Boring out a tractor axle

[octo0072000]

How about this for a solution? Its a crap drawing but I think you get the idea. A solid pin as I don't need a starting handle on a diesel. Drill the solid pin down the centre for the grease nipple, means you dont weaken the axle, and the nipple won't get knocked off as it will be protected by the axle carrier and it gets grease inside the bush directly, no need to drill the bush and line it up.

Problem is what grade of steel for the pin? EN1A would be good for machining and buying but can't really harden it. I haven't measured the axle pin length but its about 7" x 1-3/4" from memory.

Cheers
Andy

i would drill the axle at both sides for for the grease nipples one each side then just use plain bar for the axle

 

[agrimog]

not a difficult job, buy your 3" boring head, set the axle up on the table, bore it out big enough to take a sleeve about 8-10mm thick and the same oversize, press fit this sleeve, then bore the sleeve dead size to allow you to press the oilite bush in, you should find this will compress the bush enough to allow a "tight" fit on the pin, this is basic repair engineering

 

[Paul99]

En24t is good but very difficult to weld, its used for high performance crankshafts so its tough stuff.

Yep I was going to mention that - but didn't think there was any welding required so didn't seem important. When it came to making pins for my log splitter the local engineers recommended EN24T but was told that I'd not be able to weld it.

I needed to prevent the pins rotating and although perhaps not the best solution (but the quickest at the time) I simply used 6013 rods to butt weld bored out square MS plates to the 30mm EN24T pins - Welds actually looked good but almost certainly wouldn't be up to structural standards - perfectly fine for my particular application though just in case anyone else needed to do it.

 

[stormin]

The front axle pin on my david brown is fifteen inches long and new ones are not available. I went to the local tractor breakers and found some 1 1/2" diameter hydraulic ram shaft that im going to gut down to use as the pin.
Four oilite type bushes to replace and ream on mine. Think the Fergies / Dexta's are an easier repair though much more liable to wear. The play in mine was minimal but I wanted it right and the pin was seized in the axle so had to be cut and replaced.

 

[brewdexta]

Thanks guys, I'm overwhelmed with the replies, I've got plenty to go on now. I have my feelers out for some suitable steel, I like the idea of using an old ram. I snapped the ram on my neighbours Kubota mini digger a couple of years ago and its probably still lying around somewhere after I replaced it.
Cheers
Andy

 

[Welderpaul]

Managed to knock the pin out today Andy, suprisingly the bushes are almost perfect, the pin however has a slot worn in it maybe 3mm deep on the bottom. Odd as that makes me think that the pin must be softer than the bush?

Bought a new pin...yours above has a big spring washer on it? Did that come as standard?

 

[brewdexta]

Managed to knock the pin out today Andy, suprisingly the bushes are almost perfect, the pin however has a slot worn in it maybe 3mm deep on the bottom. Odd as that makes me think that the pin must be softer than the bush?

Bought a new pin...yours above has a big spring washer on it? Did that come as standard?

Hi Paul

I'm making a new pin with a grease nipple, you could have had the one I bought

There is a spacer and plain washers used to give about 1mm of free play, I got a few sets made by a mate of mine before I got the lathe and gave the spares away to other Dexta owners on the Fordson forum. here's the thread showing the size of the spacer and washers.

I got my boring head and cutters last week, will be boring out the ovality in mine in a couple of weeks when I move some junk in the workshop to find a home for the mill.

Cheers
Andy

 

[Welderpaul]

Look forward to seeing it. I have a nasty feeling that the pin will either need turning down or be a rattley fit given the quality of some of the aftermarket spares.

 

[brewdexta]

Well its been nearly a year since I said a "couple of weeks" so I thought I better pull my finger out

The hold up was that I hadn't finished the Tom Senior Light Vertical so over the last couple of weeks I've been doing a bit now and again, the last bit needed before I could use it was powering it up. I bought an NVR switch for it ages ago, but it was in a crappy plastic box so I used an old switch box I had kicking around and cut a square section out of the top with the angle grinder and last week when I had the spray gun out for the kids Land Rover I sprayed in TS green, and quickly put the tin away in case I accidently sprayed the landie TS green instead of Pastel Green

I was going to hide the new NVR switch inside and use the original bakelite stop and start buttons but they were FUBAR so I just mounted the lid of the new NVR in the old box. I also found a little pull switch to operate the separate coolant pump hidden inside the TS which I will complete later.

So after nearly 2 years I tried the TS out and the motor worked a treat. I have cleaned up and sprayed all the mill except the head and hand wheels. I shall do them once I have established if anything on the head needs any TLC.

All I need to do is adjust the gib strips and give her a lube and she should be good to go.

I bought a boring head last year and the oilite bush for the axle, all I need to do is fix it firmly to the bed before boring it, its an awkward shape so may need to make something to hold it down. Not sure which way up it will be going yet, I need to leave a gap between the bed and where I'm boring so other way up may be best, I shall invite my toolmaker neighbour round for a pint to discuss.

Same time next year?

Cheers
Andy

 

[Welderpaul]

I'd recognise that axle anywhere!

My Dexta is sitting unloved at the moment having come on leaps and bounds last year....no point rushing these things!

 

[brewdexta]

....no point rushing these things!

Too true! The dexta turned 50 years old while I've been tooling around with the axle

 

[octo0072000]

what a right pair of Dexta's you are we need to see them finished

 

[brewdexta]

In between putting the electrics in the kids toylander, I've been tinkering with the mill ready for boring the axle out. Got it all lubed, gib strips adjusted and was just looking around for a suitable bar to make sure the head is vertical when my neighbour arrived who picked up the tool rest off the Tormek grinder, worked a treat with the DTI hanging off of it, its 12mm OD so fit into the collet chuck and we had its spot on in minutes. Its easier with two as the large motor on the top makes the head top heavy however its doable with one as long as you don't loosen the bolts too much and tap it with a rubber mallet.

So we looked at the axle and decided to rest it on a 60mm square piece of 3mm aluminium plate to protect the bed. I'll set the depth stop to touch the plate then give it a half a turn more. Trouble is there's no nuts on the depth stop and I've been through the jars of imperial nuts that my dad gave me and none fit.

I run out of time tonight to get the thread gauges out however just in case, does anybody happen to know what size/thread the depth stop is on a Tom Senior Light vertical? You can see it at the top of the pic, the black threaded bar above the chuck

Cheers
Andy

 

[brewdexta]

It turns out that the depth stop thread is 22 tpi which is 5/16 BSF, a bit niche, no wonder I couldn't find a pair of nuts for it.

I was measuring the pin last night and the battery died on my calipers. So I changed the battery, no joy, took the battery out and the terminal that touches the centre of the battery dropped out and it appears to be a sealed unit, it looks like an easy fix but I can't get into it without potentially destroying it . I shall have a go anyway, not much use as it is.

I've ordered some 45mm OD EN24T for the pin as I can't find any suitable scrap. Looks like I shall be ready to rock and roll in about a week, in the mean time I shall finish off the Toylander, its good to have two or three projects on the go so you can flip to another project while ordering stuff for another. problem is I have bout 10 on the go

Cheers
Andy

 

[brewdexta]

Progress, slow but still progress. I've just about finished the kids toylander so should speed up the tractor restoration soon. I got an hour on the axle in over the weekend, I made some round bar clamps with the help of my 5 year old daughter who loved the swarf magnet doo-dah, the rapidor and pillar drill have never been so clean

I may have to make some better bolts for the outer clamps or more tee-nuts however you get the idea, I haven't tightened it down yet, I shall do that next time I get a couple of hours free so I'm not rushing it, good job this is a hobby.

Being a funny shape my tool make friend recommended round clamps, the top ones hold it down, the side ones stop lateral movement. You can just see the 3mm aluminium plate under the axle to protect the bed.

The mill has got 4 speeds, 500 to 3000. unfortunately the pulley for the slower speed has a big chip out of it so it looks like the next speed up for now until I get the pulley fixes.

Cheers
Andy

 

[Bill Edwards]

That looks to be a well thought out method of clamping it

 

[brewdexta]

Thanks guys

I did a little more today, I utilised the holes where the stub axles bolt to measure the height from the bed either side to make sure the hole is being bored straight so the axle wont be crabbing, I got it within a millimetre which should be good enough over about 2 foot. Its all bolted down tight now.

I set up the boring head and the depth stop so next time I get some time I should be good to go. I'm still a bit concerned that the lack of the last pulley may mean its a bit too fast but I have no choice. Not sure how to work out the proper speed for boring, its a 45mm hole, I believe the axle is forged steel. The boring bars are TCT tipped.

Cheers
Andy

 

[Bill Edwards]

Hmm, a quick calculation seems to be telling me that the ideal speed would be around 200 rpm...

 

[Shox Dr]

You can buy new insides for Digi verynears, Allendale sell them

 

[brewdexta]

Hmm, a quick calculation seems to be telling me that the ideal speed would be around 200 rpm...

Thanks Bill. I thought as much even if the bottom pulley was available I would still have only 500 as a bottom speed, as it is its probably nearer to 1250. I may try the bottom speed and see how the chip in the pulley affects the operation. If it means it abrades the belt a little but works OK I may go with it, its only a couple of quid for a new belt.

I think the pulley is aluminium so may need to take it to someone with a TIG and a bit of skill. Any recommendations in the north?

Cheers
Andy