Old Henry Milnes Planer Restoration- Fast and Loose Pulley problems

Hi to all

I've had a number of projects on the go and have spent a lot of time on this one....

Its a fairly rare Henry Milnes 24 in planing machine- a tiny little thing by US standards but its what I can fit in..

I'm getting near the end of the restoration and I just cant get the fast and loose belt shifting mechanism to work. The trouble is there is very little out there on optimising a fast and loose planer belt shifter and i'm working with just a catalogue picture and what was a derelict machine which hadn't worked for many years so im bound to have got something wrong....
Hopefully ive managed to attach some pictures...

There is a normal three stage pulley set on the side of the machine..centre is loose either side is drive...and a belt shifting mechanism which is a round rod driven by a control crank on the far side of the machine- operated by stops on the side of the table...

Ive got a n old lawnmover drum skimmed down to act as the countershaft drum

pulley centres are about 4ft 6in drum dia 8in which just about matches the three pulley set

contershaft speed about 220 rpm...catalogue says 205

The basic problem is that with the belt tension set so that it barely drives the outer drive pulleys...it wont shift across- it just twists up and hangs there...

I've got some questions based on my observations of US machines on youtube etc and im hoping that the knowledgible wise ones out there may be able to help...

Do the shifter forks have to work on the slack side or the tension side of the drive pulley?

how far away should they be from the drive pulley?

The machine pulleys are 2in wide so I've assumed a 2in wide belt.....I'e been looking on youtube and there seem to be bigger machines running belts which are not as wide as the pulleys...could it be that my belt is too wide for the centres and I should be running a narrower belt with more tension?

All suggestions gratefully received ...it would be nice to make some planer ships.....im quite cloes yet so far...

Regards

John

Henry Milnes Planer 24in sone further pictures

I thought that i would include just a few more images to get the over view....

All suggestions gratefully received.

Best

John

John, That is a nice looking planer. The belt shifter needs to be on the leading side belt. In your photo the belt should be running down, the belt should be good and tight too. And obviously the pulley need to be running before the belt will move. A 2" belt should work but maybe a 1 3/4" belt would give a little room on the pulleys so you don't get drag from one to the other.

enginebill said:

John, That is a nice looking planer. The belt shifter needs to be on the leading side belt. In your photo the belt should be running down, the belt should be good and tight too. And obviously the pulley need to be running before the belt will move. A 2" belt should work but maybe a 1 3/4" belt would give a little room on the pulleys so you don't get drag from one to the other.

Click to expand...

You may have a way to confirm this thought: it was not unusual in the day for the gearing on a single belt planer to present a fairly slow "cut stroke" and a fairly fast "return stroke." Single belt speed would be constant, of course, but the gears may be made in "ratio" to allow this platen speedup to happen. Examine your gear trains you may find evidence of this and determine positively the proper rotation for the drive pulleys.

Joe in NH

I don’t see a way that you are powering the drive drum so I am thinking you’re just trying to test the mechanism static. It won’t shift unless it’s running

enginebill said:

John, That is a nice looking planer. The belt shifter needs to be on the leading side belt. In your photo the belt should be running down, the belt should be good and tight too. And obviously the pulley need to be running before the belt will move. A 2" belt should work but maybe a 1 3/4" belt would give a little room on the pulleys so you don't get drag from one to the other.

Click to expand...

Hi There thank you for your help- in my case the belt is running up...so i would need to rotate the rod forks around the sliding shaft so that they move the belt as it is coming down onto the drive pulley....
which is how they are shown in the machine catalogue picture- but they donet seem to be long enough and i found that the belt twisted and then rode over the front of the forks...
although he machine hadnt worked for many years-it did have two blocks of wood rammed onto the ends of the forks when i got it and that maybe why.
I not that a lot of US machines have a rectangular ring around the belt on the shifter...please also see my other reply below...
Are any of these principles written down anywhere?
Best Regards

John

Joe in NH said:

You may have a way to confirm this thought: it was not unusual in the day for the gearing on a single belt planer to present a fairly slow "cut stroke" and a fairly fast "return stroke." Single belt speed would be constant, of course, but the gears may be made in "ratio" to allow this platen speedup to happen. Examine your gear trains you may find evidence of this and determine positively the proper rotation for the drive pulleys.

Joe in NH

Click to expand...

Hi Joe

You've actually solved part of my problem-i.e. which way should it rotate and yes you are exactly correct- there is a substantial gear train which is connected from one pulley to the other and relies on the belt crossing over the loose pulley for there not to be a clash.
The left hand pulley is geared down to give about half the travel of the right hand pulley- and this is referred to in the catalogue- see my second post above- as cutting speed 30 feet/min return 70 feet/min

So you are right- the direction of rotation has to be such that the slower table travel acts as the cutting stroke...with the table going back towards the tool...my rotation at the countershaft is correct i.e. with the pulleys rotating towards the fron of the machine - but I have the belt shifter forks arranged at the back of the pulley with the belt passing upwards...i guess this is the tension side and will now change the forks to the face front wards to act on the belt passing down wards to the pulley. This is as per the catalogue pic- but i had it rotating the other way initially..

Yes i do have it running under power- the picture of the twisted belt is taken just after i hit the stop button - and shows what happens when the belt shifter goes across...

Thank you for your help- do you know if these fundamental principles of fast and loose belt setup are written down anywhere?

Bset Regards

John

DeSelle said:

I don’t see a way that you are powering the drive drum so I am thinking you’re just trying to test the mechanism static. It won’t shift unless it’s running

Click to expand...

Hi - yes it is running under power- there is a 3 speed gearbox and motor behind the machine on the floor driving a B section V belt to the left of the main drum....the picture of the twisted belt is taken just after I hit the stop button after the belt shifter started to move across- the basic symptom is that the belt doesn't seem to slide easily when moved by the belt shifter as it is rotating...see also my replies above....

Best Regards

John

Principle 1. The belt should be as loose as possible and as tight as necessary to not slip.

Principle 2. The belt must see the shifter before seeing the pulley.

The short distance between the pulleys on your application make the belt tension problematic. Some options include, a smaller drive pulley, a smoother surface, a helper shifter to move the belt across the drive pussy.

A good portion of these "principles of design" are shown in Joshua Rose's seminal "Modern Machine Shop Practice" originally printed in 1879 (and revised at least three times in the next 40 years)

This can be found online in several places but the original printing is shown in 2 volumes at Modern Machine-Shop Practice, Volumes I and II by Joshua Rose - Free Ebook There are downloads and an HTML version for quick viewing.

Antique hard copies still exist, can be pricey depending on condition, but if you're not concerned with how the book looks on your library shelf, good deals can be found. The books have been reprinted in the Pacific Rim and these are available for less - but the books are "smaller" (Reformatted to modern standards - Epublishing!)

Be careful. Reading ANYTHING of this book can be addicting - Mr. Rose describes mechanical concepts of a century and a half ago in a style which anyone today can understand. He made his living during his life doing exactly that and one can understand his success.

Joe in NH

after moving the shifter forks

Dear Joe thank you for that link re Joshua Rose- I realise that I've got a copy of Volume 1 tucked away and I'm reading that...and I'm reading up about belts on Old Harry's website as well...

Have flipped the Forks over so the shifter is now shifting the belt in advance of the pulley..i.e.going down through the forks....and increased the tension to try and reduce the slipping of the belt on the right hand pulley.....as this is the quick return the gearing is higher and it needs much more grip to get it moving...

tried it out and the pictures show what happens ..

pic 1 table stop is contacting the lever to push the belt shifter rod...
Pic2 the belt seems to lock up and wont move..its trying to slip and creep around the back of the pulley -this is just after I hit the stop button
Pic 3 what happens if you continue rotation of the countershaft by hand for a short distance - the belt flips behind the fork and stays jammed around the back...
My thoughts having thought about it are:
bite the bullet and relocate the countershaft on the roof timbers further back and behind the machine to increase the belt run as much as possible...i can see that it would be optimum if the belt was coming from behind and above by about 20 degrees...the belt would not be able to get in front of the shifter.
Longer belt might change direction easier.
go down on the belt width to say 1.75in to give more wriggle room on the pulley- it will be less able to get onto the back corner of the pulley...
downside is that the tension may need to increase to drive the high geared return pulley as this will mean more force needed to move it sideways....
I'm beginning to get the principles...

Best John

Are the 3 pulleys on the planer the same diameter? I would expect them to be or the center one a tiny bit smaller than the two driving ones.

If they are the same dia then why is belt tension not the same obe each of the drive pulleys? Is the "lineshaft" not parallel to the centerline of the drive pulleys?

Can to make a small U bracket or keeper to connect the end of the shift forks together? This should help keep the belt flat with the pulleys, kind of like the rectangle shifters on old USA equip you mentioned earlier.
Just a piece of flat bar with a hole for each leg of the fork, 1/4" thick to take a small set screw to hold it on will let you know if it works or not.

Rob

have laid a ruler across the pulleys and yes the centre loose pulley is crowned but but a tiny bit smaller such that it will freely rotate under the ruler laid across the crown of the other two pulleys...

Have set up the machine parallel to the wall and the countershaft drum at right angles to the wall...it may not be very accurate...but the idling belt does't seem to wander unduly..more due to slight unevenness in the leather at the joints....

You are right ...a block across the forks rounded off between is on the workbench right now....

Best Regards

John

wotcherman said:

Rob

have laid a ruler across the pulleys and yes the centre loose pulley is crowned but but a tiny bit smaller such that it will freely rotate under the ruler laid across the crown of the other two pulleys...

Have set up the machine parallel to the wall and the countershaft drum at right angles to the wall...it may not be very accurate...but the idling belt does't seem to wander unduly..more due to slight unevenness in the leather at the joints....

You are right ...a block across the forks rounded off between is on the workbench right now....

Best Regards

John

Click to expand...

I would measure each end of the drum to the outer pulleys, just to make sure they are parallel, could be twisted or out of level or both. To be noticable on the belt tension it must be out an easily measured amount with a steel tape measure.

Very nice looking machine.

Can you post a video of the operation? It doesn't look like the belt wants to move at all. The countershaft belt on my Putnam planer is only about 4' from the line shaft and those tight and loose pulleys work although the shifter forks are longer on mine so the belt can't go over them.

YouTube

here a video on one shifting the belt

Hi

I'm having a reorganisation...have moved the planer forward on the floor by about three inches as i was running out of adjustment on everything....

in doing so let the leather belt hang from the pulley and then noticed that it has a distinct bend in it -one side of the belt must be stretched more than the other- in this case the bend is to the left hand side as ive been presenting it to the camera- about an inch and a half out of plumb to the left...

So ive got give things a chance here and use some new belata belting... a mate has given me some inch wide belting for free so I'll lace up a belt out of that and see what happens...i suspect that it will change direction much better but wont be able to transmit the power cleanly- so we will end up also ordering some 1.5inch new belata as well...

shame about the old leather belt it looked great..really vintage but I think that its not helping here...
Nearly fell over when I asked a supplier for 15ft..or 5 metres of 1.75 new leather belt...they wanted £130 quid with postage and tax.... OMG..

Will post some more when i get some more results and you all have been really helpful...This forum is so good as you guys really appreciate planers

If i can get it to cycle cleanly Ill do a video...

Best Regards

John

best

Dear Rob

please my post below..have moved the machine forwards and I'm going to start again with the alignment..initial measurements in the new position put the top surface of the drum at 0.9 degrees negative...the table at 0.2deg negative...that's just using the level on my phone... will then true things up on plan using a plumbob and line offset from the drum to the driven pulleys..very difficult when the adjustment is sloping due to the roof of the shed.... we'll see...

Best Regards

John

Back when I was volunteering at Tuckahoe I had occasion to set up flat belts on a number of machines off the lineshaft. Sometimes belts look fine but have issues in use- not just slip but tracking wrong even if the pulleys are dialed in. OTOH there were some machines where we cobbled together belts out of 2 or 3 mismatched pieces and never had a problem.

The toughest belt shifter problem I ran into involved the workpiece rotation belt; shifter forks were on the wrong side of the belt because the prev owner ran his lineshaft on the opposite side of the machine, welded extensions to the forks which worked fine.

IIRC isn't the preferred location of the belt shifting forks just in front of the slack side of the driving pulley? Even so, we had cases with shifting forks on the slack side of the driven pulley which worked fine.

hi everyone

finally sourced a new thicker belt - was too wide but cut this down from 2 3/8 wide to 1 7/8 dressed with neatsfoot oil on one side only....dry side against the pulley....took two goes to get the tension right....

have found that the gearbox out put shaft bearing is duff hence the noise under some load...well that can be fixed....finally the belt shifter seems to be trying to work....

thank you all for your help..especially the principles one and two..very succinct advice that...

YouTube

now got to scrape in the adjustment gib on the table ...then we will be ready to make some chips...

Found a Biax scraper plus some blades at an autojumble for 30 quid so need to start practising...

Best

John