Looking for a pic pre 1970 4in1 Gemmasta

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joe

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Hi guys, would any of you had a pic of a 4in1 Gemmasta cabbing machine? Pre 1970. Doing a restoration of the below.
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Thank you. Joe
 
Thanks mate, yes have seen these ones they are post 1972 or so.
 
Hey Joe,
Have you tried contacting Gemcuts in Ballina. They have taken over the manufacturing of Gemmasta and might have some original photos as well as be the source of some of your new parts.
 
Thanks Martys, havent tried yet but will do as last resort.
 
Looks great Joe. I know its hindsight but I carefully taped over the original Gemmasta sticker on mine because I knew I couldnt get another one. If youve done all that work in the last two days then youre quicker than me.
Its great to see another machine even older than mine brought back to life. I hope it brings you just as much joy. :Y: :Y:
 
Hey Joe,
I just noticed that youre motor is going to be bolted down on four sides. If you want to change the speed of your machine by shifting the belt onto a different pulley wheel then you will have to loosen the bolts. The person who owned my machine set the motor up on a hinge so that if you are using the slicing wheel you can easily speed it up by just tilting the motor and shifting the belt. Works great.
1634163394_f6fd9f9b-2e15-4999-97ac-c898a6b66e28.jpg
 
Nice Marty, yes the masking tape still over the logo. Smart re: changing speed for the cutter. What speed is your motor?
 
I dont really know much about electric motors but here is the specification plate.
1634188776_1fc1d2f8-cac8-4b7a-b22e-9bb91c16a266.jpg
 
You should check the speed rating on your grinding wheels . Do not exceed that or they could shatter .

The speed can be calculated by knowing the size of the pulleys . If the motor pulley is 4 inch and the shaft pulley is 2 inch then that is a ratio of 2 to 1 . So it is going to now spin at 2 X 1425 = 2850 R.P.M. Just be careful about increasing the speed .

Make sure the frame is earthed , clean the paint off and make a good clean metal to metal contact . Water and electricity do not mix . Has the power point or your house got an R.C.D. fitted ?
 
Handy tip Mike. Thanks

Motor pulley = 71mm
Shaft pulley = 53mm

71/53= 1.34 (ratio 1:1.34)

1.34x1425rpm =1909rpm at the shaft

Recommend rpm on the wheels is 1600rpm

300rpm over recommendation hmm.
 
Thanks Mike. I had to run off and check my pulley ratios to make sure nothing was going to self destruct.
For cutting and polishing I use a 1:1 ratio, so about 1425 rpm.
For slicing I sometimes like to drop to a smaller pulley on the machine which brings it to 1:1.25 or about 1780 rpm.
Ideally Id like to be able to drop the speed lower than 1425 rpm for polishing but I get the job done.
 
Martyz said:
Thanks Mike. I had to run off and check my pulley ratios to make sure nothing was going to self destruct.
For cutting and polishing I use a 1:1 ratio, so about 1425 rpm.
For slicing I sometimes like to drop to a smaller pulley on the machine which brings it to 1:1.25 or about 1780 rpm.
Ideally Id like to be able to drop the speed lower than 1425 rpm for polishing but I get the job done.

.................................................................................

Maybe one of these, i put one similar on my wood lathe.

https://www.jaycar.com.au/240v-10a-deluxe-motor-speed-controller-kit/p/KC5478
 
I think the motors we have are induction.

Note: This project is designed for brush type motors and is not suitable for induction motors or shaded pole motors.
 
Thanks Rockrat. Electrics are not really my thing and it sounds like my old motor might not be the right type. If I ever have to change my motor I might look at a setup that works this way.
 

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