Chester 626 mill power feed install....

[John Rudd]

So the saga continues.....
I thought I'd take some photos of hoe I installed mine and some of the issues I had when putting it sll together....

The powerfeed unit I bought is the Align 500 X axis unit supplied by Chester. I am told reliably that it was originally designed for a Bridgeport, so some metal mangling will be required....

Having removed the end bearing support from the table, 2 holes were needed to mount the power feed unit....First job, make a locating peg to align the bearing centre with the needle bearing on the pf unit....

[John Rudd]

Once the two items were aligned axially, using transfer punches, the two mounting holes were located.

Putting the block in the mill vice, the holes were drilled and tapped..nothing exciting...

[John Rudd]

We all know these far eastern machines are built to a price and mine was no exception.
There are two locating dowels in the end bearing support.....look how well installed they are!
The square gives an idea of how far out they are....

[John Rudd]

I apologise for the orientation of the pictures....I cant seem to rotate them....

[appletree]

Jobs often go easier than envisaged, once the nettle is grabbed so to speak.

Phil

[John Rudd]

So having got the mounting holes done, time to try the powerfeed....
The holes line up perfectly...

[John Rudd]

Now there are more issues.....

With the bearing block back on the table, the leadscrew has a shoulder some 20mm in diameter.
In the pf unit, there is a needle bearing, a sleeve takes the shoulder diameter up from 20 to 24 mm which is the bore of the needle roller......

[John Rudd]

The sleeve is not long enough, and neither is the 20 mm diameter shoulder of the leadscrew....
As the pf unit is offered to the leadscrew, the sleeve slips backwards resulting in the pf falling onto the leadscrew....

[John Rudd]

So now I need a workaround.....

I could make another sleeve that will fit onto the leadscrew, stepped to accomodate the existing 20mm shoulder, with an o/d to suite the needle roller, then a further section machined to accomodate the bevel gear...

OR you guys could suggest an alternative?

I'm going to call a halt to things at the moment while I have a think.....

Stay tuned for more ramblings and metal mangling....

[BaronJ]

We all know these far eastern machines are built to a price and mine was no exception.
There are two locating dowels in the end bearing support.....look how well installed they are!
The square gives an idea of how far out they are....

Hi John,
The dowels on mine were fine, yours do look very badly out of square.  Also the dowels on mine had a threaded hole in them, presumably so that they could be jacked out with a screw and a collar.

I returned the power feed that I bought, which is why I decided to build my own.

[RobWilson]

We all know these far eastern machines are built to a price and mine was no exception.
There are two locating dowels in the end bearing support.....look how well installed they are!
The square gives an idea of how far out they are....

Hi Mate 

I did warn you   


Rob

[John Rudd]

We all know these far eastern machines are built to a price and mine was no exception.
There are two locating dowels in the end bearing support.....look how well installed they are!
The square gives an idea of how far out they are....

Hi Mate 

I did warn you   


Rob

Huh....no need to rub it in........


Not got much more done....my 10 mm boring bar is broken...the tip has snapped and so has the torx screw....cant find my other one    so job stopped.
On a brighter note, the inverter and motor I ordered last Tuesday have arrived....so more mill modding to be done

[John Rudd]

 Right, more done tonight......
I needed a spacer between the pf unit and the bearing at the end of the leadscrew, so after a bit of metal mangling, Igot to where I needed to be.....
Then there's the bush that fits in the needle brg....so plan B....make them into one.....

My spacer on the left, bush right......

[John Rudd]

So a bit of 1-1/4" bar duly sourced from the stockpile turned down to size and bored.....and I ended up with this....

[John Rudd]

The moment of truth.....will it fit?
I measured, cut/measured/cut and so on......surely my efforts are not in vain....?
Well no need to worry, the 1st bore that fit the larger diameter of the leadscrew was such a good fit that it wouldnt come unstuck after lathering it in grease.....so the excess was wiped off and the fit was......errrr perfect!
A trial fit of the pf unit and all is good......

[John Rudd]

So the next hurdle is the fact that the leadscrew is too short by about 60-70mm.....
The bevel gear is a good fit, obviously needs shimming to ensure good tooth alignment, but because the leadscrew is too short I need to do something to retain the gear on it.....
Time for a beer and a think

Stay tuned....
Oh by the way, here's the motor and invertor that I'm fitting next as a taster.....

[John Rudd]

So more shop time today....

Today's task, I decided on the key for the bevel gear....rather than broaching the keyway out to take the existing key, I decided to make a new key from brass....

[John Rudd]

Why? Well its softer and will shear if anything goes wrong....I also made it stepped....so it fits the original keyway in the leadscrew and fits the existing keyway in the bevel......
A perfect fit.....and some spare brass key, just in case...( so long as I dont forget where I put it....)

[awemawson]

The base plastic cover of the Align units usually has a spare gear in it - put your spare key in there with it.

[vintageandclassicrepairs]

Hi John,

Then there's the bush that fits in the needle brg....so plan B....make them into one.....

If I am reading your posts correctly you replaced the inner sleeve with a combined spacer sleeve ??
The sleeve that fits the needle bearing is a hardened and ground  precision part
The needle bearing will not last very long running on a turned mild steel part 

John (another one)

[John Rudd]

If that is the case, I shall have to machine my new part to accept the hardened and ground sleeve....
I dont want my roller falling apart.....

[vintageandclassicrepairs]

Hi,John

I dont want my roller falling apart.....

That would never do 
At least its an easy fix

 
John (number ??)

[John Rudd]

Spent time today madmoddering the sleeve to take the hardened steel bush....
Also turned up a bit of bar to fit inside the bevel gear to make up for the shortfall in length of the lead screw....
The whole assembly is now back together and looks good....I suppose I ought to get some micrometer blue to determine the tooth engagement of bevel gear and its mating pinion....and add the correct amount of shims.....job for another day....

The plastic box for housing the inverter arrived yestarday, the box backplate turned up today....I got some DIN rail and an mcb from Screwfix too...So another job to sort.

Photos to follow....

[John Rudd]

So, while I mull over options....

I have completed the new dial, minus the divisions and added a small section of bar to retain the bevel gear.....and made a bolt to go in the pre threaded M6 hole in the leadscrew.....
All assembled and working well....just need to add the limit switch assembly, box the transformer and complete its wiring...

more to follow....