Bauer T151 belt change - not sure how

[Rob Booker]

Hello,
I mean T171 not 151.

Recently my trusty old Eumig 824 stopped threading properly and still can't figure out why or I don't have the competence. With no repairer anywhere near and in any case costing quite a lot just to check the machine, I got another projector off eBay which was supposed to be just fine but turned out to have a fault (spools don't turn) and it seems it's the belt. When I opened the machine, I moved the belt to the 24 fps wheel and now the spools turn for 24 fps to some degree but probably not reliably. No turns at all for 18 fps, of course.
So although the belt is in one piece, it is not gripping sufficiently for both speeds 18 and 24 and I assume it is too stretched for the 18 fps cog. I looked here and on YT for videos on how to get to the belt on this or a similar machine such as maybe its Silma equivalent. Unfortunately, I can't find anything for the 171 or similar model that is clear enough for someone like me who is not experienced at this sort of thing. Any pointers would be appreciated on how I get to the belt so as to change it. Also if anyone knows if I can improvise with a cheap belt and what sort of belts might do. Thank you.
Photo attached of belt at 18 fps setting.

[Rob Booker]

I've not been able to find any info on how to remove a stretched belt except narrowly generic tutorials (such as some lucky Sankyo owners' projectors have a narrow gap that the belt can be pulled through, with nothing to undo or get (more, in my case) grey hairs over. I've been all over Google in multiple languages, and I just cannot find out how. The nearest repairer said he doesn't know for sure either but he'll assess it and look if I cross his palm with quite a bit of silver. Anyway, if I find out how, I'll post it here with some photos to show others.

[Dominique De Bast]

On some projectors, the access to the belts is almost impossible for a non specialist while on others models its an easy job. Hope for you you will be able to sort that out.

[Rob Booker]

Thanks Dominique! I checked a page at avi-plus.com/repair-tips-forum for a Bauer T81 and it is slightly similar but not similar enough for me to be confident. But I'm going to try later, maybe this weekend, and I'll take photos to post here if it works out ok.

edit PS
At the moment the belt is not slipping much and works at 24 fps forward/reverse without falling off because yesterday I sprayed anti-slip for car engine belts on it :-) Initially it became a bit of slimey mess but overnight it seems to have made some improvement, which I assume will be temporary but I was able to watch 2x cartoon shorts I've not seen since I was a kid although they seem to have turned a bit magenta despite being in a dark plastic can all these years :-( The top pulley wheel belt probably comes off if I remove the circlip (round spring clip) at the fan hub (very fiddly to get on and off) and the lower pulley wheel I have no idea, but probably take the motor off or move it and then perhaps some way reveals itself.