Thread: HM52 CNC Conversion

Ray,
Sorry to hear Murphy's visited on the weekend.
Repair looking good so far and hope it works out for you.
Was there two AL330 models as mine has a geared drive with rotary selection where that looks like a Norton style lever.

Originally Posted by RayG

We have re-toothed the idler, using the mill with rotary table and fly cutter,

My brain cant picture that

How does one do that....cut straight teeth on a round disc of metal with a fly cutter ....isnt the cutter going circular????

Ah!....think I just figured it out
the cutter is not being used as you would use a face type mill...but rather as radial (if thats the word) cutter

Hi Eskimo,
The fly cutter is ground to the tooth profile, this one is made from a piece of 1" shaft turned down to fit a 20mm ER32 collet, the cutter is ground from the shank of an 8mm drill bit, and then that's held in place with a couple of 5mm cap screws. The profile is ground close to the profile on the wheel, and then finished off with a dremel, by test fitting and holding up to the light. The gear being cut is held vertically on a three jaw chuck bolted to the rotary table (mounted vertically) (EDIT: I MEANT HORIZONTAL )and then the indexing wheel is set up to whatever number of teeth you require. I should have taken some pictures...


Sorry about the blurry photo..

The Lathe is now back up and running.

Here is the replacement selector lever.



The replacement selector arm was made from 3 pieces of Aluminium plate cut out on the bandsaw, bolted together and filed and linished to shape. The holes for the shaft were bored on the mill. I will still go ahead and buy the spare part (when I can find out what the part number is !) meantime this one works nicely.



Here is the part finally installed and running....

Regards
Ray

After the lathe hassles, it's good to get back to the conversion project, the timing gears and belts have arrived, they were from this supplier... Mechanical Components Timing Belts Pulleys Spur Gears Pulley Couplings Bearings Brakes Gear Clutches Shafts Shaftloc Sprockets Retaining Rings Fairloc ConiDrive Manufacturing The local suppliers quoted ridiculous prices and didn't return phone calls, etc... In the end I bought exactly what I wanted on line and they turned up a few days later..



The reduction is 4:1 The servo is 18 teeth and the ballscrew 72 teeth.
The 4:1 reduction should give me 180 x 4 = 720 oz-in and peak torque of 2160 oz-in

The motor is rated at 3000 rpm, so that is 750 rpm on the ballscrew, or 12.5 revs per second, times the pitch (5mm) equals 62.5 mm/sec or 147 ipm.

Here is the setup for boring to suit the shafts.


And first trial fit.


The next job is to determine the final locations for the front panel which holds the servo.

Regards
Ray

Ta Ray...?i think
"The gear being cut is held vertically on a three jaw chuck bolted to the rotary table (mounted vertically) and then the indexing wheel is set up to whatever number of teeth you require. I should have taken some pictures..."??? you should have....hahaha

I am having trouble picturing that, how you used indexing to cut a gear (then proceed to the next one etc etc), while the gear is held vertically with a cutter running horizontally in a circular motion ...

I need a big thinking cap

Judgeing by the method described I would say that his Cutter is held in the Horizontal Spindle.

The Rotary table would need to be running true.

The Gear Blank would be set so the Centre of it was on the same Centre as the Cutter.

Not sure if the Teeth would of been cut in 1 or 2 or more passes.

Depth of cut would of been taken with the Z axis.

The Knee would of been raised and lowered to perform the cut.

If the cut had been done in one go the Cutter may have been raised back through the cut tooth and then the Rotary table indexed the correct number of degrees.

The cutter may have been left at the finished side of the Gear,Table rotated and a cut taken with the Knee in the opposite direction.

If the cuts were done in stages they may have been done to finish 1 tooth at a time or the Gear may have been rotated each time untill the finished cut was taken.

This is only my guess as to how it was done with the information given.

Pipeclay......ta...but now i am in a state of information overload
The cutter tool holder is in the horizontal plane with the cutter in the radial plane of that.
The gear is held vertically in a 3 jaw chuck on a rotary table mounted vertically

so that means the rotary table when rotated goes around on the horizontal plane
and you cut each tooth by indexing the table....

?????

I really do need a picture....video would be good

What part are you having trouble understanding?

Can you understand how it would be done with the vertical spindle?

This is cutting a group of 127 tooth gears in the Vertical,just imagine it on its side for Horizontal,but without the Tailstock.

Thanks pipeclay
i quote Ray "rotary table (mounted vertically)"
so the rotary table was mounted horizontal and not vertically as Ray said above

No, his table would of been Vertical,his Cutter would of been Horizontal.

His blank would of been mounted the same way as his 72 tooth gear is mounted in his CNC conversion.

With his cutter in the Horizontal Spindle he would just bring the Gear blank into the Depth of cut he required then just raise and lower his table.

I'm getting there ...hahaha
so the cutter would have come in from either end (the side) of the table

The Cutter would not move,the Gear Blank would be set at the Centre of the Cutting Tool and the Gear Blank would be moved towards the Cutter for Depth of Cut, and then the Table would be Raised to perform the Cut.

Eskimo,
This might help you. Reg lives around the corner from me.
gearcutting
Dave

ah ah got it
a couple of pics does wonders for my brain...same as looking at a pic of jenifer hawkins, but only different

thanks guys

Reg has some great stuff there!!