Member postings for Lionel Titchener

Ah, Yes, I thought I would be picked up using dual measurements.

I didn't know if Myford originally designed the gear in Metric or Imperial.

It measures .998" But it also measures 25.4mm (1 inch) as you move around and measure in different locations.

I was not sure which is correct.

Thanks John for confirming my calculations, not had to work with gears before so spent the last few evenings using Google to try and understand how the calculations work. So far most of the catalogues only offer 22 degrees PA as you mention.

Also thanks to everyone that has taken the time to read such a long post.

I have been contacted by someone that can make me a gear.

Lionel

Edited for typo, catalogue changed to catalogues

Edited By Lionel Titchener on 01/03/2015 09:21:16

The was an article in a magazine a while back about a padlock manufacturng business that was based in a row of terraced houses, I cannot remember if they had decided to move as the space was getting too cramped, or future generations had decided the business was no longer profitable.

They had been in business since around WW1, I think in Birmingham or the Black Country.

Last time I used rat poison the rats were gone within weeks. Problem was a couple of weeks later everywhere had a terrible smell. In the end we had to take up the floorboards to remove the dead rats. Found three under the floor.

Another two were in the workshop which took three holes in the roof insulation to find them. now use spring traps and an electric trap that so far has caught nothing.

Having a cafe next door keeps them coming back.

Need to, edit the above post, should have said you do not get 90 degree sides to a slot when moving in the C axis.

If you think of the C axis as the same as the Y axis on a mill, it's easier to visualise how it's programed.

The C axis will allow just about any shape to be made. The X axis just moves in and out as the spindle turns slowly converting the degrees to the Y movements.

Working on the face is OK, slots on the outside surface have a curved bottom as the spindle turns, It will slot OK on centreline with driven tooling, but when the slot needs to be off centre you get the curved base.

Hello,

I've been lurking around this forum for some time, and now have a problem that members here may be able to help me with.

After running the saddle into the stop, the clutch did not stop a pin being sheared in the feed drive gear train in the apron.

After stripping it down I found some of the gears were badly corroded. Bought replacements from Myford except for one gear, the hand wheel pinion, no stock. The pinion is badly worn and impossible to measure accurately

It has 16 teeth.

Gear is about .998” or 24.4mm diameter

Width of gear .515” or 13mm

Length of shaft including gear 3.900” or 99mm

Diameter .550” or 14mm

It meshes with the larger gear on the Rack Pinion Assembly.

I am told by Myford the gears have a pressure angle of 14.5°, and are normally 20DP.

The large gear on the Rack & Pinion Assembly appears to be 18DP As the O.D. for DP 18 is close to what the gear measures, 2.766” Diameter. At 20DP is come out at 2.500”

Never needed to make any gears in the past so used Google to try and understand how gears are measured, hopefully I have got this correct.

This is what I have worked out.

48 Teeth and 2.766” diameter

Measure across 5 teeth is 0.771”

Measure across 4 teeth is 0.610”

So is the pitch 0.161”?

For 18DP Gear I get these results.

PCD. Teeth Divided by DP = 2.666” For 20DP 2.400”

OD. Teeth +2 Divided by DP = 2.777” For 20 DP 2.500”

Module. 25.4 Divided by DP So 25.4 divided by 18 = 1.41 For 20DP 1.27

No of Teeth PCD x DP So 2.666” x DP18 = 47.98 For 20DP 48

This leads me to believe that the DP is 18.

Therefore I need to find a 16 tooth 18DP Spur Gear either on a shaft, or a gear that can be pinned to a new shaft.

I’ve looked at HPC Gears, they do pinion gears on shafts but not one long enough.

Contacted **LINK** but not yet had a reply.

Anyone able to suggest where I can obtain a suitable part or get one made?

Thanks

Photo 1

Shows the Pinion next to the gear it meshes with, I have used this gear for my calculations as it is a new gear.

Photo 2

Shows where the gear locates, it’s not pushed all the way in it sits under the larger gear at about 4 o’clock.

All the four gears at the top of the apron are new, unfortunately Myford no longer stock the pinion with the small gear.

Photo 3

Pinion is part number 45 in the diagram.