laser cutter/engraver rebuild build log

[Robin Hewitt]

Presumably you would only go for engraving speed on the lightest axis, call it X? Making it fast will make it heavy so you will need a different motor and much lower target speed for the Y. In my day if you wanted enormous speed and acceleration then you used a pancake motor, is that what the Trotec uses?

[gavztheouch]

I think the Trotec uses a small dc motor and everything mechanical is kept very light.

May just go with the closed loop stepper motors for now and then maybe upgrade to a servo motor (on just the x axis) in the future if need be. Going to buy the stepper sets from Aliexpress and hope for a similer good experience. I don't think they will come till after christmas, so I can get to work on the frame in the meantime.

Im thinking box section construction, which I will level with epoxy to mount all the components on a flat plane. I could use shims but id like to give the epoxy method a try.

[Boyan Silyavski]

Interesting. About the Mjunit. Looks Well thought. Could you tell us some more info please?

-What is the sliding element? I can not figure that from the photos.
- v or u bearings ? balls like Hiwin?
-size/type timing belt?
-What the price for the setup you bought? Looking at aliexpress but all say same price, may be the price of an element
-Does it seem precise, i mean move smoothly and without play?

[gavztheouch]

Hi Silyavski,

I paid £600 for the 900 by 600mm laser kit, import tax brought the total up to £750. You contact the seller and he/she will send you a quote.

The sliding element is 4 U bearings. The extrusion is Alu alloy but the tracks that the U bearings slide on is not, I guess stainless steel or chrome plated steel? I will take some pictures to show you.

Im not sure about the timing belt will need to measure.

It seems quite precise and smooth with no play. Time will tell how it really performs.

After buying this kit I recently spotted a second company selling smiler items. http://www.ccmmade.com/ I think the mjunit laser stuff looks better, but this other company has videos on their website and facebook page you can check out. Their prices are also cheaper.

[Boyan Silyavski]

Thanks.

At the second link they seem they have also slightly bigger 60x60mm.

i figured why the 3:1 ratio, they build it for time lapse photography, where a resolution is needed.

[gavztheouch]

i figured why the 3:1 ratio, they build it for time lapse photography, where a resolution is needed.

Its also common for lasers to have a 3:1 reduction ratio. I think it is to help the motor overcome the inertia due to the high acceleration and quick changes in direction?