What's new
What's new

Mitsubishi HL-300-au / Oerlikon ? 12.795 x 29.527 Toolroom lathe

interested to read you have contact with Tony G-he is an archivist/scholar in the finest british tradition

his website will be the standard long after we exit the scene
good luck contacting Mitsubishi--they may prove an excellent resource
 
Tony G gave me a link to a website to called Smash, It allows high resolution photos to be sent.
Emals limit the ammount of data you can send.
I use my Android note 9 for taking photos.
He also asked for 2 or 3 m.b. photos.
I have been sending test photo files to my email and they look good.

jholand
Tony's website will live on long after we are gone. I run into that daily on the forum when I read posts sent fom members we have lost. Back in the 1980's when my grandfather died. I remember thinking that his lifetime of knowledge was gone. The internet keeps growing with every post. When I do a search on any machine tool, I get hits on the P.M. website. On a lathe I also get Tony's website. Tonys website does set a standard for information.
It all continues to grow.

I'll get back to documenting the Mitsubishi Carriage and Apron here next post
.
Thanks Mike
 
Last edited:
Great thread for a great lathe.

You've got module and diametral threading. Not many lathes have this.

Have you determined why some of the change gears with a identical tooth count have a suffix? Maybe one fits the idler stud and one is driven?

Google "base pitch" and "base pitch tables" for an explanation on the foolproof method of determining your change gear pitch and pressure angle. Then you can determine if off the shelf is available or if you have to make them.

Any external threading dial assembly from a lathe with the same leadscrew pitch will work. Find one being parted out and buy the whole assembly. I expect somebody took it off because it was in the way and it was lost.

Too bad you didn't get the steady rest. Another thing that frequently gets lost in tge shuffle. They aren't hard to mod from another lathe but prices are outrageous.
 
Thanks for the thread dial information.

The only thing that I see on gears with the same tooth count on the chart and one or both having a suffix is the speed or the type of tooth is different.
The drive and Idler gears may require a swap on some threads. I need a manual.

A question I had is with my current Change gears, they do match the chart on the gear change door.
Those four gears are all the change gears that I have.
Acording to the chart it appears that, that is all the change gears that came with the lathe to give me. Info below
From Tonys website; This lathe has.
Thirty English pitches from 4 to 112 t.p.i., twenty-four metric from 7 to 0.25 mm pitch as well as MOD and DP available.

Where there is the same tooth count with a suffiix go to the left and you will see a different speed or type of tooth is different.
20231003_100901.jpg

I Not a very good photo. This chart is
on the inside of the end cover door. I'm not sure if I posted it.
I have work to do on these charts. Most of it is fairly easy
I had the same issue trying to understand why the a and b with the same tooth count.
20231003_100910 (1).jpg
Thanks Mike
 
Last edited:
Ill get the threading figured out by getting some 3/4-inch bar stock and go down the chart doing scratch passed and get some practice cutting threads. I have some 4140 drops for getting some practice.
O.J.T. sticks with me better.

I'll get the Carriage and Tracer documented here next. There iis so little information online about these lathes is why I wanted to get this lathhe documented and availabe online.
I appreciate your experience in getting there.

Soon I'll need carbide cutting tools.
I think these lathes came into the market a little late when machine tools started changing towards the early CNC era, before Dos.
I am very interested in the Hydraulic Tracer attachment. Those were pretty common.
Happy Holidays

Mike
 
Ok
Guythatbrews
I now see why you asked about the suffix thay have an 52a and 67a on gears in the b-column.
I do not understand why they marked them that way.

I also see how many gears by tooth count that are missing from my sets of change gears.
I need to count teeth of all four gears that I have and see what gears are missing from my sets.
Jholland went through all of this with me.

I apologize.
My doctor started me on thyroid meds and had me off the charts once. Now I think it's off again... I'm just stopping that medication.
It's like 30 cups of coffee in a pill.
 
Ok
Guythatbrews
I now see why you asked about the suffix thay have an 52a and 67a on gears in the b-column.
I do not understand why they marked them that way.

Is there a quadrant in the changegear box? I can't see one. If there is not there must different pitch gears maybe with non-standard pd's to fit the fixed center distances. That's crazy but the suffixes aren't mutually exclusive to the I, II, and III studs.
 
There is no Quadrant.
I pulled the center gears, and they are Idlers that both are on a splined hub that rides on a bronze bushing. They are intended to turn fixed together but are free spinning idlers.

Thats a 39 tooth and 52 tooth idler gears
The gear in position "A" is 24 tooth and position "D" is 39 tooth.

24 tooth in Position A
52 tooth in position B
39 tooth in position C
39 tooth in position D

I see that setup in the second row.
20231117_080956 (4).jpg


The idlers removed.
20231221_041641.jpg

The idlers are on a splined 4 flute hub as a fixed pair with a bronze idler bushing
20231221_043334.jpg
There are still gear sets on the chart that won't fit between the fixed centers.
As guythat brews said unless different pd's but I agree thats crazy.
It missing gears are standard as jholland suspects I can cut the four flute center.

I still cant cut metric yet.
 
If the missing gears are a standard tooth as jholland suspects I may be able to cut the 4 flute spline but it looks like I still dont have metric cutting at this time.:D

With fixed center distances the gears are very likely not standard.

The advantage of a quadrant is standard gears may be used. The disadvantage is you gotta adjust the backlash every time you change.

Fixed center distance change gears just the opposite is true.

It will take some figuring to determine the particulars of the missing gear sets. Likely they will be different pitches and modified pitch diameters. If this is the case they can't be cut with involute form cutters, but must be hobbed. You can make some nice blanks and send them out for hobbing.
 
With fixed center distances the gears are very likely not standard.

The advantage of a quadrant is standard gears may be used. The disadvantage is you gotta adjust the backlash every time you change.

Fixed center distance change gears just the opposite is true.

It will take some figuring to determine the particulars of the missing gear sets. Likely they will be different pitches and modified pitch diameters. If this is the case they can't be cut with involute form cutters, but must be hobbed. You can make some nice blanks and send them out for hobbing.
So if I sent two blanks the right diameter and gave them the tooth count would they do the math? What other specs would they need?
 
Last edited:
So if I sent two blanks the right diameter and gave them the tooth count would they do the math? What other specs would they need?

You are better off and it will cost you less to send them more info. Start with the center distances within .001 or so then back figure the best fit pitch. A good gear shop can take it from there.
 
It seems that not knowing the diameter would be a critical sticking point. The tooth count may not give you that unless you would just scale the current gears up or down.
I'll try to find someone that ownes one of these lathes. Not likely!
I'll have to put this on the back burner for now.
I doubt Mitsubishi would help but I'll try contacting them.
I need to ask about an owners manual anyway.
Thanks
Mike
 
It seems that not knowing the diameter would be a critical sticking point. The tooth count may not give you that unless you would just scale the current gears up or down.
I'll try to find someone that ownes one of these lathes. Not likely!
I'll have to put this on the back burner for now.
I doubt Mitsubishi would help but I'll try contacting them.
I need to ask about an owners manual anyway.
Thanks
Mike

Mike, the relative pitch diameters of the gear pairs will be proportional to N-2 where N is the number of teeth. That is the easiest part once you know how to go about it. I'm busy today getting ready for xmas house guests so back burner. Yeah. Give me a bit and I can walk you through it.

I agree mits will be of little help. But it will really be cool if you can arrive at a full set of gears. Or at least be able to cut metric pitches. I had a Mori Seiki MS-1250 for a long time that would cut DP and MOD pitches also. I thought that was really cool but can't remember ever using that feature. It is great for cutting worms.

Getting one of the many high quality old lathes back close to new is a great endeavor! We won't see new lathes like this ever again. But it is a ton of work!

Greg
 
Mike I made an excel spreadsheet to guess at the manufacturing pitch required for each gear pair. It's not an forum-allowed file type but I can email it to you. I attached a dumb example that shows the choices for the A and B studs.

To use the spreadsheet, input the measured A-B center distance and tooth counts from the lathe chart. In this case I guessed a 78mm center distance based on a guess of 2 MOD for the first gear pair. The spreadsheet calculates the all the exact pitches required for standard gears on the 78mm distance, both MOD and DP. The final column is the pitch that makes the most sense to use for manufacturing, and is user input based on normally available gear generating cutters.

It's possible that odd special cutters were made to the calculated pitches, but more likely that standard cutters were used and the PD was expanded to fit the fixed center distance. This is common in fixed center gear trains. The cutter determines the manufacturing pitch and pressure angle. The expanded gear data is called the operating pitch and operating pressure angle. The expansion may be applied equally to both gears or all on one gear or unequally.

The expanded gears cannot be cut with form cutters but must be generated by hobbing, etc. In general, finding the OD is not as easy as with standard gears. A good gear guy can tell you the special blank OD needed if you give him the spreadsheet info. I no longer have the software to do this, and while it can of course be done manually it is pretty cumbersome. I don't recommend it and in no way can I remember how to do it!

The trouble is finding a gear place that wants to help. And won't charge an exorbitant amount. And knows how to do all this.

If you get very lucky, all the gears you need to cut your desired pitches are standard and can be cut with involute form cutters.

A whole different way to go about this is to eliminate stud II and make a quadrant. Then you can use standard gears that may be available off the shelf. Stud II is just an idler so it will exist on the quadrant, and the quadrant will swing on stud I or III. This is probably the cheaper way to go, since custom cutting one gear is pretty expensive. Or you need to find a buddy with a gear shop!
 

Attachments

  • CHANGE GEAR PITCH CALCULATOR.pdf
    58.1 KB · Views: 1
Greg
Thanks for all the work you put into this.
jholland also put some time into helping me working this out.
I will PM you my email addres for sending the spreadsheet.
I'll work through this from your spreadsheet and what you posted here.
I'll take a good look at adding a quadrant in place of the fixed Idler. That sure would simplify things.
I seen a Owners Manual in a add for a HL-300-ua for sale in Switzerland. I emailed them about scanning me a copy. No word back yet, thats asking a lot but I would pay handsomely for a copy. The manual looked pretty thick.

It's a sin that these gears get seperated from so many lathes.:angry:

Thanks again and Happy New year.:cheers:

I'll be in bed by 8pm but get woke up at midnight by the gunfire and tell my wife happy new year and go back to sleep. No partys here. :Yawn:
Mike
 
I wired the lathe up for a test run. No cutting yet just listening to the gearbox and checking oil flow. The pump is working well although I havnt added the pressure gauge yet that jholland suggested. I will add a gauge and some type of interlock for low or lack of oil pressure warning before cutting chips.

The bearings and gearbox sound, or lack of noise is great. One of three belts has a bad spot and needs replaced. I'll replace all three while there.

This spindle switch works great. When you release it from forward or reverse it returns to center but doesnt brake unless you push the handle into the center slot. I like that because the brake isnt always needed. The chuck stops fairly quick without the brake. The brake stops it dead.
20231003_100739ffff.jpg

The next two photos shows two different aprons. The photo below is on my lathe.
20231110_142654RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR...jpg

This apron below was used on the earlier lh300au lathes.
jholland mentioned that earlier models had the handwheel on the right.
I havnt spent enough continous hours in front of a lathe to say which apron layout is more comfortable running on eight-hour shifts.
The lathe below is for sale in Switzerland and looks looks like original paint and very nice overall.
mitsu300hl (2).JPG

This is my compound while I had it appart.There are odd staining patterns that look like scraping but I dont think it is. I dont know if they could have done some type of etching or if its oil staining.
Its in nice condition.
20231118_085354.jpg

There is about eight thou play on the dial but mostly in gear play.
I flushed the gears out better after this photo.
20231118_085257 (1).jpg
20231118_085209 (1).jpg
20231118_085430.jpg

One hole drilled and tapped to lock the T nut down I'm guessing. It's usually pulled up.
20231118_085500 (1).jpg
 
Last edited:








 
Back
Top