Harrison L5A 11" - VFD set up & spare parts needed

Hi guys!

Had enough of the Clarke’s Lathe I had. I'm 27 and wanted something that would last me and still function. Haven't had the best experience with the newer Clarke’s stuff. Got a couple of their older grinders

So bought myself Harrison L5A, believe it to be a MK4 but it would be great if someone knew a rough year.

[img]https://i.imgur.com/O2w0u6W.jpg[/img]

[img]https://i.imgur.com/wBPgFH6.jpg[/img]

However it's been dropped in its lifetime. Bed is mint but the saddle has cracked, having that welded at the moment, no real problem. But I'm having issue finding hand wheels. They're splined rather than just a keyway, would anyone know where I could get a tail stock and apron hand wheels? Or perhaps the same splined wheels are used on different makes/models lathes.

Tail stock wheel: ID - 15mm OD: 5"

Apron wheel - ID: 12mm OD: Nothing left to measure

[img]https://i.imgur.com/YWAD1SU.jpg[/img]

[img]https://i.imgur.com/6n8lkGv.jpg[/img]

Secondly just seeing if there are any do's and don'ts when it comes to the L5A. I'm only on single phase at my shop so bought an Invertek 1.5kw VFD 1PH to 3PH, motor isn't dual voltage so as far as I'm aware it's pretty much plug and play. Going to wire it up and hopefully still use on the lathes originally buttons and levers, but are there an tips and tricks when using a VFD or with the Harrison L5 itself?

[img]https://i.imgur.com/dXwQvqq.jpg[/img]

Thanks for your time guys!

Edited By JasonB on 16/12/2019 14:39:52

Read the inverter instructions. I expect it will prohibit motor starting from anywhere but the inverter controls. Likely damage the inverter if switched between it and the motor.

Handwheel - if you can't find a used handwheel at machinery supply / breakers or by want ads, I have an idea for a fix. See if you can find a commercial replacement steel or cast iron handwheel of the right size with a good sized central hub. Take your splined hub fragment, put it on a homemade close fitting stub shaft with a securing screw, and turn it round with a flange. Make this bushing's main OD say a mm and a half, or two mm bigger per side than the spline max dia. Bore your new handwheel to fit the bush OD and flange, Loctite and/or pin the bush into the new handwheel.

For that matter you could make your own handwheel with a slice of thickwall steel pipe from a scrap dealer the right OD. A spoke plate could be cut from some 4 to 6 mm thick plate and bent to shape if needed, then spoke ends skimmed , again on a homemade stub shaft w securing screw, to correct OD to fit in the pipe ID. Weld or braze spoke plate to pipe rim, dress sharp edges. Make a steel bush to go in the spoke plate, and fit the cast iron splined bush as noted above.

Just food for thought. Better to get on with making something than waiting / searching for rare parts. If you do ever find a correct used handwheel you can always fit it - since you used the old splined bit as the bush for the improvised one.

Edited By Jeff Dayman on 16/12/2019 15:54:46

Your inverter is 1 phase 230vac in and 3 phase 230vac output so may not perform as you think. You need to check if it is wired Star or Delta. It usually needs to be wired in Delta for best effect. " For a given motor, the fundamental difference between the star and delta connections is that the rated voltage for the star connection is 1.731 X the rated voltage for the delta connection. ... With a VFD the effect would be the same, the motor will produce less torque per amp of current."

Do a search here in the forum for VFD threads to learn a bit more. Also check with the supplier for suitability of the vfd on a 440v motor. The manual will probably be of little help in this respect.

regards

You will need to take the motor apart and dig out the star point to run it from an inverter. I would forget using the original switches and contactors etc. Wire the inverter direct to the motor.

L5a has a clutch, so once the motor is running, just leave it running and use clutch for stop start.

Forward and reverse is handled mechanically.

Harrison serial number/year list .http://www.lathes.co.uk/harrison/page14.html

Edited By Alan Waddington 2 on 16/12/2019 16:20:20

As Alan says you will need to dig out the star point from the winding so you can connect the motor in delta.

Not usually difficult on Brook motors. All the ones I've seen have the star point readily accessible on top of the windings.

However if funds permit its probably easier to buy a new motor, star / delta connections are standard now, and be done with it. These days a 6 pole, 900 rpm, 3 Hp (1.1 KW) motor of perfectly adequate quality can be found for around £100 to £150. A 900 rpm motor makes much better use of the VFD as it allows lower speeds before you notice any power drop off. Using the uber conservative "always satisfactory" ± 1/3rd nameplate speed range a 6 pole motor gives you 600 to 1200 rpm. The usual 4 pole one gives 960 to 1920 rpm, most of which you will never use as the higher end is too fast for all but very small jobs. As jobs needing high speeds are invariably small you will never notice any power losses when running above the conservative + 1/3 rd range but you may very well do so when running slowly with larger job.

In a practical world ± 1/2 nameplate speed is usually more than acceptable but you may have to compromise cutting loads at the bottom end.

I'd use a separate pendant box put somewhere easy to get at to control the inverter and take the opportunity to add an emergency stop stamp on bar underneath. I prefer a calibrated dial on the speed potentiometer to watching a digital display. Easily made.

Clive

Edited By Clive Foster on 16/12/2019 16:37:43

Just remembered Bede Tool and Machinery are breaking an L5, not sure if parts are interchangeable but worth an ask. Advert is on Facebook, but probably worth giving them a call to discuss.

Thanks for all your input guys, all taken on board, much appreciated. I have a little update:

Handwheels - Thanks Alan for the lead on Bebe Tool and Machinery. Got in touch with them but sadly no luck. As expected the splined version is near impossible to find and they had to get some pattern wheels splined. So I have two 5" wheels on order and will use my existing handwheels for their splines. Most likely use them as bushes, remove the centers on the new wheels and seam weld them together.

VFD/Motor - Took the motor apart to try and find the star point and I'm starting to think getting another motor might be the best option. Never messed around with electric motors and I'm getting a little scared looking in on all the windings. Seems a shame to just shelf this motor though. VFD arrived yesterday and I'm working my way through the manual. certainly glad I opted for a branded VFDs rather than the cheaper Chinese VFDs on eBay, the Chinglish manual would of really hurt my head.

There is a local guy who re-winds 3 phase motors, might pop it over to him and no doubt he can re-wire in Delta with his eyes shut, if it's cost effective.

I'll keep this updated, no one likes a dead thread.

Thanks!