28 replies to this topic

[Ethel]

or you could buy the real thing from Somerford for the bargain price of £425.94 - clicky

Send me the change

[bmcecosse]

Just put a new shaft in - unless the wear is REALLY excessive - a new shaft will tighten it up nicely.

[dklawson]

or you could buy the real thing from Somerford for the bargain price of £425.94 - clicky

OUCH !!!

I paid $20 for my reamer and spent about an hour making, tacking in place, and finish machining the guide boss to fit the needle bearings. My goodness they think a lot of their tools !

[minidaves]

or you can make your own reamer from a 2 raduis arm pins agrinder and a dremel and little time and and hey presto. diy reamer for doing the odd raduis arm

dave

[MRA]

The main points to get good quality and longer reliability are.......

1) Concentricity between both bearing and bush
2) Accurate alignment between both bearing and bush
3) Good surface finish
4) Accurate working tolerance (running fit)

it will be almost impossible to get good results without using either a dedicated machine or a supported reamer, using a hone or an adjustable reamer you can get good results (points 3 & 4) within the bush itself, however it won't give you points 1 & 2.

The expensive S/M's item is because they sell very few of these per year, although this tool is expensive it covers all of the 4 points (above).

if you use an unsupported reamer or hone then slide the pin in to the bush with a good fit..... then try pushing it in to the bearing and see how much it tightens up If it doesn't tighten up on the shaft then you have one of two possible outcomes here....

1) That you have too much clearance in the bush
2) You have been very lucky
3) Or you have used the correct tooling

Edited by mra-minis.co.uk, 24 January 2010 - 09:59 AM.

[freaker]

so best thing is to get it done ?

if you want it perfect ?


freaker

[stevede]

I did mine myself using some equipment at a pals workshop. (check project pages for info)



We set the bits up on a lathe, had the correct reamer and ran it all through in line. I still had to do a very minor bit of fettling after as the pins were a bit tight.

Getting the bronze bush in straight was the biggest pain, (damaged the first one before we turned a shaft to align it)

Even with access to all the kit again, I suspect I would consider the exchange arm route. Especially for one where it is still on the car. Job done in an hour or so instead of what could easily turn into a full day or more.

If you want more detail on how I went on, send me a PM.

Good luck

Steve

[mini670]

the pin on my radius arms is 0.6mm down on diameter!!! A new pin will definately make them tighter.
im hoping to borrow a reamer from a local engineering company.

The reamer has to have enough length to go through the roller size first, with the straight shank keeping the reamer concentric.
The adjustable reamers will work, but there is a good chance if you use these you will loose allignment and concentricity between rollers and the bush. This is because the shaft of these reamers has a smaller diameter and will not run cencentric in the rollers, although i suppose a bush could be engineered to fit the shank of the reamer, with an o/d to suit the rollers.

[Meepo]

I looked into using a brake cylinder honer, but wasn’t happy about keeping things concentric, so I bought a second hand 13/16” x 9” long Hand Reamer with a 4” cutting edge from the USA. It was loads cheaper than buying one over here, think I paid about £15 including shipping, and it works a treat

[Ivor Badger]

Chronos sell an expanding reamer of the correct size for £10.21 inc postage.

The fact is, that it does need to be dead accurately reamed. It does not rotate at speed, it just ossolates at quite a low rate on about a 30' arc

[minimuk]

Interesting article - clicky

excellent way of doing the reaming, cheers I am ready for the challenge now!!

[dklawson]

Interesting article - clicky

excellent way of doing the reaming, cheers I am ready for the challenge now!!

Several of us tried to make the point earlier that the method shown in that link is not ideal for several reasons. It works for some people but the method is not controlled and does not insure that in the end the bushing bore is straight (not conical) and concentric with the needle bearing. If you must do this yourself and don't have access to piloted reamers or other precision tools I guess it is a viable option but other methods are preferred.

[minimuk]

Interesting article - clicky

excellent way of doing the reaming, cheers I am ready for the challenge now!!

Several of us tried to make the point earlier that the method shown in that link is not ideal for several reasons. It works for some people but the method is not controlled and does not insure that in the end the bushing bore is straight (not conical) and concentric with the needle bearing. If you must do this yourself and don't have access to piloted reamers or other precision tools I guess it is a viable option but other methods are preferred.

if I use an adjustable reamer, wich slides into the bush and ream it bit by bit, that will be my method. But I do understand your valued comment.

[Saxo-Fiesta-Mini]

thanks for all the comments i did use the brake honer and it broke half way thru so i improvised with some 400 grit wet and dry and alot of patients managed to get it bob on

amazing what 4 hours a can of wd40 and a bosch drill can achieve
fitted and its fine
before anyone says let see how long it last too late i already did hahhaa
also whilst at himley treated bertie to a camber and tracking kit from mini sport which is now fitted handles alot better now even lowered him again