length is what will prevent over tightening of the washer/nut to avoid over-stressing the PU itself.

Re: Reaming polyurethane bushes

PostPosted: Fri Aug 19, 2016 12:48 pm
by Storkfoot
Good thinking but the hole in the bush is too big for the mount on the scoot.

WT, I agree, however, in this case the polyurethane bush will be too long. I could shave it to expose the metal insert to the nut and washer though. That is a future possibility.

I am just messing around really. I just hate discarding a perfectly good shock absorber !

Re: Reaming polyurethane bushes

PostPosted: Fri Aug 19, 2016 2:42 pm
by coaster
Warkton Tornado No.1 wrote:.............The inner sleeve not only serves as the item to control the position/geometry of the shock absorber but it’s length is what will prevent over tightening of the washer/nut to avoid over-stressing the PU itself.


Good point WT, the example I was thinking of with the R1 shock conversion uses nyloc half nuts tightened to not much more than finger tightness to reduce stress on the top mounting eye as the engine mounts flex sideways.

Re: Reaming polyurethane bushes

PostPosted: Fri Aug 19, 2016 6:39 pm
by gaz_powell
Got them and i'm on it!